1/* vi:set ts=8 sts=4 sw=4:
2 *
3 * VIM - Vi IMproved	by Bram Moolenaar
4 * X-Windows communication by Flemming Madsen
5 *
6 * Do ":help uganda"  in Vim to read copying and usage conditions.
7 * Do ":help credits" in Vim to see a list of people who contributed.
8 * See README.txt for an overview of the Vim source code.
9 *
10 * Client for sending commands to an '+xcmdsrv' enabled vim.
11 * This is mostly a de-Vimified version of if_xcmdsrv.c in vim.
12 * See that file for a protocol specification.
13 *
14 * You can make a test program with a Makefile like:
15 *  xcmdsrv_client: xcmdsrv_client.c
16 *	cc -o $@ -g -DMAIN -I/usr/X11R6/include -L/usr/X11R6/lib $< -lX11
17 *
18 */
19
20#include <stdio.h>
21#include <string.h>
22#ifdef HAVE_SELECT
23#include <sys/time.h>
24#include <sys/types.h>
25#include <unistd.h>
26#else
27#include <sys/poll.h>
28#endif
29#include <X11/Intrinsic.h>
30#include <X11/Xatom.h>
31
32#define __ARGS(x) x
33
34/* Client API */
35char * sendToVim __ARGS((Display *dpy, char *name, char *cmd, int asKeys, int *code));
36
37#ifdef MAIN
38/* A sample program */
39main(int argc, char **argv)
40{
41    char    *res;
42    int	    code;
43
44    if (argc == 4)
45    {
46	if ((res = sendToVim(XOpenDisplay(NULL), argv[2], argv[3],
47			     argv[1][0] != 'e', &code)) != NULL)
48	{
49	    if (code)
50		printf("Error code returned: %d\n", code);
51	    puts(res);
52	}
53	exit(0);
54    }
55    else
56	fprintf(stderr, "Usage: %s {k|e} <server> <command>", argv[0]);
57
58    exit(1);
59}
60#endif
61
62/*
63 * Maximum size property that can be read at one time by
64 * this module:
65 */
66
67#define MAX_PROP_WORDS 100000
68
69/*
70 * Forward declarations for procedures defined later in this file:
71 */
72
73static int	x_error_check __ARGS((Display *dpy, XErrorEvent *error_event));
74static int	AppendPropCarefully __ARGS((Display *display,
75		    Window window, Atom property, char *value, int length));
76static Window	LookupName __ARGS((Display *dpy, char *name,
77		    int delete, char **loose));
78static int	SendInit __ARGS((Display *dpy));
79static char	*SendEventProc __ARGS((Display *dpy, XEvent *eventPtr,
80				      int expect, int *code));
81static int	IsSerialName __ARGS((char *name));
82
83/* Private variables */
84static Atom	registryProperty = None;
85static Atom	commProperty = None;
86static Window	commWindow = None;
87static int	got_x_error = FALSE;
88
89
90/*
91 * sendToVim --
92 *	Send to an instance of Vim via the X display.
93 *
94 * Results:
95 *	A string with the result or NULL. Caller must free if non-NULL
96 */
97
98    char *
99sendToVim(dpy, name, cmd, asKeys, code)
100    Display	*dpy;			/* Where to send. */
101    char	*name;			/* Where to send. */
102    char	*cmd;			/* What to send. */
103    int		asKeys;			/* Interpret as keystrokes or expr ? */
104    int		*code;			/* Return code. 0 => OK */
105{
106    Window	    w;
107    Atom	    *plist;
108    XErrorHandler   old_handler;
109#define STATIC_SPACE 500
110    char	    *property, staticSpace[STATIC_SPACE];
111    int		    length;
112    int		    res;
113    static int	    serial = 0;	/* Running count of sent commands.
114				 * Used to give each command a
115				 * different serial number. */
116    XEvent	    event;
117    XPropertyEvent  *e = (XPropertyEvent *)&event;
118    time_t	    start;
119    char	    *result;
120    char	    *loosename = NULL;
121
122    if (commProperty == None && dpy != NULL)
123    {
124	if (SendInit(dpy) < 0)
125	    return NULL;
126    }
127
128    /*
129     * Bind the server name to a communication window.
130     *
131     * Find any survivor with a serialno attached to the name if the
132     * original registrant of the wanted name is no longer present.
133     *
134     * Delete any lingering names from dead editors.
