reformat help output

[code/molly-guard.git] / shutdown

diff --git a/shutdown b/shutdown
index 24898273d6fc6ab41691583bbe716e8c84048118..f12fde0fdb8ae5ca059af3d9318901a98bdede3f 100755 (executable)
--- a/shutdown
+++ b/shutdown
@@ -5,11 +5,10 @@
 # Copyright © martin f. krafft <madduck@madduck.net>
 # Released under the terms of the Artistic Licence 2.0
 #
-# $Id: shutdown 299 2006-10-16 14:40:47Z madduck $
-#
 set -eu
 
 ME=molly-guard
+CHECKSDIR=/etc/molly-guard/checks.d
 
 CMD="${0##*/}"
 EXEC="/sbin/$CMD"
@@ -37,15 +36,30 @@ usage()
        Usage: $ME [options]
               (shielding $EXEC)
 
-       Instead of invoking $EXEC directly, $ME will prompt the user for the
-       machine's hostname to guard against accidental shutdowns/reboots, if the
-       current shell is a child of an SSH connection (or --pretend-ssh) has been
-       given on the command line, if the shell is connected to an interactive
-       terminal, and the actual command to execute is does not involve --help or is
-       \`shutdown -c'.
-
-       Only if the user enters the machine's hostname correctly will $ME take
-       action. Specifying --molly-guard-do-nothing as argument to the command will
+       Instead of invoking $EXEC directly, $ME will run a number of checks
+        to guard against accidental shutdowns/reboots.
+
+        Some of the checks available are:
+        - Prompt the user for the machine's if the current shell is a child
+          of an SSH connection (or --pretend-ssh) has been given on the
+          command line, if the shell is connected to an interactive
+         terminal, and the actual command to execute is does not involve
+          --help or is \`shutdown -c'.
+
+         $ME will always interpose the prompt if the environment variable
+          ALWAYS_MOLLY is set to '1'.  This variable may be set in the file
+         /etc/default/${ME} .
+
+        - Print out a warning message with information about this host
+         before the action takes place.  You can use:
+               /etc/molly-guard.<Action>.message
+         To print out a message specific to the command you're trying to
+         use.  Or:
+               /etc/molly-guard.message
+         For a general warning message.
+
+       Only if the user satisfies all the checks will $ME take action.
+       Specifying --molly-guard-do-nothing as argument to the command will
        make $ME echo the command it would execute rather than actually executing
        it.
 
@@ -56,7 +70,7 @@ usage()
 
 ARGS=
 DO_NOTHING=0
-PRETEND_SSH=0
+CHECK_ARGS=
 for arg in "$@"; do
   case "$arg" in
     (*-molly-guard-do-nothing) DO_NOTHING=1;;
@@ -65,7 +79,7 @@ for arg in "$@"; do
       eval $EXEC --help 2>&1
       exit 0
       ;;
-    (*-pretend-ssh) PRETEND_SSH=1;;
+    (*-pretend-ssh) CHECK_ARGS="${CHECK_ARGS:+$CHECK_ARGS }--arg --pretend-ssh";;
     *) ARGS="${ARGS:+$ARGS }$arg";;
   esac
 done
@@ -84,45 +98,18 @@ if [ $DO_NOTHING -eq 1 ]; then
   echo "I: demo mode; $ME will not do anything due to --molly-guard-do-nothing."
 fi
 
-# require an interactive terminal connected to stdin
-test -t 0                    || do_real_cmd
-
-# only run if we are being called over SSH, that is if the current terminal
-# was created by sshd.
-PTS=$(readlink /proc/$$/fd/0)
-if ! pgrep -f "^sshd.+${PTS#/dev/}[[:space:]]*$" >/dev/null; then
-  if [ $PRETEND_SSH -eq 1 ]; then
-    echo "I: this is not an SSH session, but --pretend-ssh was given..."
-  else
-    do_real_cmd
-  fi
-else
-  echo "W: $ME: SSH session detected!"
-fi
-
 # pass through certain commands
 case "$CMD $ARGS" in
   (*shutdown\ *-c*) 
-    echo "I: executing $CMD $ARGS regardless of SSH session."
+    echo "I: executing $CMD $ARGS regardless of check results."
     do_real_cmd
     ;;
 esac
 
-HOSTNAME="$(hostname --short)"
+run-parts --exit-on-error --arg $CMD $CHECK_ARGS /etc/molly-guard/checks.d
 
-sigh()
-{
-  echo "Good thing I asked; I won't $CMD $HOSTNAME ..."
-  exit 2
-}
-
-trap 'echo;sigh' 1 2 3 9 10 12 15
-
-echo -n "Please type in hostname of the machine to $CMD: "
-read HOSTNAME_USER || :
-
-[ "$HOSTNAME_USER" = "$HOSTNAME" ] || sigh
-
-trap - 1 2 3 9 10 12 15
-
-do_real_cmd
+# run-parts won't return to us if there are failures, but I'm paranoid.
+if [ $? == 0 ]; then
+  do_real_cmd
+  exit
+fi