src/unistd/getcwd.c

   1 #include <unistd.h>
   2 #include <errno.h>
   3 #include <limits.h>
   4 #include <string.h>
   5 #include "syscall.h"
   6
   7 char *getcwd(char *buf, size_t size)
   8 {
   9         char tmp[buf ? 1 : PATH_MAX];
  10         if (!buf) {
  11                 buf = tmp;
  12                 size = sizeof tmp;
  13         } else if (!size) {
  14                 errno = EINVAL;
  15                 return 0;
  16         }
  17         long ret = syscall(SYS_getcwd, buf, size);
  18         if (ret < 0)
  19                 return 0;
  20         if (ret == 0 || buf[0] != '/') {
  21                 errno = ENOENT;
  22                 return 0;
  23         }
  24         return buf == tmp ? strdup(buf) : buf;
  25 }