#!/usr/bin/perl
# extract_base_path.pl - extract base path from two paths
# http://delphi.about.com/b/2009/05/06/delphi-programming-challenge-extractbasepath.htm
# dprelec, 2009-05-07
use strict;
use warnings;
my $path1 = '/usr/bin/perl/lib/';
my $path2 = '/usr/bin/perl/';
my @parts = split('/', $path1);
my $last = '';
my $re = join('|', reverse map { $last .= $_ . '/'; $last } @parts);
if ($path2 =~ /($re)/) {
print $1, "\n";
}
Thursday, May 07, 2009
Extract base path
Simple solution to a Delphi task: extract base path from two paths:
Subscribe to:
Post Comments (Atom)
3 comments:
Interesting! As an alternative appraoch, what about determining which path is shorter, then iteratively shortening the shorter path until a regex matches?
Something like this (very roughly):
#!/usr/bin/perl
my $longer = '/usr/local/apache/htdocs/';
my $shorter = '/usr/bin/';
while ($longer !~ /^$shorter/){
$shorter =~ s|[^\/]*/$||;
}
print $shorter;
@rjbond3rd: I feel there must be a simple solution to this via regular expression only. Something like:
if ($path1 =~ /($magic$path2)/) { say $1; }
Another approach, using Text::Abbrev
#!/usr/bin/perl
use Text::Abbrev;
use strict;
use warnings;
my $str1 = '/usr/bin/perl/lib/';
my $str2 = '/usr/bin/perl/lub/';
my %hash = abbrev ($str1, $str2);
(keys %hash)[0] =~m[^(.*/)] ;
print $1,"\n";
Post a Comment