src/vlock.sh

   1 #!%BOURNE_SHELL%
   2 #
   3 # vlock.sh -- start script for vlock, the VT locking program for linux
   4 #
   5 # This program is copyright (C) 2007 Frank Benkstein, and is free
   6 # software which is freely distributable under the terms of the
   7 # GNU General Public License version 2, included as the file COPYING in this
   8 # distribution.  It is NOT public domain software, and any
   9 # redistribution not permitted by the GNU General Public License is
  10 # expressly forbidden without prior written permission from
  11 # the author.
  12
  13 # Ignore some signals.
  14 trap : HUP INT QUIT TSTP
  15
  16 # Exit on error.
  17 set -e
  18
  19 # Magic characters to clear the terminal.
  20 CLEAR_SCREEN="`echo -e '\033[H\033[J'`"
  21
  22 # Enter message that is common to different the messages.
  23 VLOCK_ENTER_PROMPT="Please press [ENTER] to unlock."
  24
  25 # Message that is displayed when console switching is disabled.
  26 VLOCK_ALL_MESSAGE="${CLEAR_SCREEN}\
  27 The entire console display is now completely locked.
  28 You will not be able to switch to another virtual console.
  29
  30 ${VLOCK_ENTER_PROMPT}"
  31
  32 # Message that is displayed when only the current terminal is locked.
  33 VLOCK_CURRENT_MESSAGE="${CLEAR_SCREEN}\
  34 This TTY is now locked.
  35
  36 ${VLOCK_ENTER_PROMPT}"
  37
  38 # Read user settings.
  39 if [ -r "${HOME}/.vlockrc" ] ; then
  40   . "${HOME}/.vlockrc"
  41 fi
  42
  43 # "Compile" time variables.
  44 VLOCK_MAIN="%PREFIX%/sbin/vlock-main"
  45 VLOCK_VERSION="%VLOCK_VERSION%"
  46 # If set to "y" plugin support is enabled in vlock-main.
  47 VLOCK_ENABLE_PLUGINS="%VLOCK_ENABLE_PLUGINS%"
  48
  49 print_help() {
  50   echo >&2 "vlock: locks virtual consoles, saving your current session."
  51   if [ "${VLOCK_ENABLE_PLUGINS}" = "yes" ] ; then
  52     echo >&2 "Usage: vlock [options] [plugins...]"
  53   else
  54     echo >&2 "Usage: vlock [options]"
  55   fi
  56   echo >&2 "       Where [options] are any of:"
  57   echo >&2 "-c or --current: lock only this virtual console, allowing user to"
  58   echo >&2 "       switch to other virtual consoles."
  59   echo >&2 "-a or --all: lock all virtual consoles by preventing other users"
  60   echo >&2 "       from switching virtual consoles."
  61   if [ "${VLOCK_ENABLE_PLUGINS}" = "yes" ] ; then
  62     echo >&2 "-n or --new: allocate a new virtual console before locking,"
  63     echo >&2 "       implies --all."
  64     echo >&2 "-s or --disable-sysrq: disable SysRq while consoles are locked to"
  65     echo >&2 "       prevent killing vlock with SAK, implies --all."
  66     echo >&2 "-t <seconds> or --timeout <seconds>: run screen saver plugins"
  67     echo >&2 "       after the given amount of time."
  68   fi
  69   echo >&2 "-v or --version: Print the version number of vlock and exit."
  70   echo >&2 "-h or --help: Print this help message and exit."
  71 }
  72
  73 # Export variables only if they are set.  Some shells create an empty variable
  74 # on export even if it was previously unset.
  75 export_if_set() {
  76   while [ $# -gt 0 ] ; do
  77     if ( eval [ "\"\${$1+set}\"" = "set" ] ) ; then
  78       eval export $1
  79     fi
  80     shift
  81   done
  82 }
  83
  84 main() {
  85   local options long_options short_options plugins
  86
  87   short_options="acvh"
  88   long_options="all,current,version,help"
  89
  90   if [ "${VLOCK_ENABLE_PLUGINS}" = "yes" ] ; then
  91     short_options="${short_options}nst:"
  92     long_options="${long_options},new,disable-sysrq,timeout:"
  93   fi
  94
  95   # Test for GNU getopt.
  96   ( getopt -T >/dev/null )
  97
  98   if [ $? -eq 4 ] ; then
  99     # GNU getopt.
 100     options=`getopt -o "${short_options}" --long "${long_options}" -n vlock -- "$@"` || getopt_error=1
 101   else
 102     # Other getopt, e.g. BSD.
 103     options=`getopt "${short_options}" "$@"` || getopt_error=1
 104   fi
 105
 106   if [ -n "${getopt_error}" ] ; then
 107     print_help
 108     exit 1
 109   fi
 110
 111   eval set -- "${options}"
 112
 113   while : ; do
 114     case "$1" in
 115       -a|--all)
 116         plugins="${plugins} all"
 117         shift
 118         ;;
 119       -c|--current)
 120         unset plugins
 121         shift
 122         ;;
 123       -n|--new)
 124         plugins="${plugins} new"
 125         shift
 126         ;;
 127       -s|--disable-sysrq)
 128         plugins="${plugins} nosysrq"
 129         shift
 130         ;;
 131       -t|--timeout)
 132         shift
 133         VLOCK_TIMEOUT="$1"
 134         shift
 135         ;;
 136       -h|--help)
 137        print_help
 138        exit
 139        ;;
 140       -v|--version)
 141         if [ "${VLOCK_ENABLE_PLUGINS}" = "yes" ] ; then
 142           echo >&2 "vlock version ${VLOCK_VERSION}"
 143         else
 144           echo >&2 "vlock version ${VLOCK_VERSION} (no plugin support)"
 145         fi
 146         exit
 147         ;;
 148       --)
 149         # End of option list.
 150         shift
 151         break
 152         ;;
 153       *)
 154         echo >&2 "getopt error: $1"
 155         exit 1
 156         ;;
 157     esac
 158   done
 159
 160   # Export variables for vlock-main.
 161   export_if_set VLOCK_TIMEOUT VLOCK_PROMPT_TIMEOUT
 162   export_if_set VLOCK_MESSAGE VLOCK_ALL_MESSAGE VLOCK_CURRENT_MESSAGE
 163
 164   if [ "${VLOCK_ENABLE_PLUGINS}" = "yes" ] ; then
 165     exec "${VLOCK_MAIN}" ${plugins} ${VLOCK_PLUGINS} "$@"
 166   else
 167     exec "${VLOCK_MAIN}" ${plugins}
 168   fi
 169 }
 170
 171 main "$@"