FD_CLR sys/select.h pselect, select - synchronous I/O multiplexing void FD_CLR(int fd, fd_set *fdset);
FD_ISSET sys/select.h pselect, select - synchronous I/O multiplexing int FD_ISSET(int fd, fd_set *fdset);
FD_SET sys/select.h pselect, select - synchronous I/O multiplexing void FD_SET(int fd, fd_set *fdset);
FD_ZERO sys/select.h pselect, select - synchronous I/O multiplexing void FD_ZERO(fd_set *fdset);
_Exit stdlib.h unistd.h _Exit, _exit - terminate a process void _Exit(int status);
_exit stdlib.h unistd.h _Exit, _exit - terminate a process void _exit(int status);
_longjmp setjmp.h OB XSI _longjmp, _setjmp - non-local goto void _longjmp(jmp_buf env, int val);
_setjmp setjmp.h OB XSI _longjmp, _setjmp - non-local goto int _setjmp(jmp_buf env);
_tolower ctype.h OB XSI _tolower - transliterate uppercase characters to lowercase int _tolower(int c);
_toupper ctype.h OB XSI _toupper - transliterate lowercase characters to uppercase int _toupper(int c);
a64l stdlib.h XSI a64l, l64a - convert between a 32-bit integer and a radix-64 ASCII string long a64l(const char *s);
abort stdlib.h abort - generate an abnormal process abort void abort(void);
abs stdlib.h abs - return an integer absolute value int abs(int i);
accept sys/socket.h accept - accept a new connection on a socket int accept(int socket, struct sockaddr *restrict address, socklen_t *restrict address_len);
access unistd.h access, faccessat - determine accessibility of a file relative to directory file descriptor int access(const char *path, int amode);
acos math.h acos, acosf, acosl - arc cosine functions double acos(double x);
acosf math.h acos, acosf, acosl - arc cosine functions float acosf(float x);
acosh math.h acosh, acoshf, acoshl - inverse hyperbolic cosine functions double acosh(double x);
acoshf math.h acosh, acoshf, acoshl - inverse hyperbolic cosine functions float acoshf(float x);
acoshl math.h acosh, acoshf, acoshl - inverse hyperbolic cosine functions long double acoshl(long double x);
acosl math.h acos, acosf, acosl - arc cosine functions long double acosl(long double x);
aio_cancel aio.h aio_cancel - cancel an asynchronous I/O request int aio_cancel(int fildes, struct aiocb *aiocbp);
aio_error aio.h aio_error - retrieve errors status for an asynchronous I/O operation int aio_error(const struct aiocb *aiocbp);
aio_fsync aio.h aio_fsync - asynchronous file synchronization int aio_fsync(int op, struct aiocb *aiocbp);
aio_read aio.h aio_read - asynchronous read from a file int aio_read(struct aiocb *aiocbp);
aio_return aio.h aio_return - retrieve return status of an asynchronous I/O operation ssize_t aio_return(struct aiocb *aiocbp);
aio_suspend aio.h aio_suspend - wait for an asynchronous I/O request int aio_suspend(const struct aiocb *const list[], int nent, const struct timespec *timeout);
aio_write aio.h aio_write - asynchronous write to a file int aio_write(struct aiocb *aiocbp);
alarm unistd.h alarm - schedule an alarm signal unsigned alarm(unsigned seconds);
alphasort dirent.h alphasort, scandir - scan a directory int alphasort(const struct dirent **d1, const struct dirent **d2);
asctime time.h OB OB CX asctime, asctime_r - convert date and time to a string char *asctime(const struct tm *timeptr);
asctime_r time.h OB OB CX asctime, asctime_r - convert date and time to a string char *asctime_r(const struct tm *restrict tm, char *restrict buf);
asin math.h asin, asinf, asinl - arc sine function double asin(double x);
asinf math.h asin, asinf, asinl - arc sine function float asinf(float x);
asinh math.h asinh, asinhf, asinhl - inverse hyperbolic sine functions double asinh(double x);
asinhf math.h asinh, asinhf, asinhl - inverse hyperbolic sine functions float asinhf(float x);
asinhl math.h asinh, asinhf, asinhl - inverse hyperbolic sine functions long double asinhl(long double x);
asinl math.h asin, asinf, asinl - arc sine function long double asinl(long double x);
assert assert.h assert - insert program diagnostics void assert(scalar expression);
atan math.h atan, atanf, atanl - arc tangent function double atan(double x);
atan2 math.h atan2, atan2f, atan2l - arc tangent functions double atan2(double y, double x);
atan2f math.h atan2, atan2f, atan2l - arc tangent functions float atan2f(float y, float x);
atan2l math.h atan2, atan2f, atan2l - arc tangent functions long double atan2l(long double y, long double x);
atanf math.h atan, atanf, atanl - arc tangent function float atanf(float x);
atanh math.h atanh, atanhf, atanhl - inverse hyperbolic tangent functions double atanh(double x);
atanhf math.h atanh, atanhf, atanhl - inverse hyperbolic tangent functions float atanhf(float x);
atanhl math.h atanh, atanhf, atanhl - inverse hyperbolic tangent functions long double atanhl(long double x);
atanl math.h atan, atanf, atanl - arc tangent function long double atanl(long double x);
atexit stdlib.h atexit - register a function to run at process termination int atexit(void (*func)(void));
atof stdlib.h atof - convert a string to a double-precision number double atof(const char *str);
atoi stdlib.h atoi - convert a string to an integer int atoi(const char *str);
atol stdlib.h atol, atoll - convert a string to a long integer long atol(const char *str);
atoll stdlib.h atol, atoll - convert a string to a long integer long long atoll(const char *nptr);
basename libgen.h XSI basename - return the last component of a pathname char *basename(char *path);
bind sys/socket.h bind - bind a name to a socket int bind(int socket, const struct sockaddr *address, socklen_t address_len);
bsearch stdlib.h bsearch - binary search a sorted table void *bsearch(const void *key, const void *base, size_t nel, size_t width, int (*compar)(const void *, const void *));
btowc stdio.h wchar.h btowc - single byte to wide character conversion wint_t btowc(int c);
cabs complex.h cabs, cabsf, cabsl - return a complex absolute value double cabs(double complex z);
cabsf complex.h cabs, cabsf, cabsl - return a complex absolute value float cabsf(float complex z);
cabsl complex.h cabs, cabsf, cabsl - return a complex absolute value long double cabsl(long double complex z);
cacos complex.h cacos, cacosf, cacosl - complex arc cosine functions double complex cacos(double complex z);
cacosf complex.h cacos, cacosf, cacosl - complex arc cosine functions float complex cacosf(float complex z);
cacosh complex.h cacosh, cacoshf, cacoshl - complex arc hyperbolic cosine functions double complex cacosh(double complex z);
cacoshf complex.h cacosh, cacoshf, cacoshl - complex arc hyperbolic cosine functions float complex cacoshf(float complex z);
cacoshl complex.h cacosh, cacoshf, cacoshl - complex arc hyperbolic cosine functions long double complex cacoshl(long double complex z);
cacosl complex.h cacos, cacosf, cacosl - complex arc cosine functions long double complex cacosl(long double complex z);
calloc stdlib.h calloc - a memory allocator void *calloc(size_t nelem, size_t elsize);
carg complex.h carg, cargf, cargl - complex argument functions double carg(double complex z);
cargf complex.h carg, cargf, cargl - complex argument functions float cargf(float complex z);
cargl complex.h carg, cargf, cargl - complex argument functions long double cargl(long double complex z);
casin complex.h casin, casinf, casinl - complex arc sine functions double complex casin(double complex z);
casinf complex.h casin, casinf, casinl - complex arc sine functions float complex casinf(float complex z);
casinh complex.h casinh, casinhf, casinhl - complex arc hyperbolic sine functions double complex casinh(double complex z);
casinhf complex.h casinh, casinhf, casinhl - complex arc hyperbolic sine functions float complex casinhf(float complex z);
casinhl complex.h casinh, casinhf, casinhl - complex arc hyperbolic sine functions long double complex casinhl(long double complex z);
casinl complex.h casin, casinf, casinl - complex arc sine functions long double complex casinl(long double complex z);
catan complex.h catan, catanf, catanl - complex arc tangent functions double complex catan(double complex z);
catanf complex.h catan, catanf, catanl - complex arc tangent functions float complex catanf(float complex z);
catanh complex.h catanh, catanhf, catanhl - complex arc hyperbolic tangent functions double complex catanh(double complex z);
catanhf complex.h catanh, catanhf, catanhl - complex arc hyperbolic tangent functions float complex catanhf(float complex z);
catanhl complex.h catanh, catanhf, catanhl - complex arc hyperbolic tangent functions long double complex catanhl(long double complex z);
catanl complex.h catan, catanf, catanl - complex arc tangent functions long double complex catanl(long double complex z);
catclose nl_types.h catclose - close a message catalog descriptor int catclose(nl_catd catd);
catgets nl_types.h catgets - read a program message char *catgets(nl_catd catd, int set_id, int msg_id, const char *s);
catopen nl_types.h catopen - open a message catalog nl_catd catopen(const char *name, int oflag);
cbrt math.h cbrt, cbrtf, cbrtl - cube root functions double cbrt(double x);
cbrtf math.h cbrt, cbrtf, cbrtl - cube root functions float cbrtf(float x);
cbrtl math.h cbrt, cbrtf, cbrtl - cube root functions long double cbrtl(long double x);
ccos complex.h ccos, ccosf, ccosl - complex cosine functions double complex ccos(double complex z);
ccosf complex.h ccos, ccosf, ccosl - complex cosine functions float complex ccosf(float complex z);
ccosh complex.h ccosh, ccoshf, ccoshl - complex hyperbolic cosine functions double complex ccosh(double complex z);
ccoshf complex.h ccosh, ccoshf, ccoshl - complex hyperbolic cosine functions float complex ccoshf(float complex z);
ccoshl complex.h ccosh, ccoshf, ccoshl - complex hyperbolic cosine functions long double complex ccoshl(long double complex z);
ccosl complex.h ccos, ccosf, ccosl - complex cosine functions long double complex ccosl(long double complex z);
ceil math.h ceil, ceilf, ceill - ceiling value function double ceil(double x);
ceilf math.h ceil, ceilf, ceill - ceiling value function float ceilf(float x);
ceill math.h ceil, ceilf, ceill - ceiling value function long double ceill(long double x);
cexp complex.h cexp, cexpf, cexpl - complex exponential functions double complex cexp(double complex z);
cexpf complex.h cexp, cexpf, cexpl - complex exponential functions float complex cexpf(float complex z);
cexpl complex.h cexp, cexpf, cexpl - complex exponential functions long double complex cexpl(long double complex z);
cfgetispeed termios.h cfgetispeed - get input baud rate speed_t cfgetispeed(const struct termios *termios_p);
cfgetospeed termios.h cfgetospeed - get output baud rate speed_t cfgetospeed(const struct termios *termios_p);
cfsetispeed termios.h cfsetispeed - set input baud rate int cfsetispeed(struct termios *termios_p, speed_t speed);
cfsetospeed termios.h cfsetospeed - set output baud rate int cfsetospeed(struct termios *termios_p, speed_t speed);
chdir unistd.h chdir - change working directory int chdir(const char *path);
chmod sys/stat.h chmod, fchmodat - change mode of a file relative to directory file descriptor int chmod(const char *path, mode_t mode);
chown unistd.h chown, fchownat - change owner and group of a file relative to directory file descriptor int chown(const char *path, uid_t owner, gid_t group);
cimag complex.h cimag, cimagf, cimagl - complex imaginary functions double cimag(double complex z);
cimagf complex.h cimag, cimagf, cimagl - complex imaginary functions float cimagf(float complex z);
cimagl complex.h cimag, cimagf, cimagl - complex imaginary functions long double cimagl(long double complex z);
clearerr stdio.h clearerr - clear indicators on a stream void clearerr(FILE *stream);
clock time.h clock - report CPU time used clock_t clock(void);
clock_getcpuclockid time.h CPT clock_getcpuclockid - access a process CPU-time clock (ADVANCED REALTIME) int clock_getcpuclockid(pid_t pid, clockid_t *clock_id);
clock_getres time.h CX clock_getres, clock_gettime, clock_settime - clock and timer functions int clock_getres(clockid_t clock_id, struct timespec *res);
clock_gettime time.h CX clock_getres, clock_gettime, clock_settime - clock and timer functions int clock_gettime(clockid_t clock_id, struct timespec *tp);
clock_nanosleep time.h CX clock_nanosleep - high resolution sleep with specifiable clock int clock_nanosleep(clockid_t clock_id, int flags, const struct timespec *rqtp, struct timespec *rmtp);
clock_settime time.h CX clock_getres, clock_gettime, clock_settime - clock and timer functions int clock_settime(clockid_t clock_id, const struct timespec *tp);
clog complex.h clog, clogf, clogl - complex natural logarithm functions double complex clog(double complex z);
clogf complex.h clog, clogf, clogl - complex natural logarithm functions float complex clogf(float complex z);
clogl complex.h clog, clogf, clogl - complex natural logarithm functions long double complex clogl(long double complex z);
close unistd.h close - close a file descriptor int close(int fildes);
closedir dirent.h closedir - close a directory stream int closedir(DIR *dirp);
closelog syslog.h XSI closelog, openlog, setlogmask, syslog - control system log void closelog(void);
confstr unistd.h confstr - get configurable variables size_t confstr(int name, char *buf, size_t len);
conj complex.h conj, conjf, conjl - complex conjugate functions double complex conj(double complex z);
conjf complex.h conj, conjf, conjl - complex conjugate functions float complex conjf(float complex z);
conjl complex.h conj, conjf, conjl - complex conjugate functions long double complex conjl(long double complex z);
connect sys/socket.h connect - connect a socket int connect(int socket, const struct sockaddr *address, socklen_t address_len);
copysign math.h copysign, copysignf, copysignl - number manipulation function double copysign(double x, double y);
copysignf math.h copysign, copysignf, copysignl - number manipulation function float copysignf(float x, float y);
copysignl math.h copysign, copysignf, copysignl - number manipulation function long double copysignl(long double x, long double y);
cos math.h cos, cosf, cosl - cosine function double cos(double x);
cosf math.h cos, cosf, cosl - cosine function float cosf(float x);
cosh math.h cosh, coshf, coshl - hyperbolic cosine functions double cosh(double x);
coshf math.h cosh, coshf, coshl - hyperbolic cosine functions float coshf(float x);
coshl math.h cosh, coshf, coshl - hyperbolic cosine functions long double coshl(long double x);
cosl math.h cos, cosf, cosl - cosine function long double cosl(long double x);
cpow complex.h cpow, cpowf, cpowl - complex power functions double complex cpow(double complex x, double complex y);
cpowf complex.h cpow, cpowf, cpowl - complex power functions float complex cpowf(float complex x, float complex y);
cpowl complex.h cpow, cpowf, cpowl - complex power functions long double complex cpowl(long double complex x, long double complex y);
cproj complex.h cproj, cprojf, cprojl - complex projection functions double complex cproj(double complex z);
cprojf complex.h cproj, cprojf, cprojl - complex projection functions float complex cprojf(float complex z);
cprojl complex.h cproj, cprojf, cprojl - complex projection functions long double complex cprojl(long double complex z);
creal complex.h creal, crealf, creall - complex real functions double creal(double complex z);
crealf complex.h creal, crealf, creall - complex real functions float crealf(float complex z);
creall complex.h creal, crealf, creall - complex real functions long double creall(long double complex z);
creat sys/stat.h fcntl.h OH creat - create a new file or rewrite an existing one int creat(const char *path, mode_t mode);
crypt unistd.h XSI crypt - string encoding function (CRYPT) char *crypt(const char *key, const char *salt);
csin complex.h csin, csinf, csinl - complex sine functions double complex csin(double complex z);
csinf complex.h csin, csinf, csinl - complex sine functions float complex csinf(float complex z);
csinh complex.h csinh, csinhf, csinhl - complex hyperbolic sine functions double complex csinh(double complex z);
csinhf complex.h csinh, csinhf, csinhl - complex hyperbolic sine functions float complex csinhf(float complex z);
csinhl complex.h csinh, csinhf, csinhl - complex hyperbolic sine functions long double complex csinhl(long double complex z);
csinl complex.h csin, csinf, csinl - complex sine functions long double complex csinl(long double complex z);
csqrt complex.h csqrt, csqrtf, csqrtl - complex square root functions double complex csqrt(double complex z);
csqrtf complex.h csqrt, csqrtf, csqrtl - complex square root functions float complex csqrtf(float complex z);
csqrtl complex.h csqrt, csqrtf, csqrtl - complex square root functions long double complex csqrtl(long double complex z);
ctan complex.h ctan, ctanf, ctanl - complex tangent functions double complex ctan(double complex z);
ctanf complex.h ctan, ctanf, ctanl - complex tangent functions float complex ctanf(float complex z);
ctanh complex.h ctanh, ctanhf, ctanhl - complex hyperbolic tangent functions double complex ctanh(double complex z);
ctanhf complex.h ctanh, ctanhf, ctanhl - complex hyperbolic tangent functions float complex ctanhf(float complex z);
ctanhl complex.h ctanh, ctanhf, ctanhl - complex hyperbolic tangent functions long double complex ctanhl(long double complex z);
ctanl complex.h ctan, ctanf, ctanl - complex tangent functions long double complex ctanl(long double complex z);
ctermid stdio.h CX ctermid - generate a pathname for the controlling terminal char *ctermid(char *s);
ctime time.h OB OB CX ctime, ctime_r - convert a time value to a date and time string char *ctime(const time_t *clock);
ctime_r time.h OB OB CX ctime, ctime_r - convert a time value to a date and time string char *ctime_r(const time_t *clock, char *buf);
daylight time.h XSI CX daylight, timezone, tzname, tzset - set timezone conversion information
dbm_clearerr ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions int dbm_clearerr(DBM *db);
dbm_close ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions void dbm_close(DBM *db);
dbm_delete ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions int dbm_delete(DBM *db, datum key);
dbm_error ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions int dbm_error(DBM *db);
dbm_fetch ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions datum dbm_fetch(DBM *db, datum key);
dbm_firstkey ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions datum dbm_firstkey(DBM *db);
dbm_nextkey ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions datum dbm_nextkey(DBM *db);
dbm_open ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions DBM *dbm_open(const char *file, int open_flags, mode_t file_mode);
dbm_store ndbm.h XSI dbm_clearerr, dbm_close, dbm_delete, dbm_error, dbm_fetch, dbm_firstkey, dbm_nextkey, dbm_open, dbm_store - database functions int dbm_store(DBM *db, datum key, datum content, int store_mode);
difftime time.h difftime - compute the difference between two calendar time values double difftime(time_t time1, time_t time0);
dirfd dirent.h dirfd - extract the file descriptor used by a DIR stream int dirfd(DIR *dirp);
dirname libgen.h XSI dirname - report the parent directory name of a file pathname char *dirname(char *path);
div stdlib.h div - compute the quotient and remainder of an integer division div_t div(int numer, int denom);
dlclose dlfcn.h dlclose - close a dlopen object int dlclose(void *handle);
dlerror dlfcn.h dlerror - get diagnostic information char *dlerror(void);
dlopen dlfcn.h dlopen - gain access to an executable object file void *dlopen(const char *file, int mode);
dlsym dlfcn.h dlsym - obtain the address of a symbol from a dlopen object void *dlsym(void *restrict handle, const char *restrict name);
dprintf stdio.h CX dprintf, fprintf, printf, snprintf, sprintf - print formatted output int dprintf(int fildes, const char *restrict format, ...);
drand48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers double drand48(void);
dup unistd.h dup, dup2 - duplicate an open file descriptor int dup(int fildes);
dup2 unistd.h dup, dup2 - duplicate an open file descriptor int dup2(int fildes, int fildes2);
duplocale locale.h CX duplocale - duplicate a locale object locale_t duplocale(locale_t locobj);
encrypt unistd.h XSI encrypt - encoding function (CRYPT) void encrypt(char block[64], int edflag);
