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/****************************************************************************
* bfs *
* Copyright (C) 2015-2021 Tavian Barnes <tavianator@tavianator.com> *
* *
* Permission to use, copy, modify, and/or distribute this software for any *
* purpose with or without fee is hereby granted. *
* *
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF *
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR *
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES *
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN *
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF *
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. *
****************************************************************************/
/**
* - main(): the entry point for bfs(1), a breadth-first version of find(1)
* - main.c (this file)
*
* - bfs_parse_cmdline(): parses the command line into an expression tree
* - ctx.[ch] (struct bfs_ctx, the overall bfs context)
* - expr.h (declares the expression tree nodes)
* - parse.[ch] (the parser itself)
* - opt.[ch] (the optimizer)
*
* - bfs_eval(): runs the expression on every file it sees
* - eval.[ch] (the main evaluation functions)
* - exec.[ch] (implements -exec[dir]/-ok[dir])
* - printf.[ch] (implements -[f]printf)
*
* - bftw(): used by bfs_eval() to walk the directory tree(s)
* - bftw.[ch] (an extended version of nftw(3))
*
* - Utilities:
* - bfs.h (constants about bfs itself)
* - bar.[ch] (a terminal status bar)
* - color.[ch] (for pretty terminal colors)
* - darray.[ch] (a dynamic array library)
* - diag.[ch] (formats diagnostic messages)
* - dir.[ch] (a directory API facade)
* - dstring.[ch] (a dynamic string library)
* - fsade.[ch] (a facade over non-standard filesystem features)
* - mtab.[ch] (parses the system's mount table)
* - pwcache.[ch] (a cache for the user/group tables)
* - spawn.[ch] (spawns processes)
* - stat.[ch] (wraps stat(), or statx() on Linux)
* - time.[ch] (date/time handling utilities)
* - trie.[ch] (a trie set/map implementation)
* - typo.[ch] (fuzzy matching for typos)
* - util.[ch] (everything else)
*/
#include "ctx.h"
#include "eval.h"
#include "parse.h"
#include <errno.h>
#include <fcntl.h>
#include <locale.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
/**
* Check if a file descriptor is open.
*/
static bool isopen(int fd) {
return fcntl(fd, F_GETFD) >= 0 || errno != EBADF;
}
/**
* Open a file and redirect it to a particular descriptor.
*/
static int redirect(int fd, const char *path, int flags) {
int newfd = open(path, flags);
if (newfd < 0 || newfd == fd) {
return newfd;
}
int ret = dup2(newfd, fd);
int err = errno;
close(newfd);
errno = err;
return ret;
}
/**
* Make sure the standard streams std{in,out,err} are open. If they are not,
* future open() calls may use those file descriptors, and std{in,out,err} will
* use them unintentionally.
*/
static int open_std_streams(void) {
#ifdef O_PATH
const int inflags = O_PATH, outflags = O_PATH;
#else
// These are intentionally backwards so that bfs >&- still fails with EBADF
const int inflags = O_WRONLY, outflags = O_RDONLY;
#endif
if (!isopen(STDERR_FILENO) && redirect(STDERR_FILENO, "/dev/null", outflags) < 0) {
return -1;
}
if (!isopen(STDOUT_FILENO) && redirect(STDOUT_FILENO, "/dev/null", outflags) < 0) {
perror("redirect()");
return -1;
}
if (!isopen(STDIN_FILENO) && redirect(STDIN_FILENO, "/dev/null", inflags) < 0) {
perror("redirect()");
return -1;
}
return 0;
}
/**
* bfs entry point.
*/
int main(int argc, char *argv[]) {
int ret = EXIT_FAILURE;
// Make sure the standard streams are open
if (open_std_streams() != 0) {
goto done;
}
// Use the system locale instead of "C"
setlocale(LC_ALL, "");
struct bfs_ctx *ctx = bfs_parse_cmdline(argc, argv);
if (ctx) {
ret = bfs_eval(ctx);
}
if (bfs_ctx_free(ctx) != 0 && ret == EXIT_SUCCESS) {
ret = EXIT_FAILURE;
}
done:
return ret;
}
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