xref: /vim-8.2.3635/src/evalbuffer.c (revision 02aaad91)
1 /* vi:set ts=8 sts=4 sw=4 noet:
2  *
3  * VIM - Vi IMproved	by Bram Moolenaar
4  *
5  * Do ":help uganda"  in Vim to read copying and usage conditions.
6  * Do ":help credits" in Vim to see a list of people who contributed.
7  * See README.txt for an overview of the Vim source code.
8  */
9 
10 /*
11  * evalbuffer.c: Buffer related builtin functions
12  */
13 
14 #include "vim.h"
15 
16 #if defined(FEAT_EVAL) || defined(PROTO)
17 /*
18  * Mark references in functions of buffers.
19  */
20     int
21 set_ref_in_buffers(int copyID)
22 {
23     int		abort = FALSE;
24     buf_T	*bp;
25 
26     FOR_ALL_BUFFERS(bp)
27     {
28 	listener_T *lnr;
29 	typval_T tv;
30 
31 	for (lnr = bp->b_listener; !abort && lnr != NULL; lnr = lnr->lr_next)
32 	{
33 	    if (lnr->lr_callback.cb_partial != NULL)
34 	    {
35 		tv.v_type = VAR_PARTIAL;
36 		tv.vval.v_partial = lnr->lr_callback.cb_partial;
37 		abort = abort || set_ref_in_item(&tv, copyID, NULL, NULL);
38 	    }
39 	}
40 # ifdef FEAT_JOB_CHANNEL
41 	if (!abort && bp->b_prompt_callback.cb_partial != NULL)
42 	{
43 	    tv.v_type = VAR_PARTIAL;
44 	    tv.vval.v_partial = bp->b_prompt_callback.cb_partial;
45 	    abort = abort || set_ref_in_item(&tv, copyID, NULL, NULL);
46 	}
47 	if (!abort && bp->b_prompt_interrupt.cb_partial != NULL)
48 	{
49 	    tv.v_type = VAR_PARTIAL;
50 	    tv.vval.v_partial = bp->b_prompt_interrupt.cb_partial;
51 	    abort = abort || set_ref_in_item(&tv, copyID, NULL, NULL);
52 	}
53 # endif
54 	if (abort)
55 	    break;
56     }
57     return abort;
58 }
59 
60     buf_T *
61 buflist_find_by_name(char_u *name, int curtab_only)
62 {
63     int		save_magic;
64     char_u	*save_cpo;
65     buf_T	*buf;
66 
67     // Ignore 'magic' and 'cpoptions' here to make scripts portable
68     save_magic = p_magic;
69     p_magic = TRUE;
70     save_cpo = p_cpo;
71     p_cpo = (char_u *)"";
72 
73     buf = buflist_findnr(buflist_findpat(name, name + STRLEN(name),
74 						    TRUE, FALSE, curtab_only));
75 
76     p_magic = save_magic;
77     p_cpo = save_cpo;
78     return buf;
79 }
80 
81 /*
82  * Find a buffer by number or exact name.
83  */
84     buf_T *
85 find_buffer(typval_T *avar)
86 {
87     buf_T	*buf = NULL;
88 
89     if (avar->v_type == VAR_NUMBER)
90 	buf = buflist_findnr((int)avar->vval.v_number);
91     else if (avar->v_type == VAR_STRING && avar->vval.v_string != NULL)
92     {
93 	buf = buflist_findname_exp(avar->vval.v_string);
94 	if (buf == NULL)
95 	{
96 	    // No full path name match, try a match with a URL or a "nofile"
97 	    // buffer, these don't use the full path.
98 	    FOR_ALL_BUFFERS(buf)
99 		if (buf->b_fname != NULL
100 			&& (path_with_url(buf->b_fname)
101 #ifdef FEAT_QUICKFIX
102 			    || bt_nofilename(buf)
103 #endif
104 			   )
105 			&& STRCMP(buf->b_fname, avar->vval.v_string) == 0)
106 		    break;
107 	}
108     }
109     return buf;
110 }
111 
112 /*
113  * If there is a window for "curbuf", make it the current window.
