usr_bin/grml-screen

   1 #!/bin/dash
   2 # Filename:      grml-screen
   3 # Purpose:       wrapper for screen to start with appropriate configuration
   4 # Authors:       grml-team (grml.org), (c) Michael Prokop <mika@grml.org>
   5 # Bug-Reports:   see http://grml.org/bugs/
   6 # License:       This file is licensed under the GPL v2.
   7 ################################################################################
   8
   9 # export variable USER for use withing GNU screen:
  10   export USER=`id -un`
  11
  12 # fix tty permissions
  13   TTY=`tty`
  14   sudo chmod 660       $TTY
  15   sudo chown $USER.tty $TTY
  16
  17 # FIXME: fix for screen race-conditions
  18 PID_FILE_="/var/run/grml-screen"
  19 PID_FILE_CREATED_="false"
  20 MY_PID_="$$"
  21 if [ ! -d "/var/run/screen/S-$USER" ]; then
  22     # no /var/run/screen/S-$USER and possible no /var/run/screen either -> locking
  23     for i in `seq 40`; do   # 40*0.25 = 10 seconds
  24         if lockfile-create --retry 0 $PID_FILE_; then
  25             echo $MY_PID_ >$PID_FILE_
  26             PID_FILE_CREATED_="true"
  27             break
  28         fi
  29         sleep 0.25
  30     done
  31 fi
  32 if [ $PID_FILE_CREATED_ = "true" ]; then
  33     if [ -f $PID_FILE_ ]; then
  34         # FORK BEGIN
  35         (
  36         for i in `seq 40`; do   # 40*0.25 = 10 seconds
  37             if [ ! -d "/var/run/screen/S-$USER" ]; then
  38                 sleep 0.25  # educated guess
  39             else
  40                 break
  41             fi
  42         done
  43         if [ `cat $PID_FILE_` = $MY_PID_ ]; then
  44             rm $PID_FILE_
  45             lockfile-remove $PID_FILE_
  46         fi
  47         )&
  48         # FORK END
  49     else
  50         SLEEP_TIME_="$(( $$ % 5 * 5 + 5 ))"
  51         echo "grml-screen: Error could not create lockfile! (sleeping for $SLEEP_TIME_)"
  52         sleep $SLEEP_TIME_
  53     fi
  54 fi
  55
  56 # now run screen with config
  57   cd $HOME     # important for e.g. hardcopy-feature
  58   # do we have a utf8 enabled terminal?
  59   [ -x /usr/bin/vt-is-UTF8 ] && /usr/bin/vt-is-UTF8 -q && UTF='-U'
  60   if [ `id -u` = 0 ] ; then
  61     exec screen $UTF -c /etc/grml/screenrc
  62   elif [ -r "$HOME/.screenrc" ] ; then
  63     exec screen $UTF -c "$HOME/.screenrc"
  64   else
  65     exec screen $UTF -c /etc/grml/screenrc_grml
  66   fi
  67
  68 ## END OF FILE #################################################################