ttcn3.sh: add getopts

Add getopts parsing. The idea was to add support for setting a different
IMAGE_SUFFIX argument, but later on it became clear it is not worth
implementing here. Add the getopts logic anyway because it can be used
to add other arguments in the future.

Change-Id: If55a982d92b2a24a175ab7f3a8f048f054033dc2
---
M ttcn3/ttcn3.sh
1 file changed, 45 insertions(+), 9 deletions(-)

diff --git a/ttcn3/ttcn3.sh b/ttcn3/ttcn3.sh
index 74e87cc..3563062 100755
--- a/ttcn3/ttcn3.sh
+++ b/ttcn3/ttcn3.sh
@@ -1,6 +1,6 @@
 #!/bin/sh -e
-PROJECT="$1"
-PROJECT_UPPER="$(echo "$PROJECT" | tr '[:lower:]' '[:upper:]')"
+PROJECT=""
+PROJECT_UPPER=""
 DIR_OSMODEV="$(readlink -f "$(dirname $0)/..")"
 DIR_MAKE="${DIR_MAKE:-${DIR_OSMODEV}/ttcn3/make}"
 DIR_OUTPUT="${DIR_OUTPUT:-${DIR_OSMODEV}/ttcn3/out}"
@@ -14,15 +14,36 @@
 DOCKER_IMG_BUILD="debian-bookworm-build"
 DOCKER_IMG_TITAN="debian-bookworm-titan"
 
+parse_args() {
+	while getopts 'h' OPTION; do
+		case "$OPTION" in
+		h|*)
+			local name="$(basename $0)"
+			echo "usage: $name [-h] PROJECT"
+			echo "arguments:"
+			echo "  -h       show help"
+			echo "  PROJECT  the testsuite project to run"
+			echo "examples:"
+			echo "  $name bsc"
+			echo "  $name bsc-sccplite"
+			echo "  $name hlr"
+			exit 1
+			;;
+		esac
+	done
+	shift "$(($OPTIND - 1))"
+
+	if [ "$#" != "1" ]; then
+		parse_args -h
+	fi
+
+	PROJECT="$1"
+	PROJECT_UPPER="$(echo "$PROJECT" | tr '[:lower:]' '[:upper:]')"
+}
+
 check_usage() {
-	local name="$(basename $0)"
 	if [ -z "$PROJECT" ]; then
-		echo "usage: $name PROJECT"
-		echo "examples:"
-		echo "  * $name bsc"
-		echo "  * $name bsc-sccplite"
-		echo "  * $name hlr"
-		exit 1
+		parse_args -h
 	fi
 }
 
@@ -359,6 +380,7 @@
 	echo "---"
 }
 
+parse_args "$@"
 check_usage
 check_ttcn3_install
 setup_dir_make

