This is simple XOR cipher code implementation to do simple encoding and decoding via using XOR concept

XorCipher.c

#include <stdio.h>
int main(int args, char *argv[])
{
  char ch;
  char key = argv[3][0];
  FILE *fp;
  FILE *fp1;
  fp = fopen(argv[1], "r");
  fp1 = fopen(argv[2], "w+");
  if (fp == NULL)
  {
    printf("Cannot open the file \n");
    return -1;
  }
  while (!feof(fp))
  {
    fscanf(fp, "%c", &ch);
    fprintf(fp1, "%c", ch ^ key);
  }
  fclose(fp);
  fclose(fp1);
  return 0;
}