+/*
+ * Exports from printing.c.
+ */
+typedef struct printer_enum_tag printer_enum;
+typedef struct printer_job_tag printer_job;
+printer_enum *printer_start_enum(int *nprinters);
+char *printer_get_name(printer_enum *, int);
+void printer_finish_enum(printer_enum *);
+printer_job *printer_start_job(char *printer);
+void printer_job_data(printer_job *, void *, int);
+void printer_finish_job(printer_job *);
+
+/*
+ * Exports from cmdline.c (and also cmdline_error(), which is
+ * defined differently in various places and required _by_
+ * cmdline.c).
+ */
+int cmdline_process_param(char *, char *, int, Config *);
+void cmdline_run_saved(Config *);
+void cmdline_cleanup(void);
+int cmdline_get_passwd_input(prompts_t *p, unsigned char *in, int inlen);
+#define TOOLTYPE_FILETRANSFER 1
+#define TOOLTYPE_NONNETWORK 2
+extern int cmdline_tooltype;
+
+void cmdline_error(char *, ...);
+
+/*
+ * Exports from config.c.
+ */
+struct controlbox;
+void setup_config_box(struct controlbox *b, int midsession,
+ int protocol, int protcfginfo);
+
+/*
+ * Exports from minibidi.c.
+ */
+typedef struct bidi_char {
+ wchar_t origwc, wc;
+ unsigned short index;
+} bidi_char;
+int do_bidi(bidi_char *line, int count);
+int do_shape(bidi_char *line, bidi_char *to, int count);
+int is_rtl(int c);
+
+/*
+ * X11 auth mechanisms we know about.
+ */
+enum {
+ X11_NO_AUTH,
+ X11_MIT, /* MIT-MAGIC-COOKIE-1 */
+ X11_XDM, /* XDM-AUTHORIZATION-1 */
+ X11_NAUTHS
+};
+extern const char *const x11_authnames[]; /* declared in x11fwd.c */
+
+/*
+ * Miscellaneous exports from the platform-specific code.
+ */
+Filename filename_from_str(const char *string);
+const char *filename_to_str(const Filename *fn);
+int filename_equal(Filename f1, Filename f2);
+int filename_is_null(Filename fn);
+char *get_username(void); /* return value needs freeing */
+char *get_random_data(int bytes); /* used in cmdgen.c */
+
+/*
+ * Exports and imports from timing.c.
+ *
+ * schedule_timer() asks the front end to schedule a callback to a
+ * timer function in a given number of ticks. The returned value is
+ * the time (in ticks since an arbitrary offset) at which the
+ * callback can be expected. This value will also be passed as the
+ * `now' parameter to the callback function. Hence, you can (for
+ * example) schedule an event at a particular time by calling
+ * schedule_timer() and storing the return value in your context
+ * structure as the time when that event is due. The first time a
+ * callback function gives you that value or more as `now', you do
+ * the thing.
+ *
+ * expire_timer_context() drops all current timers associated with
+ * a given value of ctx (for when you're about to free ctx).
+ *
+ * run_timers() is called from the front end when it has reason to
+ * think some timers have reached their moment, or when it simply
+ * needs to know how long to wait next. We pass it the time we
+ * think it is. It returns TRUE and places the time when the next
+ * timer needs to go off in `next', or alternatively it returns
+ * FALSE if there are no timers at all pending.
+ *
+ * timer_change_notify() must be supplied by the front end; it
+ * notifies the front end that a new timer has been added to the
+ * list which is sooner than any existing ones. It provides the
+ * time when that timer needs to go off.
+ *
+ * *** FRONT END IMPLEMENTORS NOTE:
+ *
+ * There's an important subtlety in the front-end implementation of
+ * the timer interface. When a front end is given a `next' value,
+ * either returned from run_timers() or via timer_change_notify(),
+ * it should ensure that it really passes _that value_ as the `now'
+ * parameter to its next run_timers call. It should _not_ simply
+ * call GETTICKCOUNT() to get the `now' parameter when invoking
+ * run_timers().
+ *
+ * The reason for this is that an OS's system clock might not agree
+ * exactly with the timing mechanisms it supplies to wait for a
+ * given interval. I'll illustrate this by the simple example of
+ * Unix Plink, which uses timeouts to select() in a way which for
+ * these purposes can simply be considered to be a wait() function.
+ * Suppose, for the sake of argument, that this wait() function
+ * tends to return early by 1%. Then a possible sequence of actions
+ * is:
+ *
+ * - run_timers() tells the front end that the next timer firing
+ * is 10000ms from now.
+ * - Front end calls wait(10000ms), but according to
+ * GETTICKCOUNT() it has only waited for 9900ms.
+ * - Front end calls run_timers() again, passing time T-100ms as
+ * `now'.
+ * - run_timers() does nothing, and says the next timer firing is
+ * still 100ms from now.
+ * - Front end calls wait(100ms), which only waits for 99ms.
+ * - Front end calls run_timers() yet again, passing time T-1ms.
+ * - run_timers() says there's still 1ms to wait.
+ * - Front end calls wait(1ms).
+ *
+ * If you're _lucky_ at this point, wait(1ms) will actually wait
+ * for 1ms and you'll only have woken the program up three times.
+ * If you're unlucky, wait(1ms) might do nothing at all due to
+ * being below some minimum threshold, and you might find your
+ * program spends the whole of the last millisecond tight-looping
+ * between wait() and run_timers().
+ *
+ * Instead, what you should do is to _save_ the precise `next'
+ * value provided by run_timers() or via timer_change_notify(), and
+ * use that precise value as the input to the next run_timers()
+ * call. So:
+ *
+ * - run_timers() tells the front end that the next timer firing
+ * is at time T, 10000ms from now.
+ * - Front end calls wait(10000ms).
+ * - Front end then immediately calls run_timers() and passes it
+ * time T, without stopping to check GETTICKCOUNT() at all.
+ *
+ * This guarantees that the program wakes up only as many times as
+ * there are actual timer actions to be taken, and that the timing
+ * mechanism will never send it into a tight loop.
+ *
+ * (It does also mean that the timer action in the above example
+ * will occur 100ms early, but this is not generally critical. And
+ * the hypothetical 1% error in wait() will be partially corrected
+ * for anyway when, _after_ run_timers() returns, you call
+ * GETTICKCOUNT() and compare the result with the returned `next'
+ * value to find out how long you have to make your next wait().)
+ */
+typedef void (*timer_fn_t)(void *ctx, long now);
+long schedule_timer(int ticks, timer_fn_t fn, void *ctx);
+void expire_timer_context(void *ctx);
+int run_timers(long now, long *next);
+void timer_change_notify(long next);