micro-utils/coreutils/ls.c

#include <pwd.h>
#include <grp.h>
#include <time.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include "make_path.h"
#include "get_stat.h"

unsigned int a_flag;
unsigned int l_flag;
unsigned int p_flag;

struct d_node {
	char *name;
	struct d_node *next;
	struct stat stats;
};

struct d_node *stat_file(char *filename) {
	struct d_node *file = malloc(sizeof(struct d_node));
	if (file == NULL)
		return NULL;

	if (mu_get_lstat("ls", filename, &file->stats))
		return NULL;

	return file;
}

struct d_node **list(const char *path, size_t *nfiles) {
	DIR *dp = opendir(path);
	if (dp == NULL) {
		fprintf(stderr, "ls: %s: %s\n", path, strerror(errno));
		return NULL;
	}

	struct d_node **dir, *cur, *dr = NULL;
	size_t files = 0;

	struct dirent *ep;
	while ((ep = readdir(dp)) != NULL) {
		if (ep->d_name[0] == '.' && !a_flag)
			continue;

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

		cur = stat_file(full_path);
		if (cur == NULL) {
			free(full_path);
			continue;
		}

		free(full_path);

		cur->name = ep->d_name;
		cur->next = dr;
		dr = cur;

		files++;
	}

	if (dr == NULL)
		return NULL;

	*nfiles = files;

	dir = malloc((files + 1) * sizeof(struct d_node *));
	if (dir == NULL) {
		fprintf(stderr, "ls: malloc failed\n");
		exit(1);
	}

	for (size_t i = 0; ; i++) {
		dir[i] = dr;
		dr = dr->next;
		if (dr == NULL)
			break;
	}

	closedir(dp);
	return dir;
}

void dfree(struct d_node **dir) {
	if (dir == NULL)
		return;

	struct d_node *cur = dir[0], *next;
	while (cur != NULL) {
		next = cur->next;
		free(cur);
		cur = next;
	}

	free(dir);
}

int main(int argc, char **argv) {
	int opt;
	while ((opt = getopt(argc, argv, "al")) != -1) {
		switch (opt) {
			case 'a':
				a_flag = 1;
				break;

			case 'l':
				l_flag = 1;
				break;

			default:
				printf("ls [path]\n\t[-a Show hidden files] [-l Use a long listing format]\n");
				return 0;
		}
	}

	argv += optind;
	argc -= optind;

	struct d_node **dir = NULL;
	size_t files = 0;

	if (argc < 1)
		dir = list(".", &files);

	if (argc == 1)
		dir = list(argv[0], &files);

	for (size_t i = 0; i < files; i++)
		puts(dir[i]->name);

	dfree(dir);
	return 0;
}