Bash auto-completion with aliases. Aliases are nice to shorten often used commands. But ever got frustrated when bash's tab completion did not work? Instead of "git checkout" I just type "go". But I also want to type "go m<tab>" to get completed to "go master" automatically. This script creates a wrapper function to be used with the alias. (Also…

alias-completion

/usr/local/bin/make-completion-wrapper:
#!/bin/sh
# Author.: Ole J
# Date...: 23.03.2008
# License: Whatever

# Wraps a completion function
# make-completion-wrapper <actual completion function> <name of new func.> <alias>
#                         <command name> <list supplied arguments>
# eg.
# 	alias agi='apt-get install'
# 	make-completion-wrapper _apt_get _apt_get_install apt-get install
# defines a function called _apt_get_install (that's $2) that will complete
# the 'agi' alias. (complete -F _apt_get_install agi)
#
#make-completion-wrapper _git_checkout _git_checkout_shortcut go git checkout
function make-completion-wrapper () {
	local comp_function_name="$1"
	local function_name="$2"
	local alias_name="$3"
	local arg_count=$(($#-4))
	shift 3
	local args="$*"
	local function="
function $function_name {
	COMP_LINE=\"$@\${COMP_LINE#$alias_name}\"
	let COMP_POINT+=$((${#args}-${#alias_name}))
	((COMP_CWORD+=$arg_count))
	COMP_WORDS=("$@" \"\${COMP_WORDS[@]:1}\")

	local cur words cword prev
	_get_comp_words_by_ref -n =: cur words cword prev
	"$comp_function_name"
	return 0
}"
	eval "$function"
#	echo $function_name
#	echo "$function"
}
    __git_shortcut () {
	# Because cherry-pick has the function _git_cherry_pick
	n2=${2//-/_}
        type _git_${n2}_shortcut &>/dev/null || make-completion-wrapper _git_$n2 _git_${n2}_shortcut $1 git $2
        complete -o bashdefault -o default -o nospace -F _git_${n2}_shortcut $1
    }

    __apt_cache_shortcut () {
        type _apt_cache_$2_shortcut &>/dev/null || make-completion-wrapper _apt_cache _apt_cache_$2_shortcut $1 apt-cache $2
        # is not executed automatically. Normally only on first apt-cache <tab>
        [ ! -f /usr/share/bash-completion/completions/apt-cache ] || source /usr/share/bash-completion/completions/apt-cache
        complete -F _apt_cache_$2_shortcut $1
    }

$HOME/.bash_aliases:
alias qhe="VISUAL=nano quilt header -e"
alias gs='git status '
alias ga='git add '
alias gb='git branch '
alias gc='git commit'
alias gd='git diff'
alias gds='git diff --staged'
alias go="git checkout"
alias gcp='git cherry-pick'
alias apt-policy="apt-cache policy"
alias apt-show="apt-cache show"

$HOME/.bashrc:
if [ -f /usr/local/bin/make-completion-wrapper ]; then
        . /usr/local/bin/make-completion-wrapper

        # qhe
        make-completion-wrapper _quilt_completion _qhe qhe quilt header -e
        complete -o filenames -F _qhe qhe
        # apt-policy
        __apt_cache_shortcut apt-policy policy
        # apt-show
        __apt_cache_shortcut apt-show show

        # __git_shortcut  gs   status # no completion for git status
        __git_shortcut  ga   add
        __git_shortcut  gb   branch
        __git_shortcut  gc   commit
        __git_shortcut  gd   diff
        __git_shortcut  go   checkout
        __git_shortcut  gcp  cherry-pick
fi