From fb9cd125ffbfb1d01c457ca492f6ce7d3e482def Mon Sep 17 00:00:00 2001
From: sensslen <sensslen@users.noreply.github.com>
Date: Mon, 17 Jan 2022 10:18:05 +0100
Subject: [PATCH] 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 <post@0x21.biz>
---
 CHANGELOG.md                |  1 +
 README.md                   |  3 +++
 examples/RPi-OpenWRT.Pifile |  4 ++++
 stages/00-commands.sh       |  4 ++++
 stages/30-chroot.sh         | 16 ++++++++++++++++
 5 files changed, 28 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b24a666..83694bc 100644
--- a/CHANGELOG.md
+++ b/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
diff --git a/README.md b/README.md
index 671c1a0..71b0d16 100644
--- a/README.md
+++ b/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.
 
diff --git a/examples/RPi-OpenWRT.Pifile b/examples/RPi-OpenWRT.Pifile
index e801d36..9997a37 100644
--- a/examples/RPi-OpenWRT.Pifile
+++ b/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
diff --git a/stages/00-commands.sh b/stages/00-commands.sh
index e499526..f2c6f33 100644
--- a/stages/00-commands.sh
+++ b/stages/00-commands.sh
@@ -49,6 +49,10 @@ INSTALL() {
   :
 }
 
+EXTRACT() {
+  :
+}
+
 PATH() {
   :
 }
diff --git a/stages/30-chroot.sh b/stages/30-chroot.sh
index bc1fa94..cc199f7 100644
--- a/stages/30-chroot.sh
+++ b/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.
 #