+#define F_ULOCK 0
+#define F_LOCK 1
+#define F_TLOCK 2
+#define F_TEST 3
+
+#if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE)
+int lockf(int, int, off_t);
+int setpgrp(void);
+char *crypt(const char *, const char *);
+void encrypt(char *, int);
+void swab(const void *, void *, ssize_t);
+long gethostid(void);
+int nice(int);
+void sync(void);
+int getdtablesize(void);
+#endif
+
+#ifdef _GNU_SOURCE
+int brk(void *);
+void *sbrk(intptr_t);
+pid_t vfork(void);
+int vhangup(void);
+int chroot(const char *);
+int getpagesize(void);
+int sethostname(const char *, size_t);
+int usleep(unsigned);
+unsigned ualarm(unsigned, unsigned);
+int setgroups(int, const gid_t []);
+int setresuid(uid_t, uid_t, uid_t);
+int setresgid(gid_t, gid_t, gid_t);
+#endif
+