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/*********************************************************************
* bfs *
* Copyright (C) 2015 Tavian Barnes <tavianator@tavianator.com> *
* *
* This program is free software. It comes without any warranty, to *
* the extent permitted by applicable law. You can redistribute it *
* and/or modify it under the terms of the Do What The Fuck You Want *
* To Public License, Version 2, as published by Sam Hocevar. See *
* the COPYING file or http://www.wtfpl.net/ for more details. *
*********************************************************************/
#include "bfs.h"
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
/**
* Check if a file descriptor is open.
*/
static bool is_fd_open(int fd) {
return fcntl(fd, F_GETFD) >= 0 || errno != EBADF;
}
/**
* Ensure that a file descriptor is open.
*/
static int ensure_fd_open(int fd, int flags) {
if (is_fd_open(fd)) {
return 0;
}
int devnull = open("/dev/null", flags);
if (devnull < 0) {
perror("open()");
return -1;
}
int ret = 0;
if (devnull != fd) {
// Probably not reachable
if (dup2(devnull, fd) < 0) {
perror("dup2()");
ret = -1;
}
if (close(devnull) != 0) {
perror("close()");
ret = -1;
}
}
return ret;
}
/**
* bfs entry point.
*/
int main(int argc, char *argv[]) {
int ret = EXIT_FAILURE;
if (ensure_fd_open(STDIN_FILENO, O_RDONLY) != 0) {
goto done;
}
if (ensure_fd_open(STDOUT_FILENO, O_WRONLY) != 0) {
goto done;
}
if (ensure_fd_open(STDERR_FILENO, O_WRONLY) != 0) {
goto done;
}
struct cmdline *cmdline = parse_cmdline(argc, argv);
if (cmdline) {
if (eval_cmdline(cmdline) == 0) {
ret = EXIT_SUCCESS;
}
}
free_cmdline(cmdline);
done:
return ret;
}
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