David Remahl wrote:
I have spent some time trying to get to know the completion system. My
aim is to create completion functions for some of the useful and
surprisingly well-documented command line tools specific to Mac OS X
(hdiutil, diskutil, defaults, SystemStarter, ditto to mention a few).
The thing is, some of them use rather peculiar and complex command
syntaxes, so creating useful completions is quite a challenge.
There's a few other commands that follow a similar scheme. _sccs might
be a better example than _ifconfig. Also worth looking at are _xauth
and _cdcd which are simpler and _cvs which is more complicated.
I will begin by describing the command line syntax of hdiutil, using
snippets from the man page.
hdiutil verb [options]
Can any options appear between hdiutil and the verb? If so, begin with
an _arguments for those options finishing with a '*:: :->verbs' rule to
complete the sub commands in a state.
Verb is one of the following:
attach, detach, verify, create, convert, burn, help, info, load,
checksum, eject (synonym for detach), flatten, unflatten, imageinfo,
mount (synonym for attach), mountvol, unmount, plugins,
internet-enable, resize, segment, partition, makehybrid, pmap
Just completing those should be straight-forward. If you can use
_describe to give descriptions for them, that is better. For the
synonyms, give them the same description, e.g:
in zsh 4.1, they will then be grouped together.
What does the help verb output? You might be able to parse this to get
descriptions. If you get a recent _cvs from CVS, it does this.
Then follow the pattern of one of the examples:
This puts the verb into $service and into the zstyle context (so you
will have, e.g. hdiutil-attach in the command part of the zstyle
context). Then, just have a case statement for each possible verb:
case $service in
The set of allowed options depends on the sub command (verb). All
accept the following optional options (duh), all mutually exclusive:
Stick the _arguments specifcations for them in an array at the
beginning and include the array in all later calls to _arguments. e.g:
then later, _arguments "$args[@]" \
The lists in parenthesis at the start of the specifications specifies
that they are mutually exclusive.
Many verbs accept these options:
-encryption [crypto method]
-shadow [shadow file]
Again, put the specifications for those options in an array and use the
array with those sub-commands that need them.
Many verbs take additional options that are specific to that verb. For
example, convert takes the following additional arguments / options:
Specify these options in each branch of the case statement.
info|internet-enable|resize|segment|partition|pmap) take exactly one
filename argument - of a .dmg file. That corresponds to imagefile in
teh above convert example.
So they need an _arguments specification that looks like:
'1:file:_files -g "*.dmg"'
Hope that helps