Subversion Repositories livecd

#!/bin/bash
#
################################################################
#
# Enable or disable auto login to the system
#
# Urs Beyerle
#
################################################################

function usage() {

   ## Usage
   # ----------------------------------------------------------

   cat <<EOF

Enable or disables auto login

Usage: 

   livecd-autologin [-h] [-u <user>] [-s <session> ] on | off

   on:   enable autologin to system
   off:  disable autologin to system

   Optional Options:

   -u <user>:     define user for auto login, default is sluser
   -s <session>:  define session startup command, default is icewm-session
   -h:            print this screen

   Note: Works only for users with bash shell.

EOF

}

###############################################################
### definitions
###############################################################

AUTOLOGIN=""
ROOTLOGIN=""
LOCALUSER_EXISTS=""
LOCALUSER="sluser"
STARTSESSION="icewm-session"


###############################################################
### Read options from command-line
###############################################################

if [ $# -eq 0 ]; then
     usage; exit
fi

while [ $# -gt 0 ]; do

    case "$1" in
       -h)
            usage; exit;;
       -u)
            shift; LOCALUSER=$1; shift; continue;;
       -s)
            shift; STARTSESSION=$1; shift; continue;;
       on)
            AUTOLOGIN=on; shift; continue;;
       off)
            AUTOLOGIN=off; shift; continue;;
       *)
            usage; exit;;
    esac

done

###############################################################
### User
###############################################################

### test if $LOCALUSER exists
id $LOCALUSER >/dev/null 2>&1
[ "$?" = "0" ] && LOCALUSER_EXISTS="true"

### home directory of $LOCALUSER
[ $LOCALUSER_EXISTS ] && LOCALUSER_HOME=$(grep "^${LOCALUSER}:" /etc/passwd | cut -d":" -f6)

### warn message
[ ! $LOCALUSER_EXISTS ] && echo "$LOCALUSER does not exisit. Create user first and run script again."


###############################################################
# Enable autologin 
###############################################################
if [ $AUTOLOGIN = on ]; then
    
    echo "Enable auto login for $LOCALUSER ..."

    ### backup /etc/inittab
    echo " - Backup /etc/inittab"
    if [ ! -f /etc/inittab.no_autologin ]; then
        cp -a /etc/inittab /etc/inittab.no_autologin
    fi

    ### change init runlevel to 3
    echo " - Change init runlevel to 3"
    sed -i "s/id\:.\:initdefault/id\:3\:initdefault/" /etc/inittab

    ### autologin at tty6
    echo " - Modify /etc/inittab"
    line="6:2345:respawn:\/sbin\/mingetty --autologin $LOCALUSER tty6"
    sed -i "s/.*respawn.*tty6.*/$line/" /etc/inittab
    
    if [ $LOCALUSER_EXISTS ]; then

        echo " - Create user files ~/.xinitrc, ~/.xsession"
        ### create .xinitrc for LOCALUSER
        XINITRC=$LOCALUSER_HOME/.xinitrc
        echo "[ -x ~/autostart ] && ~/autostart" > $XINITRC
        echo "exec $STARTSESSION" >> $XINITRC
        chmod 755 $XINITRC

        ### link .xsession to .xinitrc
        ln -sf .xinitrc $LOCALUSER_HOME/.xsession

        echo " - Modify user file ~/.bashrc"
        ### run startx  (over .bashrc) at autotlogin of LOCALUSER and root
        grep -q "/dev/tty6" $LOCALUSER_HOME/.bashrc >/dev/null 2>&1
        if [ "$?" = "1" ]; then
            echo 'if [ "$( tty )" = "/dev/tty6" ]; then startx; fi' >> $LOCALUSER_HOME/.bashrc
        fi
    fi

    echo "done."

fi


###############################################################
# Disable autologin 
###############################################################
if [ $AUTOLOGIN = off ]; then
    
    echo "Disable auto login for $LOCALUSER ..."

    ### restore /etc/inittab
    echo " - Restore original /etc/inittab"
    if [ -f /etc/inittab.no_autologin ]; then
        mv /etc/inittab.no_autologin /etc/inittab
    else
        # fall back if no original /etc/inittab found
        sed -i "s|.*respawn.*tty6.*|6:2345:respawn:/sbin/mingetty tty6|" /etc/inittab
    fi

    ### disable auto login for $LOCALUSER and root 

    if [ $LOCALUSER_EXISTS ]; then

        echo " - Delete user files ~/.xinitrc, ~/.xsession"
        # remove .xinitrc
        [ $LOCALUSER_EXISTS ] && rm -f $LOCALUSER_HOME/.xinitrc

        # remove link .xsession
        [ $LOCALUSER_EXISTS ] && rm -f $LOCALUSER_HOME/.xsession

        echo " - Modify user file ~/.bashrc"
        # remove startx line from .bashrc
        [ $LOCALUSER_EXISTS ] && sed -i "/.*\/dev\/tty6.*then startx.*/d" $LOCALUSER_HOME/.bashrc
    fi

    echo "done."

fi

###############################################################
# Final note
###############################################################

echo
echo "Please note, you may have to reboot to make the changes active."
echo