135     */
136
137    old_handler = XSetErrorHandler(x_error_check);
138    while (TRUE)
139    {
140	got_x_error = FALSE;
141	w = LookupName(dpy, name, 0, &loosename);
142	/* Check that the window is hot */
143	if (w != None)
144	{
145	    plist = XListProperties(dpy, w, &res);
146	    XSync(dpy, False);
147	    if (plist != NULL)
148		XFree(plist);
149	    if (got_x_error)
150	    {
151		LookupName(dpy, loosename ? loosename : name,
152			   /*DELETE=*/TRUE, NULL);
153		continue;
154	    }
155	}
156	break;
157    }
158    if (w == None)
159    {
160	fprintf(stderr, "no registered server named %s\n", name);
161	return NULL;
162    }
163    else if (loosename != NULL)
164	name = loosename;
165
166    /*
167     * Send the command to target interpreter by appending it to the
168     * comm window in the communication window.
169     */
170
171    length = strlen(name) + strlen(cmd) + 10;
172    if (length <= STATIC_SPACE)
173	property = staticSpace;
174    else
175	property = (char *) malloc((unsigned) length);
176
177    serial++;
178    sprintf(property, "%c%c%c-n %s%c-s %s",
179		      0, asKeys ? 'k' : 'c', 0, name, 0, cmd);
180    if (name == loosename)
181	free(loosename);
182    if (!asKeys)
183    {
184	/* Add a back reference to our comm window */
185	sprintf(property + length, "%c-r %x %d", 0, (uint) commWindow, serial);
186	length += strlen(property + length + 1) + 1;
187    }
188
189    res = AppendPropCarefully(dpy, w, commProperty, property, length + 1);
190    if (length > STATIC_SPACE)
191	free(property);
192    if (res < 0)
193    {
194	fprintf(stderr, "Failed to send command to the destination program\n");
195	return NULL;
196    }
197
198    if (asKeys) /* There is no answer for this - Keys are sent async */
199	return NULL;
200
201
202    /*
203     * Enter a loop processing X events & pooling chars until we see the result
204     */
205
206#define SEND_MSEC_POLL 50
207
208    time(&start);
209    while ((time((time_t *) 0) - start) < 60)
210    {
211	/* Look out for the answer */
212#ifndef HAVE_SELECT
213	struct pollfd   fds;
214
215	fds.fd = ConnectionNumber(dpy);
216	fds.events = POLLIN;
217	if (poll(&fds, 1, SEND_MSEC_POLL) < 0)
218	    break;
219#else
220	fd_set	    fds;
221	struct timeval  tv;
222
223	tv.tv_sec = 0;
224	tv.tv_usec =  SEND_MSEC_POLL * 1000;
225	FD_ZERO(&fds);
226	FD_SET(ConnectionNumber(dpy), &fds);
227	if (select(ConnectionNumber(dpy) + 1, &fds, NULL, NULL, &tv) < 0)
228	    break;
229#endif
230	while (XEventsQueued(dpy, QueuedAfterReading) > 0)
231	{
232	    XNextEvent(dpy, &event);
233	    if (event.type == PropertyNotify && e->window == commWindow)
234		if ((result = SendEventProc(dpy, &event, serial, code)) != NULL)
235		    return result;
236	}
237    }
238    return NULL;
239}
240
241
242/*
243 * SendInit --
244 *	This procedure is called to initialize the
245 *	communication channels for sending commands and
246 *	receiving results.
247 */
248
249    static int
250SendInit(dpy)
251    Display *dpy;
252{
253    XErrorHandler old_handler;
254
255    /*
256     * Create the window used for communication, and set up an
257     * event handler for it.
258     */
259    old_handler = XSetErrorHandler(x_error_check);
260    got_x_error = FALSE;
261
262    commProperty = XInternAtom(dpy, "Comm", False);
263    /* Change this back to "InterpRegistry" to talk to tk processes */
264    registryProperty = XInternAtom(dpy, "VimRegistry", False);
265
266    if (commWindow == None)
267    {
268	commWindow =
269	    XCreateSimpleWindow(dpy, XDefaultRootWindow(dpy),
270				getpid(), 0, 10, 10, 0,
271				WhitePixel(dpy, DefaultScreen(dpy)),
272				WhitePixel(dpy, DefaultScreen(dpy)));
273	XSelectInput(dpy, commWindow, PropertyChangeMask);
274    }
275
276    XSync(dpy, False);
277    (void) XSetErrorHandler(old_handler);
278
279    return got_x_error ? -1 : 0;
280}
281
282/*
283 * LookupName --
284 *	Given an interpreter name, see if the name exists in
285 *	the interpreter registry for a particular display.
