add command-line arguments

3 files changed, 77 insertions, 0 deletions

diff --git a/src/options/CMakeLists.txt b/src/options/CMakeLists.txt
new file mode 100644
index 0000000..39ed7db
--- /dev/null
+++ b/src/options/CMakeLists.txt
@@ -0,0 +1,5 @@
+project(honey_engine)
+
+target_sources(honey PUBLIC
+	${CMAKE_CURRENT_LIST_DIR}/options.c
+)
diff --git a/src/options/options.c b/src/options/options.c
new file mode 100644
index 0000000..4488837
--- /dev/null
+++ b/src/options/options.c
@@ -0,0 +1,56 @@
+#include <stdio.h>
+#include <cargs.h>
+#include "options.h"
+
+static struct cag_option opts[] = {
+	{
+		.identifier = 's',
+		.access_letters = "s",
+		.access_name = "script",
+		.value_name = "SCRIPT_FILE",
+		.description = "The filename of the main script. (default: main.lua)"
+	},
+	{
+		.identifier = 'h',
+		.access_letters = "h",
+		.access_name = "help",
+		.value_name = NULL,
+		.description = "Shows this help message"
+	},
+};
+
+
+void print_help(char *program_name)
+{
+	printf("usage: %s [OPTIONS]\n", program_name);
+	cag_option_print(opts, CAG_ARRAY_SIZE(opts), stdout);
+}
+
+
+enum outcomes_t parse_options(struct honey_options *options, int argc, char **argv)
+{
+	/* default values */
+	options->script_file = "main.lua";
+
+	/* parse options */
+	char id;
+	const char *value;
+	cag_option_context context;
+
+	cag_option_prepare(&context, opts, CAG_ARRAY_SIZE(opts), argc, argv);
+	while(cag_option_fetch(&context)) {
+		id = cag_option_get(&context);
+		switch(id) {
+		case 's':
+			options->script_file = cag_option_get_value(&context);
+			break;
+		case 'h':
+			print_help(argv[0]);
+			return EXIT_SUCCESS;
+		default:
+			return EXIT_FAILURE;
+		}
+	}
+
+	return CONTINUE_SUCCESS;
+}
diff --git a/src/options/options.h b/src/options/options.h
new file mode 100644
index 0000000..cb07b1a
--- /dev/null
+++ b/src/options/options.h
@@ -0,0 +1,16 @@
+#ifndef HONEY_OPTIONS_H
+#define HONEY_OPTIONS_H
+
+struct honey_options {
+	const char *script_file; // main entry point
+};
+
+enum outcomes_t {
+	CONTINUE_SUCCESS,
+	EXIT_SUCCESS,
+	EXIT_FAILURE,
+};
+
+enum outcomes_t parse_options(struct honey_options *options, int argc, char **argv);
+
+#endif