+/// Do some work just once.
+void init(int argc, char ** argv[]);
+
+/// Returns the i-th program argument in utf8 encoding.
+std::string utf8_argv(int i);
+
+/// Removes from the internal copy \p num program arguments starting from \p i.
+void remove_internal_args(int i, int num);
+
+/// Returns the name of the NULL device (/dev/null, null).
+std::string const & nulldev();
+
+/// Returns "/" on *nix, "C:/", etc on Windows.
+std::string current_root();
+
+///
+shell_type shell();
+
+/// Returns no. of minutes allowed for a command to complete.
+int timeout_min();
+
+/// Name of the python interpreter
+/// @param reset True if the python path should be recomputed
+std::string const python(bool reset = false);
+
+///
+bool isFilesystemCaseSensitive();
+
+/// Extract the path common to both @c p1 and @c p2. DBCS aware!
+/// \p p1 and \p p2 are encoded in ucs4, \returns the index to the end of
+/// the last matching path component (the index may be pointing after the
+/// end of @c p1 or @c p2 if their last char is not the path separator).
+std::size_t common_path(docstring const & p1, docstring const & p2);
+
+/// Converts a unix style path to host OS style.
+/// \p p and the return value are encoded in utf8.
+std::string external_path(std::string const & p);
+
+/// Converts a host OS style path to unix style.
+/// \p p and the return value are encoded in utf8.
+std::string internal_path(std::string const & p);
+
+/// Converts a host OS style path to a unicode safe unix style.
+/// On Windows, this is achieved by using the short form of the path,
+/// which can be safely passed to standard I/O functions expecting narrow
+/// char paths even when the path contains non-ascii chars.
+/// As the short form is only available for existing files, if the file is
+/// to be accessed for writing, \param how should be set to CREATE.
+/// \p p and the return value are encoded in utf8.
+std::string safe_internal_path(std::string const & p, file_access how = EXISTING);
+
+/// Converts a unix style path list to host OS style.
+/// \p p and the return value are encoded in utf8.
+std::string external_path_list(std::string const & p);
+
+/// Converts a host OS style path list to unix style.
+/// \p p and the return value are encoded in utf8.
+std::string internal_path_list(std::string const & p);
+
+/**
+ * Converts a unix style path into a form suitable for inclusion in a LaTeX
+ * document.
+ * \p p is encoded in utf8.
+ * Caution: This function handles only the OS specific part of that task.
+ * Never use it directly, use lyx::support::latex_path instead.
+ */
+std::string latex_path(std::string const & p);
+
+/**
+ * Converts a platform style path list into a form suitable for the TeX engine.
+ * \p p is encoded in utf8.
+ */
+std::string latex_path_list(std::string const & p);
+
+/** Returns a string suitable to be passed to popen when
+ * reading a file.
+ */
+char const * popen_read_mode();
+
+enum path_type {
+ PLATFORM,
+ TEXENGINE
+};