AcTools.Utils.FileUtils.EnsureUnique C# (CSharp) Method

        public static string EnsureUnique(string filename) {
            if (!Exists(filename)) return filename;
            
            var ext = Path.GetExtension(filename) ?? "";
            var start = filename.Substring(0, filename.Length - ext.Length);

            for (var i = 1; i < 99999; i++) {
                var result = start + "-" + i + ext;
                if (!Exists(result)) return result;
            }

            throw new Exception("Can’t find unique filename");
        }