Beefy Boxes and Bandwidth Generously Provided by pair Networks
Clear questions and runnable code
get the best and fastest answer
 
PerlMonks  

Crosslink

by BrentDax (Hermit)
on Feb 02, 2004 at 08:40 UTC ( #325809=sourcecode: print w/replies, xml ) Need Help??
Category: Utility scripts
Author/Contact Info Brent Dax <brent@brentdax.com>
Description:

For a Web project using Embperl, I have to show a small, fixed set of pages with several different templates (base.epl scripts, essentially, although I used a different extension). I chose to do this by creating hard links between the content files in each directory.

crosslink.pl (or whatever you choose to call it) takes a source directory, a destination directory, and a list of files. It then runs link("sourcedir/filename", "destdir/filename") (or symlink) on each file. This allows me to do things like: crosslink template1 template2 index.epl bio.epl links.epl images/picture.jpg

#!/usr/bin/perl

use strict;
use warnings;

if(@ARGV < 3) {
    print <<"END";
Usage: $0 [options] srcdir destdir file1 [file2 [file3 [...]]]
    Hard links given files in destdir to originals in srcdir.
      Options:
        -s    Use soft links
        -v    Verbose--list each file as it's linked
END
    exit;
}

my %opts;

$opts{pop @ARGV}=1 while $ARGV[0] =~ /^-/;

my($srcdir, $destdir, @files)=@ARGV;

for(@files) {
    do_link("$srcdir/$_", "$destdir/$_") or die "Can't link $srcdir/$_
+ to $destdir/$_: $!";
    print "$srcdir/$_ -> $destdir/$_\n" if $opts{-v};
}

sub do_link {
    if($opts{-s}) {
        return symlink($_[0], $_[1]);
    }
    else {
        return link($_[0], $_[1]);
    }
}
Replies are listed 'Best First'.
•Re: Crosslink
by merlyn (Sage) on Feb 02, 2004 at 11:38 UTC
    For symlinks, that won't work unless the sourcedir is absolute, or calculated properly relative to the destdir. I don't see a disclaimer there for that, so I imagine people will be using it naively in a broken way.

    For example, the following won't work:

    $ mkdir src dst $ touch src/foo $ ln -s src/foo dst/bar
    It doesn't work because the kernel will be trying to find dst/src/foo when dst/bar is referenced. The symlink actually needs to be created non-intuitively as:
    $ ln -s ../src/foo dst/bar
    Perhaps if your code computed the proper relative path from an apparent relative path for symlinks, it'd be more useful.

    -- Randal L. Schwartz, Perl hacker
    Be sure to read my standard disclaimer if this is a reply.

      D'oh! That's what I get for not testing that bit... *sighs*

      =cut
      --Brent Dax
      There is no sig.

        File::Spec's methods rel2abs() and abs2rel() are a convenient way to handle relative and absolute pathing. Also, why not use one of the Getopt::* modules instead of parsing the flags by hand? The performance might not be quite as good, but it does print a warning when someone types an unknown option.
        «Rich36»

Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Node Status?
node history
Node Type: sourcecode [id://325809]
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others contemplating the Monastery: (3)
As of 2022-05-17 07:19 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Do you prefer to work remotely?



    Results (65 votes). Check out past polls.

    Notices?