How to take command line argument and use it to run an upgrade script.

[Jeff Collins]

I'm a perl newby.
I'm looking on taking a command line argument from
STDIN and use it for input to a script that upgrades
software. Any examples would be greatly appreciated.

Thanks

=====
Jeffrey T. Collins
[email]jtbaca@yahoo.com[/email]

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[Dan Anderson]

On Thu, 2004-01-22 at 18:14, Jeff Collins wrote:

> I'm a perl newby.
> I'm looking on taking a command line argument from
> STDIN and use it for input to a script that upgrades
> software. Any examples would be greatly appreciated.

STDIN is already open when your perl script starts so you can read in
from it by using:

my $variable = <STDIN>

And there are interfaces to curses, tk, and gtk if you feel like
creating a nice user interface.

Dan

[Wolf Blaum]

> I'm a perl newby.
me too:-) Right list, I assume.

> I'm looking on taking a command line argument from
> STDIN and use it for input to a script that upgrades
> software. Any examples would be greatly appreciated.

@ARGV holds your command line arguments.

call:
scriptname.pl Universe 42 douglas 'Zappod Beblebrox'

#! /usr/bin/perl
use strict;
use warnings;
print "You called me with ", scalar @ARGV, " Arguments.\n";
if (@ARGV) {
print " Param to script: $_\n" foreach (@ARGV);
}

Notice that there is a nice wa of processing command line args with the
getopt:: modules from CPAN.

Also take a look at perldoc perlvar for detailed info about @ARGV, ARGV and
$ARGV.

Hope that helps, Wolf

[Drieux]

On Jan 22, 2004, at 3:39 PM, wolf blaum wrote:
[..]

>
> call:
> scriptname.pl Universe 42 douglas 'Zappod Beblebrox'
>
> #! /usr/bin/perl
> use strict;
> use warnings;
> print "You called me with ", scalar @ARGV, " Arguments.\n";
> if (@ARGV) {
> print " Param to script: $_\n" foreach (@ARGV);
> }

My Compliments on a well done piece.

One of the stock modules most of us use is Getopt::Long
which is really good for the more complex command line optioning.
cf:
perldoc Getopt::Long

An Illustration:
<[url]http://www.wetware.com/drieux/pbl/perlTrick/CommandLine/[/url]
do_get_opt_long.txt>




ciao
drieux

---

[Wolf Blaum]

> My Compliments on a well done piece.

OT:
see, a logical problem I have with newsgroups is that you learn most (at least
I do) by trying to explain things you think you understood to others -
"beginning explainers" however make mistakes -
Thats of course not what you want in a newsgroup, since there is the one
asking, who is learning too, whom you dont want to confuse with "slightly
right" answers.

Nevertheless Im happy it seems this is a group were you can even learn how to
explain (and what the group-iquette is anyway).

Thanks for that,
Wolf

[Drieux]

On Jan 22, 2004, at 5:56 PM, wolf blaum wrote:
[..]

> Nevertheless Im happy it seems this is a group were
> you can even learn how to explain (and what the group-iquette is
> anyway).

[..]

Good point there.

A part of the struggle is always sort out what
the OP is really working with, and where are they
really trying to go with their idea. The only way
that a person can sort that out is by trial and error.


ciao
drieux

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