blob: 7cd771bbe772d90e4354378e522d98bfad3829bc [file] [log] [blame]
lh9ed821d2023-04-07 01:36:19 -07001#!/bin/sh -efu
2# This file comes from rpm 4.x distribution
3
4fatal() {
5 echo "$*" >&2
6 exit 1
7}
8
9pkg="$1"
10[ -n "$pkg" -a -e "$pkg" ] ||
11 fatal "No package supplied"
12
13_dd() {
14 local o="$1"; shift
15 dd if="$pkg" skip="$o" iflag=skip_bytes status=none $*
16}
17
18calcsize() {
19 offset=$(($1 + 8))
20
21 local i b b0 b1 b2 b3 b4 b5 b6 b7
22
23 i=0
24 while [ $i -lt 8 ]; do
25 b=$(_dd $(($offset + $i)) bs=1 count=1; echo X)
26 b=${b%X}
27 [ -z "$b" ] &&
28 b="0" ||
29 b="$(exec printf '%u\n' "'$b")"
30 eval "b$i=\$b"
31 i=$(($i + 1))
32 done
33
34 rsize=$((8 + ((($b0 << 24) + ($b1 << 16) + ($b2 << 8) + $b3) << 4) + ($b4 << 24) + ($b5 << 16) + ($b6 << 8) + $b7))
35 offset=$(($offset + $rsize))
36}
37
38case "$(_dd 0 bs=8 count=1)" in
39 "$(printf '\355\253\356\333')"*) ;; # '\xed\xab\xee\xdb'
40 *) fatal "File doesn't look like rpm: $pkg" ;;
41esac
42
43calcsize 96
44sigsize=$rsize
45
46calcsize $(($offset + (8 - ($sigsize % 8)) % 8))
47hdrsize=$rsize
48
49case "$(_dd $offset bs=3 count=1)" in
50 "$(printf '\102\132')"*) _dd $offset | bunzip2 ;; # '\x42\x5a'
51 "$(printf '\037\213')"*) _dd $offset | gunzip ;; # '\x1f\x8b'
52 "$(printf '\375\067')"*) _dd $offset | xzcat ;; # '\xfd\x37'
53 "$(printf '\135\000')"*) _dd $offset | unlzma ;; # '\x5d\x00'
54 *) fatal "Unrecognized rpm file: $pkg" ;;
55esac