/*
** vfsh.c - for the really random among us
**
** Copyright (c) 1999 Peter Eriksson <pen@lysator.liu.se>
**
** Version: 1.0
**
** This program is free software; you can redistribute it and/or
** modify it as you wish - as long as you don't claim that you wrote
** it.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*/

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

static char *
shells[] =
{
    "/bin/sh",
    "/bin/csh",
    "/bin/ksh",
    "/bin/tcsh",
    "/bin/bash",
    "/bin/zsh"
    "/usr/local/bin/tcsh",
    "/usr/local/bin/bash",
    "/usr/local/bin/zsh"
};


int
main(int argc,
     char *argv[])
{
    char shn[256];
    int is_login = (argv[0] && argv[0][0] == '-');
    char *shp, *cp;
    unsigned int attempt = 0;


    srand((unsigned int) time(NULL));
    do
    {
	shp = shells[((unsigned int) rand()) %
		    (sizeof(shells)/sizeof(shells[0]))];
	
	cp = strrchr(shp, '/');
	if (is_login)
	    shn[0] = '-';
	strcat(shn+is_login, cp ? cp+1 : shp);
	argv[0] = shn;
	
	execv(shp, argv);
    } while (errno == ENOENT && attempt++ < 16);
    
    fprintf(stderr, "vfsh: execv(\"%s\"): %s\n",
	    shp, strerror(errno));
    exit(1);
}