CODEWITHSUNDEEP
regexperl
Bablu
Bablu

Reputation: 39

Determine the directory based on a default directory

I want to split out a directory based on a given directory path with comparison to a default directory in perl preferably in regex. I have two default directories, lets say /root/demo/ and /etc/demo/.

Given a directory path, lets say /root/demo/home/test/sample/somefile.txt OR /etc/demo/home/test/sample/somefile.txt,

I want to extract the /home/test/sample/somefile.txt from the given directory path. Kindly assist.

Thanks

Upvotes: 0

Views: 50

Answers (3)

user557597
user557597

Reputation:

Here is another way using quotemeta.

Perl sample: 

use strict;
use warnings;

my @defaults = ('/root/demo/', '/etc/demo/');

$/ = undef;
my $testdata = <DATA>;

my $regex = '(?:' . join( '|', map(quotemeta($_), @defaults) ) . ')(\S*)';
print $regex, "\n\n";

while ( $testdata =~ /$regex/g )
{
    print "Found /$1\n";
}

__DATA__

/root/demo/home/test/sample/somefile.txt
/etc/demo/home/test/sample/somefile.txt

Output: 

(?:\/root\/demo\/|\/etc\/demo\/)(\S*)

Found /home/test/sample/somefile.txt
Found /home/test/sample/somefile.txt

Upvotes: 1

Miller
Miller

Reputation: 35198

Build your list of prefix dirs into a regex alteration. Be sure to sort by length descending, and also to use quotemeta.

The following demonstrates:

use strict;
use warnings;

my @dirs = qw(
    /root/demo
    /etc/demo
);

# Sorted by length descending in case there are subdirs.
my $list_dirs = join '|', map {quotemeta} sort { length($b) <=> length($a) } @dirs;

while (<DATA>) {
    chomp;
    if ( my ($subdir) = m{^(?:$list_dirs)(/.*)} ) {
        print "$subdir\n";
    }
}

__DATA__
/root/demo/home/test/sample/someroot.txt
/etc/demo/home/test/sample/someetc.txt

Outputs:

/home/test/sample/someroot.txt
/home/test/sample/someetc.txt

Upvotes: 1

Avinash Raj
Avinash Raj

Reputation: 174706

Use \K to discard the previously matched characters.

\/(?:root|etc)\/demo\K\S+

DEMO

Upvotes: 2

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