From 117aa8f4c56285a42b45712205aa36c4e45afb9c Mon Sep 17 00:00:00 2001
From: "Kyle J. McKay" <mackyle@gmail.com>
Date: Fri, 23 Jun 2017 13:25:36 -0700
Subject: [PATCH] tg.sh: add is_empty_dir function

Utility function to test a directory for "emptyness" potentially
with exceptions (e.g. such as .* or .git).

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
---
 tg.sh | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/tg.sh b/tg.sh
index 93d21a9..6cf5196 100644
--- a/tg.sh
+++ b/tg.sh
@@ -184,6 +184,32 @@ vcmp()
 	return 1
 }
 
+# true if "$1" is an existing dir and is empty except for
+# any additional files given as extra arguments.  If "$2"
+# is the single character "." then all ".*" files will be
+# ignored for the test (plus any further args, if any)
+is_empty_dir() {
+	test -n "$1" && test -d "$1" || return 1
+	iedd_="$1"
+	shift
+	ieddnok_='\.?$'
+	if [ z"$1" = z"." ]; then
+		ieddnok_=
+		shift
+		while ! case "$1" in "."*) ! :; esac; do shift; done
+	fi
+	if [ $# -eq 0 ]; then
+		! \ls -a1 "$iedd_" | grep -q -E -v '^\.'"$ieddnok_"
+	else
+		# we only handle ".git" right now for efficiency
+		[ z"$*" = z".git" ] || {
+			fatal "[BUG] is_empty_dir not implemented for arguments: $*"
+			exit 70
+		}
+		! \ls -a1 "$iedd_" | grep -q -E -v -i -e '^\.\.?$' -e '^\.git$'
+	fi
+}
+
 precheck() {
 	if ! git_version="$(git version)"; then
 		die "'git version' failed"
-- 
2.11.4.GIT