114  */
115     static void
116 find_win_for_curbuf(void)
117 {
118     wininfo_T *wip;
119 
120     FOR_ALL_BUF_WININFO(curbuf, wip)
121     {
122 	if (wip->wi_win != NULL)
123 	{
124 	    curwin = wip->wi_win;
125 	    break;
126 	}
127     }
128 }
129 
130 /*
131  * Set line or list of lines in buffer "buf".
132  */
133     static void
134 set_buffer_lines(
135 	buf_T	    *buf,
136 	linenr_T    lnum_arg,
137 	int	    append,
138 	typval_T    *lines,
139 	typval_T    *rettv)
140 {
141     linenr_T    lnum = lnum_arg + (append ? 1 : 0);
142     char_u	*line = NULL;
143     list_T	*l = NULL;
144     listitem_T	*li = NULL;
145     long	added = 0;
146     linenr_T	append_lnum;
147     buf_T	*curbuf_save = NULL;
148     win_T	*curwin_save = NULL;
149     int		is_curbuf = buf == curbuf;
150 
151     // When using the current buffer ml_mfp will be set if needed.  Useful when
152     // setline() is used on startup.  For other buffers the buffer must be
153     // loaded.
154     if (buf == NULL || (!is_curbuf && buf->b_ml.ml_mfp == NULL) || lnum < 1)
155     {
156 	rettv->vval.v_number = 1;	// FAIL
157 	return;
158     }
159 
160     if (!is_curbuf)
161     {
162 	curbuf_save = curbuf;
163 	curwin_save = curwin;
164 	curbuf = buf;
165 	find_win_for_curbuf();
166     }
167 
168     if (append)
169 	// appendbufline() uses the line number below which we insert
170 	append_lnum = lnum - 1;
171     else
172 	// setbufline() uses the line number above which we insert, we only
173 	// append if it's below the last line
174 	append_lnum = curbuf->b_ml.ml_line_count;
175 
176     if (lines->v_type == VAR_LIST)
177     {
178 	l = lines->vval.v_list;
179 	if (l == NULL || list_len(l) == 0)
180 	{
181 	    // set proper return code
182 	    if (lnum > curbuf->b_ml.ml_line_count)
183 		rettv->vval.v_number = 1;	// FAIL
184 	    goto done;
185 	}
186 	CHECK_LIST_MATERIALIZE(l);
187 	li = l->lv_first;
188     }
189     else
190 	line = tv_get_string_chk(lines);
191 
192     // default result is zero == OK
193     for (;;)
194     {
195 	if (l != NULL)
196 	{
197 	    // list argument, get next string
198 	    if (li == NULL)
199 		break;
200 	    line = tv_get_string_chk(&li->li_tv);
201 	    li = li->li_next;
202 	}
203 
204 	rettv->vval.v_number = 1;	// FAIL
205 	if (line == NULL || lnum > curbuf->b_ml.ml_line_count + 1)
206 	    break;
207 
208 	// When coming here from Insert mode, sync undo, so that this can be
209 	// undone separately from what was previously inserted.
210 	if (u_sync_once == 2)
211 	{
212 	    u_sync_once = 1; // notify that u_sync() was called
213 	    u_sync(TRUE);
214 	}
215 
216 	if (!append && lnum <= curbuf->b_ml.ml_line_count)
217 	{
218 	    // Existing line, replace it.
219 	    // Removes any existing text properties.
