Bash autocompletion plugin for TACC's module system

lmod_autocompletion.bash

#!/bin/bash

# Bash autocompletion module for TACC's lmod
# http://www.tacc.utexas.edu/tacc-projects/mclay/lmod

# Written by Jean-Philippe Ouellet <jpo@vt.edu> at ARC
# http://www.arc.vt.edu/


# Try to intelligently narrow the completion suggestions
# instead of showing all suggestions all the time.
[ -z "$_LMOD_INTELLIGENT_GUESSING" ] && _LMOD_INTELLIGENT_GUESSING=true

# Enable completion of alias commands
[ -z "$_LMOD_USE_ALIASES" ] && _LMOD_USE_ALIASES=true


_lmod_loadable() {
	module avail "^$1" 2>&1 \
	| grep '^   .*/' \
	| tr ' ' '\n' \
	| grep /
	return 0
}

_lmod_unloadable() {
	module list "^$1" 2>&1 \
	| grep -vF 'Currently Loaded Modules Matching: ' \
	| tr ' ' '\n' \
	| grep /
	return 0
}

_lmod_all() {
	module spider "^$1" 2>&1 \
	| grep -E '^  [^ ]+:' \
	| sed 's/:.*$//; s/^[ ]*//'
}

_lmod_presets() {
	[[ "system" == "$1"* ]] && echo system
	module savelist 2>&1 \
	| grep -E '^  [0-9]+\) ' \
	| tr ' ' '\n' \
	| grep -vE '^[0-9]+\)$|^$' \
	| grep "^$1"
	return 0
}

_lmod() {
	local primary_commands="help load try-load unload swap purge list avail spider whatis"
	local uncommon_commands="save restore savelist show use unuse tablelist"

	local alias_commands
	if $_LMOD_USE_ALIASES; then
		alias_commands="add try-add rm del switch sw av"
		# aliased to: load try-load unload unload swap swap avail
	fi

	# This script ignores the following commands:
	#   reset        deprecated in favor of 'restore system'
	#   getdefault   deprecated in favor of 'restore'
	#   setdefault   deprecated in favor of 'save'
	#   record       isn't very useful and shorthand competes with 'restore'

	this="${COMP_WORDS[COMP_CWORD]}"

	if [ "$COMP_CWORD" -eq 1 ]; then
		COMPREPLY=($(compgen -W "${primary_commands}" "$this"))
		if ! $_LMOD_INTELLIGENT_GUESSING; then
			COMPREPLY+=($(compgen -W "$uncommon_commands $alias_commands" "$this"))
		elif [ -z "$this" -o "${#COMPREPLY[@]}" -gt 1 ]; then
			COMPREPLY+=($(compgen -W "$uncommon_commands" "$this"))
		elif [ "${#COMPREPLY[@]}" -eq 0 ]; then
			COMPREPLY+=($(compgen -W "$uncommon_commands" "$this"))
			if [ "${#COMPREPLY[@]}" -ne 1 ]; then
				COMPREPLY+=($(compgen -W "$alias_commands" "$this"))
			fi
		fi
		return 0
	fi


	# not sure if try-load and try-add should complete to loadable or any

	case "${COMP_WORDS[1]}" in
	"load" | "add")
		# <loadable module> ...
		COMPREPLY=($(_lmod_loadable "$this"))
		;;

	"unload" | "rm" | "del")
		# <unloadable module> ...
		COMPREPLY=($(_lmod_unloadable "$this"))
		;;

	"spider" | "whatis" | "show" | "try-load" | "try-add")
		# <any module> ...
		COMPREPLY=($(_lmod_all "$this"))
		;;

	"swap" | "switch" | "sw")
		# <loaded module> <unloaded module>
		if [ "$COMP_CWORD" -eq 2 ]; then
			COMPREPLY=($(_lmod_unloadable "$this"))
		elif [ "$COMP_CWORD" -eq 3 ]; then
			COMPREPLY=($(_lmod_loadable "$this"))
		fi
		;;

	"restore" | "getdefault")
		# preset
		COMPREPLY=($(_lmod_presets "$this"))
		;;

	"save" | "setdefault")
		# any arg, but still suggest presets in case you want to overwrite one
		COMPREPLY=($(_lmod_presets "$this"))
		;;

	"use")
		# [--append] path
		if [ "$COMP_CWORD" -eq 2 ]; then
			COMPREPLY=($(compgen -W "--append" "$this"))
		fi
		;;

	"unuse")
		# $MODULEPATH component
		COMPREPLY=($(compgen -W "$(echo $MODULEPATH | tr ':' '\n')" "$this"))
		;;
	esac

	# The following commands take no arguments:
	# help purge reset tablelist record

	# The following commands take free-form arguments:
	# list avail av savelist

	return 0
}
complete -o dirnames -F _lmod module