Testing functions to open files from bundle

src/bundle_open.m

@@ -0,0 +1,47 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#import <Foundation/Foundation.h>
+
+#include "bundle_open.h"
+
+const char *resource_path_from_bundle()
+{ @autoreleasepool
+{
+    NSFileManager* file_manager = [NSFileManager defaultManager];
+    NSString* resource_path = [[NSBundle mainBundle] resourcePath];
+    const char *resource_path_c = [resource_path UTF8String];
+    size_t len = strlen(resource_path_c);
+    char *resource_path_s = malloc(len + 1);
+    if (resource_path_s) {
+        memcpy(resource_path_s, resource_path_c, len + 1);
+    }
+    return resource_path_s;
+}}
+
+FILE* open_fp_from_bundle_or_fallback(const char *file, const char *mode)
+{ @autoreleasepool
+{
+    FILE* fp = NULL;
+
+    /* If the file mode is writable, skip all the bundle stuff because generally the bundle is read-only. */
+    if(strcmp("r", mode) && strcmp("rb", mode)) {
+        return fopen(file, mode);
+    }
+
+    NSFileManager* file_manager = [NSFileManager defaultManager];
+    NSString* resource_path = [[NSBundle mainBundle] resourcePath];
+
+    NSString* ns_string_file_component = [file_manager stringWithFileSystemRepresentation:file length:strlen(file)];
+
+    NSString* full_path_with_file_to_try = [resource_path stringByAppendingPathComponent:ns_string_file_component];
+    if([file_manager fileExistsAtPath:full_path_with_file_to_try]) {
+        fp = fopen([full_path_with_file_to_try fileSystemRepresentation], mode);
+    } else {
+        fp = fopen(file, mode);
+    }
+
+    return fp;
+}}
+