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

}
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