Here is a possibility. It checks whether anything in your input contains something else than digits or decimal point.
It fails with strings like '....' or '1.2.333.44..55' : 
#!/usr/bin/perl -l
use strict;
my @inputs = ( qw[1 2 878787 777s7 3.4 3,4 77 abcdef ABCSDEF :: איט !!
+!?]);
foreach (@inputs) {
    if ( m/[^0-9.]/ ) {print "$_ \tis not numeric";}
    else              {print "$_ \tis     numeric";}
}

__OUTPUT__
1     is     numeric
2     is     numeric
878787     is     numeric
777s7     is not numeric
3.4     is     numeric
3,4     is not numeric
77     is     numeric
abcdef     is not numeric
ABCSDEF is not numeric
::     is not numeric
איט     is not numeric
!!!?     is not numeric
__END__

[download]

pelagic
-------------------------------------
I can resist anything but temptation.

In reply to Re: How to check Inputs if Numeric by pelagic
in thread How to check Inputs if Numeric by kasmot

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • 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! —
  • 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:
    & &amp;
    < &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.