Check for Numeric output in Perl


 
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# 1  
Old 05-06-2009
Check for Numeric output in Perl

Hi All,

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


Code:
# 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  
Old 05-06-2009
Code:
if ($tested=~/^(\d+)$/) { # Block will only be entered when it's only digits
    $tested1 = $1; #Leading zeros are automagically removed.
}

# 3  
Old 05-06-2009
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  
Old 05-06-2009
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, $3, ...
Another option might be to save those captures to an array using
Code:
@arr=$tested=~/(\d+)/g

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

Good follow-up reading: perldoc perlre
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