add rmdir shell command and folder_delete api call

mfapi/apicalls/folder_delete.c

@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2013 Bryan Christ <bryan.christ@mediafire.com>
+ *               2014 Johannes Schauer <j.schauer@email.de>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2, as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "../../utils/http.h"
+#include "../mfconn.h"
+#include "../apicalls.h"        // IWYU pragma: keep
+
+int mfconn_api_folder_delete(mfconn * conn, const char *folderkey)
+{
+    char           *api_call;
+    int             retval;
+    mfhttp         *http;
+
+    if (conn == NULL)
+        return -1;
+
+    if (folderkey == NULL)
+        return -1;
+
+    if (strlen(folderkey) != 13)
+        return -1;
+
+    api_call = mfconn_create_signed_get(conn, 0, "folder/delete.php",
+                                        "?folder_key=%s&response_format=json",
+                                        folderkey);
+
+    http = http_create();
+    retval = http_get_buf(http, api_call, NULL, NULL);
+    http_destroy(http);
+
+    return retval;
+}