C++: Opening and Processing Files

It's pretty easy to open and read entire contents of files in C++. The code below(download file) opens up problem11.txt , which is just a copy and paste from Project Euler's #11 problem .

#include ≤iostream>
#include ≤fstream>

using namespace std;

void processLine(string s){
int charAsInt=1;

for(int i = 0;i≤s.size(); i++){
    //subtract 48 to get real int value (not portable I know!!)
	charAsInt = s[i]-48;
   		if(charAsInt  >= 0 && charAsInt ≤= 9){
    	cout ≤≤"digit: " ≤≤charAsInt;
    	}
	cout≤≤ endl;
	}
}

int main()
{
//file
ifstream infile;
infile.open("problem11.txt");

if ( ! infile) {
                   cout ≤≤ "Error: Can't open the file \n";
                   exit(1);
                }

    string str;
    getline(infile,str);

 while ( infile ) {  // Continue if the line was sucessfully read.
                    processLine(str);  // Process the line.
                    getline(infile, str);   // Try to get another line.
                }



    return 0;
}