Re^3: Replacing substrings with links

[LanX]

I think it's easier and more efficient to switch the loops.

for (values %copy) {
    1 while                              # repeat till no replacement 
+left
        s/^($pattern)/$h_orig->{$1}/g; 
}

But I have trouble to come up with a test case covering the complicated implications. ( Update Anyone? )

use strict;
use warnings;
use Data::Dump qw/pp dd/;

my $h_orig =
  {
  '/a/b/c/dt/data/SUSE/tool/0.9.0' => '/a/b/c/dt/tools/SUSE/tool/0.9.0
+',
  '/nfs/us' => '/usr/bin',
  '/a/b/c' => '/nfs/us'
  };


my $pattern = join "|", map quotemeta, keys %$h_orig;

my %copy = %$h_orig;

for (values %copy) {
    1 while s/^($pattern)/$h_orig->{$1}/g; 
}

pp $h_orig, \%copy;

-*- mode: compilation; default-directory: "d:/tmp/pm/" -*-
Compilation started at Sun Feb  6 15:59:06

C:/Strawberry/perl/bin\perl.exe -w d:/tmp/pm/replace_pat2.pl 
(
  {
    "/a/b/c" => "/nfs/us",
    "/a/b/c/dt/data/SUSE/tool/0.9.0" => "/a/b/c/dt/tools/SUSE/tool/0.9
+.0",
    "/nfs/us" => "/usr/bin",
  },
  {
    "/a/b/c" => "/usr/bin",
    "/a/b/c/dt/data/SUSE/tool/0.9.0" => "/usr/bin/dt/tools/SUSE/tool/0
+.9.0",
    "/nfs/us" => "/usr/bin",
  },
)

Compilation finished at Sun Feb  6 15:59:06

[choroba]

I tested my previous code with

my $h_orig = {
    '/a/b/c/dt/data/SUSE/tool/0.9.0' => '/a/b/c/dt/tools/SUSE/tool/0.9
+.0',
    '/nfs/us/tools/SUSE'             => '/usr/bin',
    '/a/b/c'                         => '/p',
    '/p/dt'                          => '/nfs/us'};

Your code gives the same result for the input.

Update: Ordering is important. I have no idea what the expected output of

my $h_orig = { '/a' => '/b/c',
               '/b/c' => '/a',
               };

is.

[LanX]

I think the results with this test case really depend on the randomization of the hash.

(testing with hash order is tricky, I wonder if there is a general solution for that)

update

tho /p/dt is not a "absolute path" if /p is a link. 🤷🏽