Friday, May 17, 2013

Shell skeletons

Shell skeletons --- a tool to start using a sequence of commands

When I started to build debian packages from Git, I adopted git-buildpackage.
The steps I used were (at least) 7:

  • git-dch  --release "--debian-tag=michal/%(version)s"
  • git add debian/changelog; 
  • git commit -m release
  • git-buildpackage --git-tag "--git-debian-tag=michal/%(version)s" 
  • debi --debs-dir ../build-area/
  • git-buildpackage -S
  • debrelease -S  --debs-dir=../build-area --dput

I had this recipe in a file/editor, and pasted line by line into shell, possibly adapting the text, and then invoked.
In case of error I could reinvoke the command, with some modification.

Then I learned that with Zsh, I can programmatically use that feature which implements C-q (push-line):  there is a stack which I can pre-populate, and then
ZLE will  prefill the command line by popping the strings from the stack.

So I came up with this function:

zload-file () {
        setopt nomonitor
        coproc tac $file &|
        while read line
                builtin print -z $line
        done <&p
        setopt monitor

Sure, I have to put the lines in reverser order -- the last one to be pushed as first, so that it ends at the bottom.

PS: After a while I learned/realized all the arguments of those commands, and made scripts (release & snapshot) which hide all the details, and expose different set of options-- those which I care about.