PreshWiki

perl:tricks

David Precious — 2010-02-26T09:48:08+00:00

Here's some random useful tricks with Perl, which aren't long enough to warrant their own pages. Find longest entry in array A quick way to find the length of the longest value in an array: my @array = ('foo', 'bar', 'badger', 'wibble'); my $longest = (reverse sort { $a <=> $b } map { length($_) } @array)[0];

perl:scripts:mp3-rename

David Precious — 2008-05-28T13:26:57+00:00

mp3-rename.pl A simple script to rename MP3 files based on the ID3 tags. #!/usr/bin/perl # Rename MP3s in a given directory based on their ID3 # tags. # # David Precious, originally 10/04/2006 # # $Id: mp3-rename.pl 376 2008-05-28 12:21:59Z davidp $ # # TODO: if ID3 'track' tags not given, auto-number tracks # based on the order we saw them in # TODO: extend to support Ogg Vorbis (.ogg) and MP4 files use strict; use File::Recurse; use MP3::Tag; use Cwd; use Term::ReadKey; my $star…

postgresql:mysqlcompare

David Precious — 2008-03-04T16:42:04+00:00

PostgreSQL for MySQL users Quick tips for people who are familiar with MySQL, to help migrate to using PostgreSQL. Quick command reference MySQL PostgreSQL USE database \c[onnect] database SHOW TABLES [FROM database] \dt DESCRIBE TABLE table \d table (Finish this later)

start

David Precious — 2008-03-04T16:28:52+00:00

Welcome to my wiki. I had a page of notes I'd jotted down as I went along, useful reminders on quick ways to do stuff, but it was not easy enough to manage, so I've installed DokuWiki to make it easy to make notes, both for myself and for anyone else who may find them useful.

perl:daterange

David Precious — 2007-09-06T12:30:57+00:00

I needed to calculate a date range in Perl, to work out today's date and the 14 previous days. There are plenty of ways to do it, but I didn't really want to install a module like Date::Range to do something this simple. So, my solution was: my $ctime = time; my $days = 14; my @dates; while (@dates < $days) { push @dates, scalar localtime $ctime; $ctime -= (60 * 60 * 24); } print "dates are:\n"; print "$_\n" for @dates;

linux:linendings

David Precious — 2007-07-21T17:55:54+00:00

Quick ways to convert Windows/DOS style line endings (CRLF / \r\n) with Unix style (LF / \n). If the dos2unix / unix2dos commands are available, they're a quick, simple way to do it. If not, the following commands ought to do it: sed -e 's/$/\r/' inputfile > outputfile # Unix to DOS sed -e 's/\r//' inputfile > outputfile # DOS to Unix # or to get sed to make the changes to the file directly (edit in-place), # use the -i option... this means you can also glob to apply it to several # file…

svn:basicguide

David Precious — 2007-06-20T13:23:14+00:00

This is a very basic quick start guide to the most common SVN commands. Creating a Repository Use the svnadmin command to create and manage repositories: svnadmin create /path/to/repository Importing files into repository To import existing dirs and files into the repository:

linux:mailman

David Precious — 2007-06-20T13:02:41+00:00

Clearing held messages from moderator queue With the amount of spam these days, the moderation queue can quickly become unmanageable. If you need to clear all messages from the queue, look at data/heldmsg* (for my installation, that's /usr/local/mailman/data/heldmsg*).