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-rwxr-xr-xscripts/rpm2cpio.sh108
1 files changed, 55 insertions, 53 deletions
diff --git a/scripts/rpm2cpio.sh b/scripts/rpm2cpio.sh
index 5df8c0f705..cf23472ba9 100755
--- a/scripts/rpm2cpio.sh
+++ b/scripts/rpm2cpio.sh
@@ -1,53 +1,55 @@
-#!/bin/sh
-
-# This comes from the RPM5 5.4.0 distribution.
-
-pkg=$1
-if [ "$pkg" = "" -o ! -e "$pkg" ]; then
- echo "no package supplied" 1>&2
- exit 1
-fi
-
-leadsize=96
-o=`expr $leadsize + 8`
-set `od -j $o -N 8 -t u1 $pkg`
-il=`expr 256 \* \( 256 \* \( 256 \* $2 + $3 \) + $4 \) + $5`
-dl=`expr 256 \* \( 256 \* \( 256 \* $6 + $7 \) + $8 \) + $9`
-# echo "sig il: $il dl: $dl"
-
-sigsize=`expr 8 + 16 \* $il + $dl`
-o=`expr $o + $sigsize + \( 8 - \( $sigsize \% 8 \) \) \% 8 + 8`
-set `od -j $o -N 8 -t u1 $pkg`
-il=`expr 256 \* \( 256 \* \( 256 \* $2 + $3 \) + $4 \) + $5`
-dl=`expr 256 \* \( 256 \* \( 256 \* $6 + $7 \) + $8 \) + $9`
-# echo "hdr il: $il dl: $dl"
-
-hdrsize=`expr 8 + 16 \* $il + $dl`
-o=`expr $o + $hdrsize`
-EXTRACTOR="dd if=$pkg ibs=$o skip=1"
-
-COMPRESSION=`($EXTRACTOR |file -) 2>/dev/null`
-if echo $COMPRESSION |grep -iq gzip; then
- DECOMPRESSOR=gunzip
-elif echo $COMPRESSION |grep -iq bzip2; then
- DECOMPRESSOR=bunzip2
-elif echo $COMPRESSION |grep -iq xz; then
- DECOMPRESSOR=unxz
-elif echo $COMPRESSION |grep -iq cpio; then
- DECOMPRESSOR=cat
-else
- # Most versions of file don't support LZMA, therefore we assume
- # anything not detected is LZMA
- DECOMPRESSOR=`which unlzma 2>/dev/null`
- case "$DECOMPRESSOR" in
- /* ) ;;
- * ) DECOMPRESSOR=`which lzmash 2>/dev/null`
- case "$DECOMPRESSOR" in
- /* ) DECOMPRESSOR="lzmash -d -c" ;;
- * ) DECOMPRESSOR=cat ;;
- esac
- ;;
- esac
-fi
-
-$EXTRACTOR 2>/dev/null | $DECOMPRESSOR
+#!/bin/sh -efu
+
+# This file comes from rpm 4.x distribution
+
+fatal() {
+ echo "$*" >&2
+ exit 1
+}
+
+pkg="$1"
+[ -n "$pkg" -a -e "$pkg" ] ||
+ fatal "No package supplied"
+
+_dd() {
+ local o="$1"; shift
+ dd if="$pkg" skip="$o" iflag=skip_bytes status=none $*
+}
+
+calcsize() {
+ offset=$(($1 + 8))
+
+ local i b b0 b1 b2 b3 b4 b5 b6 b7
+
+ i=0
+ while [ $i -lt 8 ]; do
+ b="$(_dd $(($offset + $i)) bs=1 count=1)"
+ [ -z "$b" ] &&
+ b="0" ||
+ b="$(exec printf '%u\n' "'$b")"
+ eval "b$i=\$b"
+ i=$(($i + 1))
+ done
+
+ rsize=$((8 + ((($b0 << 24) + ($b1 << 16) + ($b2 << 8) + $b3) << 4) + ($b4 << 24) + ($b5 << 16) + ($b6 << 8) + $b7))
+ offset=$(($offset + $rsize))
+}
+
+case "$(_dd 0 bs=8 count=1)" in
+ "$(printf '\355\253\356\333')"*) ;; # '\xed\xab\xee\xdb'
+ *) fatal "File doesn't look like rpm: $pkg" ;;
+esac
+
+calcsize 96
+sigsize=$rsize
+
+calcsize $(($offset + (8 - ($sigsize % 8)) % 8))
+hdrsize=$rsize
+
+case "$(_dd $offset bs=3 count=1)" in
+ "$(printf '\102\132')"*) _dd $offset | bunzip2 ;; # '\x42\x5a'
+ "$(printf '\037\213')"*) _dd $offset | gunzip ;; # '\x1f\x8b'
+ "$(printf '\375\067')"*) _dd $offset | xzcat ;; # '\xfd\x37'
+ "$(printf '\135\000')"*) _dd $offset | unlzma ;; # '\x5d\x00'
+ *) fatal "Unrecognized rpm file: $pkg" ;;
+esac