[Linux,C] ls 명령어 만들기

#include <sys/types.h>
#include <dirent.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

void main(int argc, char *argv[]){
        DIR *dirp;
        struct dirent *dentry;
        char *directory;

        if(argc == 1){
                directory = ".";
        } else if(argc == 2) {
                directory = argv[1];
        }

        if((dirp = opendir(directory)) == NULL) exit(1);

                while(dentry = readdir(dirp)) {
                        if(dentry->d_ino != 0)  // ino == 0, delete file
                                printf("%s\n", dentry->d_name);
                }

        closedir(dirp);
}