Check if requested OPDS dir exists

src/main.c

@@ -1,5 +1,6 @@
 #include <microhttpd.h>
 #include <sha256.h>
+#include <dirent.h>
 #define NOH_IMPLEMENTATION
 #include "noh.h"
 
@@ -29,8 +30,24 @@ static enum MHD_Result handle_opds(struct MHD_Connection *connection, SV url, SV
     noh_string_append_sv(&fs_path, username);
     noh_string_append_cstr(&fs_path, "/");
     noh_string_append_sv(&fs_path, url);
+    noh_string_append_null(&fs_path);
 
     noh_log(NOH_INFO, "Physical path: "Nsv_Fmt, Nsv_Arg(fs_path));
+
+    DIR* dir = opendir(fs_path.elems);
+    if (dir) {
+        noh_log(NOH_INFO, "Exists.");
+        closedir(dir);
+    } else if (ENOENT == errno) {
+        noh_log(NOH_INFO, "Does not exist.");
+        closedir(dir);
+        /* Directory does not exist. */
+    } else {
+        noh_log(NOH_ERROR, "Opening directory failed.");
+        return send_response(connection, 500, sv(""));
+    }
+
+
     return send_response(connection, 200, sv("TODO: OPDS\n"));
 }