Programmable Completion

Note:

Before proceeding, keep the zshcompctl man page in mind. The syntax for completion can occasionally get a bit tricky.

Completion refers to zsh's ability to finish your command lines for you. It comes in many forms. By default, the < TAB > key is bound to a completion command in zsh.

A quick example:

> ls
array.NOTES  array.c      array.h      launch.c
> wc -l arr< TAB >

Upon hitting the < TAB > key, zsh will take the string arr, and resolve it to a filename that starts with arr.

Since there is more than one file that mathes, you can make zsh present a menu of choices, or you can make zsh cycle through each option by hitting the < TAB > key repeatedly.

And this is just the beginning. Filenames are the default item to complete on. In zsh, ANYTHING can be completed, including:

Filenames
Filesystems paths
builtin commands
external commands
aliases
shell functions
reserved words
global aliases
disabled hash table elements
shell options
shell parameter names
environment variables
named directories
key bindings
running jobs
suspended jobs
user names
anything else you can imagine - you can program it yourself easily.