nbdkit/0002-Add-simple-bash-completion-script.patch

From 772cfefad72f4c2ec5a72bc73f75a2921fe6054b Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Sat, 9 Jun 2018 17:01:06 +0100
Subject: [PATCH 2/2] Add simple bash completion script.

So far this can complete plugin names:

  $ nbdkit <TAB>
  curl       example4   libvirt    perl       ruby       vddk
  example1   file       memory     python     split      xz
  example2   guestfs    nbd        python2    streaming
  example3   gzip       null       python3    tar

Plugin parameters:

  $ nbdkit curl <TAB>
  password=   sslverify=  timeout=    url=        user=

Filter names:

  $ nbdkit --filter=<TAB>
  cache      cow        delay      offset     partition

General options (short or long or both):

  $ nbdkit -<TAB>
  --dump-config       --new-style         --single
  --dump-plugin       --newstyle          --stdin
  -e                  --no-fork           -t
  --exit-with-parent  -o                  --threads
  --export            --old-style         --tls
  --export-name       --oldstyle          --tls-certificates
  --exportname        -p                  --tls-verify-peer
  -f                  -P                  -u
  --filter            --pid-file          -U
  --foreground        --pidfile           --unix
  -g                  --port              --user
  --group             -r                  -v
  --help              --read-only         -V
  -i                  --readonly          --verbose
  --ip-addr           --run               --version
  --ipaddr            -s
  -n                  --selinux-label

And --tls options:

  $ nbdkit --tls=<TAB>
  off      on       require

There is still quite a lot more which it doesn't do, such as
completing filter parameters, and smarter completion for options.
---
 Makefile.am      |   1 +
 README           |   4 ++
 TODO             |   2 -
 bash/Makefile.am |  40 ++++++++++++++++++++
 bash/README      |   8 ++++
 bash/nbdkit      | 113 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 configure.ac     |  15 ++++++++
 src/main.c       |  17 +++++++++
 8 files changed, 198 insertions(+), 2 deletions(-)
 create mode 100644 bash/Makefile.am
 create mode 100644 bash/README
 create mode 100644 bash/nbdkit

diff --git a/Makefile.am b/Makefile.am
index 9c5b4c3..9d097f5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -44,6 +44,7 @@ EXTRA_DIST = \
 noinst_SCRIPTS = nbdkit
 
 SUBDIRS = \
+	bash \
 	docs \
 	include \
 	src
diff --git a/README b/README
index e58df8b..a589d77 100644
--- a/README
+++ b/README
@@ -91,6 +91,10 @@ For the OCaml plugin:
  - OCaml >= 4.02.2 which has support for shared libraries, see:
    http://caml.inria.fr/mantis/view.php?id=6693
 
+For bash tab completion:
+
+ - bash-completion >= 1.99
+
 To run the test suite:
 
  - bash
diff --git a/TODO b/TODO
index fe0af0c..07f40cc 100644
--- a/TODO
+++ b/TODO
@@ -10,8 +10,6 @@ General ideas for improvements
 
 * Performance - measure and improve it.
 
-* Bash tab completion.
-
 * Exit on last connection (the default behaviour of qemu-nbd unless
   you use -t).
 
diff --git a/bash/Makefile.am b/bash/Makefile.am
new file mode 100644
index 0000000..2a2799a
--- /dev/null
+++ b/bash/Makefile.am
@@ -0,0 +1,40 @@
+# nbdkit
+# Copyright (C) 2018 Red Hat Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution.
+#
+# * Neither the name of Red Hat nor the names of its contributors may be
+# used to endorse or promote products derived from this software without
+# specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+
+EXTRA_DIST = README
+
+if HAVE_BASH_COMPLETION
+
+bashcompdir = @bashcompdir@
+dist_bashcomp_DATA = nbdkit
+
+endif
diff --git a/bash/README b/bash/README
new file mode 100644
index 0000000..21a4f71
--- /dev/null
+++ b/bash/README
@@ -0,0 +1,8 @@
+This directory contains the scripts for tab-completing commands in
+bash.  Note these new-style demand-loaded scripts require
+bash-completion >= 1.99.
+
+Tip: To test the bash completions without having to install them,
+simply start a new shell and do:
+
+  source ./bash/nbdkit; PATH=$PWD:$PATH
diff --git a/bash/nbdkit b/bash/nbdkit
new file mode 100644
index 0000000..3db531d
--- /dev/null
+++ b/bash/nbdkit
@@ -0,0 +1,113 @@
+# nbdkit bash completion script -*- shell-script -*-
+# Copyright (C) 2010-2018 Red Hat Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+# * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution.
+#
+# * Neither the name of Red Hat nor the names of its contributors may be
+# used to endorse or promote products derived from this software without
+# specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY RED HAT AND CONTRIBUTORS ''AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
+# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL RED HAT OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+
+_nbdkit_list_plugins ()
+{
+    local plugindir
+    plugindir="$(
+        nbdkit --dump-config | grep ^plugindir= | sed 's/^plugindir=//'
+    )"
+    ls -1 "$plugindir" | sed 's/^nbdkit-//' | sed 's/-plugin.*//'
+}
+
+_nbdkit_list_filters ()
+{
+    local filterdir
+    filterdir="$(
+        nbdkit --dump-config | grep ^filterdir= | sed 's/^filterdir=//'
+    )"
+    ls -1 "$filterdir" | sed 's/^nbdkit-//' | sed 's/-filter.*//'
+}
+
+# This handler function is called when the user presses tab.
+_nbdkit ()
+{
+    local cur prev words cword split
+    local shortopts longopts plugin plugins filters args i
+
+    _init_completion -s || return
+
+    # Did we get the plugin name yet?
+    # This is only a heuristic because it can be confused by
+    # long opt parameters with an arguments.  XXX
+    plugin=
+    for (( i=1; i < ${#words[@]}; ++i)) ; do
+        if [[ "${words[i]}" =~ ^[a-zA-Z0-9]+$ ]]; then
+            plugin="${words[i]}"
+            break
+        fi
+    done
+
+    # Previous item on the current line is a completable flag or plugin name?
+    case "$prev" in
+        --filter)
+            filters="$(_nbdkit_list_filters)"
+            COMPREPLY=( $(compgen -W "$filters" "$cur") )
+            return ;;
+        --tls)
+            COMPREPLY=( $(compgen -W "off on require" "$cur") )
+            return ;;
+        # Could complete -u and -g options too.  XXX
+    esac
+
+    # Current item is an option we can expand?
+    case "$cur" in
+        --*)
+            longopts="$(nbdkit --long-options)"
+            COMPREPLY=( $(compgen -W "$longopts" -- "$cur") )
+            return ;;
+        -*)
+            shortopts="$(nbdkit --short-options)"
+            longopts="$(nbdkit --long-options)"
+            COMPREPLY=( $(compgen -W "$shortopts $longopts" -- "$cur") )
+            return ;;
+        *)
+            if [ "$plugin" = "" ]; then
+                # Complete plugin name.
+                plugins="$(_nbdkit_list_plugins)"
+                COMPREPLY=( $(compgen -W "$plugins" "$cur") )
+                return
+            else
+                # Complete plugin args.
+                args="$(
+                    nbdkit $plugin --help 2>/dev/null |
+                        grep -E '^[a-z0-9]+=' | sed 's/=.*/=/'
+                )"
+                COMPREPLY=( $(compgen -W "$args" "$cur") )
+                return
+            fi
+            ;;
+    esac
+}
+
+# Install the handler function.
+complete -o default -F _nbdkit nbdkit
diff --git a/configure.ac b/configure.ac
index 0ef9673..abf7048 100644
--- a/configure.ac
+++ b/configure.ac
@@ -164,6 +164,20 @@ AS_IF([test "$GNUTLS_LIBS" != ""],[
 dnl Check for valgrind.
 AC_CHECK_PROG([VALGRIND],[valgrind],[valgrind],[no])
 
