#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void recurse(const char *path) {
	DIR *d = opendir(path);
	if (!d) {
		warn("couldn't open %s", path);
		return;
	}
	for (;;) {
		struct dirent *dent;
		errno = 0;
		dent = readdir(d);
		if (!dent) {
			if (errno) {
				warn("when reading %s", path);
			}
			break;
		}
		printf("%s%s\n", path, dent->d_name);
		/* if the string ends with '/' */
		if (strchr(dent->d_name, '\0')[-1] == '/') {
			char *next;
			if (asprintf(&next, "%s%s", path, dent->d_name) >= 0) {
				recurse(next);
				free(next);
			}
		}
	}
	closedir(d);
}

int main(int argc, char **argv) {
	if (argc < 2) {
		recurse("/");
	} else {
		for (int i = 1; i < argc; i++)
			recurse(argv[i]);
	}
	return 0;
}