Get arguments with getopt

README

@@ -16,9 +16,9 @@ $ make
 
 RUN
 ===
-$ <SLE binary path> <tileset> <KBLE level to open>
+$ <SLE binary path> -tileset <tileset> -level <KBLE level to open>
 Example:
-$ build/sle assets/tileset.png sample.kble
+$ build/sle -tileset assets/tileset.png -level sample.kble
 
 USAGE
 =====

include/editing_area/main.h

@@ -4,5 +4,5 @@
 
 #include "shared_data.h"
 
-int editing_area_main(int argc, char **argv,
+int editing_area_main(char *level_path, char *tileset_path,
                       struct SharedData *shared_data);

include/tile_picker/main.h

@@ -4,5 +4,5 @@
 
 #include "shared_data.h"
 
-int tile_picker_main(int argc, char **argv,
+int tile_picker_main(char *tileset_path,
                      struct SharedData *shared_data);

src/editing_area/main.c

@@ -16,7 +16,7 @@ static void init_mouse(void);
 static void update_mouse(int *mouse_x, int *mouse_y, struct Level level,
                          struct SharedData *shared_data);
 
-int editing_area_main(int argc, char **argv,
+int editing_area_main(char *level_path, char *tileset_path,
                       struct SharedData *shared_data)
 {
 	int mouse_x;
@@ -32,7 +32,7 @@ int editing_area_main(int argc, char **argv,
 	SetTargetFPS(editor_target_fps);
 	init_mouse();
 	/* load textures */
-	tileset = LoadTexture(argv[1]);
+	tileset = LoadTexture(tileset_path);
 
 	/* only proceed if tileset is large enough */
 	if (tileset.width < TILESET_MIN_WIDTH_PX ||
@@ -46,7 +46,7 @@ int editing_area_main(int argc, char **argv,
 	}
 
 	/* load level */
-	if (level_read(&level, argv[2]))
+	if (level_read(&level, level_path))
 		goto panic;
 
 	while (!WindowShouldClose()) {
@@ -64,7 +64,7 @@ int editing_area_main(int argc, char **argv,
 	}
 
 	/* save level */
-	level_write(level, argv[2]);
+	level_write(level, level_path);
 
 panic:
 

src/main.c

@@ -4,37 +4,43 @@
 #include "editing_area/main.h"
 #include "shared_data.h"
 #include "tile_picker/main.h"
+#include <getopt.h>
 #include <raylib.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <unistd.h>
 
+static const int buffer_size = 256;
+
 static void *create_shared_memory(size_t size);
+static void overflow_prevention(void); /* work on optarg */
+static void process_arguments(int argc, char **argv,
+                              char tileset_path[buffer_size],
+                              char level_path[buffer_size]);
 
 /* The editor fork to create two windows. One will be the level editor
  * and the other the tile selection. This is done to allow the user to
  * organize these panels in the way they want to. */
 int main(int argc, char **argv)
 {
+	pid_t child_process;
+	char level_path[buffer_size] = "";
+	char tileset_path[buffer_size] = "";
 	struct SharedData *shared_data =
 	    (struct SharedData *)create_shared_memory(
 		sizeof(struct SharedData));
 	shared_data->end_child = false;
 	shared_data->selected_tile = 69;
-	pid_t child_process;
 
 	/* set log level */
 	SetTraceLogLevel(LOG_ERROR);
 
-	/* check for argument count */
-	if (argc != 3) {
-		fprintf(stderr, "ERROR: expected 2 arguments, got %d\n",
-		        argc - 1);
-		return EXIT_FAILURE;
-	};
+	/* process arguments */
+	process_arguments(argc, argv, tileset_path, level_path);
 
 	/* forking here */
 	child_process = fork();
@@ -43,10 +49,11 @@ int main(int argc, char **argv)
 		return EXIT_FAILURE;
 	} else if (child_process == 0) {
 		/* child process, start the tile picker */
-		return tile_picker_main(argc, argv, shared_data);
+		return tile_picker_main(tileset_path, shared_data);
 	} else {
 		/* main process, start the editing area */
-		editing_area_main(argc, argv, shared_data);
+		editing_area_main(level_path, tileset_path,
+		                  shared_data);
 		return EXIT_SUCCESS;
 	}
 }
@@ -60,3 +67,75 @@ static void *create_shared_memory(size_t size)
 	int visibility = MAP_SHARED | MAP_ANONYMOUS;
 	return mmap(NULL, size, protection, visibility, -1, 0);
 }
+
+static void overflow_prevention(void)
+{
+	/* make sure arguments won't overflow */
+	if (strlen(optarg) > buffer_size) {
+		fprintf(stderr,
+		        "ERROR: option size %lu is "
+		        "bigger than maximum %d\n",
+		        strlen(optarg), buffer_size);
+		exit(EXIT_FAILURE);
+	}
+}
+
+static void process_arguments(int argc, char **argv,
+                              char tileset_path[buffer_size],
+                              char level_path[buffer_size])
+{
+	int opt;
+	while (1) {
+		static struct option long_options[] = {
+		    {"level", required_argument, 0, 'l'},
+		    {"tileset", required_argument, 0, 't'},
+		    {0, 0, 0, 0},
+		};
+		/* getopt_long stores the option index here */
+		int option_index = 0;
+
+		opt = getopt_long_only(argc, argv, "", long_options,
+		                       &option_index);
+		/* detect the end of the options */
+		if (opt == -1)
+			break;
+
+		switch (opt) {
+		case 'l':
+			overflow_prevention();
+			strcpy(level_path, optarg);
+			break;
+		case 't':
+			overflow_prevention();
+			strcpy(tileset_path, optarg);
+			break;
+		case '?':
+			/* getopt_long already printed an error message
+			 */
+			exit(EXIT_FAILURE);
+		default:
+			fprintf(stderr,
+			        "ERROR: option -%c non handled "
+			        "(open an issue!)\n",
+			        opt);
+			exit(EXIT_FAILURE);
+		}
+	}
+	/* missing arguments? */
+	{
+		int error = 0;
+		if (level_path[0] == '\0') {
+			fprintf(stderr, "ERROR: no level path "
+			                "specified (-level <path>)\n");
+			error = 1;
+		}
+		if (tileset_path[0] == '\0') {
+			fprintf(stderr,
+			        "ERROR: no tileset path specified "
+			        "(-tileset <path>)\n");
+			error = 1;
+		}
+		if (error)
+			exit(EXIT_FAILURE);
+	}
+}

src/tile_picker/main.c

@@ -14,8 +14,7 @@ static void init_mouse(void);
 static void update_mouse(int *mouse_x, int *mouse_y,
                          struct SharedData *shared_data);
 
-int tile_picker_main(int argc, char **argv,
-                     struct SharedData *shared_data)
+int tile_picker_main(char *tileset_path, struct SharedData *shared_data)
 {
 	int mouse_x;
 	int mouse_y;
@@ -27,7 +26,7 @@ int tile_picker_main(int argc, char **argv,
 	SetTargetFPS(picker_target_fps);
 	init_mouse();
 	/* load textures */
-	tileset = LoadTexture(argv[1]);
+	tileset = LoadTexture(tileset_path);
 
 	/* only proceed if tileset is well loaded */
 	if (tileset.width > 0) {