Create save folder on startup

file.c

@@ -18,7 +18,11 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
 #include <unistd.h>
+#include <sys/stat.h>
 #include "system4.h"
 
 void *file_read(const char *path, size_t *len_out)
@@ -55,3 +59,42 @@ bool file_exists(const char *path)
 {
 	return access(path, F_OK) != -1;
 }
+
+// Adapted from http://stackoverflow.com/a/2336245/119527
+int mkdir_p(const char *path)
+{
+	const size_t len = strlen(path);
+	char _path[PATH_MAX];
+	char *p;
+
+	errno = 0;
+
+	// Copy string so its mutable
+	if (len > sizeof(_path)-1) {
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+	strcpy(_path, path);
+
+	// Iterate the string
+	for (p = _path + 1; *p; p++) {
+		if (*p == '/') {
+			// Temporarily truncate
+			*p = '\0';
+
+			if (mkdir(_path, S_IRWXU) != 0) {
+				if (errno != EEXIST)
+					return -1;
+			}
+
+			*p = '/';
+		}
+	}
+
+	if (mkdir(_path, S_IRWXU) != 0) {
+		if (errno != EEXIST)
+			return -1;
+	}
+
+	return 0;
+}

file.h

@@ -22,5 +22,6 @@
 
 void *file_read(const char *path, size_t *len_out);
 bool file_exists(const char *path);
+int mkdir_p(const char *path);
 
 #endif /* SYSTEM4_FILE_H */

system4.c

@@ -24,6 +24,7 @@
 #include "ain.h"
 #include "ald.h"
 #include "debugger.h"
+#include "file.h"
 #include "ini.h"
 #include "utfsjis.h"
 
@@ -189,6 +190,7 @@ static void config_init(void)
 	char *new_save_dir = get_save_path(config.save_dir);
 	free(config.save_dir);
 	config.save_dir = new_save_dir;
+	mkdir_p(new_save_dir);
 }
 
 int main(int argc, char *argv[])