fix getopt wrongly treating colons in optstring as valid option chars

[musl] / src / misc / realpath.c

diff --git a/src/misc/realpath.c b/src/misc/realpath.c
index f6b5549..88c849c 100644 (file)
--- a/src/misc/realpath.c
+++ b/src/misc/realpath.c
@@ -1,6 +1,45 @@
 #include <stdlib.h>
+#include <limits.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include "syscall.h"
 
-char *realpath(const char *filename, char *resolved)
+void __procfdname(char *, unsigned);
+
+char *realpath(const char *restrict filename, char *restrict resolved)
 {
+       int fd;
+       ssize_t r;
+       struct stat st1, st2;
+       char buf[15+3*sizeof(int)];
+       char tmp[PATH_MAX];
+
+       if (!filename) {
+               errno = EINVAL;
+               return 0;
+       }
+
+       fd = sys_open(filename, O_PATH|O_NONBLOCK|O_CLOEXEC);
+       if (fd < 0) return 0;
+       __procfdname(buf, fd);
+
+       r = readlink(buf, tmp, sizeof tmp - 1);
+       if (r < 0) goto err;
+       tmp[r] = 0;
+
+       fstat(fd, &st1);
+       r = stat(tmp, &st2);
+       if (r<0 || st1.st_dev != st2.st_dev || st1.st_ino != st2.st_ino) {
+               if (!r) errno = ELOOP;
+               goto err;
+       }
+
+       __syscall(SYS_close, fd);
+       return resolved ? strcpy(resolved, tmp) : strdup(tmp);
+err:
+       __syscall(SYS_close, fd);
        return 0;
 }