Redo dir_hash with new file_hash functionality

2 files changed, 36 insertions, 3 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0af0434..0e752aa 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -28,6 +28,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   GNU+Linux distributions.
 - The `$BASHTARD_PLATFORM` variable now contains an additional entry, `init`, to
   allow for handling different init systems on GNU+Linux in a cleaner fashion.
+- A `file_hash` utility function has been added. It currently uses `md5`, but is
+  written in such a fashion that this can easily be updated for the future. Its
+  intent is to encapsulate differences between naming and usage of hashing
+  utilities found on different systems.
 - A `dir_hash` utility function has been added, which will give you a hash based
   on the file contents of a directory. This function will find files
   recursively, calculate a hash for each of them, and then calculate a hash
diff --git a/lib/util.bash b/lib/util.bash
index c36b576..fac492c 100644
--- a/lib/util.bash
+++ b/lib/util.bash
@@ -63,9 +63,19 @@ die() {
 # in a directory. It can be used to check whether contents changed after
 # templating files in a given directory.
 dir_hash() {
-	find "$1" -type f -exec sha1sum {} \; \
-		| sha1sum \
-		| awk '{ print $1 }'
+	local path
+
+	path="$1" ; shift
+
+	for entry in "$path"/*
+	do
+		if [[ -d "$entry" ]]
+		then
+			dir_hash "$entry"
+		fi
+
+		file_hash "$entry"
+	done | file_hash -
 }
 
 # Fetch a file from an URL. Using this function introduces a dependency on curl.
@@ -108,6 +118,25 @@ fetch_http_wget() {
 	wget --quiet --output-document "$2" "$1"
 }
 
+# Hash a given file. This is a convenience function to work around different
+# systems calling their file hashing programs differently, and generating
+# different output. This function only expects 1 file as argument, and only
+# outputs the hash of this particular file.
+file_hash() {
+	file_hash_md5 "$@"
+}
+
+file_hash_md5() {
+	local file
+
+	file="$1" ; shift
+
+	case "${BASHTARD_PLATFORM[key]}" in
+		freebsd) md5 "$file" | awk '{ print $NF }' ;;
+		linux-*) md5sum "$file" | awk '{ print $1 }' ;;
+	esac
+}
+
 # A very simple means of templating a file, using sed and awk. The template
 # file is assumed to exist within the share directory of the current playbook.
 # Variables are passed as key=value pairs to this function. Inside the