CODEWITHSUNDEEP
perl
jjennifer
jjennifer

Reputation: 1315

validate a parameter from querystring

Hi I am very new to perl. as you can see in my code below, I need to fetch a parameter "page" from querystring. and I also want to validate the parameter value. if the parameter is not in querystring or not a number, then assign 1 to $current_page, else just assign the value to $current_page. how can I do this in perl? please help me.

use strict;

use CGI qw/:standard/;
my $querystring = CGI::Vars();

my $current_page = $querystring->{page};

print $current_page;  # I would get a warning "Use of uninitialized value..."

Upvotes: 0

Views: 122

Answers (1)

ikegami
ikegami

Reputation: 386481

This will use 1 if the param is missing:

my $current_page = $querystring->{page} || 1;

It won't check to make sure it's a number, though. That would be something like:

my $current_page = $querystring->{page};
$current_page = 1
   if !defined($current_page)
   || $current_page =~ /[^0-9]/
   || $current_page == 0;

If you need to validate multiple parameters, you might want something like Data::FormValidator. Once you start using it, you get all of its benefits including the ability to trim leading and trailing spaces for example.

Upvotes: 2

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