Re: Regex to match "bad" characters in a parameter

2016-01-26 Thread SSC_perl 
On Jan 25, 2016, at 4:59 PM, Shawn H Corey wrote:
> 
> Use the negative match operator !~
> 
>  if( $QUERY_STRING !~ m{ itemid = [-0-9A-Za-z_]+? (?: \& | \z ) }msx ){
>print "bad: $QUERY_STRING\n";
>  }

Thanks for that, Shawn.  It works perfectly except for one criteria 
that I inadvertently forgot to include.  It's possible that the string will 
_not_ contain the itemid parameter at all.  When that's missing, the regex 
matches and it shouldn't.  I guess that's why I was trying to stay with the 
positive match operator.

I tried inverting your regex:

if ( $QUERY_STRING =~ m/ itemid= .*? [^-0-9A-Za-z_]+? .*? (?: \& | \z ) /sx ) {
   say "bad: $QUERY_STRING";
}

but that doesn't work either.  It catches even good item numbers.

In the meantime, I got it to work by grabbing the itemid and working 
with that separately:

my $item_id = $1 if ($QUERY_STRING =~ m/ itemid=([^&]*) /x);
if ( $item_id =~ m/ [^a-zA-Z0-9_-] /x ) { ...

however, I'd like to do that with a single line, if possible, so I don't have 
to create a new variable just for that.

Thanks,
Frank
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Re: Regex to match "bad" characters in a parameter

2016-01-26 Thread Chris Charley 



"SSC_perl"  wrote in message 
news:ef7499af-b4a5-4b07-8c69-3192ef782...@surfshopcart.com...



On Jan 25, 2016, at 4:59 PM, Shawn H Corey wrote:


Use the negative match operator !~

 if( $QUERY_STRING !~ m{ itemid = [-0-9A-Za-z_]+? (?: \& | \z ) }msx ){
   print "bad: $QUERY_STRING\n";
 }


Thanks for that, Shawn.  It works perfectly except for one criteria that I 
inadvertently forgot to >include.  It's possible that the string will _not_ 
contain the itemid parameter at all.  When that's >missing, the regex 
matches and it shouldn't.  I guess that's why I was trying to stay with the 
>positive match operator.


I tried inverting your regex:

if ( $QUERY_STRING =~ m/ itemid= .*? [^-0-9A-Za-z_]+? .*? (?: \& | \z ) 
/sx ) {

 > say "bad: $QUERY_STRING";

}

but that doesn't work either.  It catches even good item numbers.

In the meantime, I got it to work by grabbing the itemid and working with 
that separately:


my $item_id = $1 if ($QUERY_STRING =~ m/ itemid=([^&]*) /x);
if ( $item_id =~ m/ [^a-zA-Z0-9_-] /x ) { ...

however, I'd like to do that with a single line, if possible, so I don't 
have to create a new variable >just for that.


Thanks,
Frank=


###
###

Hello Frank,

You could do that in 1 line - See the following small program.
(The line using a 'grep' solution is commented out. It would work as well).


#!/usr/bin/perl
use strict;
use warnings;

while (my $id = ) {
   chomp $id;
   #if (grep /itemid=.*?[^\w-]/, split /&/, $id) {
   if ($id =~ /itemid/ && $id !~ /itemid=[\w-]+(?:&|$)/) {
   print "Bad id: <$id>\n";
   }
}

__DATA__
itemid=AT18C_AT18C=1=main.htm=1=1=detail.htm=asc
c=detail.htm=AT18C
itemid=AT18/C
t=main.htm=1=1=detail.htm=asc
itemid=?AT18C


When this is run, it prints out:

Bad id:

Re: Regex to match "bad" characters in a parameter

2016-01-26 Thread SSC_perl 
On Jan 26, 2016, at 11:22 AM, Chris Charley wrote:
> 
> You could do that in 1 line - See the following small program.

Thanks, Chris.  That'll do the trick.  And the grep alternative is 
interesting, too.  I hadn't thought of that.

Regards,
Frank
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