unistd.c

   1 #include <time.h>
   2 #include <unistd.h>
   3 #include <stdarg.h>
   4
   5 int sleep(int n)
   6 {
   7         struct timespec req = {n, 0};
   8         struct timespec rem;
   9         if (nanosleep(&req, &rem))
  10                 return rem.tv_sec;
  11         return 0;
  12 }
  13
  14 #define EXECARGS        (1 << 7)
  15
  16 int execle(char *path, ...)
  17 {
  18         va_list ap;
  19         char *argv[EXECARGS];
  20         char **env;
  21         int argc = 0;
  22         va_start(ap, path);
  23         while (argc + 1 < EXECARGS && (argv[argc] = va_arg(ap, char *)))
  24                 argc++;
  25         env = va_arg(ap, char **);
  26         va_end(ap);
  27         argv[argc] = NULL;
  28         execve(path, argv, env);
  29 }
  30
  31 int wait(int *status)
  32 {
  33         return waitpid(-1, status, 0);
  34 }