endgrent grp.h XSI endgrent, getgrent, setgrent - group database entry functions void endgrent(void);
endhostent netdb.h endhostent, gethostent, sethostent - network host database functions void endhostent(void);
endnetent netdb.h endnetent, getnetbyaddr, getnetbyname, getnetent, setnetent - network database functions void endnetent(void);
endprotoent netdb.h endprotoent, getprotobyname, getprotobynumber, getprotoent, setprotoent - network protocol database functions void endprotoent(void);
endpwent pwd.h XSI endpwent, getpwent, setpwent - user database functions void endpwent(void);
endservent netdb.h endservent, getservbyname, getservbyport, getservent, setservent - network services database functions void endservent(void);
endutxent utmpx.h XSI endutxent, getutxent, getutxid, getutxline, pututxline, setutxent - user accounting database functions void endutxent(void);
environ unistd.h environ, execl, execle, execlp, execv, execve, execvp, fexecve - execute a file
erand48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers double erand48(unsigned short xsubi[3]);
erf math.h erf, erff, erfl - error functions double erf(double x);
erfc math.h erfc, erfcf, erfcl - complementary error functions double erfc(double x);
erfcf math.h erfc, erfcf, erfcl - complementary error functions float erfcf(float x);
erfcl math.h erfc, erfcf, erfcl - complementary error functions long double erfcl(long double x);
erff math.h erf, erff, erfl - error functions float erff(float x);
erfl math.h erf, erff, erfl - error functions long double erfl(long double x);
errno errno.h errno - error return value
execl unistd.h environ, execl, execle, execlp, execv, execve, execvp, fexecve - execute a file int execl(const char *path, const char *arg0, ... /*, (char *)0 */);
execle unistd.h environ, execl, execle, execlp, execv, execve, execvp, fexecve - execute a file int execle(const char *path, const char *arg0, ... /*, (char *)0, char *const envp[]*/);
execlp unistd.h environ, execl, execle, execlp, execv, execve, execvp, fexecve - execute a file int execlp(const char *file, const char *arg0, ... /*, (char *)0 */);
execv unistd.h environ, execl, execle, execlp, execv, execve, execvp, fexecve - execute a file int execv(const char *path, char *const argv[]);
execve unistd.h environ, execl, execle, execlp, execv, execve, execvp, fexecve - execute a file int execve(const char *path, char *const argv[], char *const envp[]);
execvp unistd.h environ, execl, execle, execlp, execv, execve, execvp, fexecve - execute a file int execvp(const char *file, char *const argv[]);
exit stdlib.h exit - terminate a process void exit(int status);
exp math.h exp, expf, expl - exponential function double exp(double x);
exp2 math.h exp2, exp2f, exp2l - exponential base 2 functions double exp2(double x);
exp2f math.h exp2, exp2f, exp2l - exponential base 2 functions float exp2f(float x);
exp2l math.h exp2, exp2f, exp2l - exponential base 2 functions long double exp2l(long double x);
expf math.h exp, expf, expl - exponential function float expf(float x);
expl math.h exp, expf, expl - exponential function long double expl(long double x);
expm1 math.h expm1, expm1f, expm1l - compute exponential functions double expm1(double x);
expm1f math.h expm1, expm1f, expm1l - compute exponential functions float expm1f(float x);
expm1l math.h expm1, expm1f, expm1l - compute exponential functions long double expm1l(long double x);
fabs math.h fabs, fabsf, fabsl - absolute value function double fabs(double x);
fabsf math.h fabs, fabsf, fabsl - absolute value function float fabsf(float x);
fabsl math.h fabs, fabsf, fabsl - absolute value function long double fabsl(long double x);
faccessat unistd.h access, faccessat - determine accessibility of a file relative to directory file descriptor int faccessat(int fd, const char *path, int amode, int flag);
fattach stropts.h OB XSR fattach - attach a STREAMS-based file descriptor to a file in the file system name space (STREAMS) int fattach(int fildes, const char *path);
fchdir unistd.h fchdir - change working directory int fchdir(int fildes);
fchmod sys/stat.h fchmod - change mode of a file int fchmod(int fildes, mode_t mode);
fchmodat sys/stat.h chmod, fchmodat - change mode of a file relative to directory file descriptor int fchmodat(int fd, const char *path, mode_t mode, int flag);
fchown unistd.h fchown - change owner and group of a file int fchown(int fildes, uid_t owner, gid_t group);
fchownat unistd.h chown, fchownat - change owner and group of a file relative to directory file descriptor int fchownat(int fd, const char *path, uid_t owner, gid_t group, int flag);
fclose stdio.h fclose - close a stream int fclose(FILE *stream);
fcntl fcntl.h fcntl - file control int fcntl(int fildes, int cmd, ...);
fdatasync unistd.h SIO fdatasync - synchronize the data of a file (REALTIME) int fdatasync(int fildes);
fdetach stropts.h OB XSR fdetach - detach a name from a STREAMS-based file descriptor (STREAMS) int fdetach(const char *path);
fdim math.h fdim, fdimf, fdiml - compute positive difference between two floating-point numbers double fdim(double x, double y);
fdimf math.h fdim, fdimf, fdiml - compute positive difference between two floating-point numbers float fdimf(float x, float y);
fdiml math.h fdim, fdimf, fdiml - compute positive difference between two floating-point numbers long double fdiml(long double x, long double y);
fdopen stdio.h CX fdopen - associate a stream with a file descriptor FILE *fdopen(int fildes, const char *mode);
fdopendir dirent.h fdopendir, opendir - open directory associated with file descriptor DIR *fdopendir(int fd);
feclearexcept fenv.h feclearexcept - clear floating-point exception int feclearexcept(int excepts);
fegetenv fenv.h fegetenv, fesetenv - get and set current floating-point environment int fegetenv(fenv_t *envp);
fegetexceptflag fenv.h fegetexceptflag, fesetexceptflag - get and set floating-point status flags int fegetexceptflag(fexcept_t *flagp, int excepts);
fegetround fenv.h fegetround, fesetround - get and set current rounding direction int fegetround(void);
feholdexcept fenv.h feholdexcept - save current floating-point environment int feholdexcept(fenv_t *envp);
feof stdio.h feof - test end-of-file indicator on a stream int feof(FILE *stream);
feraiseexcept fenv.h feraiseexcept - raise floating-point exception int feraiseexcept(int excepts);
ferror stdio.h ferror - test error indicator on a stream int ferror(FILE *stream);
fesetenv fenv.h fegetenv, fesetenv - get and set current floating-point environment int fesetenv(const fenv_t *envp);
fesetexceptflag fenv.h fegetexceptflag, fesetexceptflag - get and set floating-point status flags int fesetexceptflag(const fexcept_t *flagp, int excepts);
fesetround fenv.h fegetround, fesetround - get and set current rounding direction int fesetround(int round);
fetestexcept fenv.h fetestexcept - test floating-point exception flags int fetestexcept(int excepts);
feupdateenv fenv.h feupdateenv - update floating-point environment int feupdateenv(const fenv_t *envp);
fexecve unistd.h environ, execl, execle, execlp, execv, execve, execvp, fexecve - execute a file int fexecve(int fd, char *const argv[], char *const envp[]);
fflush stdio.h fflush - flush a stream int fflush(FILE *stream);
ffs strings.h XSI ffs - find first set bit int ffs(int i);
fgetc stdio.h fgetc - get a byte from a stream int fgetc(FILE *stream);
fgetpos stdio.h fgetpos - get current file position information int fgetpos(FILE *restrict stream, fpos_t *restrict pos);
fgets stdio.h fgets - get a string from a stream char *fgets(char *restrict s, int n, FILE *restrict stream);
fgetwc stdio.h wchar.h fgetwc - get a wide-character code from a stream wint_t fgetwc(FILE *stream);
fgetws stdio.h wchar.h fgetws - get a wide-character string from a stream wchar_t *fgetws(wchar_t *restrict ws, int n, FILE *restrict stream);
fileno stdio.h CX fileno - map a stream pointer to a file descriptor int fileno(FILE *stream);
flockfile stdio.h CX flockfile, ftrylockfile, funlockfile - stdio locking functions void flockfile(FILE *file);
floor math.h floor, floorf, floorl - floor function double floor(double x);
floorf math.h floor, floorf, floorl - floor function float floorf(float x);
floorl math.h floor, floorf, floorl - floor function long double floorl(long double x);
fma math.h fma, fmaf, fmal - floating-point multiply-add double fma(double x, double y, double z);
fmaf math.h fma, fmaf, fmal - floating-point multiply-add float fmaf(float x, float y, float z);
fmal math.h fma, fmaf, fmal - floating-point multiply-add long double fmal(long double x, long double y, long double z);
fmax math.h fmax, fmaxf, fmaxl - determine maximum numeric value of two floating-point numbers double fmax(double x, double y);
fmaxf math.h fmax, fmaxf, fmaxl - determine maximum numeric value of two floating-point numbers float fmaxf(float x, float y);
fmaxl math.h fmax, fmaxf, fmaxl - determine maximum numeric value of two floating-point numbers long double fmaxl(long double x, long double y);
fmemopen stdio.h CX fmemopen - open a memory buffer stream FILE *fmemopen(void *restrict buf, size_t size, const char *restrict mode);
fmin math.h fmin, fminf, fminl - determine minimum numeric value of two floating-point numbers double fmin(double x, double y);
fminf math.h fmin, fminf, fminl - determine minimum numeric value of two floating-point numbers float fminf(float x, float y);
fminl math.h fmin, fminf, fminl - determine minimum numeric value of two floating-point numbers long double fminl(long double x, long double y);
fmod math.h fmod, fmodf, fmodl - floating-point remainder value function double fmod(double x, double y);
fmodf math.h fmod, fmodf, fmodl - floating-point remainder value function float fmodf(float x, float y);
fmodl math.h fmod, fmodf, fmodl - floating-point remainder value function long double fmodl(long double x, long double y);
fmtmsg fmtmsg.h XSI fmtmsg - display a message in the specified format on standard error and/or a system console int fmtmsg(long classification, const char *label, int severity, const char *text, const char *action, const char *tag);
fnmatch fnmatch.h fnmatch - match a filename or a pathname int fnmatch(const char *pattern, const char *string, int flags);
fopen stdio.h fopen - open a stream FILE *fopen(const char *restrict filename, const char *restrict mode);
fork unistd.h fork - create a new process pid_t fork(void);
fpathconf unistd.h fpathconf, pathconf - get configurable pathname variables long fpathconf(int fildes, int name);
fpclassify math.h fpclassify - classify real floating type int fpclassify(real-floating x);
fprintf stdio.h CX dprintf, fprintf, printf, snprintf, sprintf - print formatted output int fprintf(FILE *restrict stream, const char *restrict format, ...);
fputc stdio.h fputc - put a byte on a stream int fputc(int c, FILE *stream);
fputs stdio.h fputs - put a string on a stream int fputs(const char *restrict s, FILE *restrict stream);
fputwc stdio.h wchar.h fputwc - put a wide-character code on a stream wint_t fputwc(wchar_t wc, FILE *stream);
fputws stdio.h wchar.h fputws - put a wide-character string on a stream int fputws(const wchar_t *restrict ws, FILE *restrict stream);
fread stdio.h fread - binary input size_t fread(void *restrict ptr, size_t size, size_t nitems, FILE *restrict stream);
free stdlib.h free - free allocated memory void free(void *ptr);
freeaddrinfo sys/socket.h netdb.h freeaddrinfo, getaddrinfo - get address information void freeaddrinfo(struct addrinfo *ai);
freelocale locale.h CX freelocale - free resources allocated for a locale object void freelocale(locale_t locobj);
freopen stdio.h freopen - open a stream FILE *freopen(const char *restrict filename, const char *restrict mode, FILE *restrict stream);
frexp math.h frexp, frexpf, frexpl - extract mantissa and exponent from a double precision number double frexp(double num, int *exp);
frexpf math.h frexp, frexpf, frexpl - extract mantissa and exponent from a double precision number float frexpf(float num, int *exp);
frexpl math.h frexp, frexpf, frexpl - extract mantissa and exponent from a double precision number long double frexpl(long double num, int *exp);
fscanf stdio.h fscanf, scanf, sscanf - convert formatted input int fscanf(FILE *restrict stream, const char *restrict format, ...);
fseek stdio.h CX fseek, fseeko - reposition a file-position indicator in a stream int fseek(FILE *stream, long offset, int whence);
fseeko stdio.h CX fseek, fseeko - reposition a file-position indicator in a stream int fseeko(FILE *stream, off_t offset, int whence);
fsetpos stdio.h fsetpos - set current file position int fsetpos(FILE *stream, const fpos_t *pos);
fstat sys/stat.h fstat - get file status int fstat(int fildes, struct stat *buf);
fstatat sys/stat.h fstatat, lstat, stat - get file status int fstatat(int fd, const char *restrict path, struct stat *restrict buf, int flag);
fstatvfs sys/statvfs.h fstatvfs, statvfs - get file system information int fstatvfs(int fildes, struct statvfs *buf);
fsync unistd.h FSC fsync - synchronize changes to a file int fsync(int fildes);
ftell stdio.h CX ftell, ftello - return a file offset in a stream long ftell(FILE *stream);
ftello stdio.h CX ftell, ftello - return a file offset in a stream off_t ftello(FILE *stream);
ftok sys/ipc.h XSI ftok - generate an IPC key key_t ftok(const char *path, int id);
ftruncate unistd.h ftruncate - truncate a file to a specified length int ftruncate(int fildes, off_t length);
ftrylockfile stdio.h CX flockfile, ftrylockfile, funlockfile - stdio locking functions int ftrylockfile(FILE *file);
ftw ftw.h OB XSI ftw - traverse (walk) a file tree int ftw(const char *path, int (*fn)(const char *, const struct stat *ptr, int flag), int ndirs);
funlockfile stdio.h CX flockfile, ftrylockfile, funlockfile - stdio locking functions void funlockfile(FILE *file);
futimens sys/stat.h sys/time.h XSI futimens, utimensat, utimes - set file access and modification times int futimens(int fd, const struct timespec times[2]);
fwide stdio.h wchar.h fwide - set stream orientation int fwide(FILE *stream, int mode);
fwprintf stdio.h wchar.h fwprintf, swprintf, wprintf - print formatted wide-character output int fwprintf(FILE *restrict stream, const wchar_t *restrict format, ...);
fwrite stdio.h fwrite - binary output size_t fwrite(const void *restrict ptr, size_t size, size_t nitems, FILE *restrict stream);
fwscanf stdio.h wchar.h fwscanf, swscanf, wscanf - convert formatted wide-character input int fwscanf(FILE *restrict stream, const wchar_t *restrict format, ...);
gai_strerror netdb.h gai_strerror - address and name information error description const char *gai_strerror(int ecode);
getaddrinfo sys/socket.h netdb.h freeaddrinfo, getaddrinfo - get address information int getaddrinfo(const char *restrict nodename, const char *restrict servname, const struct addrinfo *restrict hints, struct addrinfo **restrict res);
getc stdio.h getc - get a byte from a stream int getc(FILE *stream);
getc_unlocked stdio.h CX getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - stdio with explicit client locking int getc_unlocked(FILE *stream);
getchar stdio.h getchar - get a byte from a .I stdin stream int getchar(void);
getchar_unlocked stdio.h CX getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - stdio with explicit client locking int getchar_unlocked(void);
getcwd unistd.h getcwd - get the pathname of the current working directory char *getcwd(char *buf, size_t size);
getdate time.h XSI getdate - convert user format date and time struct tm *getdate(const char *string);
getdate_err time.h XSI getdate - convert user format date and time
getdelim stdio.h CX getdelim, getline - read a delimited record from .I stream ssize_t getdelim(char **restrict lineptr, size_t *restrict n, int delimiter, FILE *restrict stream);
getegid unistd.h getegid - get the effective group ID gid_t getegid(void);
getenv stdlib.h getenv - get value of an environment variable char *getenv(const char *name);
geteuid unistd.h geteuid - get the effective user ID uid_t geteuid(void);
getgid unistd.h getgid - get the real group ID gid_t getgid(void);
getgrent grp.h XSI endgrent, getgrent, setgrent - group database entry functions struct group *getgrent(void);
getgrgid grp.h getgrgid, getgrgid_r - get group database entry for a group ID struct group *getgrgid(gid_t gid);
getgrgid_r grp.h getgrgid, getgrgid_r - get group database entry for a group ID int getgrgid_r(gid_t gid, struct group *grp, char *buffer, size_t bufsize, struct group **result);
getgrnam grp.h getgrnam, getgrnam_r - search group database for a name struct group *getgrnam(const char *name);
getgrnam_r grp.h getgrnam, getgrnam_r - search group database for a name int getgrnam_r(const char *name, struct group *grp, char *buffer, size_t bufsize, struct group **result);
getgroups unistd.h getgroups - get supplementary group IDs int getgroups(int gidsetsize, gid_t grouplist[]);
gethostent netdb.h endhostent, gethostent, sethostent - network host database functions struct hostent *gethostent(void);
gethostid unistd.h XSI gethostid - get an identifier for the current host long gethostid(void);
gethostname unistd.h gethostname - get name of current host int gethostname(char *name, size_t namelen);
getitimer sys/time.h OB XSI getitimer, setitimer - get and set value of interval timer int getitimer(int which, struct itimerval *value);
getline stdio.h CX getdelim, getline - read a delimited record from .I stream ssize_t getline(char **restrict lineptr, size_t *restrict n, FILE *restrict stream);
getlogin unistd.h getlogin, getlogin_r - get login name char *getlogin(void);
getlogin_r unistd.h getlogin, getlogin_r - get login name int getlogin_r(char *name, size_t namesize);
getmsg stropts.h OB XSR getmsg, getpmsg - receive next message from a STREAMS file (STREAMS) int getmsg(int fildes, struct strbuf *restrict ctlptr, struct strbuf *restrict dataptr, int *restrict flagsp);
getnameinfo sys/socket.h netdb.h getnameinfo - get name information int getnameinfo(const struct sockaddr *restrict sa, socklen_t salen, char *restrict node, socklen_t nodelen, char *restrict service, socklen_t servicelen, int flags);
getnetbyaddr netdb.h endnetent, getnetbyaddr, getnetbyname, getnetent, setnetent - network database functions struct netent *getnetbyaddr(uint32_t net, int type);
getnetbyname netdb.h endnetent, getnetbyaddr, getnetbyname, getnetent, setnetent - network database functions struct netent *getnetbyname(const char *name);
getnetent netdb.h endnetent, getnetbyaddr, getnetbyname, getnetent, setnetent - network database functions struct netent *getnetent(void);
getopt unistd.h getopt, optarg, opterr, optind, optopt - command option parsing int getopt(int argc, char * const argv[], const char *optstring);
getpeername sys/socket.h getpeername - get the name of the peer socket int getpeername(int socket, struct sockaddr *restrict address, socklen_t *restrict address_len);
getpgid unistd.h getpgid - get the process group ID for a process pid_t getpgid(pid_t pid);
getpgrp unistd.h getpgrp - get the process group ID of the calling process pid_t getpgrp(void);
getpid unistd.h getpid - get the process ID pid_t getpid(void);
getpmsg stropts.h OB XSR getmsg, getpmsg - receive next message from a STREAMS file (STREAMS) int getpmsg(int fildes, struct strbuf *restrict ctlptr, struct strbuf *restrict dataptr, int *restrict bandp, int *restrict flagsp);
getppid unistd.h getppid - get the parent process ID pid_t getppid(void);
getpriority sys/resource.h XSI getpriority, setpriority - get and set the nice value int getpriority(int which, id_t who);
getprotobyname netdb.h endprotoent, getprotobyname, getprotobynumber, getprotoent, setprotoent - network protocol database functions struct protoent *getprotobyname(const char *name);
getprotobynumber netdb.h endprotoent, getprotobyname, getprotobynumber, getprotoent, setprotoent - network protocol database functions struct protoent *getprotobynumber(int proto);
getprotoent netdb.h endprotoent, getprotobyname, getprotobynumber, getprotoent, setprotoent - network protocol database functions struct protoent *getprotoent(void);
getpwent pwd.h XSI endpwent, getpwent, setpwent - user database functions struct passwd *getpwent(void);
getpwnam pwd.h getpwnam, getpwnam_r - search user database for a name struct passwd *getpwnam(const char *name);
