From mboxrd@z Thu Jan  1 00:00:00 1970
From: wwp <subscript@free.fr>
Subject: Re: argv[0]
Date: Fri, 13 Jan 2006 10:52:44 +0100
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References: <200601130016.23410.a.biardi@tiscali.it>
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Hello Andrea,


On Fri, 13 Jan 2006 00:16:23 +0100 a.biardi@tiscali.it wrote:

> 
> Hi,
> 
> Is there any C function that can tell me what argv[0] is, outside 
> main()?
> 
> I thought to use getpid() and then look at /proc/<pid>/cmdline but 
> doesn't seem portable. Any hints?

For instance, in main(), you can store argc and argv into global const
pointers that you can use anywhere else.

Here's an example (see the attached files):

$ gcc main.c elsewhere.c
$ ./a.out

shows:
main: 1 0xbf8526f4 './a.out'
sample1: 1 0xbf8526f4 './a.out'
sample2: 1 0xbf8526f4 './a.out'


HTH,

-- 
wwp

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#include <stdio.h>

extern int prg_argc;
extern char** prg_argv;

void outside_from_main_2(void)
{
	printf("sample2: %d %p '%s'\n", prg_argc, prg_argv, prg_argv[0]);
}

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void outside_from_main_2(void);

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#include <stdio.h>

int prg_argc=0;
char** prg_argv=NULL;

void outside_from_main_1(void)
{
	printf("sample1: %d %p '%s'\n", prg_argc, prg_argv, prg_argv[0]);
}

int main(int argc, char** argv)
{
	printf("main: %d %p '%s'\n", argc, argv, argv[0]);
	prg_argc=argc;
	prg_argv=argv;
	outside_from_main_1();
	outside_from_main_2();

	exit(0);
}

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