C / C++ / MFC

CStdioFile file<br />
file.Open(...);<br />
file.WriteString("1e34efad");<br />
file.Close();

char sz[] = "ffff"; 
long lDec = strtol(sz, NULL, 16);

<br />
#include <string.h><br />
#include <iostream.h><br />
#include <stdlib.h><br />
<br />
<br />
bool ValidateNumericInput(char* psBuf);<br />
<br />
int main(int argc, char* argv[])<br />
{<br />
	char sBuf[255];<br />
	do<br />
	{<br />
		cout << "enter a number" << endl;<br />
		cin.getline(sBuf, 255, '\n');	<br />
	}while ( !ValidateNumericInput(sBuf));<br />
<br />
	// at this point, the data in sBuf (to the NULL char) is numeric but in ASCII<br />
	int iConverted = atoi(sBuf);   // this converts the ASCII to an int <br />
	cout<< endl << endl << ++iConverted;<br />
	return 0;<br />
}<br />
<br />
<br />
<br />
// both cout statements were include just to display the results<br />
bool ValidateNumericInput(char* psBuf)<br />
{<br />
	for (unsigned int index = 0; index < strlen(psBuf); index++)<br />
	{<br />
		if( psBuf[index] < 0x30  || psBuf[index] > 0x3F )<br />
		{<br />
			cout << "'" << psBuf << "' - is an invalid entry" << endl << endl;<br />
			return false;<br />
		}<br />
	}<br />
	<br />
	cout << "input was all numbers" << endl;<br />
	return true;<br />
}//end of ValidateNumericInput()<br />
// there are many ways to achieve your desired result but I thought this might <br />
// give you some ideas<br />
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