tools: Provide bash autompletion file

The only purpose of this file is to be sourced. After that one
can use completion even for their bash:

  # virsh list --<TAB><TAB>
  --all                   --inactive ...

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>

configure.ac

@@ -242,6 +242,7 @@ LIBVIRT_ARG_APPARMOR
 LIBVIRT_ARG_ATTR
 LIBVIRT_ARG_AUDIT
 LIBVIRT_ARG_AVAHI
+LIBVIRT_ARG_BASH_COMPLETION
 LIBVIRT_ARG_BLKID
 LIBVIRT_ARG_CAPNG
 LIBVIRT_ARG_CURL
@@ -278,6 +279,7 @@ LIBVIRT_CHECK_ATOMIC
 LIBVIRT_CHECK_ATTR
 LIBVIRT_CHECK_AUDIT
 LIBVIRT_CHECK_AVAHI
+LIBVIRT_CHECK_BASH_COMPLETION
 LIBVIRT_CHECK_BLKID
 LIBVIRT_CHECK_CAPNG
 LIBVIRT_CHECK_CURL
@@ -976,6 +978,7 @@ LIBVIRT_RESULT_APPARMOR
 LIBVIRT_RESULT_ATTR
 LIBVIRT_RESULT_AUDIT
 LIBVIRT_RESULT_AVAHI
+LIBVIRT_RESULT_BASH_COMPLETION
 LIBVIRT_RESULT_BLKID
 LIBVIRT_RESULT_CAPNG
 LIBVIRT_RESULT_CURL

libvirt.spec.in

@@ -306,6 +306,7 @@ BuildRequires: xen-devel
 BuildRequires: libxml2-devel
 BuildRequires: libxslt
 BuildRequires: readline-devel
+BuildRequires: bash-completion >= 2.0
 BuildRequires: ncurses-devel
 BuildRequires: gettext
 BuildRequires: libtasn1-devel
@@ -2047,6 +2048,8 @@ exit 0
 %{_datadir}/systemtap/tapset/libvirt_qemu_probes*.stp
 %{_datadir}/systemtap/tapset/libvirt_functions.stp
 
+%{_datadir}/bash-completion/completions/vsh
+
 
 %if %{with_systemd}
 %{_unitdir}/libvirt-guests.service

m4/virt-bash-completion.m4

@@ -0,0 +1,74 @@
+dnl Bash completion support
+dnl
+dnl Copyright (C) 2017 Red Hat, Inc.
+dnl
+dnl This library is free software; you can redistribute it and/or
+dnl modify it under the terms of the GNU Lesser General Public
+dnl License as published by the Free Software Foundation; either
+dnl version 2.1 of the License, or (at your option) any later version.
+dnl
+dnl This library is distributed in the hope that it will be useful,
+dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+dnl Lesser General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU Lesser General Public
+dnl License along with this library.  If not, see
+dnl <http://www.gnu.org/licenses/>.
+dnl
+dnl Inspired by libguestfs code.
+dnl
+
+AC_DEFUN([LIBVIRT_ARG_BASH_COMPLETION],[
+  LIBVIRT_ARG_WITH_FEATURE([BASH_COMPLETION], [bash-completion], [check], [2.0])
+  LIBVIRT_ARG_WITH([BASH_COMPLETIONS_DIR],
+                   [directory containing bash completions scripts],
+                   [check])
+])
+
+AC_DEFUN([LIBVIRT_CHECK_BASH_COMPLETION], [
+  AC_REQUIRE([LIBVIRT_CHECK_READLINE])
+
+  if test "x$with_readline" != "xyes" ; then
+    if test "x$with_bash_completion" != "xyes" ; then
+      with_bash_completion=no
+    else
+      AC_MSG_ERROR([readline is required for bash completion support])
+    fi
+  else
+    if test "x$with_bash_completion" = "xcheck" ; then
+      with_bash_completion=yes
+    fi
+  fi
+
+  LIBVIRT_CHECK_PKG([BASH_COMPLETION], [bash-completion], [2.0])
+
+  if test "x$with_bash_completion" = "xyes" ; then
+    if test "x$with_bash_completions_dir" = "xcheck"; then
+      AC_MSG_CHECKING([for bash-completions directory])
+      BASH_COMPLETIONS_DIR="$($PKG_CONFIG --variable=completionsdir bash-completion)"
+      AC_MSG_RESULT([$BASH_COMPLETIONS_DIR])
+
+      dnl Replace bash completions's exec_prefix with our own.
+      dnl Note that ${exec_prefix} is kept verbatim at this point in time,
+      dnl and will only be expanded later, when make is called: this makes
+      dnl it possible to override such prefix at compilation or installation
+      dnl time
+      bash_completions_prefix="$($PKG_CONFIG --variable=prefix bash-completion)"
+      if test "x$bash_completions_prefix" = "x" ; then
+        bash_completions_prefix="/usr"
+      fi
+
+      BASH_COMPLETIONS_DIR='${exec_prefix}'"${BASH_COMPLETIONS_DIR#$bash_completions_prefix}"
+    elif test "x$with_bash_completions_dir" = "xno" || test "x$with_bash_completions_dir" = "xyes"; then
+      AC_MSG_ERROR([bash-completions-dir must be used only with valid path])
+    else
+      BASH_COMPLETIONS_DIR=$with_bash_completions_dir
+    fi
+    AC_SUBST([BASH_COMPLETIONS_DIR])
+  fi
+])
+
+AC_DEFUN([LIBVIRT_RESULT_BASH_COMPLETION],[
+  LIBVIRT_RESULT_LIB([BASH_COMPLETION])
+])