getpwnam_r pwd.h getpwnam, getpwnam_r - search user database for a name int getpwnam_r(const char *name, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result);
getpwuid pwd.h getpwuid, getpwuid_r - search user database for a user ID struct passwd *getpwuid(uid_t uid);
getpwuid_r pwd.h getpwuid, getpwuid_r - search user database for a user ID int getpwuid_r(uid_t uid, struct passwd *pwd, char *buffer, size_t bufsize, struct passwd **result);
getrlimit sys/resource.h XSI getrlimit, setrlimit - control maximum resource consumption int getrlimit(int resource, struct rlimit *rlp);
getrusage sys/resource.h XSI getrusage - get information about resource utilization int getrusage(int who, struct rusage *r_usage);
gets stdio.h OB gets - get a string from a .I stdin stream char *gets(char *s);
getservbyname netdb.h endservent, getservbyname, getservbyport, getservent, setservent - network services database functions struct servent *getservbyname(const char *name, const char *proto);
getservbyport netdb.h endservent, getservbyname, getservbyport, getservent, setservent - network services database functions struct servent *getservbyport(int port, const char *proto);
getservent netdb.h endservent, getservbyname, getservbyport, getservent, setservent - network services database functions struct servent *getservent(void);
getsid unistd.h getsid - get the process group ID of a session leader pid_t getsid(pid_t pid);
getsockname sys/socket.h getsockname - get the socket name int getsockname(int socket, struct sockaddr *restrict address, socklen_t *restrict address_len);
getsockopt sys/socket.h getsockopt - get the socket options int getsockopt(int socket, int level, int option_name, void *restrict option_value, socklen_t *restrict option_len);
getsubopt stdlib.h getsubopt - parse suboption arguments from a string int getsubopt(char **optionp, char * const *keylistp, char **valuep);
gettimeofday sys/time.h OB XSI gettimeofday - get the date and time int gettimeofday(struct timeval *restrict tp, void *restrict tzp);
getuid unistd.h getuid - get a real user ID uid_t getuid(void);
getutxent utmpx.h XSI endutxent, getutxent, getutxid, getutxline, pututxline, setutxent - user accounting database functions struct utmpx *getutxent(void);
getutxid utmpx.h XSI endutxent, getutxent, getutxid, getutxline, pututxline, setutxent - user accounting database functions struct utmpx *getutxid(const struct utmpx *id);
getutxline utmpx.h XSI endutxent, getutxent, getutxid, getutxline, pututxline, setutxent - user accounting database functions struct utmpx *getutxline(const struct utmpx *line);
getwc stdio.h wchar.h getwc - get a wide character from a stream wint_t getwc(FILE *stream);
getwchar wchar.h getwchar - get a wide character from a .I stdin stream wint_t getwchar(void);
glob glob.h glob, globfree - generate pathnames matching a pattern int glob(const char *restrict pattern, int flags, int(*errfunc)(const char *epath, int eerrno), glob_t *restrict pglob);
globfree glob.h glob, globfree - generate pathnames matching a pattern void globfree(glob_t *pglob);
gmtime time.h CX gmtime, gmtime_r - convert a time value to a broken-down UTC time struct tm *gmtime(const time_t *timer);
gmtime_r time.h CX gmtime, gmtime_r - convert a time value to a broken-down UTC time struct tm *gmtime_r(const time_t *restrict timer, struct tm *restrict result);
grantpt stdlib.h XSI grantpt - grant access to the slave pseudo-terminal device int grantpt(int fildes);
hcreate search.h XSI hcreate, hdestroy, hsearch - manage hash search table int hcreate(size_t nel);
hdestroy search.h XSI hcreate, hdestroy, hsearch - manage hash search table void hdestroy(void);
hsearch search.h XSI hcreate, hdestroy, hsearch - manage hash search table ENTRY *hsearch(ENTRY item, ACTION action);
htonl arpa/inet.h htonl, htons, ntohl, ntohs - convert values between host and network byte order uint32_t htonl(uint32_t hostlong);
htons arpa/inet.h htonl, htons, ntohl, ntohs - convert values between host and network byte order uint16_t htons(uint16_t hostshort);
hypot math.h hypot, hypotf, hypotl - Euclidean distance function double hypot(double x, double y);
hypotf math.h hypot, hypotf, hypotl - Euclidean distance function float hypotf(float x, float y);
hypotl math.h hypot, hypotf, hypotl - Euclidean distance function long double hypotl(long double x, long double y);
iconv iconv.h iconv - codeset conversion function size_t iconv(iconv_t cd, char **restrict inbuf, size_t *restrict inbytesleft, char **restrict outbuf, size_t *restrict outbytesleft);
iconv_close iconv.h iconv_close - codeset conversion deallocation function int iconv_close(iconv_t cd);
iconv_open iconv.h iconv_open - codeset conversion allocation function iconv_t iconv_open(const char *tocode, const char *fromcode);
if_freenameindex net/if.h if_freenameindex - free memory allocated by if_nameindex void if_freenameindex(struct if_nameindex *ptr);
if_indextoname net/if.h if_indextoname - map a network interface index to its corresponding name char *if_indextoname(unsigned ifindex, char *ifname);
if_nameindex net/if.h if_nameindex - return all network interface names and indexes struct if_nameindex *if_nameindex(void);
if_nametoindex net/if.h if_nametoindex - map a network interface name to its corresponding index unsigned if_nametoindex(const char *ifname);
ilogb math.h ilogb, ilogbf, ilogbl - return an unbiased exponent int ilogb(double x);
ilogbf math.h ilogb, ilogbf, ilogbl - return an unbiased exponent int ilogbf(float x);
ilogbl math.h ilogb, ilogbf, ilogbl - return an unbiased exponent int ilogbl(long double x);
imaxabs inttypes.h imaxabs - return absolute value intmax_t imaxabs(intmax_t j);
imaxdiv inttypes.h imaxdiv - return quotient and remainder imaxdiv_t imaxdiv(intmax_t numer, intmax_t denom);
inet_addr arpa/inet.h inet_addr, inet_ntoa - IPv4 address manipulation in_addr_t inet_addr(const char *cp);
inet_ntoa arpa/inet.h inet_addr, inet_ntoa - IPv4 address manipulation char *inet_ntoa(struct in_addr in);
inet_ntop arpa/inet.h inet_ntop, inet_pton - convert IPv4 and IPv6 addresses between binary and text form const char *inet_ntop(int af, const void *restrict src, char *restrict dst, socklen_t size);
inet_pton arpa/inet.h inet_ntop, inet_pton - convert IPv4 and IPv6 addresses between binary and text form int inet_pton(int af, const char *restrict src, void *restrict dst);
initstate stdlib.h XSI initstate, random, setstate, srandom - pseudo-random number functions char *initstate(unsigned seed, char *state, size_t size);
insque search.h XSI insque, remque - insert or remove an element in a queue void insque(void *element, void *pred);
ioctl stropts.h OB XSR ioctl - control a STREAMS device (STREAMS) int ioctl(int fildes, int request, ... /* arg */);
isalnum ctype.h CX isalnum, isalnum_l - test for an alphanumeric character int isalnum(int c);
isalnum_l ctype.h CX isalnum, isalnum_l - test for an alphanumeric character int isalnum_l(int c, locale_t locale);
isalpha ctype.h CX isalpha, isalpha_l - test for an alphabetic character int isalpha(int c);
isalpha_l ctype.h CX isalpha, isalpha_l - test for an alphabetic character int isalpha_l(int c, locale_t locale);
isascii ctype.h OB XSI isascii - test for a 7-bit US-ASCII character int isascii(int c);
isastream stropts.h OB XSR isastream - test a file descriptor (STREAMS) int isastream(int fildes);
isatty unistd.h isatty - test for a terminal device int isatty(int fildes);
isblank ctype.h CX isblank, isblank_l - test for a blank character int isblank(int c);
isblank_l ctype.h CX isblank, isblank_l - test for a blank character int isblank_l(int c, locale_t locale);
iscntrl ctype.h CX iscntrl, iscntrl_l - test for a control character int iscntrl(int c);
iscntrl_l ctype.h CX iscntrl, iscntrl_l - test for a control character int iscntrl_l(int c, locale_t locale);
isdigit ctype.h CX isdigit, isdigit_l - test for a decimal digit int isdigit(int c);
isdigit_l ctype.h CX isdigit, isdigit_l - test for a decimal digit int isdigit_l(int c, locale_t locale);
isfinite math.h isfinite - test for finite value int isfinite(real-floating x);
isgraph ctype.h CX isgraph, isgraph_l - test for a visible character int isgraph(int c);
isgraph_l ctype.h CX isgraph, isgraph_l - test for a visible character int isgraph_l(int c, locale_t locale);
isgreater math.h isgreater - test if x greater than y int isgreater(real-floating x, real-floating y);
isgreaterequal math.h isgreaterequal - test if x is greater than or equal to y int isgreaterequal(real-floating x, real-floating y);
isinf math.h isinf - test for infinity int isinf(real-floating x);
isless math.h isless - test if x is less than y int isless(real-floating x, real-floating y);
islessequal math.h islessequal - test if x is less than or equal to y int islessequal(real-floating x, real-floating y);
islessgreater math.h islessgreater - test if x is less than or greater than y int islessgreater(real-floating x, real-floating y);
islower ctype.h CX islower, islower_l - test for a lowercase letter int islower(int c);
islower_l ctype.h CX islower, islower_l - test for a lowercase letter int islower_l(int c, locale_t locale);
isnan math.h isnan - test for a NaN int isnan(real-floating x);
isnormal math.h isnormal - test for a normal value int isnormal(real-floating x);
isprint ctype.h CX isprint, isprint_l - test for a printable character int isprint(int c);
isprint_l ctype.h CX isprint, isprint_l - test for a printable character int isprint_l(int c, locale_t locale);
ispunct ctype.h CX ispunct, ispunct_l - test for a punctuation character int ispunct(int c);
ispunct_l ctype.h CX ispunct, ispunct_l - test for a punctuation character int ispunct_l(int c, locale_t locale);
isspace ctype.h CX isspace, isspace_l - test for a white-space character int isspace(int c);
isspace_l ctype.h CX isspace, isspace_l - test for a white-space character int isspace_l(int c, locale_t locale);
isunordered math.h isunordered - test if arguments are unordered int isunordered(real-floating x, real-floating y);
isupper ctype.h CX isupper, isupper_l - test for an uppercase letter int isupper(int c);
isupper_l ctype.h CX isupper, isupper_l - test for an uppercase letter int isupper_l(int c, locale_t locale);
iswalnum wctype.h CX iswalnum, iswalnum_l - test for an alphanumeric wide-character code int iswalnum(wint_t wc);
iswalnum_l wctype.h CX iswalnum, iswalnum_l - test for an alphanumeric wide-character code int iswalnum_l(wint_t wc, locale_t locale);
iswalpha wctype.h CX iswalpha, iswalpha_l - test for an alphabetic wide-character code int iswalpha(wint_t wc);
iswalpha_l wctype.h CX iswalpha, iswalpha_l - test for an alphabetic wide-character code int iswalpha_l(wint_t wc, locale_t locale);
iswblank wctype.h CX iswblank, iswblank_l - test for a blank wide-character code int iswblank(wint_t wc);
iswblank_l wctype.h CX iswblank, iswblank_l - test for a blank wide-character code int iswblank_l(wint_t wc, locale_t locale);
iswcntrl wctype.h CX iswcntrl, iswcntrl_l - test for a control wide-character code int iswcntrl(wint_t wc);
iswcntrl_l wctype.h CX iswcntrl, iswcntrl_l - test for a control wide-character code int iswcntrl_l(wint_t wc, locale_t locale);
iswctype wctype.h CX iswctype, iswctype_l - test character for a specified class int iswctype(wint_t wc, wctype_t charclass);
iswctype_l wctype.h CX iswctype, iswctype_l - test character for a specified class int iswctype_l(wint_t wc, wctype_t charclass, locale_t locale);
iswdigit wctype.h CX iswdigit, iswdigit_l - test for a decimal digit wide-character code int iswdigit(wint_t wc);
iswdigit_l wctype.h CX iswdigit, iswdigit_l - test for a decimal digit wide-character code int iswdigit_l(wint_t wc, locale_t locale);
iswgraph wctype.h CX iswgraph, iswgraph_l - test for a visible wide-character code int iswgraph(wint_t wc);
iswgraph_l wctype.h CX iswgraph, iswgraph_l - test for a visible wide-character code int iswgraph_l(wint_t wc, locale_t locale);
iswlower wctype.h CX iswlower, iswlower_l - test for a lowercase letter wide-character code int iswlower(wint_t wc);
iswlower_l wctype.h CX iswlower, iswlower_l - test for a lowercase letter wide-character code int iswlower_l(wint_t wc, locale_t locale);
iswprint wctype.h CX iswprint, iswprint_l - test for a printable wide-character code int iswprint(wint_t wc);
iswprint_l wctype.h CX iswprint, iswprint_l - test for a printable wide-character code int iswprint_l(wint_t wc, locale_t locale);
iswpunct wctype.h CX iswpunct, iswpunct_l - test for a punctuation wide-character code int iswpunct(wint_t wc);
iswpunct_l wctype.h CX iswpunct, iswpunct_l - test for a punctuation wide-character code int iswpunct_l(wint_t wc, locale_t locale);
iswspace wctype.h CX iswspace, iswspace_l - test for a white-space wide-character code int iswspace(wint_t wc);
iswspace_l wctype.h CX iswspace, iswspace_l - test for a white-space wide-character code int iswspace_l(wint_t wc, locale_t locale);
iswupper wctype.h CX iswupper, iswupper_l - test for an uppercase letter wide-character code int iswupper(wint_t wc);
iswupper_l wctype.h CX iswupper, iswupper_l - test for an uppercase letter wide-character code int iswupper_l(wint_t wc, locale_t locale);
iswxdigit wctype.h CX iswxdigit, iswxdigit_l - test for a hexadecimal digit wide-character code int iswxdigit(wint_t wc);
iswxdigit_l wctype.h CX iswxdigit, iswxdigit_l - test for a hexadecimal digit wide-character code int iswxdigit_l(wint_t wc, locale_t locale);
isxdigit ctype.h CX isxdigit, isxdigit_l - test for a hexadecimal digit int isxdigit(int c);
isxdigit_l ctype.h CX isxdigit, isxdigit_l - test for a hexadecimal digit int isxdigit_l(int c, locale_t locale);
j0 math.h XSI j0, j1, jn - Bessel functions of the first kind double j0(double x);
j1 math.h XSI j0, j1, jn - Bessel functions of the first kind double j1(double x);
jn math.h XSI j0, j1, jn - Bessel functions of the first kind double jn(int n, double x);
jrand48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers long jrand48(unsigned short xsubi[3]);
kill signal.h CX kill - send a signal to a process or a group of processes int kill(pid_t pid, int sig);
killpg signal.h XSI killpg - send a signal to a process group int killpg(pid_t pgrp, int sig);
l64a stdlib.h XSI a64l, l64a - convert between a 32-bit integer and a radix-64 ASCII string char *l64a(long value);
labs stdlib.h labs, llabs - return a long integer absolute value long labs(long i);
lchown unistd.h lchown - change the owner and group of a symbolic link int lchown(const char *path, uid_t owner, gid_t group);
lcong48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers void lcong48(unsigned short param[7]);
ldexp math.h ldexp, ldexpf, ldexpl - load exponent of a floating-point number double ldexp(double x, int exp);
ldexpf math.h ldexp, ldexpf, ldexpl - load exponent of a floating-point number float ldexpf(float x, int exp);
ldexpl math.h ldexp, ldexpf, ldexpl - load exponent of a floating-point number long double ldexpl(long double x, int exp);
ldiv stdlib.h ldiv, lldiv - compute quotient and remainder of a long division ldiv_t ldiv(long numer, long denom);
lfind search.h XSI lsearch, lfind - linear search and update void *lfind(const void *key, const void *base, size_t *nelp, size_t width, int (*compar)(const void *, const void *));
lgamma math.h XSI lgamma, lgammaf, lgammal, signgam - log gamma function double lgamma(double x);
lgammaf math.h XSI lgamma, lgammaf, lgammal, signgam - log gamma function float lgammaf(float x);
lgammal math.h XSI lgamma, lgammaf, lgammal, signgam - log gamma function long double lgammal(long double x);
link unistd.h link, linkat - link one file to another file relative to two directory file descriptors int link(const char *path1, const char *path2);
linkat unistd.h link, linkat - link one file to another file relative to two directory file descriptors int linkat(int fd1, const char *path1, int fd2, const char *path2, int flag);
lio_listio aio.h lio_listio - list directed I/O int lio_listio(int mode, struct aiocb *restrict const list[restrict], int nent, struct sigevent *restrict sig);
listen sys/socket.h listen - listen for socket connections and limit the queue of incoming connections int listen(int socket, int backlog);
llabs stdlib.h labs, llabs - return a long integer absolute value long long llabs(long long i);
lldiv stdlib.h ldiv, lldiv - compute quotient and remainder of a long division lldiv_t lldiv(long long numer, long long denom);
llrint math.h llrint, llrintf, llrintl - round to the nearest integer value using current rounding direction long long llrint(double x);
llrintf math.h llrint, llrintf, llrintl - round to the nearest integer value using current rounding direction long long llrintf(float x);
llrintl math.h llrint, llrintf, llrintl - round to the nearest integer value using current rounding direction long long llrintl(long double x);
llround math.h llround, llroundf, llroundl - round to nearest integer value long long llround(double x);
llroundf math.h llround, llroundf, llroundl - round to nearest integer value long long llroundf(float x);
llroundl math.h llround, llroundf, llroundl - round to nearest integer value long long llroundl(long double x);
localeconv locale.h localeconv - return locale-specific information struct lconv *localeconv(void);
localtime time.h CX localtime, localtime_r - convert a time value to a broken-down local time struct tm *localtime(const time_t *timer);
localtime_r time.h CX localtime, localtime_r - convert a time value to a broken-down local time struct tm *localtime_r(const time_t *restrict timer, struct tm *restrict result);
lockf unistd.h XSI lockf - record locking on files int lockf(int fildes, int function, off_t size);
log math.h log, logf, logl - natural logarithm function double log(double x);
log10 math.h log10, log10f, log10l - base 10 logarithm function double log10(double x);
log10f math.h log10, log10f, log10l - base 10 logarithm function float log10f(float x);
log10l math.h log10, log10f, log10l - base 10 logarithm function long double log10l(long double x);
log1p math.h log1p, log1pf, log1pl - compute a natural logarithm double log1p(double x);
log1pf math.h log1p, log1pf, log1pl - compute a natural logarithm float log1pf(float x);
log1pl math.h log1p, log1pf, log1pl - compute a natural logarithm long double log1pl(long double x);
log2 math.h log2, log2f, log2l - compute base 2 logarithm functions double log2(double x);
log2f math.h log2, log2f, log2l - compute base 2 logarithm functions float log2f(float x);
log2l math.h log2, log2f, log2l - compute base 2 logarithm functions long double log2l(long double x);
logb math.h logb, logbf, logbl - radix-independent exponent double logb(double x);
logbf math.h logb, logbf, logbl - radix-independent exponent float logbf(float x);
logbl math.h logb, logbf, logbl - radix-independent exponent long double logbl(long double x);
logf math.h log, logf, logl - natural logarithm function float logf(float x);
logl math.h log, logf, logl - natural logarithm function long double logl(long double x);
longjmp setjmp.h longjmp - non-local goto void longjmp(jmp_buf env, int val);
lrand48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers long lrand48(void);
lrint math.h lrint, lrintf, lrintl - round to nearest integer value using current rounding direction long lrint(double x);
lrintf math.h lrint, lrintf, lrintl - round to nearest integer value using current rounding direction long lrintf(float x);
lrintl math.h lrint, lrintf, lrintl - round to nearest integer value using current rounding direction long lrintl(long double x);
lround math.h lround, lroundf, lroundl - round to nearest integer value long lround(double x);
lroundf math.h lround, lroundf, lroundl - round to nearest integer value long lroundf(float x);
lroundl math.h lround, lroundf, lroundl - round to nearest integer value long lroundl(long double x);
lsearch search.h XSI lsearch, lfind - linear search and update void *lsearch(const void *key, void *base, size_t *nelp, size_t width, int (*compar)(const void *, const void *));
lseek unistd.h lseek - move the read/write file offset off_t lseek(int fildes, off_t offset, int whence);
lstat sys/stat.h fstatat, lstat, stat - get file status int lstat(const char *restrict path, struct stat *restrict buf);
malloc stdlib.h malloc - a memory allocator void *malloc(size_t size);
