Posts tagged: UNIX

I love Django management commands.

For dpaste.com I’ve written several management commands for things that I don’t need a web UI for, like:

• expire - delete expired pastes (invoked by cron)
• expunge - manage TOS violations like spam
• stats - useful metrics on the current corpus of pastes, and on user activity

In running the site I also use management commands from my django-blocklist app, for tasks like deleting expired entries (via cron) or generating reports.

A step-by-step guide from real life.

Recently I switched my work environment from OS X to Ubuntu (a post on that project is in the works).

For years I’ve been using the standard Apple Keychain app, which has several points in its favor: it’s included with the OS, it integrates well with a lot of applications, and is not trying to “freemium” me into a paid tier. However, it’s OS X only, which meant I had to find something new.

In the shell, emacs is my editor of choice. However, it has one default behavior that has gotten in the way more often than it has helped – automatic generation of backup files in the same directory as the original.

Emacs is great for making quick edits to files on the web server. But I don’t want or need all those *~ files sitting around. The material is all in version control, so I can already revert to any point in history.

When I created dpaste, I tried to make it both a simple browser-based tool and a simple RESTful API. With very little work you could write a script that created a new paste item with a single POST.

Over the life of the site a few people have discovered and played with that “secret” API. I’ve now made it a bit more official. The new API has its own URL (versioned, even!) and is more tolerant of missing data, just like the web form.

This has been going around – give people a peek at what commands you run most often. I ran this on my server, where I spend most of my shell time:

> history|awk '{a[$2]++} END{for(i in a){printf "%5d\t%s\n",a[i],i}}'|sort -rn|head
  103   hg
   81   cd
   67   ll
   29   ./manage.py
   23   ab
   21   re-ap
   17   hgup
   14   svn
   13   cat
   12   ls

Notes:

• Mercurial has pushed my use of Subversion way down.
• I can’t remember what I was benchmarking with ab, but I’m sure it’s faster now!
• re-ap is my alias for restarting Apache (re-po restarts Postfix, re-my restarts MySQL, etc.).
• hgup is a simple shell script that updates the live instance of my site by fetching from the Mercurial repository in the staging instance. It would make a neat Django custom management command, but not one tied to a particular app.

An opinionated minority of advanced computer users are rebelling against the WIMP (windows, icons, menus, pointers) model of HCI. They are developing and promoting alternative interfaces (typically desiigned to work with unix-based systems) that embody their opinions.

I haven’t used any of these yet, but here are the ones I keep encountering references to:

• Ion
• Ratpoison
• Orion
• StumpWM

Most if not all of these credit the terminal-only GNU Screen (a program I do use) with inspiration. The ideas of Jef Raskin undoubtedly are a factor too.