Untitled

!/bin/sh

check_vmlinux()
{

    readelf -h $1 > /dev/null 2>&1 || return 1
    cat $1
    exit 0
}

try_decompress()
{

    for    pos in `tr "$1\n$2" "\n$2=" < "$img" | grep -abo "^$2"`
    do
        pos=${pos%%:*}
        tail -c+$pos "$img" | $3 > $tmp 2> /dev/null
        check_vmlinux $tmp
    done
}

me=${0##*/}
img=$1
if    [ $# -ne 1 -o ! -s "$img" ]
then
    echo "Usage: $me <kernel-image>" >&2
    exit 2
fi

tmp=$(mktemp /tmp/vmlinux-XXX)
trap "rm -f $tmp" 0

try_decompress '\037\213\010' xy    gunzip
try_decompress '\3757zXZ\000' abcde unxz
try_decompress 'BZh'          xy    bunzip2
try_decompress '\135\0\0\0'   xxx   unlzma
try_decompress '\211\114\132' xy    'lzop -d' 
try_decompress '\002!L\030'   xxx   'lz4 -d'
try_decompress '(\265/\375'   xxx   unzstd

check_vmlinux $img

echo "$me: Cannot find vmlinux." >&2