Run Postgresql pg_dump from your scripts

If you use Postgresql, you probably noticed that the command line tools who come with it don't accept passwords on the command line.

That's a good thing, as it prevents other users of the system from spying your command line via ps and see your password.

Ok, but what if you want to run let's say pg_dump from your script? Easy, just export an environment variable PGPASSFILE that points to a file that contains your credentials. Note that this file MUST be in mode 0600, to prevent other users to look into it.

If you use Perl, and File::Temp, that's exactly what it does, so here's a Perl snippet that uses pg_dump:

my ( $cf, $cf_name ) = File::Temp::tempfile();
print $cf '*:*:*:*:'.$password."\n";
close($cf);
system('export PGPASSFILE='.$cf_name.'; pg_dump  etc...');
## Don't forget to unlink cf_name to avoid disk pollution.
unlink $cf_name;

Also, don't forget to run in taint mode and sanitise everything you use to build your command. Managing correctly the returned value of the system call is left as an exercise to the reader :)

Happy coding!

J.

Good old days Javascript

Good old days Javascript:

if( confirm('Are you sure?') ){ ... do stuff ... }

Modern days fancy Ecma script (abridged):

1. Think a lot
2. Write 100KB of untestable code
3. Instanciate a factory.
4. Build an anonymous function.
5. Don't forget to hoist your variables.
6. Fire a dozen async events in two different frameworks
7. Don't forget to use .promise()
8. Catch your events in a completely remote and random other place.
9. Build a jQuery UI modal dialog with appropriate call backs
10. Oh no, it's too slow in IE :(
11. Go back to step 1.

J.

Mason - A Template system for us programmers

Templating Modules are a bit like editors. Every web application developer has a favourite one. And every template system is someone's favorite.

Mine is Mason. But not because the Perl MVC tutorials are full of examples using Mason. Not because it's the fastest (use xSlate if you want to trade speed for flexibility). Not because it's the most popular. It's my favourite for a very plain reason: It makes me more productive and allows me to develop web GUIs using all the powerful features a programmer should biterly miss if they are taken away. That includes writing Perl code :P

I never heard of a business that went down because they didn't have fast enough CPUs, so I'm not fussy about trading a few CPU cycles for elegance, ease and speed of development.

Enough talking. Here's my contribution to the template holy war and Mason lobbying presentation:

One more (good?) reason to consider NoSQL solutions

Btw, if you're convinced by this video - I know this is very unlikely - , Seven Databases in Seven Weeks is the book you'll like to read. It's very well written and gives you just the right amount of information so you can build yourself a broad and clear vision of what major NoSQL technologies can and cannot do for you.