Programming

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <dirent.h>

void dirlist(DIR *, const char *);

main(int argc, char *argv[]) {
	DIR *dp;
	struct dirent *dp2;

	if (argc == 1) {
		dp = opendir(".");
		if (dp == NULL) {
			perror("opendir");
		}
		dirlist(dp, "./");
	} else {
		while (--argc > 0) {
			dp = opendir(*++argv);
			if (dp == NULL) {
				perror("opendir");
			}
			dirlist(dp, *argv);

			if (argc > 1) {
				printf("\n");
			}
		}
	}
	closedir(dp);
}
void dirlist(DIR *dp, const char *name) {
	struct dirent *dp2;

	printf("%s:\n", name);
	while ((dp2 = readdir(dp)) != NULL) {
		if ((strstr(dp2->d_name, ".") != NULL &&
		     strstr(".", dp2->d_name) != NULL) ||
		    (strstr(dp2->d_name, "..") != NULL) &&
		     strstr("..", dp2->d_name) != NULL) {
			continue;
		}
		printf("%s  ", dp2->d_name);
	}
	printf("\n");
}

$ echo /path/to/dir/*