utils-std

rm.c (5445B)

// utils-std: Collection of commonly available Unix tools
// SPDX-FileCopyrightText: 2017 Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>
// SPDX-License-Identifier: MPL-2.0
#define _POSIX_C_SOURCE 200809L
// NetBSD <10 hides fdopendir behind _NETBSD_SOURCE
#if __NetBSD_Version__ < 1000000000
#define _NETBSD_SOURCE
#endif
#include "../lib/consent.h"
#include "../lib/getopt_nolong.h"
#include <ctype.h>  // isprint
#include <dirent.h> // fdopendir, readdir, closedir
#include <errno.h>  // errno
#include <fcntl.h>  // AT_FDCWD
#include <limits.h> // PATH_MAX
#include <locale.h> // setlocale
#include <stdarg.h> // va_list
#include <stdbool.h>
#include <stdio.h>    // fprintf, getline
#include <stdlib.h>   // free
#include <string.h>   // strerror
#include <sys/stat.h> // chmod, fstatat, S_ISDIR
#include <unistd.h>   // unlink, isatty
bool opt_d = false, force = false, recurse = false, verbose = false, opt_i = false;
const char *argv0 = "rm";
struct stat root_stats;
static int
do_unlinkat(int fd, char *name, char *acc_path)
{
	struct stat stats;
	int err = 0;
	if(fstatat(fd, name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
	{
		if(force && errno == ENOENT)
		{
			errno = 0;
			return 0;
		}
		fprintf(stderr, "rm: error: Failed getting status for '%s': %s\n", acc_path, strerror(errno));
		errno = 0;
		return 1;
	}
	if(stats.st_dev == root_stats.st_dev && stats.st_ino == root_stats.st_ino)
	{
		fprintf(
		    stderr, "rm: error: Target '%s' is the same inode+device as root, bailing out\n", acc_path);
		return 1;
	}
	bool is_dir = S_ISDIR(stats.st_mode);
	if(is_dir && !opt_d)
	{
		if(!recurse)
		{
			fprintf(stderr, "rm: error: Is a directory, pass -r or -d to remove: %s\n", acc_path);
			return 1;
		}
		if(!force && opt_i)
			if(!consentf("rm: Recurse into '%s' ? [y/N] ", acc_path)) return 0;
		int dir = openat(fd, name, O_RDONLY | O_DIRECTORY | O_CLOEXEC);
		if(dir == -1)
		{
			fprintf(
			    stderr, "rm: error: Couldn't open '%s' as directory: %s\n", acc_path, strerror(errno));
			errno = 0;
			return 1;
		}
		DIR *dirp = fdopendir(dir);
		if(dirp == NULL)
		{
			fprintf(stderr,
			        "rm: error: Couldn't get DIR entry for opened '%s': %s\n",
			        acc_path,
			        strerror(errno));
			errno = 0;
			return 1;
		}
		while(true)
		{
			struct dirent *dp = readdir(dirp);
			if(dp == NULL)
			{
				if(errno == 0) break;
				fprintf(
				    stderr, "rm: error: Failed reading directory '%s': %s\n", acc_path, strerror(errno));
				closedir(dirp); // error ignored
				errno = 0;
				return 1;
			}
			if(strcmp(dp->d_name, ".") == 0) continue;
			if(strcmp(dp->d_name, "..") == 0) continue;
			char new_path[PATH_MAX] = "";
			if(snprintf(new_path, PATH_MAX, "%s/%s", acc_path, dp->d_name) < 0)
			{
				fprintf(stderr,
				        "rm: error: Couldn't concatenate '%s' into parent '%s', skipping to next entry: %s",
				        name,
				        acc_path,
				        strerror(errno));
				err = 1;
				errno = 0;
				continue;
			}
			// No depth counter for now, unlikely to be a problem
			int ret = do_unlinkat(dir, dp->d_name, new_path);
			if(ret != 0) err = 1;
		}
		// fdopendir allocates memory for DIR, needs closedir
		if(closedir(dirp) != 0)
		{
			fprintf(stderr,
			        "rm: error: Deallocating directory entry for '%s' failed: %s\n",
			        acc_path,
			        strerror(errno));
			errno = 0;
			return 1;
		}
	}
	if(!force)
	{
		if(opt_i)
		{
			if(!consentf("rm: Remove '%s' ? [y/N] ", acc_path)) return 0;
		}
		else
		{
			// Don't check symbolic links, would need AT_SYMLINK_NOFOLLOW on faccessat which isn't portable
			// Can assume symbolic links are 0777 anyway
			if(!S_ISLNK(stats.st_mode) && faccessat(fd, name, W_OK, 0) != 0)
			{
				errno = 0;
				if(!consentf("rm: Remove non-writable '%s' ? [y/N] ", acc_path)) return 0;
			}
		}
	}
	if(unlinkat(fd, name, is_dir ? AT_REMOVEDIR : 0) != 0)
	{
		fprintf(stderr, "rm: error: Couldn't remove '%s': %s\n", acc_path, strerror(errno));
		errno = 0;
		return 1;
	}
	else if(verbose)
	{
		fprintf(stderr, "rm: Removed: %s\n", acc_path);
	}
	return err;
}
static void
usage(void)
{
	fprintf(stderr, "Usage: rm [-firRv] [files ...]\n");
}
int
main(int argc, char *argv[])
{
	for(int c = -1; (c = getopt_nolong(argc, argv, ":dfirRv")) != -1;)
	{
		switch(c)
		{
		case 'd':
			opt_d = true;
			break;
		case 'f':
			force = true;
			break;
		case 'i':
			opt_i = true;
			break;
		case 'r':
			recurse = true;
			break;
		case 'R':
			recurse = true;
			break;
		case 'v':
			verbose = true;
			break;
		case ':':
			fprintf(stderr, "rm: error: Missing operand for option: '-%c'\n", optopt);
			usage();
			return 1;
		case '?':
			GETOPT_UNKNOWN_OPT
			usage();
			return 1;
		default:
			abort();
		}
	}
	argc -= optind;
	argv += optind;
	char *lc_all = setlocale(LC_ALL, "");
	if(lc_all == NULL)
	{
		fprintf(stderr,
		        "%s: warning: Failed loading locales. setlocale(LC_ALL, \"\"): %s\n",
		        argv0,
		        strerror(errno));
	}
	errno = 0;
	consent_init();
	if(argc == 0 && !force)
	{
		fprintf(stderr, "rm: error: missing operand\n");
		usage();
		return 1;
	}
	if(stat("/", &root_stats) != 0)
	{
		fprintf(stderr, "rm: error: Failed getting status for '/': %s\n", strerror(errno));
		return 1;
	}
	int err = 0;
	for(int i = 0; i < argc; i++)
	{
		int ret = do_unlinkat(AT_FDCWD, argv[i], argv[i]);
		if(ret != 0) err = 1;
	}
	consent_finish();
	return err;
}