Thread: argv and argc command line params

how do i accept command line parameters onto a program running under windows, i understand argv is the number of arguements but for eg - if i wanted to accept a 2 as a command line param and act on it - how do i do it.
tia

i thought argc held the number of arguments where argv held the arguments ??

Welcome back!!!!!

I'm assuming you mean a Win32 Program that uses WinMain???

If so, the third param of WinMain is a LPSTR which will give you the command line as a string ..

Also, you can use the GetCommandLine() API at any point to get this data......

You need some sort of way to tokenise the commandline - so look at strtok from the Std C Library

i thought argc held the number of arguments where argv held the arguments ??

That is correct. Except that argc will contain number of args + 1, and argv[0] will contain the name of the program.

The data is in character format, so to extract a number, do:

int first_arg = atoi(argv[1]);

But always remember to check the count in argc, if it is 1, then nothing was entered into the command line, and the program should probably exit gracefully

By the way, the naming convention is arbitrary, you could equally do:

int main(int count, char* array_of_commands[])

Code:

#include <stdio.h>

int main(int argc, char *argv[])
{
    while (--argc)
        printf ("%s ", *++argv);
    return 0;
}


/* OR */

int main(int argc, char *argv[])
{
    int i;
    for (i = 1; i < argc; i++)
        puts(argv[i]);
    return 0;
}