Thread: Getting rid of array index brackets

Just seeking advice. I have a program for homework that I completed and runs great. The program encrypts letters. A = Z, B = Y, C = X etc. and adds 3 to ascii value for digits. The only problem is that Array index brackets should NOT APPEAR ANYWHERE in my code EXCEPT when i referr to the argv contents.

I am just seeking advice on how to go about removing the array index brackets, only line[] needs to be taken out. here is my code.

Code:

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

#include<ctype.h>

#define MAX_SIZE 256

char encryptAlpha  (char strChar);
char encryptNumber (char strNum);

int main (int argc, char *argv[])
{ 
	int i;
	char **mover;
	FILE *fpIn;
	FILE *fpOut;
	char line[MAX_SIZE];
	int size;
	

	for (i = 0; i < argc; i++)
	{
		printf("Argument %d is %s\n", i, argv[i]);
	}
	printf ("\n");
	for (mover = argv; *mover != NULL; mover++)
	{
		printf("Argument pointed at by mover is %s\n", *mover);
	}

	if(!(fpIn = fopen(argv[1], "r" )) )
	{
		printf( "Error opening the input file.\n" );
		exit(101);
	}

	if(!(fpOut = fopen(argv[2], "w" )) )
	{
		printf( "Error creating output file.\n" );
		exit(101);
	}

	while(fgets(line, MAX_SIZE, fpIn))
	{
		size = strlen(line);
		for (i = 0; i < size; i++)
		{
			if isalpha(line[i])
				line[i] = encryptAlpha(line[i]);
			else if ((line[i] >= '0') && (line[i] <= '9')) 
				line[i] = encryptNumber(line[i]);
		}
	fprintf (fpOut, "%s", line);
	}
}

char encryptAlpha (char strChar)
{

//	Local Definitions
	char firstChar;
	char lastChar;

//	Statements
	if ((strChar >= 'A') && (strChar <= 'Z'))
	{
		firstChar = 'A';
		lastChar  = 'Z';
		{
			while ((firstChar <= 'M') && (lastChar >= 'N'))
			{
			if (strChar == firstChar)
				strChar = lastChar;
			else if (strChar == lastChar)
				strChar = firstChar;

			firstChar++;
			lastChar--;
			}
		}
	}

	if ((strChar >= 'a') && (strChar <= 'z'))
	{
		firstChar = 'a';
		lastChar  = 'z';
		{
			while ((firstChar <= 'm') && (lastChar >= 'n'))
			{
			if (strChar == firstChar)
				strChar = lastChar;
			else if (strChar == lastChar)
				strChar = firstChar;

			firstChar++;
			lastChar--;
			}
		}
	}
return strChar;
}// encryptAlpha

char encryptNumber (char strNum)
{
	strNum += 3;

return strNum;
}