When I’m installing software, or doing some complicated stuff on the linux command line, which nowadays is pretty much all the time, I will sometimes want to remember exactly what I typed. Now the normal /home/david/.bash_history file is usually fine for that. Run this command, for example, and you will see the commands you typed in before you logged out of the server last time you used it: cat ~/.bash_history You can also find out what you typed in this session, ie: since you logged in, by typing this: ...

This is the absolute minimum I do when I have to log onto a new server or shell account that I haven’t used before, that I will need to edit text files with. First I figure out whether VIM is really installed. A lot of installs, especially those based on ubuntu, ship with VI aliased to VIM, but the VIM install is usually not really VIM at all, and behaves exactly like VI but with some minor bugs fixed. This is not what I want. ...

OK, so you have added a cron job that you want to perform a routine task every day at 6am. How do you test it? You probably don’t want to spend all night waiting for it to execute, and there’s every chance that when it does execute, you won’t be able to find out whether it is executing properly - the task might take 30 minutes to run, for example. So every time you debug it and want to test it again, you have to wait until 6am the following day. ...

I’ve had to solve this problem a couple of times at least, and it’s quite a common task, so I thought I’d document it here. When you send emails to users of your site through using the PHP mail() function, they will sometimes turn up in the mailbox of customers of your site with the following from address: From: Root <root@apache.ecommercecompany.com> This makes absolutely no sense to your customers, and often they will think it is spam and delete it. Often, the decision will be made for them by their web mail host, such as hotmail.com or googlemail.com, and they will never even see the email. You don’t want this to happen. ...

I’ve been using these shell scripts I wrote to convert between unix and windows text file formats. They seem to work well without any problems. If you put them in the /usr/sbin/ directory, they will be accessible on the path of the linux admin account root. /usr/sbin/unix2win `#!/bin/bash Converts a unix text file to a windows text file. usage: unix2win requirements: sed version 4.2 or later, check with sed –version sed -i -e ’s/$/r/’ $1 ` ...

I’ve just updated the design of this blog, re-enabled comments and added a contact tab. I’ve installed a strong anti-spam comment filter, but you should now be able to comment on entries. I’ve also changed the layout of things slightly, and made it easier to read.

Back in 2008, I wrote a PHP class that fetched an arbitary URL, parsed it, and coverted it into an PHP object with different attributes for the different elements of the page. I recently updated it and sent it along to a company that wanted a programming example to show I could code in PHP. I thought someone may well find a use for it - I’ve used the class in several different web scraping applications, and I found it handy. From the readme: ...

As a break from my contract work, I took the W3Schools PHP Certification. I didn’t do any revision, which probably wasn’t wise. It was a bit more difficult than I thought, but I passed still.

Today I encountered problems configuring the windows version of the popular text editor VIM , so I thought I’d write up a quick post talk about configuration files under the Windows version, if anyone becomes stuck like I did. I use Linux, OSX and Windows on a day-to-day basis, and VIM as a text editor for a lot of quick edits on all three platforms. Here’s a quick comparison: Linux Linux is easy because that’s what most people who use VIM run, and so it is very well tested. ...

I’m going to take a break from the purely technical posts to get more people to see this video. Here the late Dan Osman speed-climbs a cliff without any safety equipment. http://www.youtube-nocookie.com/v/Fpm0m6bVfrM&hl=en&fs=1&rel=0 Risky? Just a bit. A few years later he lost his life during a similar attempt. But no-one can doubt the guts required, and the level of skill he achieved, in this type of climbing.