REGEX negate XML tags

kcvenkat123 has asked for the wisdom of the Perl Monks concerning the following question:


Scenario 1

my $comment="<Comment>These are the wild characters value @#$%^&*<\Com
+ment>";

if ($comment !~ /\<Comment\>*[^|<|^>|^\/]*\<\/Comment\>/) {

   print "Passed the test as there were no > < / in the comment \n";
}

Scenario 2

my $comment="<Comment>These are the wild characters value @#$%^&*   > 
+< / <\Comment>";

if ($comment !~ /\<Comment\>*[^|<|^>|^\/]*\<\/Comment\>/) {

   print "Passed the test as there were no > < / in the comment \n";
}
else {
   print "Failed the test as there were > < / characters in the commen
+t \n";
}


User will input the following as a comment. 

And the regular expression should negate any < > / character entered a
+s sentence in the USERSTORY .

<Comment>USERSTORY<\Comment>
[download]

I need to negate XML tags(< > and /) in a sentence(basically a comment entered)

which is entered in between xml tags .

Here is what i am doing .Please let me know if the regular expression that i have is doing the right thing.

I am having two scenarios where the first one should pass and second one should fail

User will input the following as a comment.

And the regular expression should negate any < > / character entered as sentence in the USERSTORY .

<Comment>USERSTORY<\Comment>

Comment on REGEX negate XML tags Download Code

Replies are listed 'Best First'.
Re: REGEX negate XML tags by Your Mother (Archbishop) on Nov 20, 2009 at 20:58 UTC
This might be what you're after to escape (not negate) the characters- `perl -MHTML::Entities -le 'print encode_entities(shift)' '"><' "><` [download] HTML::Entities is tunable so you can set it to only escape exactly what you want.	[reply] [d/l]
Re: REGEX negate XML tags by ikegami (Patriarch) on Nov 20, 2009 at 20:58 UTC
A positive match would be: `[<>/] # char that is "<", ">" or "/"` [download] Add ^ for a negative match: `[^<>/] # char that isn't "<", ">" or "/"` [download] In addition to your pattern being bad, your tests strings are bad (`<\Comment>`). `use Test::More tests => 2; $comment = '<Comment>foo bar</Comment>'; ok( $comment =~ m{<Comment>[^<>/]</Comment>}, 'Detect no specials'); $comment = '<Comment>foo < bar</Comment>'; ok( $comment !~ m{<Comment>[^<>/]</Comment>}, 'Detect <');` [download] `$ perl -MTest::Harness -e'runtests @ARGV' 808525.t 808525.t .. ok All tests successful. Files=1, Tests=2, 0 wallclock secs Result: PASS` [download]	[reply] [d/l] [select]
Re^2: REGEX negate XML tags by kcvenkat123 (Initiate) on Nov 20, 2009 at 22:58 UTC
Thank you very much for the reply and correcting the error. It worked.	[reply]