Day 6.C

//      $$$$$$\   $$$$$$\  $$$$$$$\      $$$$$$$\                                               $$$$$$\       $$$$$$\                  $$\
//     $$ ___$$\ $$  __$$\ $$  ____|     $$  __$$\                                             $$  __$$\     $$  __$$\                 $$ |
//     \_/   $$ |$$ /  \__|$$ |          $$ |  $$ | $$$$$$\  $$\   $$\  $$$$$$$\      $$$$$$\  $$ /  \__|    $$ /  \__| $$$$$$\   $$$$$$$ | $$$$$$\
//        $$$$$ / $$$$$$$\  $$$$$$$\     $$ |  $$ | \____$$\ $$ |  $$ |$$  _____|    $$  __$$\ $$$$\         $$ |      $$  __$$\ $$  __$$ |$$  __$$\
//       \___$$\ $$  __$$\ \_____$$\     $$ |  $$ | $$$$$$$ |$$ |  $$ |\$$$$$$\      $$ /  $$ |$$  _|        $$ |      $$ /  $$ |$$ /  $$ |$$$$$$$$ |
//     $$\   $$ |$$ /  $$ |$$\   $$      $$ |  $$ |$$  __$$ |$$ |  $$ | \____$$\     $$ |  $$ |$$ |          $$ |  $$\ $$ |  $$ |$$ |  $$ |$$   ____|
//     \$$$$$$  | $$$$$$  |\$$$$$$  |    $$$$$$$  |\$$$$$$$ |\$$$$$$$ |$$$$$$$  |    \$$$$$$  |$$ |          \$$$$$$  |\$$$$$$  |\$$$$$$$ |\$$$$$$$\
//      \______/  \______/  \______/     \_______/  \_______| \____$$ |\_______/      \______/ \__|           \______/  \______/  \_______| \_______|
//                                                             $$\   $$ |
//                                                             \$$$$$$  |
//                                                              \______/
// Author : Saihaj Law
// Date : January 6th
// Project : Unix CAT simplified version

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define BUFFER_SIZE 1024

int main(int argc, char** argv) {
  if (argc > 1) {
    for (int i = 1; i < argc; i++) {
      FILE* input_file = fopen(argv[i], "r");
      if (!input_file) {
        perror("Error opening file");
        return 1;
      }

      char buffer[BUFFER_SIZE];
      while (fread(buffer, 1, BUFFER_SIZE, input_file) > 0) {
        fwrite(buffer, 1, BUFFER_SIZE, stdout);
      }

      fclose(input_file);
    }
  } else {
    char buffer[BUFFER_SIZE];
    while (fread(buffer, 1, BUFFER_SIZE, stdin) > 0) {
      fwrite(buffer, 1, BUFFER_SIZE, stdout);
    }
  }

  return 0;
}