From 3112d9ebb9c411685fbad5241c8fe32ea8041de4 Mon Sep 17 00:00:00 2001
From: Shane Carr <shane@unicode.org>
Date: Fri, 18 Sep 2020 23:50:15 -0700
Subject: [PATCH] ICU-21191 Fixing testtagsguards.sh

---
 icu4c/source/test/hdrtst/testtagsguards.sh | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/icu4c/source/test/hdrtst/testtagsguards.sh b/icu4c/source/test/hdrtst/testtagsguards.sh
index af72df4cb5..a432538a05 100755
--- a/icu4c/source/test/hdrtst/testtagsguards.sh
+++ b/icu4c/source/test/hdrtst/testtagsguards.sh
@@ -1,3 +1,4 @@
+#/usr/bin/env bash
 # Copyright © 2019 and later: Unicode, Inc. and others.
 # License & terms of use: http://www.unicode.org/copyright.html
 
@@ -6,11 +7,11 @@
 
 # set -x # echo on
 
-DEF:=-DU_NO_DEFAULT_INCLUDE_UTF_HEADERS=1
-INCL:="-Isource/common -Isource/i18n -Isource/io"
-TMPDIR:=`mktemp -d`
-DIFF:="diff -u --minimal"
-CXX:="clang++"
+: ${DEF:=-DU_NO_DEFAULT_INCLUDE_UTF_HEADERS=1}
+: ${INCL:="-Isource/common -Isource/i18n -Isource/io"}
+: ${TMPDIR:=`mktemp -d`}
+: ${DIFF:="diff -u --minimal"}
+: ${CXX:="clang++"}
 
 echo "*** testtagsguards.sh TMPDIR=$TMPDIR"