proplib/prop_du.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <sys/wait.h>    /* for waitpid() macros */
   4
   5 #define MAX_STR 100
   6
   7 int main(void)
   8 {
   9     char str[MAX_STR];
  10     int ret;
  11     FILE *fp;
  12
  13     /* Initiate pipe stream to ``du'' */
  14     fp = popen("du", "r");
  15     if (fp == NULL) {
  16         perror("popen()");
  17         exit(EXIT_FAILURE);
  18     }
  19
  20     /* Read from stream */
  21     while (fgets(str, MAX_STR, fp) != NULL) {
  22         printf("%s", str);
  23     }
  24
  25     /* Close pipe stream */
  26     ret = pclose(fp);
  27     if  (ret == -1) {
  28         perror("pclose()");
  29         exit(EXIT_FAILURE);
  30     }
  31     else {
  32         /*
  33          * Use macros described under wait() to inspect the return value
  34          * of pclose() in order to determine success/failure of command
  35          * executed by popen().
  36          */
  37
  38         if (WIFEXITED(ret)) {
  39             printf("Child exited, ret = %d\n", WEXITSTATUS(ret));
  40         } else if (WIFSIGNALED(ret)) {
  41             printf("Child killed, signal %d\n", WTERMSIG(ret));
  42         } else if (WIFSTOPPED(ret)) {
  43             printf("Child stopped, signal %d\n", WSTOPSIG(ret));
  44         }
  45         /* Not all implementations support this */
  46 #ifdef WIFCONTINUED
  47         else if (WIFCONTINUED(ret)) {
  48             printf("Child continued\n");
  49         }
  50 #endif
  51         /* Non standard case -- may never happen */
  52         else {
  53             printf("Unexpected return value, ret = 0x%x\n", ret);
  54         }
  55     }
  56
  57     return EXIT_SUCCESS;
  58 }