tools/Makefile.am

@@ -73,6 +73,7 @@ EXTRA_DIST = \
 	libvirt-guests.sysconf \
 	virt-login-shell.conf \
 	virsh-edit.c \
+	bash-completion/vsh \
 	$(PODFILES) \
 	$(MANINFILES) \
 	$(NULL)
@@ -326,9 +327,11 @@ POD2MAN = pod2man -c "Virtualization Support" -r "$(PACKAGE)-$(VERSION)"
 		< $< > $@-t && \
 	mv $@-t $@
 
-install-data-local: install-init install-systemd install-nss
+install-data-local: install-init install-systemd install-nss \
+	install-bash-completion
 
-uninstall-local: uninstall-init uninstall-systemd uninstall-nss
+uninstall-local: uninstall-init uninstall-systemd uninstall-nss \
+	uninstall-bash-completion
 
 install-sysconfig:
 	$(MKDIR_P) $(DESTDIR)$(sysconfdir)/sysconfig
@@ -414,6 +417,21 @@ libvirt-guests.service: libvirt-guests.service.in $(top_builddir)/config.status
 	    mv $@-t $@
 
 
+if WITH_BASH_COMPLETION
+install-bash-completion:
+	$(MKDIR_P) "$(DESTDIR)$(BASH_COMPLETIONS_DIR)"
+	$(INSTALL_SCRIPT) $(srcdir)/bash-completion/vsh \
+		"$(DESTDIR)$(BASH_COMPLETIONS_DIR)/vsh"
+
+uninstall-bash-completion:
+	rm -f $(DESTDIR)$(BASH_COMPLETIONS_DIR)/vsh
+	rmdir $(DESTDIR)$(BASH_COMPLETIONS_DIR) ||:
+else ! WITH_BASH_COMPLETION
+install-bash-completion:
+uninstall-bash-completion:
+endif ! WITH_BASH_COMPLETION
+
+
 EXTRA_DIST += \
 	wireshark/util/genxdrstub.pl \
 	wireshark/util/make-dissector-reg

tools/bash-completion/vsh

@@ -0,0 +1,67 @@
+#
+# virsh & virt-admin completion command
+#
+
+_vsh_complete()
+{
+    local words cword c=0 i=0 cur RO URI CMDLINE INPUT A
+
+    # Here, $COMP_WORDS is an array of words on the bash
+    # command line that user wants to complete. However, when
+    # parsing command line, the default set of word breaks is
+    # applied. This doesn't work for us as it mangles libvirt
+    # arguments, e.g. connection URI (with the default set it's
+    # split into multiple items within the array). Fortunately,
+    # there's a fixup function for the array.
+    _get_comp_words_by_ref -n "\"'><=;|&(:" -w words -i cword
+    COMP_WORDS=( "${words[@]}" )
+    COMP_CWORD=${cword}
+    cur=${COMP_WORDS[$COMP_CWORD]}
+
+    # See what URI is user trying to connect to and if they are
+    # connecting RO. Honour that.
+    while [ $c -le $COMP_CWORD ]; do
+        word="${COMP_WORDS[c]}"
+        case "$word" in
+            -r|--readonly) RO=1 ;;
+            -c|--connect) c=$((++c)); URI=${COMP_WORDS[c]} ;;
+            *) if [ $c -ne 0 ] && [ $i -eq 0 ]; then i=$c; break; fi ;;
+        esac
+        c=$((++c))
+    done
+
+    CMDLINE=
+    if [ -n "${RO}" ]; then
+        CMDLINE="${CMDLINE} -r"
+    fi
+    if [ -n "${URI}" ]; then
+        CMDLINE="${CMDLINE} -c ${URI}"
+    fi
+
+    INPUT=( "${COMP_WORDS[@]:$i:$COMP_CWORD}" )
+
+    # Uncomment these lines for easy debug.
+#    echo;
+#    echo "RO=${flag_ro}";
+#    echo "URI=${URI}";
+#    echo "CMDLINE=${CMDLINE}";
+#    echo "INPUT[${#INPUT[@]}]=**${INPUT[@]}**";
+#    echo "cur=${cur}";
+#    echo;
+#    return 0;
+
+    # Small shortcut here. According to manpage:
+    # When the function is executed, the first argument ($1) is
+    # the name of the command whose arguments are being
+    # completed.
+    # Therefore, we might just run $1.
+    A=($($1 ${CMDLINE} complete -- "${INPUT[@]}" 2>/dev/null))
+
+    COMPREPLY=($(compgen -W "${A[*]%--}" -- ${cur}))
+    __ltrim_colon_completions "$cur"
+    return 0
+} &&
+complete -o default -o filenames -F _vsh_complete virsh &&
+complete -o default -o filenames -F _vsh_complete virt-admin
+
+# vim: ft=sh:et:ts=4:sw=4:tw=80