mblen stdlib.h mblen - get number of bytes in a character int mblen(const char *s, size_t n);
mbrlen wchar.h mbrlen - get number of bytes in a character (restartable) size_t mbrlen(const char *restrict s, size_t n, mbstate_t *restrict ps);
mbrtowc wchar.h mbrtowc - convert a character to a wide-character code (restartable) size_t mbrtowc(wchar_t *restrict pwc, const char *restrict s, size_t n, mbstate_t *restrict ps);
mbsinit wchar.h mbsinit - determine conversion object status int mbsinit(const mbstate_t *ps);
mbsnrtowcs wchar.h CX mbsnrtowcs, mbsrtowcs - convert a character string to a wide-character string (restartable) size_t mbsnrtowcs(wchar_t *restrict dst, const char **restrict src, size_t nmc, size_t len, mbstate_t *restrict ps);
mbsrtowcs wchar.h CX mbsnrtowcs, mbsrtowcs - convert a character string to a wide-character string (restartable) size_t mbsrtowcs(wchar_t *restrict dst, const char **restrict src, size_t len, mbstate_t *restrict ps);
mbstowcs stdlib.h mbstowcs - convert a character string to a wide-character string size_t mbstowcs(wchar_t *restrict pwcs, const char *restrict s, size_t n);
mbtowc stdlib.h mbtowc - convert a character to a wide-character code int mbtowc(wchar_t *restrict pwc, const char *restrict s, size_t n);
memccpy string.h XSI memccpy - copy bytes in memory void *memccpy(void *restrict s1, const void *restrict s2, int c, size_t n);
memchr string.h memchr - find byte in memory void *memchr(const void *s, int c, size_t n);
memcmp string.h memcmp - compare bytes in memory int memcmp(const void *s1, const void *s2, size_t n);
memcpy string.h memcpy - copy bytes in memory void *memcpy(void *restrict s1, const void *restrict s2, size_t n);
memmove string.h memmove - copy bytes in memory with overlapping areas void *memmove(void *s1, const void *s2, size_t n);
memset string.h memset - set bytes in memory void *memset(void *s, int c, size_t n);
mkdir sys/stat.h mkdir, mkdirat - make a directory relative to directory file descriptor int mkdir(const char *path, mode_t mode);
mkdirat sys/stat.h mkdir, mkdirat - make a directory relative to directory file descriptor int mkdirat(int fd, const char *path, mode_t mode);
mkdtemp stdlib.h CX mkdtemp, mkstemp - create a unique directory or file char *mkdtemp(char *template);
mkfifo sys/stat.h mkfifo, mkfifoat - make a FIFO special file relative to directory file descriptor int mkfifo(const char *path, mode_t mode);
mkfifoat sys/stat.h mkfifo, mkfifoat - make a FIFO special file relative to directory file descriptor int mkfifoat(int fd, const char *path, mode_t mode);
mknod sys/stat.h XSI mknod, mknodat - make directory, special file, or regular file int mknod(const char *path, mode_t mode, dev_t dev);
mknodat sys/stat.h XSI mknod, mknodat - make directory, special file, or regular file int mknodat(int fd, const char *path, mode_t mode, dev_t dev);
mkstemp stdlib.h CX mkdtemp, mkstemp - create a unique directory or file int mkstemp(char *template);
mktime time.h mktime - convert broken-down time into time since the Epoch time_t mktime(struct tm *timeptr);
mlock sys/mman.h MLR mlock, munlock - lock or unlock a range of process address space (REALTIME) int mlock(const void *addr, size_t len);
mlockall sys/mman.h ML mlockall, munlockall - lock/unlock the address space of a process (REALTIME) int mlockall(int flags);
mmap sys/mman.h mmap - map pages of memory void *mmap(void *addr, size_t len, int prot, int flags, int fildes, off_t off);
modf math.h modf, modff, modfl - decompose a floating-point number double modf(double x, double *iptr);
modff math.h modf, modff, modfl - decompose a floating-point number float modff(float value, float *iptr);
modfl math.h modf, modff, modfl - decompose a floating-point number long double modfl(long double value, long double *iptr);
mprotect sys/mman.h mprotect - set protection of memory mapping int mprotect(void *addr, size_t len, int prot);
mq_close mqueue.h MSG mq_close - close a message queue (REALTIME) int mq_close(mqd_t mqdes);
mq_getattr mqueue.h MSG mq_getattr - get message queue attributes (REALTIME) int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat);
mq_notify mqueue.h MSG mq_notify - notify process that a message is available (REALTIME) int mq_notify(mqd_t mqdes, const struct sigevent *notification);
mq_open mqueue.h MSG mq_open - open a message queue (REALTIME) mqd_t mq_open(const char *name, int oflag, ...);
mq_receive mqueue.h mqueue.h time.h MSG mq_receive, mq_timedreceive - receive a message from a message queue (REALTIME) ssize_t mq_receive(mqd_t mqdes, char *msg_ptr, size_t msg_len, unsigned *msg_prio);
mq_send mqueue.h mqueue.h time.h MSG mq_send, mq_timedsend - send a message to a message queue (REALTIME) int mq_send(mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned msg_prio);
mq_setattr mqueue.h MSG mq_setattr - set message queue attributes (REALTIME) int mq_setattr(mqd_t mqdes, const struct mq_attr *restrict mqstat, struct mq_attr *restrict omqstat);
mq_timedreceive mqueue.h mqueue.h time.h MSG mq_receive, mq_timedreceive - receive a message from a message queue (REALTIME) ssize_t mq_timedreceive(mqd_t mqdes, char *restrict msg_ptr, size_t msg_len, unsigned *restrict msg_prio, const struct timespec *restrict abstime);
mq_timedsend mqueue.h mqueue.h time.h MSG mq_send, mq_timedsend - send a message to a message queue (REALTIME) int mq_timedsend(mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned msg_prio, const struct timespec *abstime);
mq_unlink mqueue.h MSG mq_unlink - remove a message queue (REALTIME) int mq_unlink(const char *name);
mrand48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers long mrand48(void);
msgctl sys/msg.h XSI msgctl - XSI message control operations int msgctl(int msqid, int cmd, struct msqid_ds *buf);
msgget sys/msg.h XSI msgget - get the XSI message queue identifier int msgget(key_t key, int msgflg);
msgrcv sys/msg.h XSI msgrcv - XSI message receive operation ssize_t msgrcv(int msqid, void *msgp, size_t msgsz, long msgtyp, int msgflg);
msgsnd sys/msg.h XSI msgsnd - XSI message send operation int msgsnd(int msqid, const void *msgp, size_t msgsz, int msgflg);
msync sys/mman.h XSI msync - synchronize memory with physical storage int msync(void *addr, size_t len, int flags);
munlock sys/mman.h MLR mlock, munlock - lock or unlock a range of process address space (REALTIME) int munlock(const void *addr, size_t len);
munlockall sys/mman.h ML mlockall, munlockall - lock/unlock the address space of a process (REALTIME) int munlockall(void);
munmap sys/mman.h munmap - unmap pages of memory int munmap(void *addr, size_t len);
nan math.h nan, nanf, nanl - return quiet NaN double nan(const char *tagp);
nanf math.h nan, nanf, nanl - return quiet NaN float nanf(const char *tagp);
nanl math.h nan, nanf, nanl - return quiet NaN long double nanl(const char *tagp);
nanosleep time.h CX nanosleep - high resolution sleep int nanosleep(const struct timespec *rqtp, struct timespec *rmtp);
nearbyint math.h nearbyint, nearbyintf, nearbyintl - floating-point rounding functions double nearbyint(double x);
nearbyintf math.h nearbyint, nearbyintf, nearbyintl - floating-point rounding functions float nearbyintf(float x);
nearbyintl math.h nearbyint, nearbyintf, nearbyintl - floating-point rounding functions long double nearbyintl(long double x);
newlocale locale.h CX newlocale - create or modify a locale object locale_t newlocale(int category_mask, const char *locale, locale_t base);
nextafter math.h nextafter, nextafterf, nextafterl, nexttoward, nexttowardf, nexttowardl - next representable floating-point number double nextafter(double x, double y);
nextafterf math.h nextafter, nextafterf, nextafterl, nexttoward, nexttowardf, nexttowardl - next representable floating-point number float nextafterf(float x, float y);
nextafterl math.h nextafter, nextafterf, nextafterl, nexttoward, nexttowardf, nexttowardl - next representable floating-point number long double nextafterl(long double x, long double y);
nexttoward math.h nextafter, nextafterf, nextafterl, nexttoward, nexttowardf, nexttowardl - next representable floating-point number double nexttoward(double x, long double y);
nexttowardf math.h nextafter, nextafterf, nextafterl, nexttoward, nexttowardf, nexttowardl - next representable floating-point number float nexttowardf(float x, long double y);
nexttowardl math.h nextafter, nextafterf, nextafterl, nexttoward, nexttowardf, nexttowardl - next representable floating-point number long double nexttowardl(long double x, long double y);
nftw ftw.h XSI nftw - walk a file tree int nftw(const char *path, int (*fn)(const char *, const struct stat *, int, struct FTW *), int fd_limit, int flags);
nice unistd.h XSI nice - change the nice value of a process int nice(int incr);
nl_langinfo langinfo.h nl_langinfo, nl_langinfo_l - language information char *nl_langinfo(nl_item item);
nl_langinfo_l langinfo.h nl_langinfo, nl_langinfo_l - language information char *nl_langinfo_l(nl_item item, locale_t locale);
nrand48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers long nrand48(unsigned short xsubi[3]);
ntohl arpa/inet.h htonl, htons, ntohl, ntohs - convert values between host and network byte order uint32_t ntohl(uint32_t netlong);
ntohs arpa/inet.h htonl, htons, ntohl, ntohs - convert values between host and network byte order uint16_t ntohs(uint16_t netshort);
open sys/stat.h fcntl.h OH open, openat - open file relative to directory file descriptor int open(const char *path, int oflag, ...);
open_memstream stdio.h wchar.h CX open_memstream, open_wmemstream - open a dynamic memory buffer stream FILE *open_memstream(char **bufp, size_t *sizep);
open_wmemstream stdio.h wchar.h CX open_memstream, open_wmemstream - open a dynamic memory buffer stream FILE *open_wmemstream(wchar_t **bufp, size_t *sizep);
openat sys/stat.h fcntl.h OH open, openat - open file relative to directory file descriptor int openat(int fd, const char *path, int oflag, ...);
opendir dirent.h fdopendir, opendir - open directory associated with file descriptor DIR *opendir(const char *dirname);
openlog syslog.h XSI closelog, openlog, setlogmask, syslog - control system log void openlog(const char *ident, int logopt, int facility);
optarg unistd.h getopt, optarg, opterr, optind, optopt - command option parsing
opterr unistd.h getopt, optarg, opterr, optind, optopt - command option parsing
optind unistd.h getopt, optarg, opterr, optind, optopt - command option parsing
optopt unistd.h getopt, optarg, opterr, optind, optopt - command option parsing
pathconf unistd.h fpathconf, pathconf - get configurable pathname variables long pathconf(const char *path, int name);
pause unistd.h pause - suspend the thread until a signal is received int pause(void);
pclose stdio.h CX pclose - close a pipe stream to or from a process int pclose(FILE *stream);
perror stdio.h perror - write error messages to standard error void perror(const char *s);
pipe unistd.h pipe - create an interprocess channel int pipe(int fildes[2]);
poll poll.h poll - input/output multiplexing int poll(struct pollfd fds[], nfds_t nfds, int timeout);
popen stdio.h CX popen - initiate pipe streams to or from a process FILE *popen(const char *command, const char *mode);
posix_fadvise fcntl.h ADV posix_fadvise - file advisory information (ADVANCED REALTIME) int posix_fadvise(int fd, off_t offset, off_t len, int advice);
posix_fallocate fcntl.h ADV posix_fallocate - file space control (ADVANCED REALTIME) int posix_fallocate(int fd, off_t offset, off_t len);
posix_madvise sys/mman.h ADV posix_madvise - memory advisory information and alignment control (ADVANCED REALTIME) int posix_madvise(void *addr, size_t len, int advice);
posix_mem_offset sys/mman.h TYM posix_mem_offset - find offset and length of a mapped typed memory block (ADVANCED REALTIME) int posix_mem_offset(const void *restrict addr, size_t len, off_t *restrict off, size_t *restrict contig_len, int *restrict fildes);
posix_memalign stdlib.h ADV posix_memalign - aligned memory allocation (ADVANCED REALTIME) int posix_memalign(void **memptr, size_t alignment, size_t size);
posix_openpt stdlib.h fcntl.h XSI posix_openpt - open a pseudo-terminal device int posix_openpt(int oflag);
posix_spawn spawn.h SPN posix_spawn, posix_spawnp - spawn a process (ADVANCED REALTIME) int posix_spawn(pid_t *restrict pid, const char *restrict path, const posix_spawn_file_actions_t *file_actions, const posix_spawnattr_t *restrict attrp, char *const argv[restrict], char *const envp[restrict]);
posix_spawn_file_actions_addclose spawn.h SPN posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen - add close or open action to spawn file actions object (ADVANCED REALTIME) int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions, int fildes);
posix_spawn_file_actions_adddup2 spawn.h SPN posix_spawn_file_actions_adddup2 - add dup2 action to spawn file actions object (ADVANCED REALTIME) int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t *file_actions, int fildes, int newfildes);
posix_spawn_file_actions_addopen spawn.h SPN posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen - add close or open action to spawn file actions object (ADVANCED REALTIME) int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *restrict file_actions, int fildes, const char *restrict path, int oflag, mode_t mode);
posix_spawn_file_actions_destroy spawn.h SPN posix_spawn_file_actions_destroy, posix_spawn_file_actions_init - destroy and initialize spawn file actions object (ADVANCED REALTIME) int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t *file_actions);
posix_spawn_file_actions_init spawn.h SPN posix_spawn_file_actions_destroy, posix_spawn_file_actions_init - destroy and initialize spawn file actions object (ADVANCED REALTIME) int posix_spawn_file_actions_init(posix_spawn_file_actions_t *file_actions);
posix_spawnattr_destroy spawn.h SPN posix_spawnattr_destroy, posix_spawnattr_init - destroy and initialize spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_destroy(posix_spawnattr_t *attr);
posix_spawnattr_getflags spawn.h SPN posix_spawnattr_getflags, posix_spawnattr_setflags - get and set the spawn-flags attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_getflags(const posix_spawnattr_t *restrict attr, short *restrict flags);
posix_spawnattr_getpgroup spawn.h SPN posix_spawnattr_getpgroup, posix_spawnattr_setpgroup - get and set the spawn-pgroup attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_getpgroup(const posix_spawnattr_t *restrict attr, pid_t *restrict pgroup);
posix_spawnattr_getschedparam spawn.h sched.h SPN PS posix_spawnattr_getschedparam, posix_spawnattr_setschedparam - get and set the spawn-schedparam attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_getschedparam(const posix_spawnattr_t *restrict attr, struct sched_param *restrict schedparam);
posix_spawnattr_getschedpolicy spawn.h sched.h SPN PS posix_spawnattr_getschedpolicy, posix_spawnattr_setschedpolicy - get and set the spawn-schedpolicy attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_getschedpolicy(const posix_spawnattr_t *restrict attr, int *restrict schedpolicy);
posix_spawnattr_getsigdefault signal.h spawn.h SPN posix_spawnattr_getsigdefault, posix_spawnattr_setsigdefault - get and set the spawn-sigdefault attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_getsigdefault(const posix_spawnattr_t *restrict attr, sigset_t *restrict sigdefault);
posix_spawnattr_getsigmask signal.h spawn.h SPN posix_spawnattr_getsigmask, posix_spawnattr_setsigmask - get and set the spawn-sigmask attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_getsigmask(const posix_spawnattr_t *restrict attr, sigset_t *restrict sigmask);
posix_spawnattr_init spawn.h SPN posix_spawnattr_destroy, posix_spawnattr_init - destroy and initialize spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_init(posix_spawnattr_t *attr);
posix_spawnattr_setflags spawn.h SPN posix_spawnattr_getflags, posix_spawnattr_setflags - get and set the spawn-flags attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags);
posix_spawnattr_setpgroup spawn.h SPN posix_spawnattr_getpgroup, posix_spawnattr_setpgroup - get and set the spawn-pgroup attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_setpgroup(posix_spawnattr_t *attr, pid_t pgroup);
posix_spawnattr_setschedparam spawn.h sched.h SPN PS posix_spawnattr_getschedparam, posix_spawnattr_setschedparam - get and set the spawn-schedparam attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_setschedparam(posix_spawnattr_t *restrict attr, const struct sched_param *restrict schedparam);
posix_spawnattr_setschedpolicy spawn.h sched.h SPN PS posix_spawnattr_getschedpolicy, posix_spawnattr_setschedpolicy - get and set the spawn-schedpolicy attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_setschedpolicy(posix_spawnattr_t *attr, int schedpolicy);
posix_spawnattr_setsigdefault signal.h spawn.h SPN posix_spawnattr_getsigdefault, posix_spawnattr_setsigdefault - get and set the spawn-sigdefault attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_setsigdefault(posix_spawnattr_t *restrict attr, const sigset_t *restrict sigdefault);
posix_spawnattr_setsigmask signal.h spawn.h SPN posix_spawnattr_getsigmask, posix_spawnattr_setsigmask - get and set the spawn-sigmask attribute of a spawn attributes object (ADVANCED REALTIME) int posix_spawnattr_setsigmask(posix_spawnattr_t *restrict attr, const sigset_t *restrict sigmask);
posix_spawnp spawn.h SPN posix_spawn, posix_spawnp - spawn a process (ADVANCED REALTIME) int posix_spawnp(pid_t *restrict pid, const char *restrict file, const posix_spawn_file_actions_t *file_actions, const posix_spawnattr_t *restrict attrp, char *const argv[restrict], char *const envp[restrict]);
posix_trace_attr_destroy trace.h OB TRC posix_trace_attr_destroy, posix_trace_attr_init - destroy and initialize the trace stream attributes object (TRACING) int posix_trace_attr_destroy(trace_attr_t *attr);
posix_trace_attr_getclockres time.h trace.h trace.h OB TRC posix_trace_attr_getclockres, posix_trace_attr_getcreatetime, posix_trace_attr_getgenversion, posix_trace_attr_getname, posix_trace_attr_setname - retrieve and set information about a trace stream (TRACING) int posix_trace_attr_getclockres(const trace_attr_t *attr, struct timespec *resolution);
posix_trace_attr_getcreatetime time.h trace.h trace.h OB TRC posix_trace_attr_getclockres, posix_trace_attr_getcreatetime, posix_trace_attr_getgenversion, posix_trace_attr_getname, posix_trace_attr_setname - retrieve and set information about a trace stream (TRACING) int posix_trace_attr_getcreatetime(const trace_attr_t *attr, struct timespec *createtime);
posix_trace_attr_getgenversion time.h trace.h trace.h OB TRC posix_trace_attr_getclockres, posix_trace_attr_getcreatetime, posix_trace_attr_getgenversion, posix_trace_attr_getname, posix_trace_attr_setname - retrieve and set information about a trace stream (TRACING) int posix_trace_attr_getgenversion(const trace_attr_t *attr, char *genversion);
posix_trace_attr_getinherited trace.h OB TRC TRI TRL TRI TRL posix_trace_attr_getinherited, posix_trace_attr_getlogfullpolicy, posix_trace_attr_getstreamfullpolicy, posix_trace_attr_setinherited, posix_trace_attr_setlogfullpolicy, posix_trace_attr_setstreamfullpolicy - retrieve and set the behavior of a trace stream (TRACING) int posix_trace_attr_getinherited(const trace_attr_t *restrict attr, int *restrict inheritancepolicy);
posix_trace_attr_getlogfullpolicy trace.h OB TRC TRI TRL TRI TRL posix_trace_attr_getinherited, posix_trace_attr_getlogfullpolicy, posix_trace_attr_getstreamfullpolicy, posix_trace_attr_setinherited, posix_trace_attr_setlogfullpolicy, posix_trace_attr_setstreamfullpolicy - retrieve and set the behavior of a trace stream (TRACING) int posix_trace_attr_getlogfullpolicy(const trace_attr_t *restrict attr, int *restrict logpolicy);
posix_trace_attr_getlogsize sys/types.h trace.h OB TRC TRL TRL posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize, posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING) int posix_trace_attr_getlogsize(const trace_attr_t *restrict attr, size_t *restrict logsize);
posix_trace_attr_getmaxdatasize sys/types.h trace.h OB TRC TRL TRL posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize, posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING) int posix_trace_attr_getmaxdatasize(const trace_attr_t *restrict attr, size_t *restrict maxdatasize);
