1#!/bin/sh -efu 2 3fatal() { 4 echo "$*" >&2 5 exit 1 6} 7 8pkg="$1" 9[ -n "$pkg" ] && [ -e "$pkg" ] || 10 fatal "No package supplied" 11 12_dd() { 13 local o="$1"; shift 14 dd if="$pkg" skip="$o" iflag=skip_bytes status=none $* 15} 16 17calcsize() { 18 offset=$(($1 + 8)) 19 20 local i b b0 b1 b2 b3 b4 b5 b6 b7 21 22 i=0 23 while [ $i -lt 8 ]; do 24 b="$(_dd $(($offset + $i)) bs=1 count=1)" 25 [ -z "$b" ] && 26 b="0" || 27 b="$(exec printf '%u\n' "'$b")" 28 eval "b$i=\$b" 29 i=$(($i + 1)) 30 done 31 32 rsize=$((8 + ((($b0 << 24) + ($b1 << 16) + ($b2 << 8) + $b3) << 4) + ($b4 << 24) + ($b5 << 16) + ($b6 << 8) + $b7)) 33 offset=$(($offset + $rsize)) 34} 35 36case "$(_dd 0 bs=8 count=1)" in 37 "$(printf '\355\253\356\333')"*) ;; # '\xed\xab\xee\xdb' 38 *) fatal "File doesn't look like rpm: $pkg" ;; 39esac 40 41calcsize 96 42sigsize=$rsize 43 44calcsize $(($offset + (8 - ($sigsize % 8)) % 8)) 45hdrsize=$rsize 46 47case "$(_dd $offset bs=3 count=1)" in 48 "$(printf '\102\132')"*) _dd $offset | bunzip2 ;; # '\x42\x5a' 49 "$(printf '\037\213')"*) _dd $offset | gunzip ;; # '\x1f\x8b' 50 "$(printf '\375\067')"*) _dd $offset | xzcat ;; # '\xfd\x37' 51 "$(printf '\135\000')"*) _dd $offset | unlzma ;; # '\x5d\x00' 52 "$(printf '\050\265')"*) _dd $offset | unzstd ;; # '\x28\xb5' 53 *) fatal "Unrecognized rpm file: $pkg" ;; 54esac 55