Check for Numeric output in Perl

Shell Programming and Scripting
1

Hi All,

I would like to convert my below csh script to Perl.
Can any expert help ?

# To check for numeric input
set tested1 = `echo "$tested"| awk '/^[0-9]+$/'`; 

# To remove un-neccessary zeros
set tested2 = `echo "$tested"|awk '{print $0+0}'`;
2 
if ($tested=~/^(\d+)$/) { # Block will only be entered when it's only digits
    $tested1 = $1; #Leading zeros are automagically removed.
}
3

Hi pludi,

Thks for your advice.
But what does $1 represent in Perl.
I only understand that $1 represent 1st field in AWK, is that the same for Perl ?

4

When using brackets in regular expressions you start a capturing group, meaning anything that matches the regex inside will also be made available outside the regex. These groups are captured to $1, $2, $3, ...
Another option might be to save those captures to an array using

@arr=$tested=~/(\d+)/g

but this usually isn't useful if you want to match the whole line.

Good follow-up reading: perldoc perlre