Hexadecimal To ASCII

This algorithm converts hexadecimal numbers to ASCII code.

• C#
• VB.Net
• C
• C++
• PHP

									/*****Please include following header files*****/
// math.h
/***********************************************/

char* GetSubString(char* str, int index, int count) {
	int strLen = strlen(str);
	int lastIndex = index + count;

	if (index >= 0 && lastIndex > strLen) return "";

	char* subStr = malloc(count + 1);

	for (int i = 0; i < count; i++) {
		subStr[i] = str[index + i];
	}

	subStr[count] = '\0';

	return subStr;
}

char* AppendString(const char* str1, const char* str2) {
	int str1Len = strlen(str1);
	int str2Len = strlen(str2);
	int strLen = str1Len + str2Len + 1;
	char* str = malloc(strLen);

	for (int i = 0; i < str1Len; i++)
		str[i] = str1[i];

	for (int i = 0; i < str2Len; i++)
		str[(str1Len + i)] = str2[i];

	str[strLen - 1] = '\0';

	return str;
}

char* CharToString(char c) {
	char* str = malloc(2);
	str[0] = c;
	str[1] = '\0';

	return str;
}

static int HexadecimalToDecimal(char* hex)
{
	int hexLength = strlen(hex);
	double dec = 0;

	for (int i = 0; i < hexLength; ++i)
	{
		char b = hex[i];

		if (b >= 48 && b <= 57)
			b -= 48;
		else if (b >= 65 && b <= 70)
			b -= 55;

		dec += b * pow(16, ((hexLength - i) - 1));
	}

	return (int)dec;
}

char* HexadecimalToASCII(char* hex) {
	char* ascii = "";
	int hexLen = strlen(hex);

	for (int i = 0; i < hexLen; i += 2)
	{
		ascii = AppendString(ascii, CharToString((char)HexadecimalToDecimal(GetSubString(hex, i, 2))));
	}

	return ascii;
}
								

Example

									char* data = "50726F6772616D6D696E6720416C676F726974686D73";
char* value = HexadecimalToASCII(data);
								

Output

									Programming Algorithms