Execute-Notify

Multitasking in the right manner helps one be productive. Do it too much, and quality declines as you get more stressed. Do it too little, and, well, you get less done. I think the crucial element is minimizing significant context switches while allowing as many things to proceed on automatic pilot as possible.

In particular, when executing long commands on the computer (like, say, compiling a binary), it is better to switch to a different activity (preferably with lower intellectual demands, so as to keep the coding context in one’s working memory) than to sit idly twiddling your thumbs. My problem when I do this, especially since I have a different virtual desktop for each context, is that I may forget to go back and check whether my compilation succeeded and my tests passed.

I recently found out (on emacsfoo) about notify-send, a useful command-line interface to libnotify that lets alerts pop up on the desktop. As is the case for many others, I like the idea of using this tool to notify me that my long-running jobs are finished, so I can switch back to my main context. Thus, I wrote a simple command-line utility (en, for “execute-notify”) that you can use to wrap an arbitrary command and be notified when it exits. I strove to make it fairly general and customizable, and may add more features to it as needed.

The simplest invocation is simply to prefix your command with en:

en  gcc -o myprogram myprogram.cc

If the compilation failed, you would see a message like this:

There are options to control the notification parameters, like so:

en --expiration 0 --title Compilation \
   --command_label "the usual gcc command" \
   --icon_success /usr/share/icons/gnome/32x32/status/info.png \
   gcc -o myprogram myprogram.cc

Here’s the help text for the command:

$ en --help
en Execute a command and notify when finished
Usage: en [FLAGS...] COMMAND [ARGS...]
   executes COMMAND ARGS... and sends a notification to the status
   panel upon completion, indicating the result of COMMAND. The
   exit code of COMMAND is the exit of en.

Each flag to en begins with "--"; flags take zero or one
arguments. The first argument to en that is not interpreted as
a flag or value is taken to be the command to execute.

Possible no-argument flags are:
  --help  Show this message
  --debug Print debugging information about en

Possible one-argument flags are:
  --title Prefix to the "Success" or "Failure" title of the
notification

  --command_label Description of the command to be used in the
notification text in place of the command itself. Useful for
succinctly describing a long command, or for use with --exit_code
flag

  --exit_code Simulated exit code from COMMAND to use when generating
the notification, Setting this flag causes COMMAND to not actually
execute, and is useful for testing that the notification is
formatted as desired without actually invoking COMMAND or of the
form

  --PROPERTY_OUTCOME where PROPERTY is one of "icon", "urgency", or
"expiration" and OUTCOME is one of "success" or "failure".
All the properties are used in creating and dispatching the
notification, but the outcome used depends on the exit code of the
command being run.
   icon: the icon to be used in the notification
   expiration: the duration of the notification (ms)
   urgency: the notification urgency, as defined by send-notify

Example:
  en --icon_success /usr/share/icons/gnome/32x32/emblems/emblem-default.png \
    --expiration 600000 --title "Directory listing" ls

Enjoy it and let me know what you think!