Match two strings based on common substring - perl

Question

I have a list of files that needs to be grouped in pairs. (I need to append an HTML 'File B' (body) to 'File A' (header) because I need to serve them statically without server-side includes).
Example:
/path/to/headers/.../matching_folder/FileA.html
/someother/path/to/.../matching_folder/body/FileB.html
Emphasizing with the ellipses that the paths are not of uniform length, nor is 'matching folder' always in the same position in the path.
It seems I need to match/join based on the common substring 'matching_folder', but I am stumped on scanning each string, storing, matching (excerpt):
my #dirs = ( $headerPath, $bodyPath );
my #files = ();
find( { wanted => \&wanted, no_chdir => 1 }, #dirs );
foreach my $file (#files) {
# pseudocode: append $file[0] to $file[1] if both paths contain same 'matching_folder'
};
sub wanted {
return unless -f and /(FileA\.html$)|(FileB\.html$)/i;
push #files, $_;
};

Answer 1

Hash the files by all the directory steps in their names.
#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };
use File::Find;
my $headerPath = 'headers';
my $bodyPath = 'bodies';
my #dirs = ($headerPath, $bodyPath);
my #files;
sub wanted {
return unless -f and /file.\.html$/;
push #files, $_;
};
find({ wanted => \&wanted, no_chdir => 1 }, #dirs);
my %common;
for my $file (#files) {
my #steps = split m(/), $file;
push #{ $common{$_} }, $file for #steps;
};
# All the headers and all the bodies share their prefixes,
# but that's not what we're interested in.
delete #common{qw{ bodies headers }};
for my $step (keys %common) {
next if 1 == #{ $common{$step} };
print "$step common for #{ $common{$step} }\n";
}
Tested on the following structure:
bodies/3/something/C/something2/fileA.html
bodies/2/junk/B/fileB.html
bodies/1/A/fileC.html
headers/a/B/fileD.html
headers/c/one/A/two/fileE.html
headers/b/garbage/C/fileF.html
Output:
B common for headers/a/B/fileD.html bodies/2/junk/B/fileB.html
C common for headers/b/garbage/C/fileF.html bodies/3/something/C/something2/fileA.html
A common for headers/c/one/A/two/fileE.html bodies/1/A/fileC.html

Answer 2

With the above, I can get to
for my $step (keys %common) {
next unless 2 == #{ $common{$step} }; # pairs
my #pairs = #{ $common{$step} };
my $html;
foreach my $f (#pairs) {
$html .= &readfile($f);
};
&writefile($html, $step . '.html');
}
And get what I need for now. Thanks all! (I love Perl, making hard things possible indeed).