usboot.sh v 1.00

#!/bin/bash
v="usboot.sh v 1.00"
# by Barry Jackson
#
# Changelog ####################################################
# v 1.00 06/06/2010
#
################################################################
# This script creates a USB grub boot stick.
# Run it as root:-  ~]# sh usboot.sh
# Simply follow the prompts.
#
# This is free software with absolutely no warranty whatsoever
# and may be freely hacked and modified for any purpose.
# Tested in Mandriva 2010 (i586)
# Enjoy!
#
# To return a stick to normal use, after use as a boot stick, it
# will need re-formatting using gparted. Diskdrake fails to run
# with a boot stick (made this way) plugged in.
#
################################################################

chksu()
{
if [ $UID -ne 0 ] || [ $USER = "root" ] ;then
   echo "Sorry, you must run this as root. (Use su NOT su -)"
   exit 1
fi
}
confirm()
{
params=( "$1" "$2" "$3" "$4" "$5" )
let rval=3
while [ $rval -gt 2 ];do
    echo -ne "${params[0]}"" ""${params[1]}"" "
    ans=
    rval=
    read ans
    if [ -z "$ans" ] || [ ${#ans} -gt 1 ];then
        rval=3
    else
        case "$ans" in
            [${params[2]}]*)
                rval=0
                ;;
            [${params[3]}]*)
                rval=1
                ;;
        [${params[4]}]*)
                rval=2
                ;;
            *)
                rval=3
                ;;
        esac
    fi
done
    return $rval
}

detect()
{
 blkid -g
  let l=0
  a=($(blkid|cut -d: -f1|cut -d/ -f3))
  echo -n "Plug in empty USB stick now. Detecting."
  while [ ${#d[@]} -eq 0 ]; do
    if [ $l -gt 30 ];then
echo
cat << NOPART
###########################################################
No device has been detected and the script has timed out.
If a device was plugged in then it may have no partitions,
or an unsupportd format for example iso9660.
Whatever the reason, usboot.sh cannot detect this device.
NOPART
       echo -en "\nHit ENTER to continue..."
      read s ; unset s
          return 1
    fi
  b=($(blkid|cut -d: -f1|cut -d/ -f3))
  d=($( echo -n "${a[@]} ${b[@]}"|tr ' ' '\n'|sort|uniq -u ))
  if echo $d | grep -q "tmp" ;then
     unset d
     continue
  fi
  sleep 1
  let l=$l+1
  echo -n "."
  done
  blkid -g
  return 0
}

# Let's get started ----
chksu
if chksession -F | grep -q "GNOME";then
/etc/init.d/haldaemon stop  > /dev/null 2>&1
halstopped=true
fi
clear
echo "USB Boot Stick Creator - "$v
echo "Please close any file managers now."
unset d
if confirm "Unplug the device now. Continue?" "[y/n]" "Yy" "Nn";then
  if detect;then
    d=$(echo $d | cut -b -3)
    echo
    echo "Device $d found"
    if confirm "To make a grub boot stick answer (Y)es - This will delete any data on $d" "[Y/N]" "Yy" "Nn";then
      echo "Creating boot stick"
      if confirm "Are you sure you want to lose all data on device $d" "[Y/N]" "Yy" "Nn";then
      cd /boot/grub
      dd if=stage1 of=/dev/$d bs=512 count=1
      dd if=stage2 of=/dev/$d bs=512 seek=1
      echo "Unplug the device now, before using it."
      fi
    fi
  fi
fi
if $halstopped ;then
/etc/init.d/haldaemon start > /dev/null 2>&1
fi
echo "Bye! :-)"
# End of usboot.sh