System.Configuration.ConfigPathUtility.IsValid C# (CSharp) Метод

        static internal bool IsValid(string configPath) {
            if (String.IsNullOrEmpty(configPath)) {
                return false;
            }

            int start = -1;
            for (int examine = 0; examine <= configPath.Length; examine++) {
                char ch;

                if (examine < configPath.Length) {
                    ch = configPath[examine];
                }
                else {
                    ch = SeparatorChar;
                }

                // backslash disallowed
                if (ch == '\\') {
                    return false;
                }

                if (ch == SeparatorChar) {
                    // double slash disallowed
                    // note this check also purposefully catches starting and ending slash
                    if (examine == start + 1) {
                        return false;
                    }

                    // "." disallowed
                    if (examine == start + 2 && configPath[start + 1] == '.') {
                        return false;
                    }

                    // ".." disallowed
                    if (examine == start + 3 && configPath[start + 1] == '.' && configPath[start + 2] == '.') {
                        return false;
                    }

                    start = examine;
                }
            }

            return true;
        }