main.c

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "steganography.h"

int
main (int argc, char *argv[])
{
  // declare variables
  char *inputFile, *messageFile, *outputFile;

  // check if the arguments are valid
  if (argc == 1)
  {
    fprintf (stderr, "Invalid arguments\n");
    fprintf (stderr,
             "Usage: %s -e input-file.png message.txt staged-image.png \n",
             argv[0]);
    fprintf (stderr, "Usage: %s -d staged-image.png \n", argv[0]);
    exit (EXIT_FAILURE);
  }

  // assign arguments to variables
  if (strcmp (argv[1], "-e") == 0)
  {
    // check if the arguments are valid
    if (argc < 5)
    {
      fprintf (stderr, "Invalid arguments\n");
      fprintf (stderr,
               "Usage: %s -e input-file.png message.txt staged-image.png \n",
               argv[0]);
      exit (EXIT_FAILURE);
    }

    inputFile = argv[2];
    messageFile = argv[3];
    outputFile = argv[4];

    encode (inputFile, messageFile, outputFile);
  }
  else if (strcmp (argv[1], "-d") == 0)
  {
    // check if the arguments are valid
    if (argc < 3)
    {
      fprintf (stderr, "Invalid arguments\n");
      fprintf (stderr, "Usage: %s -d staged-image.png \n", argv[0]);
      fprintf (stderr, "Usage: %s -d staged-imaged.png -o output-file.txt \n",
               argv[0]);
      exit (EXIT_FAILURE);
    }

    inputFile = argv[2];

    if (argc > 3 && strcmp (argv[3], "-o") == 0)
    {
      if (argc < 5)
      {
        fprintf (stderr, "Invalid arguments\n");
        fprintf (stderr,
                 "Usage: %s -d staged-imaged.png -o output-file.txt \n",
                 argv[0]);
        exit (EXIT_FAILURE);
      }

      outputFile = argv[4];
    }
    else
    {
      outputFile = "message.txt";
    }

    decode (inputFile, outputFile);
  }
  else
  {
    fprintf (stderr, "Invalid arguments\n");
    fprintf (stderr,
             "Usage: %s -e input-file.png message.txt staged-image.png \n",
             argv[0]);
    fprintf (stderr, "Usage: %s -d staged-image.png \n", argv[0]);
    exit (EXIT_FAILURE);
  }

  exit (EXIT_SUCCESS);
}