micro-utils/coreutils/chmod.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/stat.h>
#include "make_path.h"
#include "get_stat.h"
#include "parse_mode.h"

int (*get_stat)(const char *prog_name, const char *path, struct stat *stat_path);
unsigned int r_flag;
unsigned int s_flag;

int change(const char *file, const char *mode_arg) {
	struct stat old_file;
	if (get_stat("chmod", file, &old_file))
		return 1;

	mode_t mode = mu_parse_mode(mode_arg, old_file.st_mode);
	if (chmod(file, mode) == 0) {
		struct stat new_file;
		if (get_stat("chmod", file, &new_file))
			return 1;

		if (old_file.st_mode != new_file.st_mode)
			return 0;

		if (!s_flag)
			fprintf(stderr, "chmod: %s unchanged\n", file);

		return 1;
	}

	else
		fprintf(stderr, "chmod: unable to chown %s: %s\n", file, strerror(errno));

	return 0;
}

int chtree(const char *dst, const char *mode_arg) {
	int ret = change(dst, mode_arg);

	struct stat stat_path;
	if (get_stat("chmod", dst, &stat_path))
		return 1;

	if (!S_ISDIR(stat_path.st_mode) || !r_flag)
		return ret;

	DIR *dir = opendir(dst);
	if (dir == NULL) {
		if (!s_flag)
			fprintf(stderr, "chown: %s: Can`t open directory\n", dst);
		return 1;
	}

	struct dirent *ep;
	while ((ep = readdir(dir)) != NULL) {
		if (!strcmp(ep->d_name, ".") || !strcmp(ep->d_name, ".."))
			continue;

		char *full_path = mu_make_path("chmod", dst, ep->d_name);
		if (full_path == NULL)
			continue;

		if (chtree(full_path, mode_arg))
			ret = 1;

		free(full_path);
	}

	closedir(dir);
	return ret;
}

int main(int argc, char **argv) {
	int i;

	get_stat = mu_get_lstat;
	for (i = 1; i < argc; i++) {
		if (argv[i][0] != '-')
			break;

		else if (!strcmp(argv[i], "-r"))
			r_flag = 1;

		else if (!strcmp(argv[i], "-s") || !strcmp(argv[i], "-f"))
			s_flag = 1;

		else if (!strcmp(argv[i], "-H"))
			get_stat = mu_get_stat;

		else if (!strcmp(argv[i], "--help")) {
			printf("chmod [-H if a command line argument is a symbolic link] [-r recursive] [-s silent] [ugoa]{+|-|=}[rwxXst] / [sstrwxrwxrwx] [file1 file2...]\n");
			return 0;
		}

		if (argc - i <= 2)
			break;
	}

	if (argc - i < 2) {
		fprintf(stderr, "chmod: missing operand\n");
		return 1;
	}

	char *mode_arg = argv[i];
	argv++;
	argc--;

	int ret = 0;
	for (; i < argc; i++)
		if (chtree(argv[i], mode_arg))
			ret = 1;

	return ret;
}