add bash completion

Makefile

@@ -82,23 +82,38 @@ man/man1:
 # The install-man make target are for use by debian packaging.
 # The semantics should match autotools make files as dh_make expects it.
 install-man: man/man1
+	mkdir -p $(DESTDIR)/usr/share/man/man1
 	for file in man/man1/* ; do \
 	 	$(INSTALL_FILE) $$file "$(DESTDIR)/usr/share/man/man1" ; done
 
 uninstall-man: man/man1
 	for file in man/man1/* ; do \
 	 	rm "$(DESTDIR)/usr/share/$$file" ; done
+	-rmdir -p $(DESTDIR)/usr/share/man/man1
+
+install-bash-completion:
+	mkdir -p $(DESTDIR)/usr/share/bash-completion/completions
+	$(INSTALL_FILE) config/bash/charm "$(DESTDIR)/usr/share/bash-completion/completions/"
+
+uninstall-bash-completion:
+	rm "$(DESTDIR)/usr/share/bash-completion/completions/charm"
+	-rmdir -p $(DESTDIR)/usr/share/bash-completion/completions
 
 help:
 	@echo -e 'Charmstore-client - list of make targets:\n'
 	@echo 'make - Build the package.'
 	@echo 'make check - Run tests.'
-	@echo 'make install - Install the package.'
+	@echo 'make install - Install the package to $$GOPATH/bin'
 	@echo 'make clean - Remove object files from package source directories.'
 	@echo 'make deps - Set up the project Go dependencies.'
 	@echo 'make create-deps - Generate the Go dependencies file.'
 	@echo 'make format - Format the source files.'
 	@echo 'make man - Generate man pages.'
 	@echo 'make simplify - Format and simplify the source files.'
+	@echo 'make install-man - Install man pages to $$DESTDIR/usr/share/man'
+	@echo 'make uninstall-man - Remove man pages from $$DESTDIR/usr/share/man'
+	@echo 'make install-bash-completion - Install completion to $$DESTDIR/usr/share/bash-completion/completions/'
+	@echo 'make uninstall-bash-completion - Remove completion from $$DESTDIR/usr/share/bash-completion/completions/'
 
-.PHONY: build check clean create-deps deps format help install simplify
+.PHONY: build check clean create-deps deps format help install simplify \
+	install-man uninstall-man install-bash-completion uninstall-bash-completion

config/bash/charm

@@ -0,0 +1,47 @@
+# bash completion for the charm command.
+#
+# adapted from https://github.com/jjo/juju/blob/11e1a81c012a45d285545ff84db336b3ed9a4b78/etc/bash_completion.d/juju
+#
+# Copyright 2016 Canonical Ltd.
+
+_complete_with_func() {
+    local action="${1}" func=${2?}
+    local flags=$(_flags_for "${action}")
+    local cur="${COMP_WORDS[COMP_CWORD]}"
+    _get_comp_words_by_ref -n : cur
+    COMPREPLY=( $( compgen -W "$(${func} ${juju_status_file} ${postfix_str}) $flags" -- ${cur} ))
+}
+
+_list_commands() {
+    ${COMP_WORDS[0]} help 2>/dev/null | awk '{if (cmd==1){print $1}} /commands:/{cmd=1;}'
+}
+
+_flags_for() {
+    test -z "${1}" && return 0
+    ${COMP_WORDS[0]} help ${1} 2>/dev/null |egrep -o --  '(^|-)-[a-z-]+'|sort -u
+}
+
+_completion_func_for_cmd() {
+    local action=${1} cword=${2}
+    # if cword==1 or action==help use _list_commands
+    if [[ "${cword}" -eq 1 || "${action}" == help ]]; then
+        echo _list_commands
+        return 0
+    fi
+    case $(${COMP_WORDS[0]} help ${action} 2>/dev/null | head -1) in
+        ?*)     echo true;;
+        *)      echo false;;
+    esac
+}
+
+_completer() {
+    local action parsing_func
+    action="${COMP_WORDS[1]}"
+    COMPREPLY=()
+    parsing_func=$(_completion_func_for_cmd "${action}" ${COMP_CWORD})
+    test -n "${parsing_func}" && _complete_with_func "${action}" "${parsing_func}"
+    return $?
+}
+
+complete -F _completer charm
+# vim: ai et sw=2 ts=2