I like to wrestle with ideas in the area of computer science, -- data structures, algorithms, different programming paradigms. I like a programming environment that supports me in this respect.

Most of my daily work these days is centered on architecture & technical design plus program development in .NET C#. That's fine for team development of enterprise applications, but it has too much OO telescope vision and syntax overload for fast and flexible data munging and prototyping. For the latter tasks i always try to squeeze in Perl at work.

To stay on tracks with Perl (even though it's pt at most 10% of my work), I enjoy following the discussions here on PM and digesting books like Effective Perl Programming and HOP. For example I recently faced a problem at work, traversing a directory hierachy, extracting and manipulating certain files. I utilized a technique described in HOP to easily and elegantly solve this task. I could have done it in C#, but it would have taken double up the time and space.

#!C:/Perl/bin/perl.exe -w
# Program.. :  Iterate.pl: iterate over dir.tree and prefix files with
+ dir-name.
# Function. :  Recurse from current dir; Prefix each "WrappedXml.{0,9}
+\.xml" 
#              file with immediate subdir and copy this file to curren
+t/. dir.
# Usage.... :  Call Iterate.pl in the root of the dir tree to scan.
# Ref...... :  HOP Ch.4: Iterators 
# History.. :  040306 - Allan Dystrup, Ver.0, AND/KMD EDPI
# ===========================================================

use strict;
use warnings;
use File::Copy;

### -------------------------- Util -----------------------
sub Iterator (&)     { return $_[0] }
sub NEXTVAL         { $_[0]->() }

### -------------------------- Iterator -------------------
sub interesting_files {
    my $is_interesting = shift;
      my @queue = @_;
      return Iterator {
       while (@queue) {
             my $file = shift @queue;
             if (-d $file) { 
                 opendir my $dh, $file or next;
                 my @newfiles = grep {$_ ne "." && $_ ne ".."} readdir
+ $dh;
                 push @queue, map "$file/$_", @newfiles;
             }
             return $file if $is_interesting->($file);
       } 
       return;
      };
}

### -------------------------- FileMask -------------------
sub is_WrappedXml {
    my $file = shift;
    return 1 if $file =~ /WrappedXml.{0,9}\.xml/i;
    return;
}

### -------------------------- MAIN -----------------------
my $WrappedXml_file = interesting_files(\&is_WrappedXml, '.');
print "Copying xml instances :\n";
while (defined(my $file = NEXTVAL($WrappedXml_file))) {
    my $newfile = $file;
    $newfile =~ s#/(WrappedXml.{0,9}.xml)#\-$1#i;    # subst / -> -
    $newfile =~ s#.*/(.*)#$1#;                # zap base dir
    print "\t$file\n\tCopy  ->   .\\$newfile\n";    
    copy("$file", ".\\$newfile") or die "Error copy: $!";
}
[download]

Best regards
Allan Dystrup