Thread: command line arguments

You can't change the parm style that is used to pass parms to main(), unless you write your own command processor. With a typical operating system, in calling main(), it's always strings.

If you write your own command processor, I suspect you could do anything you wanted to.

Originally Posted by tempster09

I have rethought variodic functions, is there anyway to mimic the

Of course. I kind of thought this is where you were at, I just didn't want to seem patronizing and say maybe you do not understand C that well yet?

char *argv[] is a string literal array:

Code:

char *example[] = {"one", "two", "three"};

You shouldn't alter this after declaration tho, so it's usefulness is somewhat limited.

But consider a dynamic pointer array, char **example.

Code:

char **example = malloc(3*sizeof(char*));

This can be resized. Each member is a pointer:

Code:

example[1] = malloc(32);

Of course, if this were a struct or typedef array, you would just go:

Code:

example = malloc(3*sizeof(mystruct*));
example[1] = malloc(sizeof(mystruct));

So witness, you have a dynamic array of structs. This is the kind of thing you can put into initialization or allocation/deallocation functions. And:

Code:

void some_function(int len, mystruct **array);

Guess what? If "len" is like argc -- that is, the number of pointers in "array", you now have an adaptable arrangement like argc, argv.

Hope this is what you were looking for.

Originally Posted by MK27

char *argv[] is a string literal array:

Actually it's not. It's an array of pointers to characters. Which could, be if you wanted, an array of pointers to arrays of char:

Code:

#include<stdio.h>
int main( void )
{
    char foo[BUFSIZ] = "hello";
    char bar[BUFSIZ] = " ";
    char baz[BUFSIZ] = "world!\n";
    char *aop[3];
    size_t x = 0;
    
    aop[0] = foo;
    aop[1] = bar;
    aop[2] = baz;
    
    for( x = 0; x < 3; x++ )
        printf( "%s", aop[ x ] );
    
    return 0;
}

Originally Posted by MK27

You shouldn't alter this after declaration tho, so it's usefulness is somewhat limited.

You can actually modify the arguments in arv. It's allowed by the standard.


Quzah.