btrfs-progs/btrfs-completion

# original by Alfredo Esteban <aedelatorre at xxxxxxxxx>
# (http://www.spinics.net/lists/linux-btrfs/msg15899.html)
# edited by Joseph Wang <joequant at gmail.com>
# (http://lists.alioth.debian.org/pipermail/bash-completion-devel/2013-June/004868.html)
# edited by John C F <john.ch.fr at gmail.com> on 2015-02-02

_btrfs_mnts()
{
	local MNTS
	MNTS=''
	while read mnt; do MNTS+="$mnt "
	done < <(mount -t btrfs | awk '{print $3}')
	COMPREPLY+=( $( compgen -W "$MNTS" -- "$cur" ) )
}

_btrfs()
{
	local cur prev words cword
	_init_completion || return

	COMPREPLY=()

	local cmd=${words[1]}

	commands='subvolume filesystem balance device scrub check rescue restore inspect-internal property send receive quota qgroup replace help version'
	commands_subvolume='create delete list snapshot find-new get-default set-default show sync'
	commands_filesystem='defragment sync resize show df du label usage mkswapfile'
	commands_balance='start pause cancel resume status'
	commands_device='scan add delete remove ready stats usage'
	commands_scrub='start cancel resume status'
	commands_rescue='chunk-recover super-recover zero-log create-control-device'
	commands_inspect_internal='inode-resolve logical-resolve subvolid-resolve rootid min-dev-size dump-tree dump-super tree-stats'
	commands_property='get set list'
	commands_quota='enable disable rescan'
	commands_qgroup='assign remove create destroy show limit clear-stale'
	commands_replace='start status cancel'

	if [[ "$cur" == -* && $cword -le 3 && "$cmd" != "help" ]]; then
		COMPREPLY=( $( compgen -W '--help' -- "$cur" ) )
		return 0
	fi

	if [[ $cword -eq 1 ]]; then
		COMPREPLY=( $( compgen -W "$commands" -- "$cur" ) )
		return 0
	elif [[ $cword -eq 2 ]]; then
		case $cmd in
			subvolume)
				opts="$commands_subvolume"
				;;
			filesystem)
				opts="$commands_filesystem"
				;;
			balance)
				opts="$commands_balance"
				;;
			device)
				opts="$commands_device"
				;;
			scrub)
				opts="$commands_scrub"
				;;
			check)
				_filedir
				return 0
				;;
			rescue)
				opts="$commands_rescue"
				;;
			restore)
				_filedir
				return 0
				;;
			inspect-internal)
				opts="$commands_inspect_internal"
				;;
			property)
				opts="$commands_property"
				;;
			send|receive)
				_filedir -d
				return 0
				;;
			quota)
				opts="$commands_quota"
				;;
			qgroup)
				opts="$commands_qgroup"
				;;
			replace)
				opts="$commands_replace"
				;;
			help)
				opts="--full"
				;;
			version)
				return 0
				;;
		esac
		COMPREPLY=( $( compgen -W "$opts" -- "$cur" ) )
		return 0
	elif [[ $cword -eq 3 ]]; then
		case $cmd in
			filesystem)
				case $prev in
					defragment)
						_filedir
						return 0
						;;
					df|usage)
						_btrfs_mnts
						return 0
						;;
					label)
						_btrfs_mnts
						_filedir
						return 0
						;;
				esac
				;;
			device|rescue)
				_filedir
				return 0
				;;
			inspect-internal)
				case $prev in
					min-dev-size)
						_btrfs_mnts
						return 0
						;;
					dump-tree|dump-super|rootid|inode-resolve)
						_filedir
						return 0
						;;
				esac
				;;
			receive)
				case $prev in
					-f)
						_filedir
						return 0
						;;
				esac
				;;
			replace)
				case $prev in
					status|cancel)
						_btrfs_mnts
						return 0
						;;
					start)
						_filedir
						return 0
						;;
				esac
				;;
			subvolume)
				case $prev in
					list)
						_btrfs_mnts
						return 0
						;;
				esac
				;;
		esac
	fi

	_filedir -d
	return 0
}

complete -F _btrfs btrfs