From: Michael Prokop <mika@grml.org>
Date: Sun, 7 Jun 2009 22:50:40 +0000 (+0200)
Subject: grml2iso: improve command line handling; some further small cleanups
X-Git-Tag: v0.9.8~13
X-Git-Url: https://git.grml.org/?p=grml2usb.git;a=commitdiff_plain;h=fa60c0972f333c8f819b8f0bd8b081ec7da13410

grml2iso: improve command line handling; some further small cleanups
---

diff --git a/grml2iso b/grml2iso
index f6d96b9..c323e1e 100755
--- a/grml2iso
+++ b/grml2iso
@@ -1,64 +1,90 @@
 #!/bin/bash
+# Filename:      grml2iso
+# Purpose:       create a multiboot grml ISO using grml2usb
+# Authors:       Michael Prokop <mika@grml.org>,
+#                Thorsten Glaser <tg@mirbsd.org>
+# Bug-Reports:   see http://grml.org/bugs/
+# License:       This file is licensed under the GPL v2 or any later version.
 ################################################################################
-# Filename: grml2iso
-# Purpose:  create a multiboot ISO using grml2usb
-# Author:   Michael Prokop <mika@grml.org>,
-#           Thorsten Glaser <tg@mirbsd.org>
-################################################################################
-# TODO:
-# * generalise the script so we can provide it as part of the grml2usb suite
-# * improve error handling
-# * support isolinux as bootloader on the ISO
+# TODO: support isolinux as bootloader on the ISO
 ################################################################################
 
-# define function getfilesize before "set -e"
-if stat --help >/dev/null 2>&1; then
-	getfilesize='stat -c %s'	# GNU stat
-else
-	getfilesize='stat -f %z'	# BSD stat
-fi
+# define function getfilesize before "set -e" {{{
+  if stat --help >/dev/null 2>&1; then
+    getfilesize='stat -c %s'        # GNU stat
+  else
+    getfilesize='stat -f %z'        # BSD stat
+  fi
+# }}}
+
+# adjust variables if necessary through environment {{{
+# path to the grml2usb script you'd like to use
+  [ -n "$GRML2USB" ] || GRML2USB='grml2usb'
+# work directory for creating the filesystem
+  [ -n "$WRKDIR" ]   || WRKDIR='/tmp/grml2iso.tmp'
+# }}}
+
+# helper stuff {{{
+  set -e
+
+  usage() {
+    echo >&2 "Usage: $0 -o target.iso source1.iso [source2.iso ...]"
+    [ -n "$1" ] && exit $1 || exit 1
+  }
+# }}}
+
+# command line handling {{{
+  [[ $# -gt 2 ]] || usage 1
+
+  ISOFILE=''
+  while getopts ao: name; do
+    case $name in
+      o)   ISOFILE="$OPTARG";;
+      ?)   usage 2;;
+    esac
+  done
 
-usage() {
-  echo >&2 "Usage: $0 target.iso source1.iso [source2.iso ...]"
-  exit 1
-}
+# make sure -o is specified
+  [ -n "$ISOFILE" ] || usage 1
 
-set -e
-set -u
+# we don't to override any files by accident
+  if [ -e "$ISOFILE" ]; then
+    echo "Error: target file $ISOFILE exists already." >&2
+    exit 1
+  fi
 
-# ********* PLEASE ADJUST! *******************************************
-# specify path to the grml2usb script you'd like to use
-GRML2USB='grml2usb'
-# work directory for creating the filesystem
-WRKDIR='/dev/shm/grml2iso.tmp'
-# ********* PLEASE ADJUST! *******************************************
+  shift $(($OPTIND - 1))
+# }}}
 
-test $# -lt 2 && usage
-if test -e "$1"; then
-  echo >&2 Error: target file "'$1'" already exists.
-  usage
-fi
-ISOFILE=$1; shift
+# we need root permissions for executing grml2usb {{{
+  if [[ $(id -u) != 0 ]]; then
+    echo >&2 "Error: please run $0 as root."
+    exit 1
+  fi
+# }}}
 
