Neither one nor Many

December 25 2013

In shell scripting I prefer the Kornshell. A while ago I experimented with "oh my zsh", but I switched back to ksh. Their auto completion for program commands is really unsurpassed (tab completion on program parameters for grep for example). The auto-incorrect however, is quite annoying img1. There is also a git plugin that visualized the active git branch in the $PS1 prompt. I liked these features and I want to add them to ksh.

Apparently I like old things

I fixed a few things for ksh in my .kshrc at bitbucket.

Separated history amongst the different ksh shells.

My problem with the default behaviour: by default history is globally shared amongst all shells. I tend to work in a screen and do different stuff in each buffer. So it's annoying if stuff from one buffer magically appears in the other buffer.

So what I do is I make sure there is one history file ~/.ksh_history which contains all history from all shells. When starting a new shell I copy this file into a history file specific for that ("sub")shell, i.e. ~/.ksh_history_files/<shellpid>. Each new shell does this.

When a shell is started all history files from ~/.ksh_history_files/* are merged back into ~/.ksh_history. And the ones that are no longer in use (shells have exited) are removed. This is done with a simple lsof call.

Commands are processed through a simply ksh function that makes sure all history lines are unique, without changing the order.

Some funny caveats were:

  • A history file should start with the character sequence \x81\01.
  • Each command in history file should end with a \x00 character.

A prompt that embeds current git branch

If you are inside a git clone).
Maybe the oh-my-zsh git integration is more advanced, no idea. Luckily this visualization in $PS1 is very fast.

trigen@Firefly21:/projects> cd smashbattle
trigen@Firefly21:/projects/smashbattle[network_multiplayer]> git branch
* network_multiplayer

Fix "cd" (with no params) to be the equivalent of "cd ~" again

Fixed with a simple alias around cd provided by /usr/share/ksh/functions/dirs. For dirs usage check here.

trigen@Firefly21:/usr/local/src/wxWidgets-3.0.0> cd <<<< this didn't work on Ubuntu 13.10 anyways.

Integrated my "launcher tool" I wrote for windows a long time ago.

The browser is assumed to be "chromium-browser" (sudo apt-get install chromium-browser).

The result for gi dan flavin is opened in a new chromium tab.

  • i <url> - open url in browser
  • g <search terms> - search with
  • gi <search terms> - search with google images
  • gv <search terms> - search with google videos
  • gnl <search terms> - search with
  • gs <search term> - search google scholar
  • w <search term> - search wikipedia
  • wa <search terms> - search wolfram alpha
  • yv <search terms> - search youtube
  • y <search terms> - search yahoo
  • yi <search terms> - search yahoo images
  • yv <search terms> - search yahoo videos
  • imdb <search terms> - search imdb
  • h <search term> - search hyperdictionary
  • v <search term> - search vandale (dutch dictionary)

Usage example: Open run menu (ALT+F2). Then type gi dan flavin to get the example result from screenshot.

I had to abandon my pure-ksh-functions approach to make the launcher commands available everywhere. So you have call install_launcher as root to install the shortcuts as scripts in /usr/local/bin/. Ubuntu does not respect shell functions in run unfortunately.

Linux/Unix Comments (0)

Leave a Reply

Comment may not be visible immediately, because I process everything manually.**

**) I plan to automate this.., but it's on my ToDo since for ever..

Ray Burgemeestre
february 23th, 1984

C++, Linux, Webdev

Other interests:
Music, Art, Zen