posix_trace_attr_getmaxsystemeventsize sys/types.h trace.h OB TRC TRL TRL posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize, posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING) int posix_trace_attr_getmaxsystemeventsize( const trace_attr_t *restrict attr, size_t *restrict eventsize);
posix_trace_attr_getmaxusereventsize sys/types.h trace.h OB TRC TRL TRL posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize, posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING) int posix_trace_attr_getmaxusereventsize( const trace_attr_t *restrict attr, size_t data_len, size_t *restrict eventsize);
posix_trace_attr_getname time.h trace.h trace.h OB TRC posix_trace_attr_getclockres, posix_trace_attr_getcreatetime, posix_trace_attr_getgenversion, posix_trace_attr_getname, posix_trace_attr_setname - retrieve and set information about a trace stream (TRACING) int posix_trace_attr_getname(const trace_attr_t *attr, char *tracename);
posix_trace_attr_getstreamfullpolicy trace.h OB TRC TRI TRL TRI TRL posix_trace_attr_getinherited, posix_trace_attr_getlogfullpolicy, posix_trace_attr_getstreamfullpolicy, posix_trace_attr_setinherited, posix_trace_attr_setlogfullpolicy, posix_trace_attr_setstreamfullpolicy - retrieve and set the behavior of a trace stream (TRACING) int posix_trace_attr_getstreamfullpolicy(const trace_attr_t *restrict attr, int *restrict streampolicy);
posix_trace_attr_getstreamsize sys/types.h trace.h OB TRC TRL TRL posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize, posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING) int posix_trace_attr_getstreamsize(const trace_attr_t *restrict attr, size_t *restrict streamsize);
posix_trace_attr_init trace.h OB TRC posix_trace_attr_destroy, posix_trace_attr_init - destroy and initialize the trace stream attributes object (TRACING) int posix_trace_attr_init(trace_attr_t *attr);
posix_trace_attr_setinherited trace.h OB TRC TRI TRL TRI TRL posix_trace_attr_getinherited, posix_trace_attr_getlogfullpolicy, posix_trace_attr_getstreamfullpolicy, posix_trace_attr_setinherited, posix_trace_attr_setlogfullpolicy, posix_trace_attr_setstreamfullpolicy - retrieve and set the behavior of a trace stream (TRACING) int posix_trace_attr_setinherited(trace_attr_t *attr, int inheritancepolicy);
posix_trace_attr_setlogfullpolicy trace.h OB TRC TRI TRL TRI TRL posix_trace_attr_getinherited, posix_trace_attr_getlogfullpolicy, posix_trace_attr_getstreamfullpolicy, posix_trace_attr_setinherited, posix_trace_attr_setlogfullpolicy, posix_trace_attr_setstreamfullpolicy - retrieve and set the behavior of a trace stream (TRACING) int posix_trace_attr_setlogfullpolicy(trace_attr_t *attr, int logpolicy);
posix_trace_attr_setlogsize sys/types.h trace.h OB TRC TRL TRL posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize, posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING) int posix_trace_attr_setlogsize(trace_attr_t *attr, size_t logsize);
posix_trace_attr_setmaxdatasize sys/types.h trace.h OB TRC TRL TRL posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize, posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING) int posix_trace_attr_setmaxdatasize(trace_attr_t *attr, size_t maxdatasize);
posix_trace_attr_setname time.h trace.h trace.h OB TRC posix_trace_attr_getclockres, posix_trace_attr_getcreatetime, posix_trace_attr_getgenversion, posix_trace_attr_getname, posix_trace_attr_setname - retrieve and set information about a trace stream (TRACING) int posix_trace_attr_setname(trace_attr_t *attr, const char *tracename);
posix_trace_attr_setstreamfullpolicy trace.h OB TRC TRI TRL TRI TRL posix_trace_attr_getinherited, posix_trace_attr_getlogfullpolicy, posix_trace_attr_getstreamfullpolicy, posix_trace_attr_setinherited, posix_trace_attr_setlogfullpolicy, posix_trace_attr_setstreamfullpolicy - retrieve and set the behavior of a trace stream (TRACING) int posix_trace_attr_setstreamfullpolicy(trace_attr_t *attr, int streampolicy);
posix_trace_attr_setstreamsize sys/types.h trace.h OB TRC TRL TRL posix_trace_attr_getlogsize, posix_trace_attr_getmaxdatasize, posix_trace_attr_getmaxsystemeventsize, posix_trace_attr_getmaxusereventsize, posix_trace_attr_getstreamsize, posix_trace_attr_setlogsize, posix_trace_attr_setmaxdatasize, posix_trace_attr_setstreamsize - retrieve and set trace stream size attributes (TRACING) int posix_trace_attr_setstreamsize(trace_attr_t *attr, size_t streamsize);
posix_trace_clear sys/types.h trace.h OB TRC posix_trace_clear - clear trace stream and trace log (TRACING) int posix_trace_clear(trace_id_t trid);
posix_trace_close trace.h OB TRC TRL posix_trace_close, posix_trace_open, posix_trace_rewind - trace log management (TRACING) int posix_trace_close(trace_id_t trid);
posix_trace_create sys/types.h trace.h OB TRC TRL posix_trace_create, posix_trace_create_withlog, posix_trace_flush, posix_trace_shutdown - trace stream initialization, flush, and shutdown from a process (TRACING) int posix_trace_create(pid_t pid, const trace_attr_t *restrict attr, trace_id_t *restrict trid);
posix_trace_create_withlog sys/types.h trace.h OB TRC TRL posix_trace_create, posix_trace_create_withlog, posix_trace_flush, posix_trace_shutdown - trace stream initialization, flush, and shutdown from a process (TRACING) int posix_trace_create_withlog(pid_t pid, const trace_attr_t *restrict attr, int file_desc, trace_id_t *restrict trid);
posix_trace_event sys/types.h trace.h OB TRC posix_trace_event, posix_trace_eventid_open - trace functions for instrumenting application code (TRACING) void posix_trace_event(trace_event_id_t event_id, const void *restrict data_ptr, size_t data_len);
posix_trace_eventid_equal trace.h OB TRC TEF posix_trace_eventid_equal, posix_trace_eventid_get_name, posix_trace_trid_eventid_open - manipulate the trace event type identifier (TRACING) int posix_trace_eventid_equal(trace_id_t trid, trace_event_id_t event1, trace_event_id_t event2);
posix_trace_eventid_get_name trace.h OB TRC TEF posix_trace_eventid_equal, posix_trace_eventid_get_name, posix_trace_trid_eventid_open - manipulate the trace event type identifier (TRACING) int posix_trace_eventid_get_name(trace_id_t trid, trace_event_id_t event, char *event_name);
posix_trace_eventid_open sys/types.h trace.h OB TRC posix_trace_event, posix_trace_eventid_open - trace functions for instrumenting application code (TRACING) int posix_trace_eventid_open(const char *restrict event_name, trace_event_id_t *restrict event_id);
posix_trace_eventset_add trace.h OB TRC TEF posix_trace_eventset_add, posix_trace_eventset_del, posix_trace_eventset_empty, posix_trace_eventset_fill, posix_trace_eventset_ismember - manipulate trace event type sets (TRACING) int posix_trace_eventset_add(trace_event_id_t event_id, trace_event_set_t *set);
posix_trace_eventset_del trace.h OB TRC TEF posix_trace_eventset_add, posix_trace_eventset_del, posix_trace_eventset_empty, posix_trace_eventset_fill, posix_trace_eventset_ismember - manipulate trace event type sets (TRACING) int posix_trace_eventset_del(trace_event_id_t event_id, trace_event_set_t *set);
posix_trace_eventset_empty trace.h OB TRC TEF posix_trace_eventset_add, posix_trace_eventset_del, posix_trace_eventset_empty, posix_trace_eventset_fill, posix_trace_eventset_ismember - manipulate trace event type sets (TRACING) int posix_trace_eventset_empty(trace_event_set_t *set);
posix_trace_eventset_fill trace.h OB TRC TEF posix_trace_eventset_add, posix_trace_eventset_del, posix_trace_eventset_empty, posix_trace_eventset_fill, posix_trace_eventset_ismember - manipulate trace event type sets (TRACING) int posix_trace_eventset_fill(trace_event_set_t *set, int what);
posix_trace_eventset_ismember trace.h OB TRC TEF posix_trace_eventset_add, posix_trace_eventset_del, posix_trace_eventset_empty, posix_trace_eventset_fill, posix_trace_eventset_ismember - manipulate trace event type sets (TRACING) int posix_trace_eventset_ismember(trace_event_id_t event_id, const trace_event_set_t *restrict set, int *restrict ismember);
posix_trace_eventtypelist_getnext_id trace.h OB TRC posix_trace_eventtypelist_getnext_id, posix_trace_eventtypelist_rewind - iterate over a mapping of trace event types (TRACING) int posix_trace_eventtypelist_getnext_id(trace_id_t trid, trace_event_id_t *restrict event, int *restrict unavailable);
posix_trace_eventtypelist_rewind trace.h OB TRC posix_trace_eventtypelist_getnext_id, posix_trace_eventtypelist_rewind - iterate over a mapping of trace event types (TRACING) int posix_trace_eventtypelist_rewind(trace_id_t trid);
posix_trace_flush sys/types.h trace.h OB TRC TRL posix_trace_create, posix_trace_create_withlog, posix_trace_flush, posix_trace_shutdown - trace stream initialization, flush, and shutdown from a process (TRACING) int posix_trace_flush(trace_id_t trid);
posix_trace_get_attr trace.h OB TRC posix_trace_get_attr, posix_trace_get_status - retrieve the trace attributes or trace status (TRACING) int posix_trace_get_attr(trace_id_t trid, trace_attr_t *attr);
posix_trace_get_filter trace.h OB TRC TEF posix_trace_get_filter, posix_trace_set_filter - retrieve and set the filter of an initialized trace stream (TRACING) int posix_trace_get_filter(trace_id_t trid, trace_event_set_t *set);
posix_trace_get_status trace.h OB TRC posix_trace_get_attr, posix_trace_get_status - retrieve the trace attributes or trace status (TRACING) int posix_trace_get_status(trace_id_t trid, struct posix_trace_status_info *statusinfo);
posix_trace_getnext_event sys/types.h trace.h OB TRC posix_trace_getnext_event, posix_trace_timedgetnext_event, posix_trace_trygetnext_event - retrieve a trace event (TRACING) int posix_trace_getnext_event(trace_id_t trid, struct posix_trace_event_info *restrict event, void *restrict data, size_t num_bytes, size_t *restrict data_len, int *restrict unavailable);
posix_trace_open trace.h OB TRC TRL posix_trace_close, posix_trace_open, posix_trace_rewind - trace log management (TRACING) int posix_trace_open(int file_desc, trace_id_t *trid);
posix_trace_rewind trace.h OB TRC TRL posix_trace_close, posix_trace_open, posix_trace_rewind - trace log management (TRACING) int posix_trace_rewind(trace_id_t trid);
posix_trace_set_filter trace.h OB TRC TEF posix_trace_get_filter, posix_trace_set_filter - retrieve and set the filter of an initialized trace stream (TRACING) int posix_trace_set_filter(trace_id_t trid, const trace_event_set_t *set, int how);
posix_trace_shutdown sys/types.h trace.h OB TRC TRL posix_trace_create, posix_trace_create_withlog, posix_trace_flush, posix_trace_shutdown - trace stream initialization, flush, and shutdown from a process (TRACING) int posix_trace_shutdown(trace_id_t trid);
posix_trace_start trace.h OB TRC posix_trace_start, posix_trace_stop - trace start and stop (TRACING) int posix_trace_start(trace_id_t trid);
posix_trace_stop trace.h OB TRC posix_trace_start, posix_trace_stop - trace start and stop (TRACING)
posix_trace_timedgetnext_event sys/types.h trace.h OB TRC posix_trace_getnext_event, posix_trace_timedgetnext_event, posix_trace_trygetnext_event - retrieve a trace event (TRACING) int posix_trace_timedgetnext_event(trace_id_t trid, struct posix_trace_event_info *restrict event, void *restrict data, size_t num_bytes, size_t *restrict data_len, int *restrict unavailable, const struct timespec *restrict abstime);
posix_trace_trid_eventid_open trace.h OB TRC TEF posix_trace_eventid_equal, posix_trace_eventid_get_name, posix_trace_trid_eventid_open - manipulate the trace event type identifier (TRACING) int posix_trace_trid_eventid_open(trace_id_t trid, const char *restrict event_name, trace_event_id_t *restrict event);
posix_trace_trygetnext_event sys/types.h trace.h OB TRC posix_trace_getnext_event, posix_trace_timedgetnext_event, posix_trace_trygetnext_event - retrieve a trace event (TRACING) int posix_trace_trygetnext_event(trace_id_t trid, struct posix_trace_event_info *restrict event, void *restrict data, size_t num_bytes, size_t *restrict data_len, int *restrict unavailable);
posix_typed_mem_get_info sys/mman.h TYM posix_typed_mem_get_info - query typed memory information (ADVANCED REALTIME) int posix_typed_mem_get_info(int fildes, struct posix_typed_mem_info *info);
posix_typed_mem_open sys/mman.h TYM posix_typed_mem_open - open a typed memory object (ADVANCED REALTIME) int posix_typed_mem_open(const char *name, int oflag, int tflag);
pow math.h pow, powf, powl - power function double pow(double x, double y);
powf math.h pow, powf, powl - power function float powf(float x, float y);
powl math.h pow, powf, powl - power function long double powl(long double x, long double y);
pread unistd.h pread, read - read from a file ssize_t pread(int fildes, void *buf, size_t nbyte, off_t offset);
printf stdio.h CX dprintf, fprintf, printf, snprintf, sprintf - print formatted output int printf(const char *restrict format, ...);
pselect sys/select.h pselect, select - synchronous I/O multiplexing int pselect(int nfds, fd_set *restrict readfds, fd_set *restrict writefds, fd_set *restrict errorfds, const struct timespec *restrict timeout, const sigset_t *restrict sigmask);
psiginfo signal.h CX psiginfo, psignal - print signal information to standard error void psiginfo(const siginfo_t *pinfo, const char *message);
psignal signal.h CX psiginfo, psignal - print signal information to standard error void psignal(int signum, const char *message);
pthread_atfork pthread.h pthread_atfork - register fork handlers int pthread_atfork(void (*prepare)(void), void (*parent)(void), void (*child)(void));
pthread_attr_destroy pthread.h pthread_attr_destroy, pthread_attr_init - destroy and initialize the thread attributes object int pthread_attr_destroy(pthread_attr_t *attr);
pthread_attr_getdetachstate pthread.h pthread_attr_getdetachstate, pthread_attr_setdetachstate - get and set the detachstate attribute int pthread_attr_getdetachstate(const pthread_attr_t *attr, int *detachstate);
pthread_attr_getguardsize pthread.h pthread_attr_getguardsize, pthread_attr_setguardsize - get and set the thread guardsize attribute int pthread_attr_getguardsize(const pthread_attr_t *restrict attr, size_t *restrict guardsize);
pthread_attr_getinheritsched pthread.h TPS pthread_attr_getinheritsched, pthread_attr_setinheritsched - get and set the inheritsched attribute (REALTIME THREADS) int pthread_attr_getinheritsched(const pthread_attr_t *restrict attr, int *restrict inheritsched);
pthread_attr_getschedparam pthread.h pthread_attr_getschedparam, pthread_attr_setschedparam - get and set the schedparam attribute int pthread_attr_getschedparam(const pthread_attr_t *restrict attr, struct sched_param *restrict param);
pthread_attr_getschedpolicy pthread.h TPS pthread_attr_getschedpolicy, pthread_attr_setschedpolicy - get and set the schedpolicy attribute (REALTIME THREADS) int pthread_attr_getschedpolicy(const pthread_attr_t *restrict attr, int *restrict policy);
pthread_attr_getscope pthread.h TPS pthread_attr_getscope, pthread_attr_setscope - get and set the contentionscope attribute (REALTIME THREADS) int pthread_attr_getscope(const pthread_attr_t *restrict attr, int *restrict contentionscope);
pthread_attr_getstack pthread.h TSA TSS pthread_attr_getstack, pthread_attr_setstack - get and set stack attributes int pthread_attr_getstack(const pthread_attr_t *restrict attr, void **restrict stackaddr, size_t *restrict stacksize);
pthread_attr_getstacksize pthread.h TSS pthread_attr_getstacksize, pthread_attr_setstacksize - get and set the stacksize attribute int pthread_attr_getstacksize(const pthread_attr_t *restrict attr, size_t *restrict stacksize);
pthread_attr_init pthread.h pthread_attr_destroy, pthread_attr_init - destroy and initialize the thread attributes object int pthread_attr_init(pthread_attr_t *attr);
pthread_attr_setdetachstate pthread.h pthread_attr_getdetachstate, pthread_attr_setdetachstate - get and set the detachstate attribute int pthread_attr_setdetachstate(pthread_attr_t *attr, int detachstate);
pthread_attr_setguardsize pthread.h pthread_attr_getguardsize, pthread_attr_setguardsize - get and set the thread guardsize attribute int pthread_attr_setguardsize(pthread_attr_t *attr, size_t guardsize);
pthread_attr_setinheritsched pthread.h TPS pthread_attr_getinheritsched, pthread_attr_setinheritsched - get and set the inheritsched attribute (REALTIME THREADS) int pthread_attr_setinheritsched(pthread_attr_t *attr, int inheritsched);
pthread_attr_setschedparam pthread.h pthread_attr_getschedparam, pthread_attr_setschedparam - get and set the schedparam attribute int pthread_attr_setschedparam(pthread_attr_t *restrict attr, const struct sched_param *restrict param);
pthread_attr_setschedpolicy pthread.h TPS pthread_attr_getschedpolicy, pthread_attr_setschedpolicy - get and set the schedpolicy attribute (REALTIME THREADS) int pthread_attr_setschedpolicy(pthread_attr_t *attr, int policy);
pthread_attr_setscope pthread.h TPS pthread_attr_getscope, pthread_attr_setscope - get and set the contentionscope attribute (REALTIME THREADS) int pthread_attr_setscope(pthread_attr_t *attr, int contentionscope);
pthread_attr_setstack pthread.h TSA TSS pthread_attr_getstack, pthread_attr_setstack - get and set stack attributes int pthread_attr_setstack(pthread_attr_t *attr, void *stackaddr, size_t stacksize);
pthread_attr_setstacksize pthread.h TSS pthread_attr_getstacksize, pthread_attr_setstacksize - get and set the stacksize attribute int pthread_attr_setstacksize(pthread_attr_t *attr, size_t stacksize);
pthread_barrier_destroy pthread.h pthread_barrier_destroy, pthread_barrier_init - destroy and initialize a barrier object int pthread_barrier_destroy(pthread_barrier_t *barrier);
pthread_barrier_init pthread.h pthread_barrier_destroy, pthread_barrier_init - destroy and initialize a barrier object int pthread_barrier_init(pthread_barrier_t *restrict barrier, const pthread_barrierattr_t *restrict attr, unsigned count);
pthread_barrier_wait pthread.h pthread_barrier_wait - synchronize at a barrier int pthread_barrier_wait(pthread_barrier_t *barrier);
pthread_barrierattr_destroy pthread.h pthread_barrierattr_destroy, pthread_barrierattr_init - destroy and initialize the barrier attributes object int pthread_barrierattr_destroy(pthread_barrierattr_t *attr);
pthread_barrierattr_getpshared pthread.h TSH pthread_barrierattr_getpshared, pthread_barrierattr_setpshared - get and set the process-shared attribute of the barrier attributes object int pthread_barrierattr_getpshared(const pthread_barrierattr_t *restrict attr, int *restrict pshared);
pthread_barrierattr_init pthread.h pthread_barrierattr_destroy, pthread_barrierattr_init - destroy and initialize the barrier attributes object int pthread_barrierattr_init(pthread_barrierattr_t *attr);
pthread_barrierattr_setpshared pthread.h TSH pthread_barrierattr_getpshared, pthread_barrierattr_setpshared - get and set the process-shared attribute of the barrier attributes object int pthread_barrierattr_setpshared(pthread_barrierattr_t *attr, int pshared);
pthread_cancel pthread.h pthread_cancel - cancel execution of a thread int pthread_cancel(pthread_t thread);
pthread_cleanup_pop pthread.h pthread_cleanup_pop, pthread_cleanup_push - establish cancellation handlers void pthread_cleanup_pop(int execute);
pthread_cleanup_push pthread.h pthread_cleanup_pop, pthread_cleanup_push - establish cancellation handlers void pthread_cleanup_push(void (*routine)(void*), void *arg);
pthread_cond_broadcast pthread.h pthread_cond_broadcast, pthread_cond_signal - broadcast or signal a condition int pthread_cond_broadcast(pthread_cond_t *cond);
pthread_cond_destroy pthread.h pthread_cond_destroy, pthread_cond_init - destroy and initialize condition variables int pthread_cond_destroy(pthread_cond_t *cond);
pthread_cond_init pthread.h pthread_cond_destroy, pthread_cond_init - destroy and initialize condition variables int pthread_cond_init(pthread_cond_t *restrict cond, const pthread_condattr_t *restrict attr);
pthread_cond_signal pthread.h pthread_cond_broadcast, pthread_cond_signal - broadcast or signal a condition int pthread_cond_signal(pthread_cond_t *cond);
pthread_cond_timedwait pthread.h pthread_cond_timedwait, pthread_cond_wait - wait on a condition int pthread_cond_timedwait(pthread_cond_t *restrict cond, pthread_mutex_t *restrict mutex, const struct timespec *restrict abstime);