286 *
287 * Results:
288 *	If the given name is registered, return the ID of
289 *	the window associated with the name.  If the name
290 *	isn't registered, then return 0.
291 */
292
293    static Window
294LookupName(dpy, name, delete, loose)
295    Display *dpy;	/* Display whose registry to check. */
296    char *name;		/* Name of an interpreter. */
297    int delete;		/* If non-zero, delete info about name. */
298    char **loose;	/* Do another search matching -999 if not found
299			   Return result here if a match is found */
300{
301    unsigned char   *regProp, *entry;
302    unsigned char   *p;
303    int		    result, actualFormat;
304    unsigned long   numItems, bytesAfter;
305    Atom	    actualType;
306    Window	    returnValue;
307
308    /*
309     * Read the registry property.
310     */
311
312    regProp = NULL;
313    result = XGetWindowProperty(dpy, RootWindow(dpy, 0), registryProperty, 0,
314				MAX_PROP_WORDS, False, XA_STRING, &actualType,
315				&actualFormat, &numItems, &bytesAfter,
316				&regProp);
317
318    if (actualType == None)
319	return 0;
320
321    /*
322     * If the property is improperly formed, then delete it.
323     */
324
325    if ((result != Success) || (actualFormat != 8) || (actualType != XA_STRING))
326    {
327	if (regProp != NULL)
328	    XFree(regProp);
329	XDeleteProperty(dpy, RootWindow(dpy, 0), registryProperty);
330	return 0;
331    }
332
333    /*
334     * Scan the property for the desired name.
335     */
336
337    returnValue = None;
338    entry = NULL;	/* Not needed, but eliminates compiler warning. */
339    for (p = regProp; (p - regProp) < numItems; )
340    {
341	entry = p;
342	while ((*p != 0) && (!isspace(*p)))
343	    p++;
344	if ((*p != 0) && (strcasecmp(name, p + 1) == 0))
345	{
346	    sscanf(entry, "%x", (uint*) &returnValue);
347	    break;
348	}
349	while (*p != 0)
350	    p++;
351	p++;
352    }
353
354    if (loose != NULL && returnValue == None && !IsSerialName(name))
355    {
356	for (p = regProp; (p - regProp) < numItems; )
357	{
358	    entry = p;
359	    while ((*p != 0) && (!isspace(*p)))
360		p++;
361	    if ((*p != 0) && IsSerialName(p + 1)
362		    && (strncmp(name, p + 1, strlen(name)) == 0))
363	    {
364		sscanf(entry, "%x", (uint*) &returnValue);
365		*loose = strdup(p + 1);
366		break;
367	    }
368	    while (*p != 0)
369		p++;
370	    p++;
371	}
372    }
373
374    /*
375     * Delete the property, if that is desired (copy down the
376     * remainder of the registry property to overlay the deleted
377     * info, then rewrite the property).
378     */
379
380    if ((delete) && (returnValue != None))
381    {
382	int count;
383
384	while (*p != 0)
385	    p++;
386	p++;
387	count = numItems - (p-regProp);
388	if (count > 0)
389	    memcpy(entry, p, count);
390	XChangeProperty(dpy, RootWindow(dpy, 0), registryProperty, XA_STRING,
391			8, PropModeReplace, regProp,
392			(int) (numItems - (p-entry)));
393	XSync(dpy, False);
394    }
395
396    XFree(regProp);
397    return returnValue;
398}
399
400    static char *
401SendEventProc(dpy, eventPtr, expected, code)
402    Display	   *dpy;
403    XEvent	    *eventPtr;		/* Information about event. */
404    int		    expected;		/* The one were waiting for */
405    int		    *code;		/* Return code. 0 => OK */
406{
407    unsigned char   *propInfo;
408    unsigned char   *p;
409    int		    result, actualFormat;
410    int		    retCode;
411    unsigned long   numItems, bytesAfter;
412    Atom	    actualType;
413
414    if ((eventPtr->xproperty.atom != commProperty)
415	    || (eventPtr->xproperty.state != PropertyNewValue))
416    {
417	return;
418    }
419
420    /*
421     * Read the comm property and delete it.
