#!/bin/bash
#
# mount-img-partitions
#
# Skeleton of a shell script
# Does usage + help display, argument parsing and error reporting.
#
# Copyright (C) by Volker Kuhlmann
#               http://volker.top.geek.nz/contact.html
# All rights reserved.
# Released under the terms of the GNU General Public License (GPL) Version 2.
# See http://www.gnu.org/ for details.
#
# Not released - This is an un-released work.
# If you have a copy, it is an illegal one. Please delete all your copies
# and inform the author above.
#
# Volker Kuhlmann
#   1.0, 23 Apr 2015  Created.
#   1.1, 25 Apr 2015  Error if no partitions are found to mount.
#   1.2, 03 May 2015  Ensure C locale is used for fdisk output to parse.
#                     Thanks to Wojciech ...@ire.pw.edu.pl for finding it.
#
chr0(){ echo @;};chr1(){ echo .;}

VERSION="1.2, 03 May 2015"
AUTHOR="Volker Kuhlmann <VolkerKuhlmann`chr0`gmx`chr1`de>"
COPYRIGHT="Copyright (C) 2015"


####
#### Check bash is version 2 and load functions
####

unset VERSION_FUNCLIB_NUM
checkbash2=1 requireversion=63 source functions_vk.bash || exit $?
CMD_LOG_PREFIX="+ "
#CALL_WITH_HELP_TEXT=""
CMD_LOG_TRACE=1


####
#### Constants and initialised variables
####


####
#### Variables
####


####
#### Version, Usage, Help
####

#
# Call only these from application: Version, Usage, Help
#

show_usage() {
    echo "
Usage: ${0##*/} [OPTIONS] IMAGE [MOUNT-OPTIONS]
Version $VERSION
$COPYRIGHT by $AUTHOR
(Using functions_vk.bash $VERSION_FUNCLIB)
"
    test -n "$1" && echo "$1
"
}

show_help() {
    show_usage
    echo "\
Mount all partitions in disk image IMAGE, with MOUNT-OPTIONS.

OPTIONS:
  -h|--help   Show help.
  --version   Show version.
  -t|--test   Only show what would be done.
  -l|--list   List partitions in IMAGE, don't mount.
                Columns are: partition, start sector, end sector, size.
  -m PREFIX   Create mount points PREFIX-XX and mount partitions.
"
}


####
#### Error/Exit codes
####

exitwith() {
    exec 1>&2  # write stdout on stderr instead
    exitwith_funclib "$@"
  case "$1" in
 # more codes in here  --->
    errNoPartitions)
    	echo "No partitions found in '$2'"
	exit 2;;
 # <--- more codes in here
    *)
    	exitwith_illegal "$@";;
  esac
}


####
#### Parse command line parameters
####

parse_cmd_line() {
    local cmdline arg
    unset -v debug mountprefix listparts
    cmdline=("$@")
    test "$1" = "--debug" && debug=1  # Pre-check for debug.
    #set -- -opt1 "$@"  # pre-init options
    while [ -n "$1" ]; do
	test $debug && echo "Current arg: $1"
	case "$1" in
	    --) shift; break;;	    # Stop if word is "--".
#	    -[^-]?*) arg="$1";;     # "-long" or "--long" for long options.
#    	    -[^-][A-Za-ce-z]*)	    # "-long" or "--long", except for some
#		arg="$1";;  	    # shortcuts.
	    -*) arg="${1#-}";;	    # Strip one hyphen.
	    *) break;;	    	    # Stop if word does not start with "-".
	esac
	test $debug && echo "    cmd arg: $arg"
	case "$arg" in
	    -debug)	    debug=1;;
	    -version)	    Version;;
	    -usage) 	    Usage;;
	    h|help|-help)   Help;;
	    t|-test)	    dryrun=1 _drycreate=1;;
	    
	    l|-list)
		    listparts=1;;
	    m)
		    checkarg2 "$@"; mountprefix="$2"; shift;;

	    "")     break;;  # allow "-" as file arg
	    *)	    exitwith ErrBadoption "$1";;
	    #*)	    break;;  # stop option scanning with first unknown option
	esac
	shift
    done
    # save option and file arguments for later:
    FILEARGS=("$@")
    OPTARGS=("${cmdline[@]:0:${#cmdline[@]} - ${#FILEARGS[@]}}")
}


####
#### Functions
####

list_partitions() {
    local devfile="$1"
    
    checkforexist "$devfile"
    checkforexistreadable "$devfile"
    
    #cfdisk -Pt "$devfile" 2>/dev/null | {
    #	while read -r part v1 v2 v3 v4 v5 v6 v7 v8 startsec size rest; do
    #	    case "$part" in
    #	    	[0-9]|[0-9][0-9])
    #		    test "$size" -gt 0 && \
    #		    	echo -e "$part\t$startsec\t$size"
    #
    # cfdisk -Pt gives wrong/unhelpful numbers for logical partitions.

    LANG=C LC_ALL=C fdisk -l "$devfile" | {
    	while read -r line; do
	    line="${line#$devfile}"
	    line="${line/\*/}"
	    #echo "Line: '$line'"
	    echo "$line" | (
	    	read -r part startsec endsec rest
		case "$part" in
	    	    [0-9]|[0-9][0-9])
			size=$(($endsec - $startsec + 1))
			test "$size" -gt 0 && \
		    	    echo -e "$part\t$startsec\t$endsec\t$size"
			: ;;
		esac
	    )
	done
    }
}

mount_partitions() {
    local devfile="$1"
    shift
    
    local partitions
    partitions="`list_partitions "$devfile"`" || exit
    #echo "Partitions: '$partitions'"
    test -n "$partitions" || exitwith errNoPartitions "$devfile"
    echo "$partitions" | {
    	local dry=""
	ifset dryrun && dry=":"
	while read -r part start end size rest; do
	    mp="$mountprefix-$part"
	    ( set -x
    	    $dry mkdir -p "$mp"
	    $dry mount -ooffset=$((512 * $start)) "$devfile" "$mp" "$@"
	    )
	done
    }
}


####
#### Main
####

test $# -eq 0 && Usage 1

parse_cmd_line "$@"

if [ -n "$listparts" ]; then
    list_partitions "${FILEARGS[@]}"
else
    test -n "$mountprefix" || Help 1
    mount_partitions "${FILEARGS[@]}"
fi