LornaJane Blog

Today I had a problem with a development server. A little, low-traffic thing that I was testing some PHP-sends-email pages on. The emails wouldn’t send although I could see them sat in the queue.

The story gets better but there’s a techie bit between here and the punchline – sorry

Exim commands

mailq – show the emails currently in the queue

sendmail -v -q – send the emails in the queue and give plenty of output with it.

The symptoms

Sending email just caused the screen to hang, I’d get something like this:


LOG: queue_run MAIN
  Start queue run: pid=12282
delivering 1HeAZY-0002YQ-J0 (queue run pid 12282)
R: dnslookup for ****************
T: remote_smtp for **********************
Connecting to **************** [000.000.000.000]:25 … connected
  SMTP<< 220 ********************** ESMTP
  SMTP>> EHLO ****
  SMTP<< 250-***********************

        250-AUTH=LOGIN CRAM-MD5
        250-AUTH LOGIN CRAM-MD5
        250-STARTTLS
        250-PIPELINING
        250 8BITMIME
  SMTP>> STARTTLS
  SMTP<< 220 ready for tls


Randomness!!

The problem was that we didn’t have enough entropy¹ to generate the security for the connection … and getting one of my colleagues to rummage in the rack for the server and wave its mouse continuously solved the problem. It was quite a scene :)

¹ For diagnosing randomness, I used: cat /proc/sys/kernel/random/entropy_avail

Tabs seem to be out of fashion in the programming world, there are perfectly valid arguments on both sides or the tabs vs. spaces flame war, illustrated with examples from every programming language and text editor combination ever made. You can read any or all of these if you are interested, but that isn’t the issue here.

I use tabs – all the time. My tab stopping is set to 4 spaces but my intention is to use actual tab characters. Its actually surprisingly hard to do this with vim. I’ve added the following lines to my .vimrc which allow me to see whether I have tabs or spaces at the start of the line.


set list listchars=tab:\|_,trail:.
highlight SpecialKey ctermfg=DarkGray


I fiddled with some other settings too, to try to stop everything ending up as spaces (I’m driving my colleagues mad) but to no avail. With these lines:


set shiftwidth=4
set softtabstop=4
set tabstop=4
set noexpandtab
set autoindent
set smartindent


I think those are all the relevant lines … it kind of works but I still need to type the set noexpandtab when I’m editing a file to stop auto-indented new lines from getting space instead.

Its all very exasperating so if anyone has suggestions other than “use spaces” I’d be interested to hear them!

Until recently I spent a lot of time working with Oracle from the command line (via ksh on AIX, in case you’re interested). A change of job means a change of platform and I find myself working with MySQL on a daily basis. I like MySQL – like most PHP programmers this is where I started learning about databases and I’ll always have a soft spot for it.

In Oracle most developers use SQLPlus to work with the database – its the standard command-line tool and the only thing you can guarantee being available in a new environment. It has a wonderful feature where you can type a query and then type ‘ed’ and pull up an editor window with the query still in it … so useful for debugging big statements.

I’ve been struggling to get to grips with MySQL – it has more tools and phpMyAdmin is readily available. However I don’t really use a mouse if I can help it so its not as fast or convenient as the SQLPlus + ‘ed’ combination. So here’s my discovery for this week:

Type \e

Most mysql command-line tools will launch your previous query, with line breaks, if you type \e at the prompt. Fantastically useful and I’m happy and settled once more :)

I’m just getting started with running a linux machine as my main computer at work (yay!), setting everything up today. My tip for installing linux the first time is to get the repositories of software added so you can install more things though “adept” (the program that runs when you choose the “Add/Remove Programs” option from the start menu). To add the repositories just edit this file:

  /etc/apt/sources.list

Then uncomment the lines as directed in the file. You will also need to get the list of available packages by running

  sudo aptitude update

Next time you go to “Add/Remove Programs” you’ll have a much bigger list to chose from, especially if you allow unsupported and proprietary software by ticking the boxes at the top right hand side.

Just a quick one, but something that confuses me often.

<input name="input_name" id="input_identifier ....

name is what the POST request will see the field called
id is what the label tag will use to figure out which field it belongs to.

I’ve just spent the last two hours reading through (this is a disturbing link, you have been warned) Kathy Sierra’s post about the death threats she has been receiving.

Death threats.

One of the most talented and inspirational writers of our time is currently locked inside their house in fear. How can that be right?

Its created waves in the blogosphere, I picked up the news from a blogher mailing list, and they have an excellent article on the subject on their site. The blogher mailing list people have also added their words of support to Kathy onto their own blogs, here and here. And it must be true because its even on the BBC News Website.

I hope this blows over for Kathy, as much as it can, and that justice runs its course. There’s overwhelming support for her but we can’t protect her in the real world and it only takes one nutcase to carry out these threats. She may stop blogging and I can understand that although I’d be gutted. I’ve posted to her site to say this, and also want to state here my support for Kathy whose articles inspire and educate me.

So here I am, a woman blogging on mainly tech subjects, with nothing to protect me but the fact that I have a very tiny readership. It makes you think …

Bug trackers are great. Keeping track of lots of little niggly things is tedious and hard to do even if you have pink post-it notes, which I do. But for a software development team there is no subsitute for a decent bug tracker [1].

That’s why I’m trying out Mantis for size. So far I’ve installed it and had an initial play and so far I’m impressed. Its got everything I’d expect and then some more, next I shall feed it some data and have a proper play. Its less slick than other products on the market (Eventum springs immediately to mind) but on the other hand it takes seven minutes to go from “I quite fancy a shot with mantis” to “cool status colours on the overview list” which is good.

Mantis is also temping as it integrates (or can with some help) with both subversion and dokuwiki. I’ll be having a shot at getting these all talking soon, and I’ll let you know how I get on.

¹ So why have I come across so many teams that don’t use one? I have no idea, maybe you know.