void encode_file(FILE *, FILE *);
int main()
{
    FILE *in_file, *out_file;
    char infile_name[81], outfile_name[81], input;
    printf("Enter the name of the file to encode: ");
    scanf("%s", infile_name);
    if ((in_file = fopen(infile_name, "r") ) == NULL)
    {
           printf("Error opening %s\n", infile_name);
    }
    printf("Enter the output file name: ");
    scanf("%s", outfile_name);
    if ((out_file = fopen(outfile_name, "w") ) == NULL)
    {
           printf("Error opening %s\n", outfile_name);
    }
    encode_file(in_file, out_file;
    printf("The file has been encoded.\n");
    fclose(in_file);
    fclose(out_file);
}