(2017) Lab 7, Assignment 2: "Write a program that takes a string as an argument and return all the files that begins with that name in the current directory and its sub directories. For example > ./a.out foo will return all file names that begins with foo."

OS-Lab7-Assignment2.c

#include <stdio.h>
#include <dirent.h>
#include <string.h>
#include <limits.h>

void listFiles(char* path, char* str) {
  DIR *dr = opendir(path);

  if(dr != NULL) {
    struct dirent *de;

    while((de = readdir(dr)) != NULL) {
  		char *name = de->d_name;  // Get the name of the file/folder

      if(strstr(name, str)) { // Check if name starts with the given string
        printf("%s/%s\n", path, name);  // Yes, print the full path
      }

      if(de->d_type == DT_DIR) {  // If it's also a folder
        if(strcmp(name, "..") != 0 && strcmp(name, ".") != 0) { // Make sure they're not the current directory itself or its parent directory
          char npath[PATH_MAX]; // Get the maximum limit for a path from limits.h and create a new string with that limit
          sprintf(npath, "%s/%s", path, name);  // Contstruct a new string based on the new path to the next folder
          listFiles(npath, str);  // Repeat the function with the new path
        }
      }
  	}

    closedir(dr);
	}
}

int main(int argc, char* argv[]) {

  if(argc != 2) { // Must take two arguments
    printf("Usage: %s foo\n", argv[0]);
    return 1;
  }

	listFiles(".", argv[1]);  // Start listing files from the current directory with the matching string
	return 0;
}