422     */
423
424    propInfo = NULL;
425    result = XGetWindowProperty(dpy, commWindow, commProperty, 0,
426				MAX_PROP_WORDS, True, XA_STRING, &actualType,
427				&actualFormat, &numItems, &bytesAfter,
428				&propInfo);
429
430    /*
431     * If the property doesn't exist or is improperly formed
432     * then ignore it.
433     */
434
435    if ((result != Success) || (actualType != XA_STRING)
436	    || (actualFormat != 8))
437    {
438	if (propInfo != NULL)
439	{
440	    XFree(propInfo);
441	}
442	return;
443    }
444
445    /*
446     * Several commands and results could arrive in the property at
447     * one time;  each iteration through the outer loop handles a
448     * single command or result.
449     */
450
451    for (p = propInfo; (p - propInfo) < numItems; )
452    {
453	/*
454	 * Ignore leading NULs; each command or result starts with a
455	 * NUL so that no matter how badly formed a preceding command
456	 * is, we'll be able to tell that a new command/result is
457	 * starting.
458	 */
459
460	if (*p == 0)
461	{
462	    p++;
463	    continue;
464	}
465
466	if ((*p == 'r') && (p[1] == 0))
467	{
468	    int	    serial, gotSerial;
469	    char  *res;
470
471	    /*
472	     * This is a reply to some command that we sent out.  Iterate
473	     * over all of its options.  Stop when we reach the end of the
474	     * property or something that doesn't look like an option.
475	     */
476
477	    p += 2;
478	    gotSerial = 0;
479	    res = "";
480	    retCode = 0;
481	    while (((p-propInfo) < numItems) && (*p == '-'))
482	    {
483		switch (p[1])
484		{
485		    case 'r':
486			if (p[2] == ' ')
487			    res = p + 3;
488			break;
489		    case 's':
490			if (sscanf(p + 2, " %d", &serial) == 1)
491			    gotSerial = 1;
492			break;
493		    case 'c':
494			if (sscanf(p + 2, " %d", &retCode) != 1)
495			    retCode = 0;
496			break;
497		}
498		while (*p != 0)
499		    p++;
500		p++;
501	    }
502
503	    if (!gotSerial)
504		continue;
505
506	    if (code != NULL)
507		*code = retCode;
508	    return serial == expected ? strdup(res) : NULL;
509	}
510	else
511	{
512	    /*
513	     * Didn't recognize this thing.  Just skip through the next
514	     * null character and try again.
515	     * Also, throw away commands that we cant process anyway.
516	     */
517
518	    while (*p != 0)
519		p++;
520	    p++;
521	}
522    }
523    XFree(propInfo);
524}
525
526/*
527 * AppendPropCarefully --
528 *
529 *	Append a given property to a given window, but set up
530 *	an X error handler so that if the append fails this
531 *	procedure can return an error code rather than having
532 *	Xlib panic.
533 *
534 *  Return:
535 *	0 on OK - -1 on error
536 *--------------------------------------------------------------
537 */
538
539    static int
540AppendPropCarefully(dpy, window, property, value, length)
541    Display *dpy;		/* Display on which to operate. */
542    Window window;		/* Window whose property is to
543				 * be modified. */
544    Atom property;		/* Name of property. */
545    char *value;		/* Characters  to append to property. */
546    int  length;		/* How much to append */
547{
548    XErrorHandler old_handler;
549
550    old_handler = XSetErrorHandler(x_error_check);
551    got_x_error = FALSE;
552    XChangeProperty(dpy, window, property, XA_STRING, 8,
553		    PropModeAppend, value, length);
554    XSync(dpy, False);
555    (void) XSetErrorHandler(old_handler);
556    return got_x_error ? -1 : 0;
557}
558
559
560/*
561 * Another X Error handler, just used to check for errors.
562 */
563/* ARGSUSED */
564    static int
565x_error_check(dpy, error_event)
566    Display *dpy;
567    XErrorEvent	*error_event;
568{
569    got_x_error = TRUE;
570    return 0;
571}
572
573/*
574 * Check if "str" looks like it had a serial number appended.
575 * Actually just checks if the name ends in a digit.
576 */
577    static int
578IsSerialName(str)
579    char   *str;
580{
581    int len = strlen(str);
582
583    return (len > 1 && isdigit(str[len - 1]));
584}
585