pthread_cond_wait pthread.h pthread_cond_timedwait, pthread_cond_wait - wait on a condition int pthread_cond_wait(pthread_cond_t *restrict cond, pthread_mutex_t *restrict mutex);
pthread_condattr_destroy pthread.h pthread_condattr_destroy, pthread_condattr_init - destroy and initialize the condition variable attributes object int pthread_condattr_destroy(pthread_condattr_t *attr);
pthread_condattr_getclock pthread.h pthread_condattr_getclock, pthread_condattr_setclock - get and set the clock selection condition variable attribute int pthread_condattr_getclock(const pthread_condattr_t *restrict attr, clockid_t *restrict clock_id);
pthread_condattr_getpshared pthread.h TSH pthread_condattr_getpshared, pthread_condattr_setpshared - get and set the process-shared condition variable attributes int pthread_condattr_getpshared(const pthread_condattr_t *restrict attr, int *restrict pshared);
pthread_condattr_init pthread.h pthread_condattr_destroy, pthread_condattr_init - destroy and initialize the condition variable attributes object int pthread_condattr_init(pthread_condattr_t *attr);
pthread_condattr_setclock pthread.h pthread_condattr_getclock, pthread_condattr_setclock - get and set the clock selection condition variable attribute int pthread_condattr_setclock(pthread_condattr_t *attr, clockid_t clock_id);
pthread_condattr_setpshared pthread.h TSH pthread_condattr_getpshared, pthread_condattr_setpshared - get and set the process-shared condition variable attributes int pthread_condattr_setpshared(pthread_condattr_t *attr, int pshared);
pthread_create pthread.h pthread_create - thread creation int pthread_create(pthread_t *restrict thread, const pthread_attr_t *restrict attr, void *(*start_routine)(void*), void *restrict arg);
pthread_detach pthread.h pthread_detach - detach a thread int pthread_detach(pthread_t thread);
pthread_equal pthread.h pthread_equal - compare thread IDs int pthread_equal(pthread_t t1, pthread_t t2);
pthread_exit pthread.h pthread_exit - thread termination void pthread_exit(void *value_ptr);
pthread_getconcurrency pthread.h OB XSI pthread_getconcurrency, pthread_setconcurrency - get and set the level of concurrency int pthread_getconcurrency(void);
pthread_getcpuclockid pthread.h time.h TCT pthread_getcpuclockid - access a thread CPU-time clock (ADVANCED REALTIME THREADS) int pthread_getcpuclockid(pthread_t thread_id, clockid_t *clock_id);
pthread_getschedparam pthread.h TPS pthread_getschedparam, pthread_setschedparam - dynamic thread scheduling parameters access (REALTIME THREADS) int pthread_getschedparam(pthread_t thread, int *restrict policy, struct sched_param *restrict param);
pthread_getspecific pthread.h pthread_getspecific, pthread_setspecific - thread-specific data management void *pthread_getspecific(pthread_key_t key);
pthread_join pthread.h pthread_join - wait for thread termination int pthread_join(pthread_t thread, void **value_ptr);
pthread_key_create pthread.h pthread_key_create - thread-specific data key creation int pthread_key_create(pthread_key_t *key, void (*destructor)(void*));
pthread_key_delete pthread.h pthread_key_delete - thread-specific data key deletion int pthread_key_delete(pthread_key_t key);
pthread_kill signal.h CX pthread_kill - send a signal to a thread int pthread_kill(pthread_t thread, int sig);
pthread_mutex_consistent pthread.h pthread_mutex_consistent - mark state protected by robust mutex as consistent int pthread_mutex_consistent(pthread_mutex_t *mutex);
pthread_mutex_destroy pthread.h pthread_mutex_destroy, pthread_mutex_init - destroy and initialize a mutex int pthread_mutex_destroy(pthread_mutex_t *mutex);
pthread_mutex_getprioceiling pthread.h RPP pthread_mutex_getprioceiling, pthread_mutex_setprioceiling - get and set the priority ceiling of a mutex (REALTIME THREADS) int pthread_mutex_getprioceiling(const pthread_mutex_t *restrict mutex, int *restrict prioceiling);
pthread_mutex_init pthread.h pthread_mutex_destroy, pthread_mutex_init - destroy and initialize a mutex int pthread_mutex_init(pthread_mutex_t *restrict mutex, const pthread_mutexattr_t *restrict attr);
pthread_mutex_lock pthread.h pthread_mutex_lock, pthread_mutex_trylock, pthread_mutex_unlock - lock and unlock a mutex int pthread_mutex_lock(pthread_mutex_t *mutex);
pthread_mutex_setprioceiling pthread.h RPP pthread_mutex_getprioceiling, pthread_mutex_setprioceiling - get and set the priority ceiling of a mutex (REALTIME THREADS) int pthread_mutex_setprioceiling(pthread_mutex_t *restrict mutex, int prioceiling, int *restrict old_ceiling);
pthread_mutex_timedlock pthread.h time.h pthread_mutex_timedlock - lock a mutex int pthread_mutex_timedlock(pthread_mutex_t *restrict mutex, const struct timespec *restrict abstime);
pthread_mutex_trylock pthread.h pthread_mutex_lock, pthread_mutex_trylock, pthread_mutex_unlock - lock and unlock a mutex int pthread_mutex_trylock(pthread_mutex_t *mutex);
pthread_mutex_unlock pthread.h pthread_mutex_lock, pthread_mutex_trylock, pthread_mutex_unlock - lock and unlock a mutex int pthread_mutex_unlock(pthread_mutex_t *mutex);
pthread_mutexattr_destroy pthread.h pthread_mutexattr_destroy, pthread_mutexattr_init - destroy and initialize the mutex attributes object int pthread_mutexattr_destroy(pthread_mutexattr_t *attr);
pthread_mutexattr_getprioceiling pthread.h RPP pthread_mutexattr_getprioceiling, pthread_mutexattr_setprioceiling - get and set the prioceiling attribute of the mutex attributes object (REALTIME THREADS) int pthread_mutexattr_getprioceiling(const pthread_mutexattr_t *restrict attr, int *restrict prioceiling);
pthread_mutexattr_getprotocol pthread.h MC1 pthread_mutexattr_getprotocol, pthread_mutexattr_setprotocol - get and set the protocol attribute of the mutex attributes object (REALTIME THREADS) int pthread_mutexattr_getprotocol(const pthread_mutexattr_t *restrict attr, int *restrict protocol);
pthread_mutexattr_getpshared pthread.h TSH pthread_mutexattr_getpshared, pthread_mutexattr_setpshared - get and set the process-shared attribute int pthread_mutexattr_getpshared(const pthread_mutexattr_t *restrict attr, int *restrict pshared);
pthread_mutexattr_getrobust pthread.h pthread_mutexattr_getrobust, pthread_mutexattr_setrobust - get and set the mutex robust attribute int pthread_mutexattr_getrobust(const pthread_mutexattr_t *restrict attr, int *restrict robust);
pthread_mutexattr_gettype pthread.h pthread_mutexattr_gettype, pthread_mutexattr_settype - get and set the mutex type attribute int pthread_mutexattr_gettype(const pthread_mutexattr_t *restrict attr, int *restrict type);
pthread_mutexattr_init pthread.h pthread_mutexattr_destroy, pthread_mutexattr_init - destroy and initialize the mutex attributes object int pthread_mutexattr_init(pthread_mutexattr_t *attr);
pthread_mutexattr_setprioceiling pthread.h RPP pthread_mutexattr_getprioceiling, pthread_mutexattr_setprioceiling - get and set the prioceiling attribute of the mutex attributes object (REALTIME THREADS) int pthread_mutexattr_setprioceiling(pthread_mutexattr_t *attr, int prioceiling);
pthread_mutexattr_setprotocol pthread.h MC1 pthread_mutexattr_getprotocol, pthread_mutexattr_setprotocol - get and set the protocol attribute of the mutex attributes object (REALTIME THREADS) int pthread_mutexattr_setprotocol(pthread_mutexattr_t *attr, int protocol);
pthread_mutexattr_setpshared pthread.h TSH pthread_mutexattr_getpshared, pthread_mutexattr_setpshared - get and set the process-shared attribute int pthread_mutexattr_setpshared(pthread_mutexattr_t *attr, int pshared);
pthread_mutexattr_setrobust pthread.h pthread_mutexattr_getrobust, pthread_mutexattr_setrobust - get and set the mutex robust attribute int pthread_mutexattr_setrobust(pthread_mutexattr_t *attr, int robust);
pthread_mutexattr_settype pthread.h pthread_mutexattr_gettype, pthread_mutexattr_settype - get and set the mutex type attribute int pthread_mutexattr_settype(pthread_mutexattr_t *attr, int type);
pthread_once pthread.h pthread_once - dynamic package initialization int pthread_once(pthread_once_t *once_control, void (*init_routine)(void));
pthread_rwlock_destroy pthread.h pthread_rwlock_destroy, pthread_rwlock_init - destroy and initialize a read-write lock object int pthread_rwlock_destroy(pthread_rwlock_t *rwlock);
pthread_rwlock_init pthread.h pthread_rwlock_destroy, pthread_rwlock_init - destroy and initialize a read-write lock object int pthread_rwlock_init(pthread_rwlock_t *restrict rwlock, const pthread_rwlockattr_t *restrict attr);
pthread_rwlock_rdlock pthread.h pthread_rwlock_rdlock, pthread_rwlock_tryrdlock - lock a read-write lock object for reading int pthread_rwlock_rdlock(pthread_rwlock_t *rwlock);
pthread_rwlock_timedrdlock pthread.h time.h pthread_rwlock_timedrdlock - lock a read-write lock for reading int pthread_rwlock_timedrdlock(pthread_rwlock_t *restrict rwlock, const struct timespec *restrict abstime);
pthread_rwlock_timedwrlock pthread.h time.h pthread_rwlock_timedwrlock - lock a read-write lock for writing int pthread_rwlock_timedwrlock(pthread_rwlock_t *restrict rwlock, const struct timespec *restrict abstime);
pthread_rwlock_tryrdlock pthread.h pthread_rwlock_rdlock, pthread_rwlock_tryrdlock - lock a read-write lock object for reading int pthread_rwlock_tryrdlock(pthread_rwlock_t *rwlock);
pthread_rwlock_trywrlock pthread.h pthread_rwlock_trywrlock, pthread_rwlock_wrlock - lock a read-write lock object for writing int pthread_rwlock_trywrlock(pthread_rwlock_t *rwlock);
pthread_rwlock_unlock pthread.h pthread_rwlock_unlock - unlock a read-write lock object int pthread_rwlock_unlock(pthread_rwlock_t *rwlock);
pthread_rwlock_wrlock pthread.h pthread_rwlock_trywrlock, pthread_rwlock_wrlock - lock a read-write lock object for writing int pthread_rwlock_wrlock(pthread_rwlock_t *rwlock);
pthread_rwlockattr_destroy pthread.h pthread_rwlockattr_destroy, pthread_rwlockattr_init - destroy and initialize the read-write lock attributes object int pthread_rwlockattr_destroy(pthread_rwlockattr_t *attr);
pthread_rwlockattr_getpshared pthread.h TSH pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared - get and set the process-shared attribute of the read-write lock attributes object int pthread_rwlockattr_getpshared(const pthread_rwlockattr_t *restrict attr, int *restrict pshared);
pthread_rwlockattr_init pthread.h pthread_rwlockattr_destroy, pthread_rwlockattr_init - destroy and initialize the read-write lock attributes object int pthread_rwlockattr_init(pthread_rwlockattr_t *attr);
pthread_rwlockattr_setpshared pthread.h TSH pthread_rwlockattr_getpshared, pthread_rwlockattr_setpshared - get and set the process-shared attribute of the read-write lock attributes object int pthread_rwlockattr_setpshared(pthread_rwlockattr_t *attr, int pshared);
pthread_self pthread.h pthread_self - get the calling thread ID pthread_t pthread_self(void);
pthread_setcancelstate pthread.h pthread_setcancelstate, pthread_setcanceltype, pthread_testcancel - set cancelability state int pthread_setcancelstate(int state, int *oldstate);
pthread_setcanceltype pthread.h pthread_setcancelstate, pthread_setcanceltype, pthread_testcancel - set cancelability state int pthread_setcanceltype(int type, int *oldtype);
pthread_setconcurrency pthread.h OB XSI pthread_getconcurrency, pthread_setconcurrency - get and set the level of concurrency int pthread_setconcurrency(int new_level);
pthread_setschedparam pthread.h TPS pthread_getschedparam, pthread_setschedparam - dynamic thread scheduling parameters access (REALTIME THREADS) int pthread_setschedparam(pthread_t thread, int policy, const struct sched_param *param);
pthread_setschedprio pthread.h TPS pthread_setschedprio - dynamic thread scheduling parameters access (REALTIME THREADS) int pthread_setschedprio(pthread_t thread, int prio);
pthread_setspecific pthread.h pthread_getspecific, pthread_setspecific - thread-specific data management int pthread_setspecific(pthread_key_t key, const void *value);
pthread_sigmask signal.h CX pthread_sigmask, sigprocmask - examine and change blocked signals int pthread_sigmask(int how, const sigset_t *restrict set, sigset_t *restrict oset);
pthread_spin_destroy pthread.h pthread_spin_destroy, pthread_spin_init - destroy or initialize a spin lock object int pthread_spin_destroy(pthread_spinlock_t *lock);
pthread_spin_init pthread.h pthread_spin_destroy, pthread_spin_init - destroy or initialize a spin lock object int pthread_spin_init(pthread_spinlock_t *lock, int pshared);
pthread_spin_lock pthread.h pthread_spin_lock, pthread_spin_trylock - lock a spin lock object int pthread_spin_lock(pthread_spinlock_t *lock);
pthread_spin_trylock pthread.h pthread_spin_lock, pthread_spin_trylock - lock a spin lock object int pthread_spin_trylock(pthread_spinlock_t *lock);
pthread_spin_unlock pthread.h pthread_spin_unlock - unlock a spin lock object int pthread_spin_unlock(pthread_spinlock_t *lock);
pthread_testcancel pthread.h pthread_setcancelstate, pthread_setcanceltype, pthread_testcancel - set cancelability state void pthread_testcancel(void);
ptsname stdlib.h XSI ptsname - get name of the slave pseudo-terminal device char *ptsname(int fildes);
putc stdio.h putc - put a byte on a stream int putc(int c, FILE *stream);
putc_unlocked stdio.h CX getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - stdio with explicit client locking int putc_unlocked(int c, FILE *stream);
putchar stdio.h putchar - put a byte on a stdout stream int putchar(int c);
putchar_unlocked stdio.h CX getc_unlocked, getchar_unlocked, putc_unlocked, putchar_unlocked - stdio with explicit client locking int putchar_unlocked(int c);
putenv stdlib.h XSI putenv - change or add a value to an environment int putenv(char *string);
putmsg stropts.h OB XSR putmsg, putpmsg - send a message on a STREAM (STREAMS) int putmsg(int fildes, const struct strbuf *ctlptr, const struct strbuf *dataptr, int flags);
putpmsg stropts.h OB XSR putmsg, putpmsg - send a message on a STREAM (STREAMS) int putpmsg(int fildes, const struct strbuf *ctlptr, const struct strbuf *dataptr, int band, int flags);
puts stdio.h puts - put a string on standard output int puts(const char *s);
pututxline utmpx.h XSI endutxent, getutxent, getutxid, getutxline, pututxline, setutxent - user accounting database functions struct utmpx *pututxline(const struct utmpx *utmpx);
putwc stdio.h wchar.h putwc - put a wide character on a stream wint_t putwc(wchar_t wc, FILE *stream);
putwchar wchar.h putwchar - put a wide character on a stdout stream wint_t putwchar(wchar_t wc);
pwrite unistd.h pwrite, write - write on a file ssize_t pwrite(int fildes, const void *buf, size_t nbyte, off_t offset);
qsort stdlib.h qsort - sort a table of data void qsort(void *base, size_t nel, size_t width, int (*compar)(const void *, const void *));
raise signal.h raise - send a signal to the executing process int raise(int sig);
rand stdlib.h OB CX rand, rand_r, srand - pseudo-random number generator int rand(void);
rand_r stdlib.h OB CX rand, rand_r, srand - pseudo-random number generator int rand_r(unsigned *seed);
random stdlib.h XSI initstate, random, setstate, srandom - pseudo-random number functions long random(void);
read unistd.h pread, read - read from a file ssize_t read(int fildes, void *buf, size_t nbyte);
readdir dirent.h readdir, readdir_r - read a directory struct dirent *readdir(DIR *dirp);
readdir_r dirent.h readdir, readdir_r - read a directory int readdir_r(DIR *restrict dirp, struct dirent *restrict entry, struct dirent **restrict result);
readlink unistd.h readlink, readlinkat - read the contents of a symbolic link relative to a directory file descriptor ssize_t readlink(const char *restrict path, char *restrict buf, size_t bufsize);
readlinkat unistd.h readlink, readlinkat - read the contents of a symbolic link relative to a directory file descriptor ssize_t readlinkat(int fd, const char *restrict path, char *restrict buf, size_t bufsize);
readv sys/uio.h XSI readv - read a vector ssize_t readv(int fildes, const struct iovec *iov, int iovcnt);
realloc stdlib.h realloc - memory reallocator void *realloc(void *ptr, size_t size);
realpath stdlib.h XSI realpath - resolve a pathname char *realpath(const char *restrict file_name, char *restrict resolved_name);
recv sys/socket.h recv - receive a message from a connected socket ssize_t recv(int socket, void *buffer, size_t length, int flags);
recvfrom sys/socket.h recvfrom - receive a message from a socket ssize_t recvfrom(int socket, void *restrict buffer, size_t length, int flags, struct sockaddr *restrict address, socklen_t *restrict address_len);
recvmsg sys/socket.h recvmsg - receive a message from a socket ssize_t recvmsg(int socket, struct msghdr *message, int flags);
regcomp regex.h regcomp, regerror, regexec, regfree - regular expression matching int regcomp(regex_t *restrict preg, const char *restrict pattern, int cflags);
regerror regex.h regcomp, regerror, regexec, regfree - regular expression matching size_t regerror(int errcode, const regex_t *restrict preg, char *restrict errbuf, size_t errbuf_size);
regexec regex.h regcomp, regerror, regexec, regfree - regular expression matching int regexec(const regex_t *restrict preg, const char *restrict string, size_t nmatch, regmatch_t pmatch[restrict], int eflags);
regfree regex.h regcomp, regerror, regexec, regfree - regular expression matching void regfree(regex_t *preg);
remainder math.h remainder, remainderf, remainderl - remainder function double remainder(double x, double y);
remainderf math.h remainder, remainderf, remainderl - remainder function float remainderf(float x, float y);
remainderl math.h remainder, remainderf, remainderl - remainder function long double remainderl(long double x, long double y);
remove stdio.h remove - remove a file int remove(const char *path);
remque search.h XSI insque, remque - insert or remove an element in a queue void remque(void *element);
remquo math.h remquo, remquof, remquol - remainder functions double remquo(double x, double y, int *quo);
remquof math.h remquo, remquof, remquol - remainder functions float remquof(float x, float y, int *quo);
remquol math.h remquo, remquof, remquol - remainder functions long double remquol(long double x, long double y, int *quo);
rename stdio.h CX rename, renameat - rename file relative to directory file descriptor int rename(const char *old, const char *new);
renameat stdio.h CX rename, renameat - rename file relative to directory file descriptor int renameat(int oldfd, const char *old, int newfd, const char *new);
rewind stdio.h rewind - reset the file position indicator in a stream void rewind(FILE *stream);
rewinddir dirent.h rewinddir - reset the position of a directory stream to the beginning of a directory void rewinddir(DIR *dirp);
rint math.h rint, rintf, rintl - round-to-nearest integral value double rint(double x);
rintf math.h rint, rintf, rintl - round-to-nearest integral value float rintf(float x);
rintl math.h rint, rintf, rintl - round-to-nearest integral value long double rintl(long double x);
rmdir unistd.h rmdir - remove a directory int rmdir(const char *path);
round math.h round, roundf, roundl - round to the nearest integer value in a floating-point format double round(double x);
roundf math.h round, roundf, roundl - round to the nearest integer value in a floating-point format float roundf(float x);
roundl math.h round, roundf, roundl - round to the nearest integer value in a floating-point format long double roundl(long double x);
scalbln math.h scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl - compute exponent using FLT_RADIX double scalbln(double x, long n);
scalblnf math.h scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl - compute exponent using FLT_RADIX float scalblnf(float x, long n);
scalblnl math.h scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl - compute exponent using FLT_RADIX long double scalblnl(long double x, long n);
scalbn math.h scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl - compute exponent using FLT_RADIX double scalbn(double x, int n);
scalbnf math.h scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl - compute exponent using FLT_RADIX float scalbnf(float x, int n);
scalbnl math.h scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl - compute exponent using FLT_RADIX long double scalbnl(long double x, int n);
scandir dirent.h alphasort, scandir - scan a directory int scandir(const char *dir, struct dirent ***namelist, int (*sel)(const struct dirent *), int (*compar)(const struct dirent **, const struct dirent **));
