I'd build a structure that maps pretty much directly on to the information provided by 'Folder/Folder info'. Along with a little error checking and a recursive sub to generate the output something like the following should fit the bill:

use strict;
use warnings;


my %folders;
my $parentId;

while (<DATA>) {
    chomp;
    
    if (m/^Folder\s+(\d+)\s*-\s*(.*)\.$/) {
        # new folder
        my ($folderId, $folderName) = ($1, $2);
    
        die "Duplicate entry for $folderId ($folderName) at line $.\n"
            if ++$folders{$folderId}{idCount} > 1;

        # Create the new folder
        $folders{$folderId}{folders} = [];
        $folders{$folderId}{name} = $folderName;
        $parentId = $folderId;

    } elsif (m/^\s+subfolder (\d+)\.$/) {
        # New subfolder
        my $folderId = $1;
        
        die "No parent folder for $folderId. Data format error at line
+ $.\n"
            if ! defined $parentId;

        warn "Probably bad data. Subfolder $folderId has already been 
+seen\n"
            if exists $folders{$folderId};

        push @{$folders{$parentId}{folders}}, $folderId;
        $folders{$folderId}{hasParent} = 1;

    } else {
        # Bogus line
    }
    
}

genPath ($_) for sort grep {! $folders{$_}{hasParent}} keys %folders;


sub genPath {
    my ($folderId, $root) = @_;
    
    $root .= '/';

    die "Missing folder information for $folderId\n"
        if ! exists $folders{$folderId}{name};

    die "Cycle in 'tree' involving $folderId and path $root\n"
        if ++$folders{$folderId}{visits} > 1;

    $root .= $folders{$folderId}{name};
    print "$root\n";

    genPath ($_, $root) for @{$folders{$folderId}{folders}};
}


__DATA__
Folder 1298 - foldername_ten.
   subfolder 1299.
   subfolder 1300.
Folder 1299 - foldername_eleven.
    No sub folders.
Folder 1300 - foldername_twelve.
    No sub folders.
Folder 1311 - foldername_thirteen.
   subfolder 1317.
   subfolder 1318.
Folder 1317 - foldername_twelve.
    No sub folders.
Folder 1318 - foldername_twelve.
    No sub folders.

[download]

Prints:

/foldername_ten
/foldername_ten/foldername_eleven
/foldername_ten/foldername_twelve
/foldername_thirteen
/foldername_thirteen/foldername_twelve
/foldername_thirteen/foldername_twelve

[download]
True laziness is hard work

In reply to Re: Building a UNIX path from Irritating data by GrandFather
in thread Building a UNIX path from Irritating data by roswell1329

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