Do I misunderstand the question or will the following not work?

Edit: Ok, I misunderstand the nature of the problem as noted by LanX in Re^2: Distiguishing arguments: number-strings vs real integer... My apologies.

#!/usr/bin/perl
use strict;
use warnings;
#use Data::Dump qw/pp dd/;

#use Scalar::Util qw/looks_like_number/;
#use Devel::Peek;

sub is_string {
    my $arg = $_[0];
    warn "$arg looks like number \n$&\n\n\n"
      if $arg =~ /(\d+)/;
}


is_string(1);
is_string("42");

my $n=1;
my $s="42";
my $s1="this contains the number 143";
my $s2 = "Awierd123number";

is_string($n);
is_string($s);
is_string($s1);
is_string($s2);

$n.="";                                 # cast to string
$s+=0;                                    # cast to number
is_string($n);
is_string($s);
[download]

---

---

Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!

Titles consisting of a single word are discouraged, and in most cases are disallowed outright.

Read Where should I post X? if you're not absolutely sure you're posting in the right place.

Please read these before you post! —

• How do I compose an effective node title?
• How do I post a question effectively?
• Markup in the Monastery

Posts may use any of the Perl Monks Approved HTML tags:

a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr

You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)

	For:		Use:
	&		&
	<		&lt;
	>		&gt;
	[		&#91;
	]		&#93;

Link using PerlMonks shortcuts! What shortcuts can I use for linking?

See Writeup Formatting Tips and other pages linked from there for more info.