validating HTML fields in form using regex using perl - regex

Question

I have a couple of quick questions regarding using regex to validate some fields in a form. But I seem to be having some problems.
so here is the code
$userNameReg = "[a-zA-Z0-9_]+";
$passwordReg = "([a-zA-Z]*)([A-Z]+)([0-9]+)";
$emailReg = "[a-zA-Z0-9_]#[a-zA-Z]\.[a-zA-Z]{2,3}";
if ($onLoad !=1)
{
#controlValue = ($userName, $password, $phoneNumber, $email);
#regex = ($userNameReg, $passwordReg, "phoneNumber", $emailReg);
#validated;
for ($i=0; $i<4; $i++)
{
$retVal= validatecontrols ($controlValue[$i], $regex[$i]);
if ($retVal)
{
$count++;
}
if (!$retVal)
{
$validated[$i]="*"
}
}
sub validatecontrols
{
$ctrlVal = shift();
$regexVal = shift();
if ($ctrlVal =~ /$regexVal/)
{
return 1;
}
if ($ctrlVal !~ /$regexVal/)
{
return 0;
}
}
}
So what happens is that it still validates special characters, and I can't understand why. It does throw a flag if I enter a single special character but if its part of a word in the middle, beginning or end it validates.
Also please disregard the phone number part, because I haven't gotten to that part yet. I still have to create a regex that validates the phone number, digits only, first digit greater than 2.
Thank you all in advance for your help and insight.
Cheers

Answer 1

My guess is that you're missing start/end anchors. So [a-zA-Z0-9_]+ should be ^[a-zA-Z0-9_]+$. This way pattern will only match full string.
Also I strongly recommend you to enable use strict;. It can save you from a lot of mistype errors. Just add following to the beginning of the script:
use strict;
use warnings;
This will force perl to only allow defined variables. In most case you'll need to add my to first use of your variables (for example my $ctrlVal).
In validatecontrols you don't need second if statement. You can just return false like this:
sub validatecontrols
{
my $ctrlVal = shift();
my $regexVal = shift();
if ($ctrlVal =~ /$regexVal/)
{
return 1;
}
return 0;
}