Getting args

[willa]

How do I get a command line argument? It is compulsory, so I don't think I need getopt - just the kind of thing you'd do in UNIX with $1...

[joealba]

Take a look at @ARGV. It holds all your command line arguments, split by whitespace.

Update: DOH! daveorg beat me to it, so I might as well add some other useful tidbits:

• Number of arguments passed: scalar @ARGV
• Program name: $0
• If all your arguments are filenames and you want to read them all in line by line, you can use <>. That's kinda neat sometimes, if you can trust your input!

Camel 3, p. 659

[willa]

How do I pattern-match a variable with the first one?

if ($var =~ m/@ARGV[1]/) {
...
}

???

[joealba]

You were close.

if ($var =~ /$ARGV[0]/) {
...
}


A more exact match:

if ($var =~ /^$ARGV[0]$/) {
...
}


Updated: $ARGV[1] is the SECOND argument. $ARGV[0] is the first one.

[davorg]

Your command line arguments are in @ARGV.

--
<http://www.dave.org.uk>

"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg

[monk2b]

I hope this helps

#!/usr/local/bin/perl -w
use strict;

my $d;
shift = $d;


I hate posting after such experience monks,but
I think this is what you are after
learning too monk2b
update I was very backwards in the original post
I hope I did not do anyone permanent harm my apologies.
Thanks davorg

[davorg]

I think you may be a little confused.

$ARGV[0]=$d;

This overwrites the first command line argument with the value of $d - which is undefined.

shift=$d;

This doesn't even compile.

--
<http://www.dave.org.uk>

"The first rule of Perl club is you do not talk about Perl club."
-- Chip Salzenberg

[hotshot]

maybe you should consider using Getopt anyway, coz' it makes it much easier to parse arguments, especialy if you use flags (like: -e, -f, --mode etc.), that expect special values after them. it probably depends on your program. If you need any help I just wrote a command line interface for my product at work so maybe I'll have a few hints for you.

Hotshot

[Dylan]

Well, TIMTOWTDI...

All command line args go into the global array @ARGV.
shift defaults to @ARGV (when it is not in a suboutine)...
More info on that is in the Perl predefined variables node.
for one arg, you can shift it, like so: my $var = shift
or, for many args:
my ($var1,$var2,var3,$var4)=@ARGV;

Which is kinda neat.
Also, you could access them directly: print $ARGV[0]
Well, there might be even more ways, but you get the idea, right? :)

Here's some code to play with.


#!/usr/bin/perl
if ($#ARGV == 2) { 
# $#ARGV is number of args in @ARGV minus one
my $foo = shift; #First arg;
my $bar = shift; #second arg;
my $baz = shift; #Last arg;
#print it;
print "You say $foo $bar $baz?\n";
} else {
#Warn, and exit;
warn <<TEXT;
I need three arguments!
Usage: $0 arg1 arg2 arg3
TEXT

}


I hope that helps. :-)