/*
 * Utility to run commands with arbitrary timeout value
 * v1.1 - cls@seawood.org
 */
/* 
     The contents of this file are subject to the Mozilla Public License
     Version 1.1 (the "License"); you may not use this file except in
     compliance with the License. You may obtain a copy of the License at
     http://www.mozilla.org/MPL/

     Software distributed under the License is distributed on an "AS IS"
     basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
     License for the specific language governing rights and limitations
     under the License.

     The Original Code is timeout.c, a timeout utility.

     The Initial Developer of the Original Code is Chris Seawood 
     <cls@seawood.org>.  Portions created by Chris Seawood are 
     Copyright(C) 2006-2007 Chris Seawood.  All Rights Reserved.
 */
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <signal.h>
#include <errno.h>
#include <sys/wait.h>

int pid, repeat = 0, timeout = 0, use_kill = 0;
char *cmd;

void usage(char *name) {
  printf("Usage: %s -t seconds [-k] [-r] -- command [arg1] ...[argn]\n", name);
  exit(1);
}

void signal_handler(int signal) {
  if (signal == SIGALRM) {
    fprintf(stderr, "\nProcess '%s' has timed out after %d seconds!\n", cmd, timeout);
    if (use_kill)
      kill(pid, SIGKILL);
    else
      kill(pid, SIGTERM);
  }
}

int main(int argc, char *argv[]) {

  char *tostr = 0;
  int c, status;

  while ((c = getopt(argc, argv, "krt:")) > 0) {
    switch (c) {
    case 't':
      tostr = optarg;
      break;
    case 'r':
      repeat=1;
      break;
    case 'k':
      use_kill=1;
      break;
    }
  }
  if (!tostr) {
    usage(argv[0]);
  } else {
    timeout = strtol(tostr, 0, 10);
    if (errno != 0) {
      fprintf(stderr, "Could not convert argument to number: %s\n",
	      strerror(errno));
      exit(1);
    }
    if (timeout == 0) {
      fprintf(stderr, "Zero is not an acceptable timeout value\n");
      exit(1);
    }
  }
  if (optind < argc) {
    cmd = argv[optind];

    do {
      if ((pid = fork()) == 0) {
	execvp(argv[optind], argv+optind);
	fprintf(stderr, "Error running '%s': %s\n", argv[optind], 
		strerror(errno));
      } else {
	signal(SIGALRM, &signal_handler);
	alarm(timeout);
	waitpid(pid, &status, 0);
      }
    } while (!WIFEXITED(status) && repeat);
    if (WIFEXITED(status)) {
      exit(WEXITSTATUS(status));
    } else {
      exit(-1);
    }
  }
  exit(1);
}