1 files changed, 14 insertions, 11 deletions
diff --git a/install-header.sh b/install-header.sh
index 210691d..766ba0a 100755
--- a/install-header.sh
+++ b/install-header.sh
@@ -4,25 +4,29 @@
 # DO NOT CHANGE THIS without great care - it will break header length
 # calculations
 LENS=(                              )
-export SELF
-export TMP
+export SELF       # Absolute path to the installer script (me!)
+export TMP        # Path to tmp install staging directory
+export PAYLOAD    # Path to the extracted payload directory
+export NOCLEANUP  # Do not clean up deploy resources. Useful for debugging
 
 # Header:    0
 # runscript: 1
 # payload:   2
 extract_chunk_index() {
-  local script="${1}"
+  local src="${1}"
   local dest="${2}"
   local index="${3}"
-  local skip=0
+  local skip=0  # Byte count to skip into source
+  local of      # Output path with 'of=' prefix. Only used if dest is not '-'
 
   for (( i = 0; i < index; i++ )); do
     skip=$(( skip + LENS[$i] ))
   done
 
+  [ "${dest}" != '-' ] && of="${dest}"
   # Extract the requested chunk index
   dd bs=1 count=${LENS[$index]} iflag=skip_bytes skip=${skip} \
-    if=${script} of=${dest} 2>/dev/null
+    if=${src} ${of} 2>/dev/null
 }
 
 extract_header() {
@@ -30,13 +34,12 @@ extract_header() {
 }
 
 extract_runscript() {
-  extract_chunk_index "${SELF}" "${TMP}/run.sh.xz" 1
-  xz -d "${TMP}/run.sh.xz"
+  extract_chunk_index "${SELF}" '-' 1 | xz -d -c > "${TMP}/run.sh"
 }
 
 extract_payload() {
-  extract_chunk_index "${SELF}" "${TMP}/payload.tar.xz" 2
-  tar -C "${TMP}" -x -f payload.tar.xz
+  extract_chunk_index "${SELF}" '-' 2 | xz -d -c | tar -C "${TMP}" -x
+  export PAYLOAD="${TMP}/pkg"
 }
 
 
@@ -53,13 +56,13 @@ main() {
 
   # Function 'deploy' is provided by run.sh
   if [ "$(type -t deploy)" == 'function' ]; then
-    deploy
+    deploy ${@}
   else
     printf "ERROR: Deploy function not found.\n"
   fi
 
   # Cleanup
-  rm -rf "${TMP}"
+  [ -z "${NOCLEANUP:-}" ] && rm -rf "${TMP}"
 }
 
 main ${@}