unistd.c

   1 #include <time.h>
   2 #include <stdarg.h>
   3 #include <string.h>
   4 #include <stdlib.h>
   5 #include <unistd.h>
   6 #include <signal.h>
   7
   8 int sleep(int n)
   9 {
  10         struct timespec req = {n, 0};
  11         struct timespec rem;
  12         if (nanosleep(&req, &rem))
  13                 return rem.tv_sec;
  14         return 0;
  15 }
  16
  17 #define EXECARGS        (1 << 7)
  18
  19 int execle(char *path, ...)
  20 {
  21         va_list ap;
  22         char *argv[EXECARGS];
  23         char **envp;
  24         int argc = 0;
  25         va_start(ap, path);
  26         while (argc + 1 < EXECARGS && (argv[argc] = va_arg(ap, char *)))
  27                 argc++;
  28         envp = va_arg(ap, char **);
  29         va_end(ap);
  30         argv[argc] = NULL;
  31         execve(path, argv, envp);
  32         return -1;
  33 }
  34
  35 int execvp(char *cmd, char *argv[])
  36 {
  37         char path[512];
  38         char *p = getenv("PATH");
  39         if (strchr(cmd, '/'))
  40                 return execve(cmd, argv, environ);
  41         if (!p)
  42                 p = "/bin";
  43         while (*p) {
  44                 char *s = path;
  45                 while (*p && *p != ':')
  46                         *s++ = *p++;
  47                 if (s != path)
  48                         *s++ = '/';
  49                 strcpy(s, cmd);
  50                 execve(path, argv, environ);
  51                 if (*p == ':')
  52                         p++;
  53         }
  54         return -1;
  55 }
  56
  57 int wait(int *status)
  58 {
  59         return waitpid(-1, status, 0);
  60 }
  61
  62 int raise(int sig)
  63 {
  64         return kill(getpid(), sig);
  65 }
  66
  67 void abort(void)
  68 {
  69         raise(SIGABRT);
  70         while (1)
  71                 ;
  72 }