Thread: Regex or scanf()?

Hi, I'm making a console-based connect four game as a beginner project, I want have the user input a command in this syntax, "drop <int column_number>" to drop a coin. The problem is how! I want to be able to seperate the number from the command a store it into a seperate variable - and if the syntax is not as expect, I do not want the program to crash, I want it to just ask again.

I have tried something like below, which kind of works and then crashes straight after. My understanding of scanf() is limited because I do not have the MSDN library.

PHP Code:

int col;
scanf("drop %d", &col);
return col-1; 


My understanding is that where %d is, is the value that will be put into col - please correct me if I am wrong.

> My understanding of scanf() is limited because I do not have the MSDN library.
Without a decent reference, any new function you come across will leave you guessing.
Didn't something come with your compiler?

As mentioned already (partly at least), use sscanf() to pull the input apart.

Code:

#include <stdio.h>
int main ( ) {
    char buff[BUFSIZ];
    while ( fgets( buff, BUFSIZ, stdin ) != NULL ) {
        int drop;
        if ( sscanf( buff, "drop %d", &drop ) == 1 ) {
            printf( "You dropped item %d\n", drop );
        } else {
            printf( "I don't understand %s", buff );
        }
    }
    return 0;
}

Simply add more else if constructs to match all your other commands.

My understanding of scanf() is limited because I do not have the MSDN library.

MSDN

EDIT: Of course, it's impossible to find anything using the search feature at MSDN. Go to google and do it like this:

"site:msdn.microsoft.com scanf"

That will find what you need.