scripts/rpm2cpio.sh

   1 #!/bin/sh -efu
   2 # This file comes from rpm 4.x distribution
   3
   4 fatal() {
   5         echo "$*" >&2
   6         exit 1
   7 }
   8
   9 pkg="$1"
  10 [ -n "$pkg" ] && [ -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 $*
  16 }
  17
  18 calcsize() {
  19
  20         case "$(_dd $1 bs=4 count=1 | tr -d '\0')" in
  21                 "$(printf '\216\255\350')"*) ;; # '\x8e\xad\xe8'
  22                 *) fatal "File doesn't look like rpm: $pkg" ;;
  23         esac
  24
  25         offset=$(($1 + 8))
  26
  27         local i b b0 b1 b2 b3 b4 b5 b6 b7
  28
  29         i=0
  30         while [ $i -lt 8 ]; do
  31                 # add . to not loose \n
  32                 # strip \0 as it gets dropped with warning otherwise
  33                 b="$(_dd $(($offset + $i)) bs=1 count=1 | tr -d '\0' ; echo .)"
  34                 b=${b%.}    # strip . again
  35
  36                 [ -z "$b" ] &&
  37                         b="0" ||
  38                         b="$(exec printf '%u\n' "'$b")"
  39                 eval "b$i=\$b"
  40                 i=$(($i + 1))
  41         done
  42
  43         rsize=$((8 + ((($b0 << 24) + ($b1 << 16) + ($b2 << 8) + $b3) << 4) + ($b4 << 24) + ($b5 << 16) + ($b6 << 8) + $b7))
  44         offset=$(($offset + $rsize))
  45 }
  46
  47 case "$(_dd 0 bs=4 count=1 | tr -d '\0')" in
  48         "$(printf '\355\253\356\333')"*) ;; # '\xed\xab\xee\xdb'
  49         *) fatal "File doesn't look like rpm: $pkg" ;;
  50 esac
  51
  52 calcsize 96
  53 sigsize=$rsize
  54
  55 calcsize $(($offset + (8 - ($sigsize % 8)) % 8))
  56 hdrsize=$rsize
  57
  58 case "$(_dd $offset bs=2 count=1 | tr -d '\0')" in
  59         "$(printf '\102\132')") _dd $offset | bunzip2 ;; # '\x42\x5a'
  60         "$(printf '\037\213')") _dd $offset | gunzip  ;; # '\x1f\x8b'
  61         "$(printf '\375\067')") _dd $offset | xzcat   ;; # '\xfd\x37'
  62         "$(printf '\135')") _dd $offset | unlzma      ;; # '\x5d\x00'
  63         "$(printf '\050\265')") _dd $offset | unzstd  ;; # '\x28\xb5'
  64         *) fatal "Unrecognized payload compression format in rpm file: $pkg" ;;
  65 esac