From 172ca644527cfaf3bba1dbeab9e7139cca2b249a Mon Sep 17 00:00:00 2001
From: Erik Stromdahl <erik.stromdahl@gmail.com>
Date: Thu, 1 Jun 2017 19:29:18 +0200
Subject: functions: add_full_dir: path prefix strip-off

Add third argument to add_full_dir: strip_prefix.
The strip_prefix will be stripped off from the destination
path (path in the initramfs image) when adding files.

Rationale: Make it easier to add rootfs overlay hooks when
generating images.

add_full_dir can be invoked in this way:

add_full_dir /path/on/parent/rootfs-overlay * /path/on/parent/rootfs-overlay

The above invocation will add all content of */path/on/parent/rootfs-overlay*
into */* in the initramfs image.

Signed-off-by: Erik Stromdahl <erik.stromdahl@gmail.com>
---
 functions            | 9 +++++----
 man/mkinitcpio.8.txt | 7 ++++++-
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/functions b/functions
index 6cc74a4..0e1fe0f 100644
--- a/functions
+++ b/functions
@@ -433,8 +433,9 @@ add_full_dir() {
     # No parsing is performed and the contents of the directory is added as is.
     #   $1: path to directory
     #   $2: glob pattern to filter file additions (optional)
+    #   $3: path prefix that will be stripped off from the image path (optional)
 
-    local f= filter=${2:-*}
+    local f= filter=${2:-*} strip_prefix=$3
 
     if [[ -n $1 && -d $1 ]]; then
         add_dir "$1"
@@ -442,13 +443,13 @@ add_full_dir() {
         for f in "$1"/*; do
             if [[ -L $f ]]; then
                 if [[ $f = $filter ]]; then
-                    add_symlink "$f" "$(readlink "$f")"
+                    add_symlink "${f#$strip_prefix}" "$(readlink "$f")"
                 fi
             elif [[ -d $f ]]; then
-                add_full_dir "$f" "$filter"
+                add_full_dir "$f" "$filter" "$strip_prefix"
             elif [[ -f $f ]]; then
                 if [[ $f = $filter ]]; then
-                    add_file "$f"
+                    add_file "$f" "${f#$strip_prefix}"
                 fi
             fi
         done
diff --git a/man/mkinitcpio.8.txt b/man/mkinitcpio.8.txt
index 5c3118e..931a167 100644
--- a/man/mkinitcpio.8.txt
+++ b/man/mkinitcpio.8.txt
@@ -139,7 +139,7 @@ functions exist to facilitate this.
 
 	Adds a directory and its parents to the image.
 
-*add_full_dir* 'directory' [ 'glob' ]::
+*add_full_dir* 'directory' [ 'glob' ] [ 'strip_prefix' ]::
 
 	Recursively adds a directory to the image by walking the given path and
 	calling *add_file*, *add_dir*, and *add_symlink* accordingly. This function
@@ -148,6 +148,11 @@ functions exist to facilitate this.
 	If the 'glob' argument is passed, only files and symlinks matching this glob
 	will be added.
 
+	If the 'strip_prefix' argument is passed, it will be used to strip the
+	destination path (path in the initramfs image) from the prefix specified by
+	the 'strip_prefix' argument. This can be useful when writing rootfs-overlay
+	hooks.
+
 *add_symlink* 'path' [ 'link-target' ]::
 
 	Adds a symlink to the image at the specified `path`, optionally pointing to
-- 
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