scanf stdio.h fscanf, scanf, sscanf - convert formatted input int scanf(const char *restrict format, ...);
sched_get_priority_max sched.h PS sched_get_priority_max, sched_get_priority_min - get priority limits (REALTIME) int sched_get_priority_max(int policy);
sched_get_priority_min sched.h PS sched_get_priority_max, sched_get_priority_min - get priority limits (REALTIME) int sched_get_priority_min(int policy);
sched_getparam sched.h PS sched_getparam - get scheduling parameters (REALTIME) int sched_getparam(pid_t pid, struct sched_param *param);
sched_getscheduler sched.h PS sched_getscheduler - get scheduling policy (REALTIME) int sched_getscheduler(pid_t pid);
sched_rr_get_interval sched.h PS sched_rr_get_interval - get execution time limits (REALTIME) int sched_rr_get_interval(pid_t pid, struct timespec *interval);
sched_setparam sched.h PS sched_setparam - set scheduling parameters (REALTIME) int sched_setparam(pid_t pid, const struct sched_param *param);
sched_setscheduler sched.h PS sched_setscheduler - set scheduling policy and parameters (REALTIME) int sched_setscheduler(pid_t pid, int policy, const struct sched_param *param);
sched_yield sched.h sched_yield - yield the processor int sched_yield(void);
seed48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers unsigned short *seed48(unsigned short seed16v[3]);
seekdir dirent.h XSI seekdir - set the position of a directory stream void seekdir(DIR *dirp, long loc);
select sys/select.h pselect, select - synchronous I/O multiplexing int select(int nfds, fd_set *restrict readfds, fd_set *restrict writefds, fd_set *restrict errorfds, struct timeval *restrict timeout);
sem_close semaphore.h sem_close - close a named semaphore int sem_close(sem_t *sem);
sem_destroy semaphore.h sem_destroy - destroy an unnamed semaphore int sem_destroy(sem_t *sem);
sem_getvalue semaphore.h sem_getvalue - get the value of a semaphore int sem_getvalue(sem_t *restrict sem, int *restrict sval);
sem_init semaphore.h sem_init - initialize an unnamed semaphore int sem_init(sem_t *sem, int pshared, unsigned value);
sem_open semaphore.h sem_open - initialize and open a named semaphore sem_t *sem_open(const char *name, int oflag, ...);
sem_post semaphore.h sem_post - unlock a semaphore int sem_post(sem_t *sem);
sem_timedwait semaphore.h time.h sem_timedwait - lock a semaphore int sem_timedwait(sem_t *restrict sem, const struct timespec *restrict abstime);
sem_trywait semaphore.h sem_trywait, sem_wait - lock a semaphore int sem_trywait(sem_t *sem);
sem_unlink semaphore.h sem_unlink - remove a named semaphore int sem_unlink(const char *name);
sem_wait semaphore.h sem_trywait, sem_wait - lock a semaphore int sem_wait(sem_t *sem);
semctl sys/sem.h XSI semctl - XSI semaphore control operations int semctl(int semid, int semnum, int cmd, ...);
semget sys/sem.h XSI semget - get set of XSI semaphores int semget(key_t key, int nsems, int semflg);
semop sys/sem.h XSI semop - XSI semaphore operations int semop(int semid, struct sembuf *sops, size_t nsops);
send sys/socket.h send - send a message on a socket ssize_t send(int socket, const void *buffer, size_t length, int flags);
sendmsg sys/socket.h sendmsg - send a message on a socket using a message structure ssize_t sendmsg(int socket, const struct msghdr *message, int flags);
sendto sys/socket.h sendto - send a message on a socket ssize_t sendto(int socket, const void *message, size_t length, int flags, const struct sockaddr *dest_addr, socklen_t dest_len);
setbuf stdio.h setbuf - assign buffering to a stream void setbuf(FILE *restrict stream, char *restrict buf);
setegid unistd.h setegid - set the effective group ID int setegid(gid_t gid);
setenv stdlib.h CX setenv - add or change environment variable int setenv(const char *envname, const char *envval, int overwrite);
seteuid unistd.h seteuid - set effective user ID int seteuid(uid_t uid);
setgid unistd.h setgid - set-group-ID int setgid(gid_t gid);
setgrent grp.h XSI endgrent, getgrent, setgrent - group database entry functions void setgrent(void);
sethostent netdb.h endhostent, gethostent, sethostent - network host database functions void sethostent(int stayopen);
setitimer sys/time.h OB XSI getitimer, setitimer - get and set value of interval timer int setitimer(int which, const struct itimerval *restrict value, struct itimerval *restrict ovalue);
setjmp setjmp.h setjmp - set jump point for a non-local goto int setjmp(jmp_buf env);
setkey stdlib.h XSI setkey - set encoding key (CRYPT) void setkey(const char *key);
setlocale locale.h setlocale - set program locale char *setlocale(int category, const char *locale);
setlogmask syslog.h XSI closelog, openlog, setlogmask, syslog - control system log int setlogmask(int maskpri);
setnetent netdb.h endnetent, getnetbyaddr, getnetbyname, getnetent, setnetent - network database functions void setnetent(int stayopen);
setpgid unistd.h setpgid - set process group ID for job control int setpgid(pid_t pid, pid_t pgid);
setpgrp unistd.h OB XSI setpgrp - set the process group ID pid_t setpgrp(void);
setpriority sys/resource.h XSI getpriority, setpriority - get and set the nice value int setpriority(int which, id_t who, int value);
setprotoent netdb.h endprotoent, getprotobyname, getprotobynumber, getprotoent, setprotoent - network protocol database functions void setprotoent(int stayopen);
setpwent pwd.h XSI endpwent, getpwent, setpwent - user database functions void setpwent(void);
setregid unistd.h XSI setregid - set real and effective group IDs int setregid(gid_t rgid, gid_t egid);
setreuid unistd.h XSI setreuid - set real and effective user IDs int setreuid(uid_t ruid, uid_t euid);
setrlimit sys/resource.h XSI getrlimit, setrlimit - control maximum resource consumption int setrlimit(int resource, const struct rlimit *rlp);
setservent netdb.h endservent, getservbyname, getservbyport, getservent, setservent - network services database functions void setservent(int stayopen);
setsid unistd.h setsid - create session and set process group ID pid_t setsid(void);
setsockopt sys/socket.h setsockopt - set the socket options int setsockopt(int socket, int level, int option_name, const void *option_value, socklen_t option_len);
setstate stdlib.h XSI initstate, random, setstate, srandom - pseudo-random number functions char *setstate(char *state);
setuid unistd.h setuid - set user ID int setuid(uid_t uid);
setutxent utmpx.h XSI endutxent, getutxent, getutxid, getutxline, pututxline, setutxent - user accounting database functions void setutxent(void);
setvbuf stdio.h setvbuf - assign buffering to a stream int setvbuf(FILE *restrict stream, char *restrict buf, int type, size_t size);
shm_open sys/mman.h SHM shm_open - open a shared memory object (REALTIME) int shm_open(const char *name, int oflag, mode_t mode);
shm_unlink sys/mman.h SHM shm_unlink - remove a shared memory object (REALTIME) int shm_unlink(const char *name);
shmat sys/shm.h XSI shmat - XSI shared memory attach operation void *shmat(int shmid, const void *shmaddr, int shmflg);
shmctl sys/shm.h XSI shmctl - XSI shared memory control operations int shmctl(int shmid, int cmd, struct shmid_ds *buf);
shmdt sys/shm.h XSI shmdt - XSI shared memory detach operation int shmdt(const void *shmaddr);
shmget sys/shm.h XSI shmget - get an XSI shared memory segment int shmget(key_t key, size_t size, int shmflg);
shutdown sys/socket.h shutdown - shut down socket send and receive operations int shutdown(int socket, int how);
sigaction signal.h CX sigaction - examine and change a signal action int sigaction(int sig, const struct sigaction *restrict act, struct sigaction *restrict oact);
sigaddset signal.h CX sigaddset - add a signal to a signal set int sigaddset(sigset_t *set, int signo);
sigaltstack signal.h XSI sigaltstack - set and get signal alternate stack context int sigaltstack(const stack_t *restrict ss, stack_t *restrict oss);
sigdelset signal.h CX sigdelset - delete a signal from a signal set int sigdelset(sigset_t *set, int signo);
sigemptyset signal.h CX sigemptyset - initialize and empty a signal set int sigemptyset(sigset_t *set);
sigfillset signal.h CX sigfillset - initialize and fill a signal set int sigfillset(sigset_t *set);
sighold signal.h OB XSI sighold, sigignore, sigpause, sigrelse, sigset - signal management int sighold(int sig);
sigignore signal.h OB XSI sighold, sigignore, sigpause, sigrelse, sigset - signal management int sigignore(int sig);
siginterrupt signal.h OB XSI siginterrupt - allow signals to interrupt functions int siginterrupt(int sig, int flag);
sigismember signal.h CX sigismember - test for a signal in a signal set int sigismember(const sigset_t *set, int signo);
siglongjmp setjmp.h CX siglongjmp - non-local goto with signal handling void siglongjmp(sigjmp_buf env, int val);
signal signal.h signal - signal management void (*signal(int sig, void (*func)(int)))(int);
signbit math.h signbit - test sign int signbit(real-floating x);
signgam math.h XSI lgamma, lgammaf, lgammal, signgam - log gamma function
sigpause signal.h OB XSI sighold, sigignore, sigpause, sigrelse, sigset - signal management int sigpause(int sig);
sigpending signal.h CX sigpending - examine pending signals int sigpending(sigset_t *set);
sigprocmask signal.h CX pthread_sigmask, sigprocmask - examine and change blocked signals int sigprocmask(int how, const sigset_t *restrict set, sigset_t *restrict oset);
sigqueue signal.h CX sigqueue - queue a signal to a process int sigqueue(pid_t pid, int signo, const union sigval value);
sigrelse signal.h OB XSI sighold, sigignore, sigpause, sigrelse, sigset - signal management int sigrelse(int sig);
sigset signal.h OB XSI sighold, sigignore, sigpause, sigrelse, sigset - signal management void (*sigset(int sig, void (*disp)(int)))(int);
sigsetjmp setjmp.h CX sigsetjmp - set jump point for a non-local goto int sigsetjmp(sigjmp_buf env, int savemask);
sigsuspend signal.h CX sigsuspend - wait for a signal int sigsuspend(const sigset_t *sigmask);
sigtimedwait signal.h CX sigtimedwait, sigwaitinfo - wait for queued signals int sigtimedwait(const sigset_t *restrict set, siginfo_t *restrict info, const struct timespec *restrict timeout);
sigwait signal.h CX sigwait - wait for queued signals int sigwait(const sigset_t *restrict set, int *restrict sig);
sigwaitinfo signal.h CX sigtimedwait, sigwaitinfo - wait for queued signals int sigwaitinfo(const sigset_t *restrict set, siginfo_t *restrict info);
sin math.h sin, sinf, sinl - sine function double sin(double x);
sinf math.h sin, sinf, sinl - sine function float sinf(float x);
sinh math.h sinh, sinhf, sinhl - hyperbolic sine functions double sinh(double x);
sinhf math.h sinh, sinhf, sinhl - hyperbolic sine functions float sinhf(float x);
sinhl math.h sinh, sinhf, sinhl - hyperbolic sine functions long double sinhl(long double x);
sinl math.h sin, sinf, sinl - sine function long double sinl(long double x);
sleep unistd.h sleep - suspend execution for an interval of time unsigned sleep(unsigned seconds);
snprintf stdio.h CX dprintf, fprintf, printf, snprintf, sprintf - print formatted output int snprintf(char *restrict s, size_t n, const char *restrict format, ...);
sockatmark sys/socket.h sockatmark - determine whether a socket is at the out-of-band mark int sockatmark(int s);
socket sys/socket.h socket - create an endpoint for communication int socket(int domain, int type, int protocol);
socketpair sys/socket.h socketpair - create a pair of connected sockets int socketpair(int domain, int type, int protocol, int socket_vector[2]);
sprintf stdio.h CX dprintf, fprintf, printf, snprintf, sprintf - print formatted output int sprintf(char *restrict s, const char *restrict format, ...);
sqrt math.h sqrt, sqrtf, sqrtl - square root function double sqrt(double x);
sqrtf math.h sqrt, sqrtf, sqrtl - square root function float sqrtf(float x);
sqrtl math.h sqrt, sqrtf, sqrtl - square root function long double sqrtl(long double x);
srand stdlib.h OB CX rand, rand_r, srand - pseudo-random number generator void srand(unsigned seed);
srand48 stdlib.h XSI drand48, erand48, jrand48, lcong48, lrand48, mrand48, nrand48, seed48, srand48 - generate uniformly distributed pseudo-random numbers void srand48(long seedval);
srandom stdlib.h XSI initstate, random, setstate, srandom - pseudo-random number functions void srandom(unsigned seed);
sscanf stdio.h fscanf, scanf, sscanf - convert formatted input int sscanf(const char *restrict s, const char *restrict format, ...);
stat sys/stat.h fstatat, lstat, stat - get file status int stat(const char *restrict path, struct stat *restrict buf);
statvfs sys/statvfs.h fstatvfs, statvfs - get file system information int statvfs(const char *restrict path, struct statvfs *restrict buf);
stderr stdio.h stderr, stdin, stdout - standard I/O streams
stdin stdio.h stderr, stdin, stdout - standard I/O streams
stdout stdio.h stderr, stdin, stdout - standard I/O streams
stpcpy string.h CX stpcpy, strcpy - copy a string and return a pointer to the end of the result char *stpcpy(char *restrict s1, const char *restrict s2);
stpncpy string.h CX stpncpy, strncpy - copy fixed length string, returning a pointer to the array end char *stpncpy(char *restrict s1, const char *restrict s2, size_t n);
strcasecmp strings.h strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_l - case-insensitive string comparisons int strcasecmp(const char *s1, const char *s2);
strcasecmp_l strings.h strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_l - case-insensitive string comparisons int strcasecmp_l(const char *s1, const char *s2, locale_t locale);
strcat string.h strcat - concatenate two strings char *strcat(char *restrict s1, const char *restrict s2);
strchr string.h strchr - string scanning operation char *strchr(const char *s, int c);
strcmp string.h strcmp - compare two strings int strcmp(const char *s1, const char *s2);
strcoll string.h CX strcoll, strcoll_l - string comparison using collating information int strcoll(const char *s1, const char *s2);
strcoll_l string.h CX strcoll, strcoll_l - string comparison using collating information int strcoll_l(const char *s1, const char *s2, locale_t locale);
strcpy string.h CX stpcpy, strcpy - copy a string and return a pointer to the end of the result char *strcpy(char *restrict s1, const char *restrict s2);
strcspn string.h strcspn - get the length of a complementary substring size_t strcspn(const char *s1, const char *s2);
strdup string.h CX strdup, strndup - duplicate a specific number of bytes from a string char *strdup(const char *s);
strerror string.h CX strerror, strerror_l, strerror_r - get error message string char *strerror(int errnum);
strerror_l string.h CX strerror, strerror_l, strerror_r - get error message string char *strerror_l(int errnum, locale_t locale);
strerror_r string.h CX strerror, strerror_l, strerror_r - get error message string int strerror_r(int errnum, char *strerrbuf, size_t buflen);
strfmon monetary.h strfmon, strfmon_l - convert monetary value to a string ssize_t strfmon(char *restrict s, size_t maxsize, const char *restrict format, ...);
strfmon_l monetary.h strfmon, strfmon_l - convert monetary value to a string ssize_t strfmon_l(char *restrict s, size_t maxsize, locale_t locale, const char *restrict format, ...);
strftime time.h CX strftime, strftime_l - convert date and time to a string size_t strftime(char *restrict s, size_t maxsize, const char *restrict format, const struct tm *restrict timeptr);
strftime_l time.h CX strftime, strftime_l - convert date and time to a string size_t strftime_l(char *restrict s, size_t maxsize, const char *restrict format, const struct tm *restrict timeptr, locale_t locale);
strlen string.h CX strlen, strnlen - get length of fixed size string size_t strlen(const char *s);
strncasecmp strings.h strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_l - case-insensitive string comparisons int strncasecmp(const char *s1, const char *s2, size_t n);
strncasecmp_l strings.h strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_l - case-insensitive string comparisons int strncasecmp_l(const char *s1, const char *s2, size_t n, locale_t locale);
strncat string.h strncat - concatenate a string with part of another char *strncat(char *restrict s1, const char *restrict s2, size_t n);
strncmp string.h strncmp - compare part of two strings int strncmp(const char *s1, const char *s2, size_t n);
strncpy string.h CX stpncpy, strncpy - copy fixed length string, returning a pointer to the array end char *strncpy(char *restrict s1, const char *restrict s2, size_t n);
strndup string.h CX strdup, strndup - duplicate a specific number of bytes from a string char *strndup(const char *s, size_t size);
strnlen string.h CX strlen, strnlen - get length of fixed size string size_t strnlen(const char *s, size_t maxlen);
strpbrk string.h strpbrk - scan a string for a byte char *strpbrk(const char *s1, const char *s2);
strptime time.h XSI strptime - date and time conversion char *strptime(const char *restrict buf, const char *restrict format, struct tm *restrict tm);
strrchr string.h strrchr - string scanning operation char *strrchr(const char *s, int c);
strsignal string.h CX strsignal - get name of signal char *strsignal(int signum);
strspn string.h strspn - get length of a substring size_t strspn(const char *s1, const char *s2);
strstr string.h strstr - find a substring char *strstr(const char *s1, const char *s2);
strtod stdlib.h strtod, strtof, strtold - convert a string to a double-precision number double strtod(const char *restrict nptr, char **restrict endptr);
strtof stdlib.h strtod, strtof, strtold - convert a string to a double-precision number float strtof(const char *restrict nptr, char **restrict endptr);
strtoimax inttypes.h strtoimax, strtoumax - convert string to integer type intmax_t strtoimax(const char *restrict nptr, char **restrict endptr, int base);
strtok string.h CX strtok, strtok_r - split string into tokens char *strtok(char *restrict s1, const char *restrict s2);
strtok_r string.h CX strtok, strtok_r - split string into tokens char *strtok_r(char *restrict s, const char *restrict sep, char **restrict lasts);
strtol stdlib.h strtol, strtoll - convert a string to a long integer long strtol(const char *restrict str, char **restrict endptr, int base);
strtold stdlib.h strtod, strtof, strtold - convert a string to a double-precision number long double strtold(const char *restrict nptr, char **restrict endptr);
strtoll stdlib.h strtol, strtoll - convert a string to a long integer long long strtoll(const char *restrict str, char **restrict endptr, int base);
strtoul stdlib.h strtoul, strtoull - convert a string to an unsigned long unsigned long strtoul(const char *restrict str, char **restrict endptr, int base);
strtoull stdlib.h strtoul, strtoull - convert a string to an unsigned long unsigned long long strtoull(const char *restrict str, char **restrict endptr, int base);
strtoumax inttypes.h strtoimax, strtoumax - convert string to integer type uintmax_t strtoumax(const char *restrict nptr, char **restrict endptr, int base);
strxfrm string.h CX strxfrm, strxfrm_l - string transformation size_t strxfrm(char *restrict s1, const char *restrict s2, size_t n);
strxfrm_l string.h CX strxfrm, strxfrm_l - string transformation size_t strxfrm_l(char *restrict s1, const char *restrict s2, size_t n, locale_t locale);
swab unistd.h XSI swab - swap bytes void swab(const void *restrict src, void *restrict dest, ssize_t nbytes);
swprintf stdio.h wchar.h fwprintf, swprintf, wprintf - print formatted wide-character output int swprintf(wchar_t *restrict ws, size_t n, const wchar_t *restrict format, ...);
swscanf stdio.h wchar.h fwscanf, swscanf, wscanf - convert formatted wide-character input int swscanf(const wchar_t *restrict ws, const wchar_t *restrict format, ...);
symlink unistd.h symlink, symlinkat - make a symbolic link relative to directory file descriptor int symlink(const char *path1, const char *path2);
symlinkat unistd.h symlink, symlinkat - make a symbolic link relative to directory file descriptor int symlinkat(const char *path1, int fd, const char *path2);
sync unistd.h XSI sync - schedule file system updates void sync(void);
sysconf unistd.h sysconf - get configurable system variables long sysconf(int name);
