Message-Id: <199807042347.AAA32125@sable.ox.ac.uk>
Comments: Authenticated sender is <mert0407 AT sable DOT ox DOT ac DOT uk>
From: George Foot <george DOT foot AT merton DOT oxford DOT ac DOT uk>
To: Theo Landgraf <tla AT pac DOT nl>
Date: Sun, 5 Jul 1998 00:41:43 +0000
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Subject: Re: handle commandline arguments.
Reply-to: george DOT foot AT merton DOT oxford DOT ac DOT uk
CC: djgpp AT delorie DOT com
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On 19 Jun 98 at 10:04, Theo Landgraf wrote:

> how do i handle the command line options in my source.
> 
> in Borland C3.1 i use simpel _argv[0] for the programname.
> how do i do this in djgpp?

The `main' function accepts two parameters, normally called `argc'
and `argv', as follows:

    int main (int argc, char *argv[])

`argc' is the number of words on the command line (including the 
program's name), and `argv' is an array of pointers to the individual 
words, which is also terminated by a NULL pointer.

I suspect that Borland defines `_argc' and `_argv' to be global variables 
equivalent to `argc' and `argv' in `main'.  DJGPP also has similar 
global variables which are defined in `crt0.h' -- they're called 
`__crt0_argc' and `__crt0_argv'.

So, either use the standard way (i.e. arguments passed to the `main'
function), or use `__crt0_argc' and `__crt0_argv' (after #include
<crt0.h>).  You can mirror the arguments of `main' to globals 
yourself if you like:

| int _argc;
| char **_argv;
| 
| int main (int argc, char *argv[])
| {
|     _argc = argc;
|     _argv = argv;
| ...

and then use `_argc' and `_argv' elsewhere in the program.  This is 
more portable than using djgpp's `__crt0_*' variables.

Note that djgpp automatically performs Unix shell-like globbing of
command line arguments -- wildcarded arguments are expanded into
lists of existing files which match the wildcarded arguments.  You 
can turn this off if you like; see the djgpp FAQ, section 16.2.

-- 
george DOT foot AT merton DOT oxford DOT ac DOT uk