Pang wrote:

> Thanks Brian and Neil, I will take note on the advice of good coding. I
> guess the only confusion here is whether 'argv' is an array name or a
> pointer. The whole structure is in MAIN, so my understanding was that it is
> an array name, and as such operation like assignment and increment are
> illegal. But base on the example, the 'argv' has to be a pointer to be

okay. This is how i view it. argv is a pointer to an array of pointers. each element in the array of
pointers then point to each argument.

argv  arrayof pointers   the argument in the command-line
[] - > []    ->                [filename]
         []    ->                [option 1]
         []    ->                [option 2]

hope this clear things up.
K&R2 does tell you to avoid this type of expression due to it's unnature brevity.

Regards,
John Chung

>
> correct.
>
> Thanks again.
>
> Pang
>
> ----- Original Message -----
> From: "Neil Bradley" <nb@SYNTHCOM.COM>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Tuesday, April 08, 2003 1:25 PM
> Subject: Re: [OT]:C pointer Question
>
> > > There is a line of code at that section -
> > >
> > > while ( --argc > 0 && ( *++argv ) [0] == '-' )
> > >       while ( c= *++argv [0] )
> > >                switch (c)  {.......}
> > >
> > > I do not understand the portion c = *++argv[0]. From what i understand,
> the
> > > 'result' of that incrementing and dereferencing will be c = argv[0][1],
> > > which is wrong.
> >
> > Note the first (*++argv)[0] means that argv gets ++'d, so it moves past
> > argv[0] to argv[1]'s address (skipping past the launch filename).
> >
> > Now when you do c = *++argv[0], that will increment the pointer of
> > argv[1] by 1, skipping past the '-'.
> >
> > Code like the above is highly unreadable (hence your message), and authors
> > of such atrocities should be taken out and maimed, shot, and otherwise
> > tortured. ;-) (yes, I know it's K&R, but they weren't the best coders in
> > the world).
> >
> > -->Neil
> >
> > --------------------------------------------------------------------------
> -----
> > Neil Bradley            In the land of the blind, the one eyed man is not
> > Synthcom Systems, Inc.  king - he's a prisoner.
> > ICQ #29402898
> >
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