Skip to main content

Are your files SM? M? L? XL? Mid-Size

What I actually had in mind when I came up with the challenge was something like the following ... the sort of thing you find in SysAdmin magazine or Randall Schwartz's columns.



#!/usr/local/bin/perl5.10

use 5.010;
use strict;
use warnings;

use Readonly;

Readonly my $DOT              => q{.};
Readonly my $DOTDOT           => q{..};
Readonly my $ESCAPE_BACKSLASH => q{\\};

die "USAGE: $0 rootdir.\n" unless @ARGV;

my @dirs = ( @ARGV );

my %stats;
while (@dirs) {
 my $one_dir = shift @dirs;
 $one_dir =~ s{(\s)}{$ESCAPE_BACKSLASH$1}g; # escape  spaces for glob()

ENTRY:
 while ( my $entry = glob "$one_dir/*" ) {
     next ENTRY if $entry eq $DOT or $entry eq $DOTDOT;
     if ( -d $entry ) {
         push @dirs, $entry;
     }
     else {
         my $size = -s _;
         my $len = $size == 0 ? 0 : length $size;
         $stats{$len}++;
     }
 }
}

for my $size ( sort { $a <=> $b} keys %stats ) {
 my $maxsize = 10**$size;
 say sprintf( '<%8d %d', $maxsize, $stats{$size});  }


Started with some directory specified as a command-line argument, process all the directory contents: ignore '.' and '..'; add directories to the queue of directories waiting to be processed, and get the log10 size of any file, incrementing the associated count.

For all the sizes encountered, in increasing order, convert to a (unreachable) max size, and print the size and the number of files in that range.


I can do without the File::Find module, the task at hand is pretty simple. On the other hand, my tolerance for ugly punctuation has dropped in the past few years, so I need the Readonly. Without that, it becomes ...


my %stats;
while (@dirs) {
 my $one_dir = shift @dirs;
 $one_dir =~ s{(\s)}{\\$1}g; # escape  spaces for glob()

ENTRY:
while ( my $entry = glob "$one_dir/*" ) {
      next ENTRY if $entry eq q{.} or $entry eq q{..};


The dots would be more tolerable with an SQL 'in' operator, or a Perl6 Junction:



use Perl6::Junction qw/any/;
...
ENTRY:
while ( my $entry = glob "$one_dir/*" ) {
  next ENTRY if $entry eq any( q{.}, q{..} );


Using a subroutine to localize the ugliness would make the double escape bearable.



sub escape_space { $_->[0] =~ s{(\s)}{\\$1}g; };

my %stats;
while (@dirs) {
my $one_dir = escape_space shift @dirs;
ENTRY:
while ( my $entry = glob "$one_dir/*" ) {
  next ENTRY if $entry eq any( q{.}, q{..} );



So the final result is down to 35 lines, including blanks and closing curlies.

#!/usr/local/bin/perl5.10

use 5.010;
use strict;
use warnings;
use Perl6::Junction qw/any/;

sub escape_space { $_->[0] =~ s{(\s)}{\\$1}g; };

die "USAGE: $0 rootdir.\n" unless @ARGV;

my @dirs = ( @ARGV );

my %stats;
while (@dirs) {
 my $one_dir =escape_space  shift @dirs;

ENTRY:
 while ( my $entry = glob "$one_dir/*" ) {
     next ENTRY if $entry eq any( q{.}, q{..} );
     if ( -d $entry ) {
         push @dirs, $entry;
     }
     else {
         my $size = -s _;
         my $len = $size == 0 ? 0 : length $size;
         $stats{$len}++;
     }
 }
}

for my $size ( sort { $a <=> $b} keys %stats ) {
 my $maxsize = 10**$size;
 say sprintf( '<%8d %d', $maxsize, $stats{$size});

Comments

Post a Comment

Popular posts from this blog

Perl5, Moxie and Enumurated Data Types

Moxie - a new object system for Perl5 Stevan Little created the Moose multiverse to upgrade the Perl 5 programming language's object-oriented system more in line with the wonderfull world of Perl 6. Unfortunately, it's grown into a bloated giant, which has inspired light-weight alternatives Moos, Moo, Mo, and others. Now he's trying to create a modern, efficient OO system that can become built into the language. I've seen a few of his presentations at YAPC (Yet Another Perl Conference, now known as TPC, The Perl Conference), among them ‎p5 mop final final v5 this is the last one i promise tar gz While the package provides some POD documentation about the main module, Moxie, it doesn't actually explain the enum package, Moxie::Enum. But delving into the tests directory reveals its secrets. Creating an Enum package Ranks { use Moxie::Enum; enum by_ARRAY => qw( unused 2 3 4 5 6 7 8 9 10 J Q K A ); enum by_HASH => { 2 => 2, 3 =...
5 comments
Read more

Creating Perl5 Objects with Moxie

Having in the previous article prepared data types for car suits and card ranks, I can now combine them to provide a playing card class, using Stevan Little's Moxie module (version 0.04, so definitely early days.) The goal is to provide an object-oriented paradigm to the Perl 5 programming language which is more sophisticated, more powerful and less verbose than manually bless() -ing hashes. To achieve that goal it needs to be faster and light-weight compared to Moose. Currently, Moxie.pm and and MOP.pm are add-on modules, but eventually, when they are more complete, when the wrinkles have been ironed out, and when they have gained acceptance and a community of users, they might be merged into the Perl core. One significant feature of Moxie is that it reduces boilerplate code. You don't have to specify warnigns or strict . As well, the features or the perl you are using are enabled, among them say , state , signatures , and post_deref . A Simple Moxie Class packag...
Post a Comment
Read more

Book review: 390+ Python Interview Questions and Answers

I downloaded a preview portion of 390+ Python MCQs from Anazon, thinking reading through it would help me advance my Python skills beyond what I have learned from Harvard’s online CS50P (Python) course. I’m an experienced program looking to add a new skill to my repertoire, and while the course covered many significant aspects of Python programming, there are many other details to perfect, such as best practices, developing packages, and so on. The book is written by Manish Dnyandeo Salunke, who claims 15 years experience in IT,  but it is not clear who published it. It is obvious no one edited it, or verified the correctness of the questions, answers and explanations. Amazon allowed me to download a sample of (I think) 57 questions. Roughly half of these were wrong, and some of the others struck me as irrelevant. The maximum allowed length for an identifier, apparently, is 79 characters. Anything over 20 characters should be considered unusual, so sufficient to say the limit is se...
Post a Comment
Read more