removing special characters

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: removing special characters by extremely (Priest) on Feb 13, 2003 at 17:50 UTC
Don't think of it as removing the special characters. Think of it as keeping the safe/useful characters. It is a subtle thing but you'll be well served in the future if you keep that attitude. You can spend all day adding more and more special characters or you can just removed everything that you aren't sure is valid. You'll always miss things but it is easier to allow one extra thing you missed than clean up your database or hacked server when you allowed something you shouldn't have. As an example, to keep only upper case letters and numbers, you might do: `$scalar =~ s/[^A-Z0-9]+//g;` which removes from the string every character that isn't in the A-Z or 0-9 range. -- $you = new YOU; honk() if $you->love(perl)	[reply] [d/l]
Re: Re: (nrd) removing special characters by newrisedesigns (Curate) on Feb 13, 2003 at 20:37 UTC
Taint check. It is the only way.™ `my $param = $q->param("text") \|\| ''; #for example... if($param =~ /^([\w\s]+)/){ # modify as needed $param = $1; } else{ return 0; # or die, or croak, or warn, or something! }` [download] John J Reiser newrisedesigns.com	[reply] [d/l]
Re: removing special characters by John M. Dlugosz (Monsignor) on Feb 13, 2003 at 18:13 UTC
Try the `tr///d` command instead of `s///` if you simply want to remove all occurances of some characters and don't need patterns. —John	[reply] [d/l] [select]
Re: removing special characters by Tomte (Priest) on Feb 13, 2003 at 17:09 UTC
`perldoc perlre` is your friend search for `s///` regards, tomte	[reply] [d/l] [select]