I visited the restaurant La Boca in central Belfast yesterday and was extremely impressed. The airy, brightly-coloured casual restaurant had a small menu but excellent food and at a splendid price. Maybe I've been in Dublin too long but I was astounded by the price: £10 for a starter and main course. However, what most struck me was their attention to the other aspects of a dining experience: the drinks.

Their beer selection reflected their menu: small and carefully chosen. Each beer on offer was distinctive: one local beer from Argentina, one from Belfast, a porter, a wheat beer, and a high quality German lager.

However, it was in their coffee that they really shone. Discerning coffee-lovers see the end of a meal with some trepidation: should they spoil a good dinner by bad coffee, or would they be better instead to go without coffee? In this case, I had some justification to trust them: the menu said that the filter blend was 50:50 Kenyan and Guatamalan (and was delicious), and the espresso was a blend of five South American beans: again, splendid. This place serves coffee better than 95% of the coffee shops I've tried.

If ever you're in Belfast, please do pay them a visit: the pavement outside the shop is currently under construction so they need all the continued business they can get.

I wanted to try a filter brew of Has Bean’s El Salvador Pacamara but was reluctant to mess with the grind to get it nicely to a 4-minute extraction. Enter duct tape: I stuck it over the holes till the three minute mark then prised it back for the final 30 seconds' drain.

Honestly, I think I got the grind too coarse: I had been aiming for something akin to James Hoffman’s cafetière grind but wound up with something coarser still. Consequently, it was a bit on the weak side but the technique seems to show great promise.

Either this is a deeply insightful pastiche on the worst of Wikipedia articles (complete with "This article does not cite any references or sources.") or it really is a new depth in Wikipedia. Whatever it is, it’s terribly amusing.

The higher the wind speed across this surface, the faster these warm molecules will be blown away.

This is the concept of evaporative cooling.

The same applies when a company starts to fail, though there is an additional feedback cycle which compounds the problem. First, the most energetic molecules staff depart. These are the ones who can see a future for themselves outside of their current employment — and there is a high correlation between these people and those who are most valuable for an organisation. So the company becomes slightly worse due to the better people leaving. But it’s an exponential effect: it will rapidly get worse unless steps are taken to improve things. Eventually, the company stagnates as all of the interesting and innovative people have found alternative employment and only the boring ones are left.

So, the moral of the story: the more a company blows, the faster its employees leave.

The problem

To begin with, I should say that ls --color is useful. It can show you which items in your directory listing are directories, symlinks, broken symlinks, device nodes, named pipes, whatever. I am glad that it exists.

However, let’s consider the basic action of ls. It is, of course, to display which files and directories exist in a directory. This is really quick and easy in Unix. Simply use the libc function opendir() then just readdir() till it returns NULL and errno is 0. In terms of syscalls, this is an open(), one or two read()s and a close().

When you turn on the color option, every directory item incurs the weight of an extra stat() call to see what it is.

Worse still, if it’s a symlink, ls will obligingly bound across to the thing linked to, to check it exists. If this causes your automounter to wake up and mount something remote, that’s quite an overhead. If your mount hangs because the remote filesystem is unavailable, you can say goodbye to that process; it'll be stuck blocking on a syscall that will never return.

A partial solution

To fix the symlink problem, here’s what you do. ls was written to avoid chasing symlinks if configured not to. Check your environment variables for the LS_COLORS variable with:

$ env | grep ^LS_COLORS

If it exists, you have a config file for colour ls: you should edit /etc/DIR_COLORS* or copy it to $HOME/.dircolors and edit it there. Otherwise, type:

$ dircolors --print-database > $HOME/.dircolors

The edit you need to do is to remove or comment out the ORPHAN line from the file.

Unless you were able to edit the file in /etc, you now need to make sure that this new $HOME/.dircolors file is used. In your shell login script (.bash_login for bash and .login for (t)csh, put the line:

eval `dircolors $HOME/.dircolors`

(Note that these are backticks, not apostrophes.)

Next time you log in, you'll be able to use colourful ls without fear of a remote filesystem freezing your directory listings.

In conclusion

Use ls --color when you need it, but as with all powerful tools, use it with care.

Corrections: James pointed out that to dump the default config it is –print-database not –print-directory.

This whisky is a light straw colour, quite thin in consistency. However, its insipid appearance belies a splendid if subtle flavour. With overtones of honeyed vanilla, it’s a sweet and faintly floral whisky. There is little aftertaste but I can forgive this in a delicate whisky of this nature.

If only they would start putting some effort into maintaining the uptime of the web check-in site, I would be happy. That said, it beats Aer Lingus which refuses to let you print out a replacement boarding pass if (for example), Firefox crashes on getting the PDF the first time around.

Just as Pete and I were about to go, somebody cycled along the and stopped to cross Casto, halting in the middle of a gathering of police officers. One told him, "It’s illegal to cycle on the sidewalk, sir." His reply was a work of genius: "Oh, really?"

It was all very bizarre, though not at all menacing or confrontational. No guns were drawn and nobody was incapacitated by tazer or baton. Just another data point.

Then we went up to the appartment proper and watched Hot Fuzz. Excellent film, especially given that the room was still being illuminated by the occasional strobe of blue lights.

I had thought that I was just having a bad run, but then a colleague mentioned it too. It turns out that only some of the bottles have this characteristic, and we haven't determined, from analysis of the codes on the bottle tops, what determines this. Each was full-fat milk from the same dairy.

If anyone who reads this knows the answer, please mention it in a comment.