How to deal with [ and ] chars

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

Hi,

I have written a perl program that grabs text patterns like so:-

if ($rpt[$ln] =~ /^\sStartpoint/ {
     @ptlalsp = split(/\s+/,$rpt[$ln]);
     $ptsp = $ptlalsp[2];               #get name
     do {
          $ln++;
     } until ($rpt[$ln] =~ /$ptsp/);    #name will show up
                                        #again...increment
                                        #$ln until found
     #other stuff...
}
[download]

...but every so often $ptsp possesses a [ or ], which messes up my pattern matching. How do I treat [ and ] as literal characters and not special characters?

Thanks,
-Fiddler42

Comment on How to deal with [ and ] chars Download Code

Replies are listed 'Best First'.
Re: How to deal with [ and ] chars by Ven'Tatsu (Deacon) on May 04, 2004 at 19:16 UTC
Try `/\Q$ptsp\E/` from the perlre man page: \E end case modification (think vi) \Q quote (disable) pattern metacharacters till \E	[reply] [d/l]
Re: How to deal with [ and ] chars by Zaxo (Archbishop) on May 04, 2004 at 20:28 UTC
An alternative to ++Ven'Tatsu's answer is to apply quotemeta before the interpolation, `$ptsp = quotemeta $ptlalsp[2]; #get name` After Compline, Zaxo	[reply] [d/l]
Re: How to deal with [ and ] chars by geekgrrl (Pilgrim) on May 04, 2004 at 19:34 UTC
i would say to do a regex on $ptsp and insert backslashes before the square braces. `($ptsp = $ptlalsp[2]) =~ s/(\[\|\])/\\$1/g;` [download]	[reply] [d/l]