syslog syslog.h XSI closelog, openlog, setlogmask, syslog - control system log void syslog(int priority, const char *message, ... /* arguments */);
system stdlib.h system - issue a command int system(const char *command);
tan math.h tan, tanf, tanl - tangent function double tan(double x);
tanf math.h tan, tanf, tanl - tangent function float tanf(float x);
tanh math.h tanh, tanhf, tanhl - hyperbolic tangent functions double tanh(double x);
tanhf math.h tanh, tanhf, tanhl - hyperbolic tangent functions float tanhf(float x);
tanhl math.h tanh, tanhf, tanhl - hyperbolic tangent functions long double tanhl(long double x);
tanl math.h tan, tanf, tanl - tangent function long double tanl(long double x);
tcdrain termios.h tcdrain - wait for transmission of output int tcdrain(int fildes);
tcflow termios.h tcflow - suspend or restart the transmission or reception of data int tcflow(int fildes, int action);
tcflush termios.h tcflush - flush non-transmitted output data, non-read input data, or both int tcflush(int fildes, int queue_selector);
tcgetattr termios.h tcgetattr - get the parameters associated with the terminal int tcgetattr(int fildes, struct termios *termios_p);
tcgetpgrp unistd.h tcgetpgrp - get the foreground process group ID pid_t tcgetpgrp(int fildes);
tcgetsid termios.h tcgetsid - get the process group ID for the session leader for the controlling terminal pid_t tcgetsid(int fildes);
tcsendbreak termios.h tcsendbreak - send a break for a specific duration int tcsendbreak(int fildes, int duration);
tcsetattr termios.h tcsetattr - set the parameters associated with the terminal int tcsetattr(int fildes, int optional_actions, const struct termios *termios_p);
tcsetpgrp unistd.h tcsetpgrp - set the foreground process group ID int tcsetpgrp(int fildes, pid_t pgid_id);
tdelete search.h XSI tdelete, tfind, tsearch, twalk - manage a binary search tree void *tdelete(const void *restrict key, void **restrict rootp, int(*compar)(const void *, const void *));
telldir dirent.h XSI telldir - current location of a named directory stream long telldir(DIR *dirp);
tempnam stdio.h OB XSI tempnam - create a name for a temporary file char *tempnam(const char *dir, const char *pfx);
tfind search.h XSI tdelete, tfind, tsearch, twalk - manage a binary search tree void *tfind(const void *key, void *const *rootp, int(*compar)(const void *, const void *));
tgamma math.h tgamma, tgammaf, tgammal - compute gamma() function double tgamma(double x);
tgammaf math.h tgamma, tgammaf, tgammal - compute gamma() function float tgammaf(float x);
tgammal math.h tgamma, tgammaf, tgammal - compute gamma() function long double tgammal(long double x);
time time.h time - get time time_t time(time_t *tloc);
timer_create signal.h time.h CX timer_create - create a per-process timer int timer_create(clockid_t clockid, struct sigevent *restrict evp, timer_t *restrict timerid);
timer_delete time.h CX timer_delete - delete a per-process timer int timer_delete(timer_t timerid);
timer_getoverrun time.h CX timer_getoverrun, timer_gettime, timer_settime - per-process timers int timer_getoverrun(timer_t timerid);
timer_gettime time.h CX timer_getoverrun, timer_gettime, timer_settime - per-process timers int timer_gettime(timer_t timerid, struct itimerspec *value);
timer_settime time.h CX timer_getoverrun, timer_gettime, timer_settime - per-process timers int timer_settime(timer_t timerid, int flags, const struct itimerspec *restrict value, struct itimerspec *restrict ovalue);
times sys/times.h times - get process and waited-for child process times clock_t times(struct tms *buffer);
timezone time.h XSI CX daylight, timezone, tzname, tzset - set timezone conversion information
tmpfile stdio.h tmpfile - create a temporary file FILE *tmpfile(void);
tmpnam stdio.h OB tmpnam - create a name for a temporary file char *tmpnam(char *s);
toascii ctype.h OB XSI toascii - translate an integer to a 7-bit ASCII character int toascii(int c);
tolower ctype.h CX tolower, tolower_l - transliterate uppercase characters to lowercase int tolower(int c);
tolower_l ctype.h CX tolower, tolower_l - transliterate uppercase characters to lowercase int tolower_l(int c, locale_t locale);
toupper ctype.h CX toupper, toupper_l - transliterate lowercase characters to uppercase int toupper(int c);
toupper_l ctype.h CX toupper, toupper_l - transliterate lowercase characters to uppercase int toupper_l(int c, locale_t locale);
towctrans wctype.h CX towctrans, towctrans_l - wide-character transliteration wint_t towctrans(wint_t wc, wctrans_t desc);
towctrans_l wctype.h CX towctrans, towctrans_l - wide-character transliteration wint_t towctrans_l(wint_t wc, wctrans_t desc, locale_t locale);
towlower wctype.h CX towlower, towlower_l - transliterate uppercase wide-character code to lowercase wint_t towlower(wint_t wc);
towlower_l wctype.h CX towlower, towlower_l - transliterate uppercase wide-character code to lowercase wint_t towlower_l(wint_t wc, locale_t locale);
towupper wctype.h CX towupper, towupper_l - transliterate lowercase wide-character code to uppercase wint_t towupper(wint_t wc);
towupper_l wctype.h CX towupper, towupper_l - transliterate lowercase wide-character code to uppercase wint_t towupper_l(wint_t wc, locale_t locale);
trunc math.h trunc, truncf, truncl - round to truncated integer value double trunc(double x);
truncate unistd.h truncate - truncate a file to a specified length int truncate(const char *path, off_t length);
truncf math.h trunc, truncf, truncl - round to truncated integer value float truncf(float x);
truncl math.h trunc, truncf, truncl - round to truncated integer value long double truncl(long double x);
tsearch search.h XSI tdelete, tfind, tsearch, twalk - manage a binary search tree void *tsearch(const void *key, void **rootp, int (*compar)(const void *, const void *));
ttyname unistd.h ttyname, ttyname_r - find the pathname of a terminal char *ttyname(int fildes);
ttyname_r unistd.h ttyname, ttyname_r - find the pathname of a terminal int ttyname_r(int fildes, char *name, size_t namesize);
twalk search.h XSI tdelete, tfind, tsearch, twalk - manage a binary search tree void twalk(const void *root, void (*action)(const void *, VISIT, int));
tzname time.h XSI CX daylight, timezone, tzname, tzset - set timezone conversion information
tzset time.h XSI CX daylight, timezone, tzname, tzset - set timezone conversion information void tzset(void);
ulimit ulimit.h OB XSI ulimit - get and set process limits long ulimit(int cmd, ...);
umask sys/stat.h umask - set and get the file mode creation mask mode_t umask(mode_t cmask);
uname sys/utsname.h uname - get the name of the current system int uname(struct utsname *name);
ungetc stdio.h ungetc - push byte back into input stream int ungetc(int c, FILE *stream);
ungetwc stdio.h wchar.h ungetwc - push wide-character code back into the input stream wint_t ungetwc(wint_t wc, FILE *stream);
unlink unistd.h unlink, unlinkat - remove a directory entry relative to directory file descriptor int unlink(const char *path);
unlinkat unistd.h unlink, unlinkat - remove a directory entry relative to directory file descriptor int unlinkat(int fd, const char *path, int flag);
unlockpt stdlib.h XSI unlockpt - unlock a pseudo-terminal master/slave pair int unlockpt(int fildes);
unsetenv stdlib.h CX unsetenv - remove an environment variable int unsetenv(const char *name);
uselocale locale.h CX uselocale - use locale in current thread locale_t uselocale(locale_t newloc);
utime utime.h OB utime - set file access and modification times int utime(const char *path, const struct utimbuf *times);
utimensat sys/stat.h sys/time.h XSI futimens, utimensat, utimes - set file access and modification times int utimensat(int fd, const char *path, const struct timespec times[2], int flag);
utimes sys/stat.h sys/time.h XSI futimens, utimensat, utimes - set file access and modification times int utimes(const char *path, const struct timeval times[2]);
va_arg stdarg.h va_arg, va_copy, va_end, va_start - handle variable argument list type va_arg(va_list ap, type);
va_copy stdarg.h va_arg, va_copy, va_end, va_start - handle variable argument list void va_copy(va_list dest, va_list src);
va_end stdarg.h va_arg, va_copy, va_end, va_start - handle variable argument list void va_end(va_list ap);
va_start stdarg.h va_arg, va_copy, va_end, va_start - handle variable argument list void va_start(va_list ap, argN);
vdprintf stdarg.h stdio.h CX vdprintf, vfprintf, vprintf, vsnprintf, vsprintf - format output of a stdarg argument list int vdprintf(int fildes, const char *restrict format, va_list ap);
vfprintf stdarg.h stdio.h CX vdprintf, vfprintf, vprintf, vsnprintf, vsprintf - format output of a stdarg argument list int vfprintf(FILE *restrict stream, const char *restrict format, va_list ap);
vfscanf stdarg.h stdio.h vfscanf, vscanf, vsscanf - format input of a stdarg argument list int vfscanf(FILE *restrict stream, const char *restrict format, va_list arg);
vfwprintf stdarg.h stdio.h wchar.h vfwprintf, vswprintf, vwprintf - wide-character formatted output of a stdarg argument list int vfwprintf(FILE *restrict stream, const wchar_t *restrict format, va_list arg);
vfwscanf stdarg.h stdio.h wchar.h vfwscanf, vswscanf, vwscanf - wide-character formatted input of a stdarg argument list int vfwscanf(FILE *restrict stream, const wchar_t *restrict format, va_list arg);
vprintf stdarg.h stdio.h CX vdprintf, vfprintf, vprintf, vsnprintf, vsprintf - format output of a stdarg argument list int vprintf(const char *restrict format, va_list ap);
vscanf stdarg.h stdio.h vfscanf, vscanf, vsscanf - format input of a stdarg argument list int vscanf(const char *restrict format, va_list arg);
vsnprintf stdarg.h stdio.h CX vdprintf, vfprintf, vprintf, vsnprintf, vsprintf - format output of a stdarg argument list int vsnprintf(char *restrict s, size_t n, const char *restrict format, va_list ap);
vsprintf stdarg.h stdio.h CX vdprintf, vfprintf, vprintf, vsnprintf, vsprintf - format output of a stdarg argument list int vsprintf(char *restrict s, const char *restrict format, va_list ap);
vsscanf stdarg.h stdio.h vfscanf, vscanf, vsscanf - format input of a stdarg argument list int vsscanf(const char *restrict s, const char *restrict format, va_list arg);
vswprintf stdarg.h stdio.h wchar.h vfwprintf, vswprintf, vwprintf - wide-character formatted output of a stdarg argument list int vswprintf(wchar_t *restrict ws, size_t n, const wchar_t *restrict format, va_list arg);
vswscanf stdarg.h stdio.h wchar.h vfwscanf, vswscanf, vwscanf - wide-character formatted input of a stdarg argument list int vswscanf(const wchar_t *restrict ws, const wchar_t *restrict format, va_list arg);
vwprintf stdarg.h stdio.h wchar.h vfwprintf, vswprintf, vwprintf - wide-character formatted output of a stdarg argument list int vwprintf(const wchar_t *restrict format, va_list arg);
vwscanf stdarg.h stdio.h wchar.h vfwscanf, vswscanf, vwscanf - wide-character formatted input of a stdarg argument list int vwscanf(const wchar_t *restrict format, va_list arg);
wait sys/wait.h wait, waitpid - wait for a child process to stop or terminate pid_t wait(int *stat_loc);
waitid sys/wait.h waitid - wait for a child process to change state int waitid(idtype_t idtype, id_t id, siginfo_t *infop, int options);
waitpid sys/wait.h wait, waitpid - wait for a child process to stop or terminate pid_t waitpid(pid_t pid, int *stat_loc, int options);
wcpcpy wchar.h CX wcpcpy, wcscpy - copy a wide-character string, returning a pointer to its end wchar_t *wcpcpy(wchar_t *restrict ws1, const wchar_t *restrict ws2);
wcpncpy wchar.h CX wcpncpy, wcsncpy - copy a fixed-size wide-character string, returning a pointer to its end wchar_t *wcpncpy(wchar_t restrict *ws1, const wchar_t *restrict ws2, size_t n);
wcrtomb wchar.h wcrtomb - convert a wide-character code to a character (restartable) size_t wcrtomb(char *restrict s, wchar_t wc, mbstate_t *restrict ps);
wcscasecmp wchar.h CX wcscasecmp, wcscasecmp_l, wcsncasecmp, wcsncasecmp_l - case-insensitive wide-character string comparison int wcscasecmp(const wchar_t *ws1, const wchar_t *ws2);
wcscasecmp_l wchar.h CX wcscasecmp, wcscasecmp_l, wcsncasecmp, wcsncasecmp_l - case-insensitive wide-character string comparison int wcscasecmp_l(const wchar_t *ws1, const wchar_t *ws2, locale_t locale);
wcscat wchar.h wcscat - concatenate two wide-character strings wchar_t *wcscat(wchar_t *restrict ws1, const wchar_t *restrict ws2);
wcschr wchar.h wcschr - wide-character string scanning operation wchar_t *wcschr(const wchar_t *ws, wchar_t wc);
wcscmp wchar.h wcscmp - compare two wide-character strings int wcscmp(const wchar_t *ws1, const wchar_t *ws2);
wcscoll wchar.h CX wcscoll, wcscoll_l - wide-character string comparison using collating information int wcscoll(const wchar_t *ws1, const wchar_t *ws2);
wcscoll_l wchar.h CX wcscoll, wcscoll_l - wide-character string comparison using collating information int wcscoll_l(const wchar_t *ws1, const wchar_t *ws2, locale_t locale);
wcscpy wchar.h CX wcpcpy, wcscpy - copy a wide-character string, returning a pointer to its end wchar_t *wcscpy(wchar_t *restrict ws1, const wchar_t *restrict ws2);
wcscspn wchar.h wcscspn - get the length of a complementary wide substring size_t wcscspn(const wchar_t *ws1, const wchar_t *ws2);
wcsdup wchar.h CX wcsdup - duplicate a wide-character string wchar_t *wcsdup(const wchar_t *string);
wcsftime wchar.h wcsftime - convert date and time to a wide-character string size_t wcsftime(wchar_t *restrict wcs, size_t maxsize, const wchar_t *restrict format, const struct tm *restrict timeptr);
wcslen wchar.h CX wcslen, wcsnlen - get length of a fixed-sized wide-character string size_t wcslen(const wchar_t *ws);
wcsncasecmp wchar.h CX wcscasecmp, wcscasecmp_l, wcsncasecmp, wcsncasecmp_l - case-insensitive wide-character string comparison int wcsncasecmp(const wchar_t *ws1, const wchar_t *ws2, size_t n);
wcsncasecmp_l wchar.h CX wcscasecmp, wcscasecmp_l, wcsncasecmp, wcsncasecmp_l - case-insensitive wide-character string comparison int wcsncasecmp_l(const wchar_t *ws1, const wchar_t *ws2, size_t n, locale_t locale);
wcsncat wchar.h wcsncat - concatenate a wide-character string with part of another wchar_t *wcsncat(wchar_t *restrict ws1, const wchar_t *restrict ws2, size_t n);
wcsncmp wchar.h wcsncmp - compare part of two wide-character strings int wcsncmp(const wchar_t *ws1, const wchar_t *ws2, size_t n);
wcsncpy wchar.h CX wcpncpy, wcsncpy - copy a fixed-size wide-character string, returning a pointer to its end wchar_t *wcsncpy(wchar_t *restrict ws1, const wchar_t *restrict ws2, size_t n);
wcsnlen wchar.h CX wcslen, wcsnlen - get length of a fixed-sized wide-character string size_t wcsnlen(const wchar_t *ws, size_t maxlen);
wcsnrtombs wchar.h CX wcsnrtombs, wcsrtombs - convert a wide-character string to a character string (restartable) size_t wcsnrtombs(char *restrict dst, const wchar_t **restrict src, size_t nwc, size_t len, mbstate_t *restrict ps);
wcspbrk wchar.h wcspbrk - scan a wide-character string for a wide-character code wchar_t *wcspbrk(const wchar_t *ws1, const wchar_t *ws2);
wcsrchr wchar.h wcsrchr - wide-character string scanning operation wchar_t *wcsrchr(const wchar_t *ws, wchar_t wc);
wcsrtombs wchar.h CX wcsnrtombs, wcsrtombs - convert a wide-character string to a character string (restartable) size_t wcsrtombs(char *restrict dst, const wchar_t **restrict src, size_t len, mbstate_t *restrict ps);
wcsspn wchar.h wcsspn - get the length of a wide substring size_t wcsspn(const wchar_t *ws1, const wchar_t *ws2);
wcsstr wchar.h wcsstr - find a wide-character substring wchar_t *wcsstr(const wchar_t *restrict ws1, const wchar_t *restrict ws2);
wcstod wchar.h wcstod, wcstof, wcstold - convert a wide-character string to a double-precision number double wcstod(const wchar_t *restrict nptr, wchar_t **restrict endptr);
wcstof wchar.h wcstod, wcstof, wcstold - convert a wide-character string to a double-precision number float wcstof(const wchar_t *restrict nptr, wchar_t **restrict endptr);
wcstoimax stddef.h inttypes.h wcstoimax, wcstoumax - convert a wide-character string to an integer type intmax_t wcstoimax(const wchar_t *restrict nptr, wchar_t **restrict endptr, int base);
wcstok wchar.h wcstok - split a wide-character string into tokens wchar_t *wcstok(wchar_t *restrict ws1, const wchar_t *restrict ws2, wchar_t **restrict ptr);
wcstol wchar.h wcstol, wcstoll - convert a wide-character string to a long integer long wcstol(const wchar_t *restrict nptr, wchar_t **restrict endptr, int base);
wcstold wchar.h wcstod, wcstof, wcstold - convert a wide-character string to a double-precision number long double wcstold(const wchar_t *restrict nptr, wchar_t **restrict endptr);
wcstoll wchar.h wcstol, wcstoll - convert a wide-character string to a long integer long long wcstoll(const wchar_t *restrict nptr, wchar_t **restrict endptr, int base);
wcstombs stdlib.h wcstombs - convert a wide-character string to a character string size_t wcstombs(char *restrict s, const wchar_t *restrict pwcs, size_t n);
wcstoul wchar.h wcstoul, wcstoull - convert a wide-character string to an unsigned long unsigned long wcstoul(const wchar_t *restrict nptr, wchar_t **restrict endptr, int base);
wcstoull wchar.h wcstoul, wcstoull - convert a wide-character string to an unsigned long unsigned long long wcstoull(const wchar_t *restrict nptr, wchar_t **restrict endptr, int base);
wcstoumax stddef.h inttypes.h wcstoimax, wcstoumax - convert a wide-character string to an integer type uintmax_t wcstoumax(const wchar_t *restrict nptr, wchar_t **restrict endptr, int base);
wcswidth wchar.h XSI wcswidth - number of column positions of a wide-character string int wcswidth(const wchar_t *pwcs, size_t n);
wcsxfrm wchar.h CX wcsxfrm, wcsxfrm_l - wide-character string transformation size_t wcsxfrm(wchar_t *restrict ws1, const wchar_t *restrict ws2, size_t n);
wcsxfrm_l wchar.h CX wcsxfrm, wcsxfrm_l - wide-character string transformation size_t wcsxfrm_l(wchar_t *restrict ws1, const wchar_t *restrict ws2, size_t n, locale_t locale);
wctob stdio.h wchar.h wctob - wide-character to single-byte conversion int wctob(wint_t c);
wctomb stdlib.h wctomb - convert a wide-character code to a character int wctomb(char *s, wchar_t wchar);
wctrans wctype.h CX wctrans, wctrans_l - define character mapping wctrans_t wctrans(const char *charclass);
wctrans_l wctype.h CX wctrans, wctrans_l - define character mapping wctrans_t wctrans_l(const char *charclass, locale_t locale);
wctype wctype.h CX wctype, wctype_l - define character class wctype_t wctype(const char *property);
wctype_l wctype.h CX wctype, wctype_l - define character class wctype_t wctype_l(const char *property, locale_t locale);
wcwidth wchar.h XSI wcwidth - number of column positions of a wide-character code int wcwidth(wchar_t wc);
wmemchr wchar.h wmemchr - find a wide character in memory wchar_t *wmemchr(const wchar_t *ws, wchar_t wc, size_t n);
wmemcmp wchar.h wmemcmp - compare wide characters in memory int wmemcmp(const wchar_t *ws1, const wchar_t *ws2, size_t n);
wmemcpy wchar.h wmemcpy - copy wide characters in memory wchar_t *wmemcpy(wchar_t *restrict ws1, const wchar_t *restrict ws2, size_t n);
wmemmove wchar.h wmemmove - copy wide characters in memory with overlapping areas wchar_t *wmemmove(wchar_t *ws1, const wchar_t *ws2, size_t n);
wmemset wchar.h wmemset - set wide characters in memory wchar_t *wmemset(wchar_t *ws, wchar_t wc, size_t n);
wordexp wordexp.h wordexp, wordfree - perform word expansions int wordexp(const char *restrict words, wordexp_t *restrict pwordexp, int flags);
wordfree wordexp.h wordexp, wordfree - perform word expansions void wordfree(wordexp_t *pwordexp);
wprintf stdio.h wchar.h fwprintf, swprintf, wprintf - print formatted wide-character output int wprintf(const wchar_t *restrict format, ...);
write unistd.h pwrite, write - write on a file ssize_t write(int fildes, const void *buf, size_t nbyte);
writev sys/uio.h XSI writev - write a vector ssize_t writev(int fildes, const struct iovec *iov, int iovcnt);
wscanf stdio.h wchar.h fwscanf, swscanf, wscanf - convert formatted wide-character input int wscanf(const wchar_t *restrict format, ...);
y0 math.h XSI y0, y1, yn - Bessel functions of the second kind double y0(double x);
y1 math.h XSI y0, y1, yn - Bessel functions of the second kind double y1(double x);
yn math.h XSI y0, y1, yn - Bessel functions of the second kind double yn(int n, double x);