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From: aglew@ccvaxa.UUCP
Newsgroups: comp.lang.c
Subject: Re: Accessing argc & argv from a functi
Message-ID: <28700019@ccvaxa>
Date: Tue, 4-Aug-87 13:39:00 EDT
Article-I.D.: ccvaxa.28700019
Posted: Tue Aug  4 13:39:00 1987
Date-Received: Sat, 8-Aug-87 02:43:05 EDT
References: <22@flmis06.ATT.COM>
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Nf-From: ccvaxa.UUCP!aglew    Aug  4 12:39:00 1987


>The solution is to get the source for main() and modify it, or do something
>that doesn't involve the arguments, e.g. pass the information you are
>looking for in the environment, in a file, etc.  You never did get around
>to explaining what it is you *really* want to do, or why you are modifying
>subroutines' sources but don't have source to main().

I don't know what the original writer was trying to do, but I've often
wanted to get argv from deep down inside a program, without modifying
main, etc.

I write a lot of library routines. Some of them find it necessary to
print error messages, or even abort the program. I think that, it in
environment where there may be a lot of processes running about, it is
nice to know what command died, and even its arguments. I don't like
having to tell the users of my routines to arrange to put these somewhere.

So, for example, I like to be able to simply plug

	if( jhgjhgjh )
		errorf("my library has a problem\n")

and, optionally, get a message like

     	comand arg1 arg2 arg3
		my library has a problem

from it.

Since my home system has shared libraries, I occasionally like plugging things
like this into libc, replacing a standard function, without bothering to
go and modify main.

A special application: I use shared libraries to collect stats on a running
system. I like knowing which commands with what arguments are the most
extreme cases - eg. who processes the longest string.