Problem with regex substitution within windows paths

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

Dear Monks,

I wish to perform regex substitutions in a string containing Windows paths. More precisely, eliminate some paths from the string. Could someone help me out with the regex substitution, which does not seem work in the following code ?

I would appreciate if somebody explained what exactly the problem is. I fear it's something very basic that I am missing here..

Thank you in advance !

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


my $path = join ';', (
    'D:\aa\bb\cc',
    'D:\dd\ee\ff',
    'D:\gg\hh\ii',
);

my $path_component = 'D:\aa\bb\cc';

print $path, "\n\n";

$path =~ s/$path_component//i;

print $path, "\n\n";
[download]

Comment on Problem with regex substitution within windows paths Download Code

Replies are listed 'Best First'.
Re: Problem with regex substitution within windows paths by Corion (Patriarch) on Jul 08, 2011 at 15:54 UTC
Your string replacement contains characters that are special to the regex engine. See perlop on `\Q` resp. quotemeta.	[reply] [d/l]
Re^2: Problem with regex substitution within windows paths by halfcountplus (Hermit) on Jul 08, 2011 at 17:42 UTC
> characters that are special to the regex engine Namely, \, the escape character itself. So you need to escape the escape: \\.	[reply]
Re^2: Problem with regex substitution within windows paths by jmb (Novice) on Jul 11, 2011 at 12:32 UTC
Thank you Corion ! The code now works : `#!/usr/bin/perl -w use strict; use warnings; my $path = join ';', ( 'D:\aa\bb\cc', 'D:\dd\ee\ff', 'D:\gg\hh\ii', ); my $path_component = quotemeta( 'D:\aa\bb\cc;' ); print $path, "\n\n"; $path =~ s/$path_component//i; print $path, "\n\n";` [download] ... and, more importantly, I've now understood what was going wrong...	[reply] [d/l]