kdb-bash-completion

#!/usr/bin/env bash

###########################################################################
##
## This script sets up basic bash completion for the kdb command
##
##
## Put it under /etc/bash_completion.d or load it just for the current
## session with . <scriptname>
##
###########################################################################

_kdb() {
	COMPREPLY=()

	# assign the currently active word
	local cur="${COMP_WORDS[COMP_CWORD]}"
	local prev="${COMP_WORDS[COMP_CWORD - 1]}"

	# initialize
	local kdbpath=$(which kdb)

	# only kdb was entered yet, print a list of available commands
	if [[ $COMP_CWORD -eq 1 ]]; then
		local IFS=$'\n'
		local commands=($(${kdbpath} list-commands))
		COMPREPLY=($(compgen -W '${commands[@]}' -- "${cur}"))
		return
	fi

	# commands which expects a path as next parameter
	local pathcommands="export file get getmeta cp ls lsmeta mv rm set setmeta sget"
	if [[ $pathcommands =~ $prev ]]; then
		local IFS=$'\n'
		local paths=($( (${kdbpath} ls system && ${kdbpath} ls user) 2> /dev/null))
		COMPREPLY=($(compgen -W '${paths[@]}' -- "${cur}"))

		# Now escape special characters (spaces, single and double quotes),
		# so that the argument is really regarded a single argument by bash.
		# See http://stackoverflow.com/questions/1146098/properly-handling-spaces-and-quotes-in-bash-completion
		local i=0
		for entry in ${COMPREPLY[*]}; do
			if [[ ${cur:0:1} == "'" ]]; then
				# started with single quote, escaping only other single quotes
				# [']bla'bla"bla\bla bla --> [']bla'\''bla"bla\bla bla
				local escaped_single_quote="'\''"
				COMPREPLY[$i]="${entry//\'/${escaped_single_quote}}"
			elif [[ ${cur:0:1} == '"' ]]; then
				# started with double quote, escaping all double quotes and all backslashes
				# ["]bla'bla"bla\bla bla --> ["]bla'bla\"bla\\bla bla
				entry="${entry//\\/\\\\}"
				COMPREPLY[$i]="${entry//\"/\\\"}"
			else
				# no quotes in front, escaping _everything_
				# [ ]bla'bla"bla\bla bla --> [ ]bla\'bla\"bla\\bla\ bla
				entry="${entry//\\/\\\\}"
				entry="${entry//\'/\'}"
				entry="${entry//\"/\\\"}"
				COMPREPLY[$i]="${entry// /\\ }"
			fi
			((i++))
		done

		return
	fi
}

# complete the command with _kdb and fall back to filename completion
complete -o default -F _kdb kdb