New EXTRACT command (#50)

The EXTRACT command can be used to copy files back from the guest to the host; the counterpart of INSTALL.

Co-authored-by: Alvar Penning <[email protected]>

CHANGELOG.md

@@ -18,6 +18,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 ### Added
 - New `ENV` command for environment variables.
+- New `EXTRACT` command to copy files back to the host; @sensslen.
 
 ## [0.4.4] - 2021-11-09
 ### Added

README.md

@@ -156,6 +156,9 @@ The included file _has_ to have a `.Pifile` extension which need not be specifie
 `INSTALL` installs a given file or directory into the destination in the image.
 The optionally permission mode (*chmod*) can be set as the first parameter.
 
+#### `EXTRACT SOURCE DEST`
+`EXTRACT` copies a given file or directory from the image to the destination.
+
 #### `PATH /my/guest/path`
 `PATH` adds the given path to an overlaying PATH variable, used within the `RUN` command.
 

examples/RPi-OpenWRT.Pifile

@@ -23,6 +23,10 @@ INSTALL "README.md" "/tmp/"
 WORKDIR /tmp
 RUN head -n1 "README.md"
 
+# test if EXTRACT works
+RUN sh -c 'echo "hello from within the guest" > /tmp/hello'
+EXTRACT "/tmp/hello" "./hello"
+
 # test an INCLUDE - both with and without the .Pifile extension
 INCLUDE examples/Module-Hello.Pifile
 INCLUDE examples/Module-Hello

stages/00-commands.sh

@@ -49,6 +49,10 @@ INSTALL() {
   :
 }
 
+EXTRACT() {
+  :
+}
+
 PATH() {
   :
 }

stages/30-chroot.sh

@@ -43,6 +43,22 @@ INSTALL() {
   fi
 }
 
+# EXTRACT copies a given file or directory from the image to the destination. 
+#
+# Usage: EXTRACT SOURCE DEST
+EXTRACT() {
+  echo -e "\033[0;32m### EXTRACT $*\033[0m"
+
+  local src="${CHROOT_MOUNT}/$1"
+  local dst=$2
+
+  if [[ -d "${src}" ]]; then
+    cp -r -T -P --preserve=mode "${src}" "${dst}"
+  else
+    cp -r -P --preserve=mode "${src}" "${dst}"
+  fi
+}
+
 # PATH adds the given path to an overlaying PATH variable, used within the RUN
 # command.
 #