+dnl Bash completion.
+PKG_CHECK_MODULES([BASH_COMPLETION], [bash-completion >= 2.0], [
+    bash_completion=yes
+    AC_MSG_CHECKING([for bash-completions directory])
+    PKG_CHECK_VAR(bashcompdir, [bash-completion], [completionsdir], ,
+        bashcompdir="${sysconfdir}/bash_completion.d")
+    AC_MSG_RESULT([$bashcompdir])
+    AC_SUBST([bashcompdir])
+],[
+    bash_completion=no
+    AC_MSG_WARN([bash-completion not installed])
+])
+AM_CONDITIONAL([HAVE_BASH_COMPLETION],[test "x$bash_completion" = "xyes"])
+
 dnl Check for Perl POD.
 AC_CHECK_PROG([POD2MAN], [pod2man], [pod2man], [no])
 AS_IF([test "x$POD2MAN" != "xno"],[
@@ -526,6 +540,7 @@ AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_FILES([nbdkit],
                 [chmod +x,-w nbdkit])
 AC_CONFIG_FILES([Makefile
+                 bash/Makefile
                  docs/Makefile
                  include/Makefile
                  plugins/Makefile
diff --git a/src/main.c b/src/main.c
index d2e5674..660d036 100644
--- a/src/main.c
+++ b/src/main.c
@@ -126,6 +126,7 @@ static const struct option long_options[] = {
   { "group",      1, NULL, 'g' },
   { "ip-addr",    1, NULL, 'i' },
   { "ipaddr",     1, NULL, 'i' },
+  { "long-options", 0, NULL, 0 },
   { "new-style",  0, NULL, 'n' },
   { "newstyle",   0, NULL, 'n' },
   { "old-style",  0, NULL, 'o' },
@@ -137,6 +138,7 @@ static const struct option long_options[] = {
   { "readonly",   0, NULL, 'r' },
   { "run",        1, NULL, 0 },
   { "selinux-label", 1, NULL, 0 },
+  { "short-options", 0, NULL, 0 },
   { "single",     0, NULL, 's' },
   { "stdin",      0, NULL, 's' },
   { "threads",    1, NULL, 't' },
@@ -263,6 +265,14 @@ main (int argc, char *argv[])
         t->filename = optarg;
         filter_filenames = t;
       }
+      else if (strcmp (long_options[option_index].name, "long-options") == 0) {
+        for (i = 0; long_options[i].name != NULL; ++i) {
+          if (strcmp (long_options[i].name, "long-options") != 0 &&
+              strcmp (long_options[i].name, "short-options") != 0)
+            printf ("--%s\n", long_options[i].name);
+        }
+        exit (EXIT_SUCCESS);
+      }
       else if (strcmp (long_options[option_index].name, "run") == 0) {
         if (socket_activation) {
           fprintf (stderr, "%s: cannot use socket activation with --run flag\n",
@@ -276,6 +286,13 @@ main (int argc, char *argv[])
         selinux_label = optarg;
         break;
       }
+      else if (strcmp (long_options[option_index].name, "short-options") == 0) {
+        for (i = 0; short_options[i]; ++i) {
+          if (short_options[i] != ':')
+            printf ("-%c\n", short_options[i]);
+        }
+        exit (EXIT_SUCCESS);
+      }
       else if (strcmp (long_options[option_index].name, "tls") == 0) {
         tls_set_on_cli = 1;
         if (strcmp (optarg, "off") == 0 || strcmp (optarg, "0") == 0)
-- 
2.16.2