From 865fd3f4cc56e190fe18e69bc1583a0c3ba60176 Mon Sep 17 00:00:00 2001
Message-Id: <865fd3f4cc56e190fe18e69bc1583a0c3ba60176.1714036648.git.mdw@distorted.org.uk>
From: Mark Wooding <mdw@chiark.greenend.org.uk>
Date: Wed, 15 Feb 2012 00:45:09 +0000
Subject: [PATCH 1/1] keyfunc.sh.in: Infrastructure for built-in subcommands.
Organization: Straylight/Edgeware

From: Mark Wooding <mdw@distorted.org.uk>

This is the `defcmd' machinery from elsewhere, in yet another guise.
---
 cryptop.in    |   2 +-
 keyfunc.sh.in | 104 +++++++++++++++++++++++++++++++++++++-------------
 keys.in       |   2 +-
 3 files changed, 79 insertions(+), 29 deletions(-)

diff --git a/cryptop.in b/cryptop.in
index 064b595..75a553b 100755
--- a/cryptop.in
+++ b/cryptop.in
@@ -31,7 +31,7 @@ export ETC KEYS KEYSLIB
 
 . "$KEYSLIB"/keyfunc.sh
 
-usage="usage: $quis COMMAND [ARGUMENTS ...]"
+usage="COMMAND [ARGUMENTS ...]"
 prefix=cryptop
 
 runas @user@ cryptop "$@"
diff --git a/keyfunc.sh.in b/keyfunc.sh.in
index 89deccc..952a095 100644
--- a/keyfunc.sh.in
+++ b/keyfunc.sh.in
@@ -636,7 +636,7 @@ recover () {
 
 defhelp () {
   read umsg
-  usage="usage: $quis${umsg+ }$umsg"
+  usage=$umsg
   help=$(cat)
   case "$KEYS_HELP" in t) help; exit ;; esac
 }
@@ -644,13 +644,17 @@ defhelp () {
 help () { showhelp; }
 showhelp () {
   cat <<EOF
-$usage
+Usage: $quis${usage:+ $usage}
 
 $help
 EOF
 }
 
-usage_err () { echo >&2 "$usage"; exit 1; }
+usage () {
+  : ${cmdargs=$usage}
+  echo "usage: $quis${cmdname:+ $cmdname}${cmdargs:+ $cmdargs}"
+}
+usage_err () { usage >&2; exit 1; }
 
 ###--------------------------------------------------------------------------
 ### Subcommand handling.
@@ -659,6 +663,20 @@ version () {
   echo "$PACKAGE version $VERSION"
 }
 
+unset cmdargs
+unset cmdname
+cmds=""
+defcmd () {
+  cmd=$1; shift; args=$*
+  help=$(cat)
+  eval help_$cmd=\$help
+  cmds="${cmds:+$cmds
+}$cmd $args"
+}
+
+defcmd help "[COMMAND ...]" <<EOF
+Show help about the COMMANDs, or about $quis if none are named.
+EOF
 cmd_help () {
   rc=0
   version
@@ -666,30 +684,50 @@ cmd_help () {
     0)
       cat <<EOF
 
-$usage
+Usage: $quis${usage:+ $usage}
 
 Options:
   -h		Show this help text.
   -v		Show the program version number.
 
-Commands installed:
+Commands provided:
 EOF
-      cd "$KEYSLIB"
-      for i in $prefix.*; do
-	if [ ! -x "$i" ]; then continue; fi
-	sed -n "/<<HELP/{n;s/^/	${i#$prefix.} /;p;q;}" "$i"
-      done
+      while read cmd args; do echo "	$cmd${args:+ $args}"; done <<EOF
+$cmds
+EOF
+      case ${prefix+t} in
+	t)
+	  cd $KEYSLIB
+	  for i in $prefix.*; do
+	    if [ ! -x "$i" ]; then continue; fi
+	    sed -n "/<<HELP/{n;s/^/	${i#$prefix.} /;p;q;}" "$i"
+	  done
+	  ;;
+      esac
       ;;
     *)
-      for i in "$@"; do
+      for cmd in "$@"; do
 	echo
-	if [ ! -x "$KEYSLIB/$prefix.$i" ]; then
-	  echo >&2 "$quis: unrecognized command \`$i'"
-	  rc=1
-	  continue
-	elif ! KEYS_HELP=t "$KEYSLIB/$prefix.$i"; then
-	  rc=1
-	fi
+	foundp=nil
+	while read cmdname cmdargs; do
+	  case $cmdname in "$cmd") foundp=t; break ;; esac
+	done <<EOF
+$cmds
+EOF
+	case $foundp in
+	  t)
+	    eval help=\$help_$cmdname; echo "$help"
+	    ;;
+	  nil)
+	    if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
+	      echo >&2 "$quis: unrecognized command \`$cmd'"
+	      rc=1
+	      continue
+	    elif ! KEYS_HELP=t "$KEYSLIB/$prefix.$cmd"; then
+	      rc=1
+	    fi
+	    ;;
+	esac
       done
       ;;
   esac
@@ -697,16 +735,28 @@ EOF
 }
 
 dispatch () {
-  case $# in 0) echo >&2 "$usage"; exit 1 ;; esac
+  case $# in 0) usage_err ;; esac
   cmd=$1; shift
-  case "$cmd" in help) cmd_help "$@"; exit ;; esac
-  if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
-    echo >&2 "$quis: unrecognized command \`$cmd'"
-    exit 1
-  fi
-
-  unset KEYS_HELP
-  exec "$KEYSLIB/$prefix.$cmd" "$@"
+  foundp=nil
+  while read cmdname cmdargs; do
+    case $cmdname in "$cmd") foundp=t; break ;; esac
+  done <<EOF
+$cmds
+EOF
+  case $foundp in
+    t)
+      OPTIND=1
+      cmd_$cmdname "$@"
+      ;;
+    nil)
+      if [ ! -x "$KEYSLIB/$prefix.$cmd" ]; then
+	echo >&2 "$quis: unrecognized command \`$cmd'"
+	exit 1
+      fi
+      unset KEYS_HELP
+      exec "$KEYSLIB/$prefix.$cmd" "$@"
+      ;;
+  esac
 }
 
 ###----- That's all, folks --------------------------------------------------
diff --git a/keys.in b/keys.in
index 5baa9f5..cee261c 100755
--- a/keys.in
+++ b/keys.in
@@ -31,7 +31,7 @@ export ETC KEYS KEYSLIB
 
 . "$KEYSLIB"/keyfunc.sh
 
-usage="usage: $quis COMMAND [ARGUMENTS ...]"
+usage="COMMAND [ARGUMENTS ...]"
 prefix=keys
 
 runas @user@ keys "$@"
-- 
[mdw]