/*
  Name:     input.c
  Purpose:  Command-line input reader with timeout.
  Author:   M. J. Fromberger <http://www.dartmouth.edu/~sting/>
  Info:     $Id: input.c,v 1.3 2005/05/16 18:38:45 sting Exp $

  Copyright (C) 2003 Michael J. Fromberger, All Rights Reserved.

  Reads one line from the standard input with a timeout.  If the timer
  expires before a line becomes available, the default output string
  is written to standard output.  If a line does become available in
  time, it is echoed to the standard output.

  Usage:  input [<timeout-sec> [<default-value>]]
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <signal.h>

#include <unistd.h>

char           g_buf[BUFSIZ];
const char    *g_output = "nothing\n";
unsigned long  g_timeout = 10;

void time_out(int v);

int main(int argc, char *argv[])
{
  if(argc > 1)
    g_timeout = strtoul(argv[1], NULL, 0);
  if(argc > 2)
    g_output = argv[2];

  signal(SIGALRM, time_out);
  alarm(g_timeout);

  fgets(g_buf, sizeof(g_buf), stdin);
  alarm(0);
  printf("%s", g_buf);

  return 0;
}

void time_out(int v)
{
  printf("%s\n", g_output);

  exit(0);
}

/* Here there be dragons */