[NEW PATCH] os-prober output parser

[Fabian Greffrath]

I have improved the script a little bit; in particular I moved the 
tests for the required software to the beginning of the script and let 
it gracefully 'exit 0' if anything is missing.

Let me comment on these tests:
- The first test (lines 19-22) is to check if grub-probe is recent 
enough to support the '--device' option. I have changed this to grep 
for it in the '--help' output instead of test-probing a given device, 
since you never know if a device.map allready exists (imaging booting 
from knoppix).
- I have changed the second test (24-27) to not utilize the 'which' 
utility anymore. It's in the debianutils package and I don't know if 
there's a chance that this is installed on non-Debian systems. On the 
other hand, we are utilizing os-prober which is Debian-only at the 
moment...
- The third test (30-33) is redundant, strictly speaking. The script 
will never enter the for/do loop if the os-prober output is empty. 
However, I found it reasonably to 'exit 0' before even attempting to 
enter the loop, YMMV. If it doesn't suit you, it can be removed safely.

Furthermore I have removed the 'hurd' stub. For the time beeing, HURD 
kernels remain unsupported and throw a warning message just like 
macos* and all other !linux and !chain operating systems.

Best Regards,
Fabian

--
Dipl.-Phys. Fabian Greffrath

Ruhr-Universität Bochum
Lehrstuhl für Energieanlagen und Energieprozesstechnik (LEAT)
Universitätsstr. 150, IB 3/134
D-44780 Bochum

Telefon: +49 (0)234 / 32-26334
Fax:     +49 (0)234 / 32-14227
E-Mail:  address@hidden

#! /bin/sh -e

# update-grub helper script.
# Copyright (C) 2006,2007,2008  Free Software Foundation, Inc.
#
# GRUB is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# GRUB is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with GRUB.  If not, see <http://www.gnu.org/licenses/>.

if [ -z "`grub-probe --help 2> /dev/null | grep '\-d,\ \-\-device'`" ] ; then
  # grub-probe does not support '--device' option yet (introduced in 
1.96+20080228)
  exit 0
fi

if [ -x /usr/bin/os-prober -a -x /usr/bin/linux-boot-prober ] ; then : ; else
  # os-prober/linux-boot-prober not installed
  exit 0
fi

OSPROBED="`os-prober 2> /dev/null | tr ' ' '^' | paste -s -d ' '`"
if [ -z "${OSPROBED}" ] ; then
  # empty os-prober output, nothing doing
  exit 0
fi

for OS in ${OSPROBED} ; do
  DEVICE="`echo ${OS} | cut -d ':' -f 1`"
  LONGNAME="`echo ${OS} | cut -d ':' -f 2 | tr '^' ' '`"
  LABEL="`echo ${OS} | cut -d ':' -f 3 | tr '^' ' '`"
  BOOT="`echo ${OS} | cut -d ':' -f 4`"

  if [ -z "${LONGNAME}" ] ; then
    LONGNAME="${LABEL}"
  fi

  echo "Found ${LONGNAME} on ${DEVICE}" >&2

  case ${BOOT} in
    chain)
      CHAINROOT="`grub-probe --target=drive --device ${DEVICE} 2> /dev/null`"

      cat << EOF
menuentry "${LONGNAME} (on ${DEVICE})" {
        set root=${CHAINROOT}
        chainloader +1
}
EOF
    ;;
    linux)
      LINUXPROBED="`linux-boot-prober ${DEVICE} 2> /dev/null | tr ' ' '^' | 
paste -s -d ' '`"
 
      for LINUX in ${LINUXPROBED} ; do
        LROOT="`echo ${LINUX} | cut -d ':' -f 1`"
        LBOOT="`echo ${LINUX} | cut -d ':' -f 2`"
        LLABEL="`echo ${LINUX} | cut -d ':' -f 3 | tr '^' ' '`"
        LKERNEL="`echo ${LINUX} | cut -d ':' -f 4`"
        LINITRD="`echo ${LINUX} | cut -d ':' -f 5`"
        LPARAMS="`echo ${LINUX} | cut -d ':' -f 6- | tr '^' ' '`"

        LINUXROOT="`grub-probe --target=drive --device ${LBOOT} 2> /dev/null`"

        if [ -z "${LLABEL}" ] ; then
          LLABEL="${LONGNAME}"
        fi

        cat << EOF
menuentry "${LLABEL} (on ${DEVICE})" {
        set root=${LINUXROOT}
        linux ${LKERNEL} ${LPARAMS}
EOF
        if [ -n "${LINITRD}" ] ; then
          cat << EOF
        initrd ${LINITRD}
EOF
        fi
        cat << EOF
}
EOF
      done
    ;;
    hurd|*)
      echo "  ${LONGNAME} is not yet supported by update-grub." >&2
    ;;
  esac
done