-# variables
+# variables {{{
   ORIG_DIR="$(pwd)"
   # note: grub-pc_1.96+20090603-1_i386.deb seems to be b0rken
   GRUB_DEB="grub-pc_1.96+20080724-16_i386.deb"
 
-# normalise path (in mksh I’d just use the realpath builtin…)
-case $ISOFILE in
-/*) ;;
-*) ISOFILE=$ORIG_DIR/$ISOFILE ;;
-esac
+# normalise path
+  case $ISOFILE in
+    /*) ;;
+    *) ISOFILE=$ORIG_DIR/$ISOFILE ;;
+  esac
+# }}}
 
-# create necessary stuff under WRKDIR
+# create necessary stuff under WRKDIR {{{
   rm -rf "$WRKDIR/cddir" "$WRKDIR/grub_tmp"
   mkdir -p "$WRKDIR/cddir" "$WRKDIR/grub_tmp"
+# }}}}
 
-# execute grml2usb with all ISOs you'd like to install
+# execute grml2usb with all ISOs you'd like to install {{{
   $GRML2USB "$@" "$WRKDIR/cddir"
+# }}}
 
-# install grub2 files
+# install grub2 files {{{
 # as we don't want to rely on a grub2 installation on the
 # running system let's grab it from the net
   cd "$WRKDIR"/grub_tmp/
@@ -75,20 +101,23 @@ esac
   cat usr/lib/grub/i386-pc/cdboot.img "$WRKDIR"/cddir/boot/grub/core.img \
     > "$WRKDIR"/cddir/boot/grub/eltorito.img
   cd "$WRKDIR/cddir"
+# }}}
 
-# finally generate the CD/DVD-iso
+# generate the CD/DVD ISO {{{
   mkisofs -V 'grml-multiboot' -l -r -J -no-pad \
     -no-emul-boot -boot-load-size 4 -boot-info-table \
     -b boot/grub/eltorito.img -c boot/grub/eltorito.cat \
     -o "$ISOFILE" .
+# }}}
 
-# pad the output ISO to multiples of 256 KiB for partition table support
+# pad the output ISO to multiples of 256 KiB for partition table support {{{
   siz=$($getfilesize "$ISOFILE")
-  cyls=$(echo "$siz / 512 / 32 / 16 + 1" | bc)	# C=$cyls H=16 S=32
-  ofs=$(echo "$cyls * 16 * 32 * 512 - 1" | bc)	# padding offset (size - 1)
+  cyls=$(echo "$siz / 512 / 32 / 16 + 1" | bc)  # C=$cyls H=16 S=32
+  ofs=$(echo "$cyls * 16 * 32 * 512 - 1" | bc)  # padding offset (size - 1)
   dd if=/dev/zero bs=1 count=1 seek=$ofs of="$ISOFILE" 2>/dev/null
+# }}}
 
-# create a manifold-boot image with a partition table, if possible
+# create a manifold-boot image with a partition table, if possible {{{
   if mksh -c true 2>/dev/null && \
     test -e /usr/share/grml-live/scripts/bootgrub.mksh; then
       echo "Creating a manifold-boot ISO image"
@@ -99,13 +128,14 @@ esac
   else
       echo "Cannot find mksh or bootgrub.mksh, not generating manifold-boot ISO image"
   fi
+# }}}
 
-# cleanup
+# cleanup {{{
   cd "$ORIG_DIR"
   sync
   rm -rf "$WRKDIR/cddir" "$WRKDIR/grub_tmp"
-
-# we are done :)
   echo "Generated $ISOFILE"
+# }}}
 
 ## EOF #########################################################################
+# vim:foldmethod=marker ts=2 ft=sh ai expandtab tw=80 sw=3