dracut-initramfs-restore,lsinitrd: add LZ4 support

Dracut claims to have LZ4 support, but trying to use it will result in an xzcat failure at the end due to missing CAT support.

The lz4 command chokes on '--', so abstract that out into the CAT select.

Something similar will need to be done for LZO.

Signed-off-by: Koen Kooi <koen@dominion.thruhere.net>

dracut-initramfs-restore.sh

@@ -20,6 +20,8 @@ if zcat "$IMG"  | cpio -id --quiet >/dev/null; then
     rm -f -- .need_shutdown
 elif xzcat "$IMG"  | cpio -id --quiet >/dev/null; then
     rm -f -- .need_shutdown
+elif lz4 -d -c "$IMG"  | cpio -id --quiet >/dev/null; then
+    rm -f -- .need_shutdown
 else
     # something failed, so we clean up
     echo "Unpacking of $IMG to /run/initramfs failed" >&2

lsinitrd.sh

@@ -106,15 +106,17 @@ fi
 read -N 6 bin < "$image"
 case $bin in
     $'\x1f\x8b'*)
-        CAT="zcat";;
+        CAT="zcat --";;
     BZh*)
-        CAT="bzcat";;
+        CAT="bzcat --";;
     $'\x71\xc7'*|070701)
-        CAT="cat";;
+        CAT="cat --";;
+    $'\x04\x22'*)
+        CAT="lz4 -d -c";;
     *)
-        CAT="xzcat";
+        CAT="xzcat --";
         if echo "test"|xz|xzcat --single-stream >/dev/null 2>&1; then
-            CAT="xzcat --single-stream"
+            CAT="xzcat --single-stream --"
         fi
         ;;
 esac
@@ -126,7 +128,7 @@ if (( ${#filenames[@]} > 0 )); then
     for f in ${!filenames[@]}; do
         [[ $nofileinfo ]] || echo "initramfs:/$f"
         [[ $nofileinfo ]] || echo "========================================================================"
-        $CAT -- $image | cpio --extract --verbose --quiet --to-stdout $f 2>/dev/null
+        $CAT $image | cpio --extract --verbose --quiet --to-stdout $f 2>/dev/null
         ((ret+=$?))
         [[ $nofileinfo ]] || echo "========================================================================"
         [[ $nofileinfo ]] || echo
@@ -134,16 +136,16 @@ if (( ${#filenames[@]} > 0 )); then
 else
     echo "Image: $image: $(du -h $image | while read a b; do echo $a;done)"
     echo "========================================================================"
-    version=$($CAT -- "$image" | cpio --extract --verbose --quiet --to-stdout -- '*lib/dracut/dracut-*' 2>/dev/null)
+    version=$($CAT "$image" | cpio --extract --verbose --quiet --to-stdout -- '*lib/dracut/dracut-*' 2>/dev/null)
     ((ret+=$?))
     echo "$version with dracut modules:"
-    $CAT -- "$image" | cpio --extract --verbose --quiet --to-stdout -- '*lib/dracut/modules.txt' 2>/dev/null
+    $CAT "$image" | cpio --extract --verbose --quiet --to-stdout -- '*lib/dracut/modules.txt' 2>/dev/null
     ((ret+=$?))
     echo "========================================================================"
     if [ "$sorted" -eq 1 ]; then
-        $CAT -- "$image" | cpio --extract --verbose --quiet --list | sort -n -k5
+        $CAT "$image" | cpio --extract --verbose --quiet --list | sort -n -k5
     else
-        $CAT -- "$image" | cpio --extract --verbose --quiet --list | sort -k9
+        $CAT "$image" | cpio --extract --verbose --quiet --list | sort -k9
     fi
     ((ret+=$?))
     echo "========================================================================"