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Diffstat (limited to 'src/main.c')
| -rw-r--r-- | src/main.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/src/main.c b/src/main.c new file mode 100644 index 0000000..9d8b206 --- /dev/null +++ b/src/main.c @@ -0,0 +1,149 @@ +// Copyright © Tavian Barnes <tavianator@tavianator.com> +// SPDX-License-Identifier: 0BSD + +/** + * - 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: + * - alloc.[ch] (memory allocation) + * - atomic.h (atomic operations) + * - bar.[ch] (a terminal status bar) + * - bit.h (bit manipulation) + * - bfstd.[ch] (standard library wrappers/polyfills) + * - color.[ch] (for pretty terminal colors) + * - prelude.h (configuration and feature/platform detection) + * - 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) + * - ioq.[ch] (an async I/O queue) + * - list.h (linked list macros) + * - mtab.[ch] (parses the system's mount table) + * - pwcache.[ch] (a cache for the user/group tables) + * - sanity.h (sanitizer interfaces) + * - stat.[ch] (wraps stat(), or statx() on Linux) + * - thread.h (multi-threading) + * - trie.[ch] (a trie set/map implementation) + * - typo.[ch] (fuzzy matching for typos) + * - xregex.[ch] (regular expression support) + * - xspawn.[ch] (spawns processes) + * - xtime.[ch] (date/time handling utilities) + */ + +#include "prelude.h" +#include "bfstd.h" +#include "ctx.h" +#include "diag.h" +#include "eval.h" +#include "parse.h" +#include <errno.h> +#include <fcntl.h> +#include <locale.h> +#include <stdio.h> +#include <stdlib.h> +#include <time.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); + close_quietly(newfd); + 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[]) { + // Make sure the standard streams are open + if (open_std_streams() != 0) { + return EXIT_FAILURE; + } + + // Use the system locale instead of "C" + int locale_err = 0; + if (!setlocale(LC_ALL, "")) { + locale_err = errno; + } + + // Apply the environment's timezone + tzset(); + + // Parse the command line + struct bfs_ctx *ctx = bfs_parse_cmdline(argc, argv); + if (!ctx) { + return EXIT_FAILURE; + } + + // Warn if setlocale() failed, unless there's no expression to evaluate + if (locale_err && ctx->warn && ctx->expr) { + bfs_warning(ctx, "Failed to set locale: %s\n\n", xstrerror(locale_err)); + } + + // Walk the file system tree, evaluating the expression on each file + int ret = bfs_eval(ctx); + + // Free the parsed command line, and detect any last-minute errors + if (bfs_ctx_free(ctx) != 0 && ret == EXIT_SUCCESS) { + ret = EXIT_FAILURE; + } + + return ret; +} |