bouncesaying.c

linux下qmail的源码 本人加了一些注释

//实用工具程序之一，作用是允许用户将消息转发给程序或者程序不可用时反弹回信息

#include "fork.h"
#include "strerr.h"
#include "error.h"
#include "wait.h"
#include "sig.h"
#include "exit.h"

#define FATAL "bouncesaying: fatal: "

void main(argc,argv)
int argc;
char **argv;
{
  int pid;
  int wstat;

  if (!argv[1])
    strerr_die1x(100,"bouncesaying: usage: bouncesaying error [ program [ arg ... ] ]");

  if (argv[2]) {
    pid = fork();
    if (pid == -1)
      strerr_die2sys(111,FATAL,"unable to fork: ");
    if (pid == 0) {
      execvp(argv[2],argv + 2);
      if (error_temp(errno)) _exit(111);
      _exit(100);
    }
    if (wait_pid(&wstat,pid) == -1)
      strerr_die2x(111,FATAL,"wait failed");
    if (wait_crashed(wstat))
      strerr_die2x(111,FATAL,"child crashed");
    switch(wait_exitcode(wstat)) {
      case 0: break;
      case 111: strerr_die2x(111,FATAL,"temporary child error");
      default: _exit(0);
    }
  }

  strerr_die1x(100,argv[1]);
}