One more q: on: parsing file/regex question

Thanks for all of the help on this so far...I took the suggestions and I expanded the sample program to see if that makes a difference...

I am hoping to get this as data driven as possible to reduce errors (especially when I cut-n-paste ;-)

I am looking to process some lines in a file and validate text (I am not yet using Taint, but will at some point ;) My problem is how to validate \n or \t, as sometimes it is allowed in the text field.

The following code should work, but I just want to make sure that the s/\\t/\t/g; (and the other ones that I might need) are the best way to go)

Thanks again for any help!!!!

$PRE    = '\[\s*';
$VALID1 = '[-a-zA-Z0-9_.* \t\n]';
$VALID2 = '[-a-z0-9_.*\n]';
$VALID3 = '[a-zA-Z]';
$VALID4 = '[-a-zA-Z0-9]';
$PST    = '\s*\]';
while (<DATA>)
{
    s/\\n/\n/g; #Are these harmless if
    s/\\t/\t/g; #not needed???
    print "yep\n"  if m/$PRE($VALID1+)$PST
                        $PRE($VALID2+)$PST
                        $PRE($VALID3+)$PST
                        $PRE($VALID4+)$PST
                      /ox;
}


__DATA__
[TEST \n DATA] [ TEST DATA ]  [ 2345423 ] [ TEST DATA ]\n
[TEST \n DATA] [ TEST DATA ]  [ 2345423 ] [ TEST\tDATA ]\n
[TEST \n DATA] [ TEST DATA ]  [ 2345423 ] [ TEST DATA ]\n
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Re: One more q: on: parsing file/regex question
by graff (Chancellor) on Oct 24, 2003 at 03:35 UTC

You do have the right notion for converting a literal (two character) '\n' or '\t' into the corresponding regex for the given type of whitespace.

Note that some portions of your regexes can be simplified: [a-zA-Z0-9_] is really just "\w", and if you want to match space, newline and tab, you might as well just use "\s".

Are $VALID1 and $VALID2 really supposed to accept periods and asterisks, as well as alphanumerics and whitespace? (Just checking... sometimes people tend to make the mistake of putting ".*" inside of square brackets when they really have something else in mind.)

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