Cyanide & Happiness @ Explosm.net
Archive for December, 2007
So a couple of days ago someone (forgotten who though, sorry!) put up an interesting post about using Regex (Regular Expressions) in Eclipse to save you loads of repetative typing. As a follow up I thought I’d show a real life example of using regex that just saved me a whole heap of laborious grunt work.
A client asked me to update the images on a site I’m building for them. The image details are all in a simple xml file with some details and a link to the image file, e.g…
<images> <image file="img1.jpg"><client>Foobar</client><by>Someone</by></image> <image file="img2.jpg"><client>Barfoo</client><by>Somebody Else</by></image> ... </images>
The client however supplied me with a text doucument that looked something like…
1. Foobar/Someone 2. Barfoo/Somebody Else ....
…and a bunch of jpeg files that had been named to match the document, so they were actually called ’1. Foobar_Someone.jpg’ etc and needed to be renamed for safe use on the web (I never like having mixed case and spaces in web filenames).
Now as there were around 80 of these files it could have been a long and boring ‘rename & save’ job, then a whole bunch of cutting and pasting, so instead I used Eclipse and Perl’s regex powers.
The first thing I did was load the text file in Eclipse, then hit CTRL + F for the find & replace dialogue and checked the ‘Regular Expressions’ box. In the ‘find’ box I put
This is a fairly simple pattern match using the braces to capture matching ‘groups’ that we can use later. Taking it from the begining…
- the ^ character matches the start of a line, the (\d*) matches the first numbers
- the \. matches a litteral dot (the slash is an escape character as the dot normally means match anything)
- It may be hard to see here, but there’s then a space which we ignore
- the (.*)/(.*) matches the two groups of words around the slash
- and the $ matches the end of the line
Then in the replace box I put
The dollar+number means use the contents of capture group n, so you can see I’m simply ‘pasting’ the captured bits in the correct places.
Then just hit ‘replace all’ and job done!
(Hint: You can also use CTRL+SPACE in the find & replace input boxes to remind you of the regex syntax)
Of course I still needed to rename all the files, so next I used the ‘rename’ command. I’m working on Linux, but I believe ‘rename’ comes as part of Perl, so it should be somewhere on your system and work the same no matter what platform.
The syntax for the rename command is…
rename perlexpr [ files ]
…and basically runs the regular expression ‘perlexpr’ on the filename of all files matching [files]. The expression I used here is…
rename -v 's/(d*)\..*/img$1.jpg/' *.jpg
The regular expression is the messy looking bit inside the inverted commas, and it’s matching all the .jpg’s in the folder. Again taking the regex from the top…
- The “s” means substitute. The syntax is s/old/new/ — substitute the old with the new
- The (d*) captures the intial number in the filename
- The \. matches a litteral dot
- The .* matches anything else after it
- We then discard all the other crap apart from the captured number, and use it in the substituted filename.
(Hint: more info : http://tips.webdesign10.com/how-to-bulk-rename-files-in-linux-in-the-terminal)
Well it’s taken me a hell of a lot longer to write this post than it did to rename all those files, I wouldn’t like to guess how long it would have taken by hand but I’m sure it was much easier this way.
Try bit of regex yourself, you just might like it!
I’ve just finished playing Crysis for the PC and have been constantly blown away by the graphics over the 10 or so hours it took me. The game itself is ok… the AI’s a bit dumb and for all out action it’s not a patch on CallOfDuty4 (which is the best game I’ve played for a very long time!)… but graphically Crysis stands alone.
I’ve put together a little gallery of shots I took in the game (using F12), these are all real in game shots, no tweaking or post processing, and of course it all looks ever better when it’s moving. If you have a hefty PC and graphics card I’d recommend you give it a try, if only for the eye candy. (It ran fine for me at 1024×768 with everything on max and the extra DX10 hacks on XP with a Quad Core 2.4 & 640Mb GTS).
Just spotted an add for this shop in my Gmail, they are selling CS3 Flash Pro and Photoshop for just £65 each…
Thats like 85% off the £575 RRP, seems too good to be true and the site looks a bit thrown together, but they are advertising on Google… anyone got any info…?