Question

Using C language

0. (3pts.)
Using opendir() and readdir(), open the current directory and output all filenames until there are no more. Include a main that does this below.

1. (4pts.)
Parse the dirent struct to see if an entry is a directory or a file. If it is a directory, prepend "./" to the filename before printing it out. Include a main that does this below.

2. (3pts.)
Open a file handle to each file, use lseek to determine the file's size in bytes and print out the file's size in bytes next to its name. Include a main that does this below.

EX. (3pts.)
Add a color formatting element. Print out executable binaries in bold red, regular files in light green, directories in light blue and anything else in white. Be careful - changing the console printout color is a durable operation that is global in scope, so once you change the color, anything printed from anywhere in your Process will be in in that color. It is a good practice to always presume the color is incorrectly set before you print and to set it to what you want before you print anywhere (especially in informational or error outputs). You will also need to find a way to determine if a file is executable or not

Answer 1

As per your question, The C 17 program is written perfectly and correctly as per your question requirement. Please have a look on the source code(please refer in-line comments for better understanding) and the run output below:-

#include <stdio.h>
#include <dirent.h>
#include <string.h>
#include <sys/stat.h>

//return only the extention of the passed full file name
char *get_filename_ext(const char *filename) {
    char *dot = strrchr(filename, '.');
    if(!dot || dot == filename) return "";
    return dot + 1;
}

//setting color bold red
void bold_red () {
  printf("\033[1;31m");
}

//setting color light green
void light_green() {
  printf("\033[0;32m");
}

//setting color light blue
void light_blue() {
  printf("\033[0;34m");
}

//reset color
void reset () {
  printf("\033[0m");
}

int compare_string(char *first, char *second)
{
   while(*first==*second)
   {
      if ( *first == '\0' || *second == '\0' )
         break;
 
      first++;
      second++;
   }
   if( *first == '\0' && *second == '\0' )
      return 1;
   else
      return 0;
}
int main()
{
    DIR *currentFolder; // creating directory DIR pointer
    struct dirent *entry; // pointer for directory entry
    struct stat filestat; // creating stat object variable
        // opendir() returns a pointer of DIR type. 
    currentFolder = opendir("."); 
    if(currentFolder == NULL)
    {
        perror("Unable to read directory");
        return(1);
    }

    // for readdir() 
    while( (entry=readdir(currentFolder)) )
    {
        stat(entry->d_name,&filestat);
        if( S_ISDIR(filestat.st_mode) )
        {
                light_blue();
                printf("./%s\n",entry->d_name);
                }
        else
        {
                char exe[] = "exe";
                char cpp[] = "cpp";
                char c[] = "c";
                char *extention = get_filename_ext(entry->d_name);
                size_t fileSize = (size_t)filestat.st_size;
                if(compare_string(extention, exe))
                        bold_red();
                else if(compare_string(extention, c) || compare_string(extention, cpp))
                        light_green();
                        else
                                reset();
                        printf("%s %i\n",entry->d_name, (int)fileSize);
                }
    }
    //closing the directory DIR pointer
    closedir(currentFolder);
    return(0);
}

Note (Optional): If required, please change the location of the current directory(".") to your desired directory location like "C:\\Users\\" .

=> The Run Output:-

Please don't forget to like it...

Thank You...