Sometimes, this is useful like ($me) for usage info (usage: $me [ARGS]).

use strict;
use warnings;

use Path::Tiny ();

my $me     = Path::Tiny::path( $0 )->basename();
my $abs_me = Path::Tiny::path( $0 )->realpath();

print "1) original: $0\n";
print "2) short   : $me\n";
print "3) long    : $abs_me\n";
[download]

Result:

rp@linux:local: perl ../me.pl
1) original: ../me.pl
2) short   : me.pl
3) long    : /home/rp/me.pl
[download]