IronRuby.Builtins.RubyProcess.GetAbsolutePaths C# (CSharp) Method

        private static IEnumerable<string>/*!*/ GetAbsolutePaths(PlatformAdaptationLayer/*!*/ pal, string/*!*/ path) {
            if (pal.IsAbsolutePath(path)) {
                yield return path;
            } else {
                yield return pal.GetFullPath(path);

                string var = pal.GetEnvironmentVariable("PATH");
                if (!String.IsNullOrEmpty(var)) {
                    foreach (var prefix in var.Split(Path.PathSeparator)) {
                        if (prefix.Length > 0) {
                            yield return Path.Combine(prefix, path);
                        }
                    }
                }

                var = Environment.GetFolderPath(Environment.SpecialFolder.System);
                if (!String.IsNullOrEmpty(var)) {
                    yield return Path.Combine(var, path);
                }

                var = pal.GetEnvironmentVariable("SystemRoot");
                if (!String.IsNullOrEmpty(var)) {
                    yield return Path.Combine(var, path);
                }
            }
        }