1 files changed, 87 insertions, 0 deletions
diff --git a/app/bin/validator.c b/app/bin/validator.c
new file mode 100644
index 0000000..c415471
--- /dev/null
+++ b/app/bin/validator.c
@@ -0,0 +1,87 @@
+/** \file validator.c
+* Validators for misc textformats
+*/
+
+/*  XTrackCAD - Model Railroad CAD
+*  Copyright (C) 2019 Martin Fischer
+*
+*  This program is free software; you can redistribute it and/or modify
+*  it under the terms of the GNU General Public License as published by
+*  the Free Software Foundation; either version 2 of the License, or
+*  (at your option) any later version.
+*
+*  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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+*/
+
+#include <stdbool.h>
+#include "validator.h"
+
+/**
+* Simplistic checking of URL syntax validity. Checks:
+* if scheme is present, it has to be terminated by double /
+* hostname has at least 5 characters
+*
+* \param testString
+* \return TRUE if valid, FALSE otherwise
+*/
+
+enum URLSCANSTATE { STATE_SCHEME, STATE_ENDOFSCHEME, STATE_HIER, STATE_PATH, STATE_ERROR };
+
+#define MINURLLENGTH 5 /* 2 chars domain name, dot, 2 chars TLD */
+
+bool
+IsValidURL(char *testString)
+{
+	char *result = testString;
+	char *hostname = testString;
+	enum URLSCANSTATE state = STATE_SCHEME;
+
+	if (!*result) {
+		return(false);
+	}
+
+	while (*result && state != STATE_ERROR) {
+		switch (*result) {
+		case ':':
+			if (state == STATE_SCHEME) {
+				if (result == testString) {
+					state = STATE_ERROR;
+				} else {
+					state = STATE_ENDOFSCHEME;
+				}
+			}
+			break;
+		case '/':
+			if (state == STATE_ENDOFSCHEME) {
+				if (*(result + 1) == '/') {
+					state = STATE_HIER;
+					hostname = result + 2;
+					result++;
+				} else {
+					state = STATE_ERROR;
+				}
+			} else {
+				if (state == STATE_HIER || state == STATE_SCHEME) {
+					state = STATE_PATH;
+					if (result - hostname < MINURLLENGTH) {
+						state = STATE_ERROR;
+					}
+				}
+			}
+			break;
+		default:
+			break;
+
+		}
+		result++;
+	}
+
+	return (state != STATE_ERROR);
+}