220 	    if (u_savesub(lnum) == OK && ml_replace_len(
221 		      lnum, line, (colnr_T)STRLEN(line) + 1, TRUE, TRUE) == OK)
222 	    {
223 		changed_bytes(lnum, 0);
224 		if (is_curbuf && lnum == curwin->w_cursor.lnum)
225 		    check_cursor_col();
226 		rettv->vval.v_number = 0;	// OK
227 	    }
228 	}
229 	else if (added > 0 || u_save(lnum - 1, lnum) == OK)
230 	{
231 	    // append the line
232 	    ++added;
233 	    if (ml_append(lnum - 1, line, (colnr_T)0, FALSE) == OK)
234 		rettv->vval.v_number = 0;	// OK
235 	}
236 
237 	if (l == NULL)			// only one string argument
238 	    break;
239 	++lnum;
240     }
241 
242     if (added > 0)
243     {
244 	win_T	    *wp;
245 	tabpage_T   *tp;
246 
247 	appended_lines_mark(append_lnum, added);
248 
249 	// Only adjust the cursor for buffers other than the current, unless it
250 	// is the current window.  For curbuf and other windows it has been
251 	// done in mark_adjust_internal().
252 	FOR_ALL_TAB_WINDOWS(tp, wp)
253 	    if (wp->w_buffer == buf
254 		    && (wp->w_buffer != curbuf || wp == curwin)
255 		    && wp->w_cursor.lnum > append_lnum)
256 		wp->w_cursor.lnum += added;
257 	check_cursor_col();
258 	update_topline();
259     }
260 
261 done:
262     if (!is_curbuf)
263     {
264 	curbuf = curbuf_save;
265 	curwin = curwin_save;
266     }
267 }
268 
269 /*
270  * "append(lnum, string/list)" function
271  */
272     void
273 f_append(typval_T *argvars, typval_T *rettv)
274 {
275     linenr_T	lnum = tv_get_lnum(&argvars[0]);
276 
277     set_buffer_lines(curbuf, lnum, TRUE, &argvars[1], rettv);
278 }
279 
280 /*
281  * "appendbufline(buf, lnum, string/list)" function
282  */
283     void
284 f_appendbufline(typval_T *argvars, typval_T *rettv)
285 {
286     linenr_T	lnum;
287     buf_T	*buf;
288 
289     buf = tv_get_buf(&argvars[0], FALSE);
290     if (buf == NULL)
291 	rettv->vval.v_number = 1; // FAIL
292     else
293     {
294 	lnum = tv_get_lnum_buf(&argvars[1], buf);
295 	set_buffer_lines(buf, lnum, TRUE, &argvars[2], rettv);
296     }
297 }
298 
299 /*
300  * "bufadd(expr)" function
301  */
302     void
303 f_bufadd(typval_T *argvars, typval_T *rettv)
304 {
305     char_u *name = tv_get_string(&argvars[0]);
306 
307     rettv->vval.v_number = buflist_add(*name == NUL ? NULL : name, 0);
308 }
309 
310 /*
311  * "bufexists(expr)" function
312  */
313     void
314 f_bufexists(typval_T *argvars, typval_T *rettv)
315 {
316     rettv->vval.v_number = (find_buffer(&argvars[0]) != NULL);
317 }
318 
319 /*
320  * "buflisted(expr)" function
321  */
322     void
323 f_buflisted(typval_T *argvars, typval_T *rettv)
324 {
325     buf_T	*buf;
326 
327     buf = find_buffer(&argvars[0]);
328     rettv->vval.v_number = (buf != NULL && buf->b_p_bl);
329 }
330 
331 /*
332  * "bufload(expr)" function
333  */
334     void
335 f_bufload(typval_T *argvars, typval_T *rettv UNUSED)
336 {
337     buf_T	*buf = get_buf_arg(&argvars[0]);
338 
339     if (buf != NULL)
340 	buffer_ensure_loaded(buf);
341 }
342 
343 /*
344  * "bufloaded(expr)" function
345  */
346     void
347 f_bufloaded(typval_T *argvars, typval_T *rettv)
348 {
349     buf_T	*buf;
350 
351     buf = find_buffer(&argvars[0]);
352     rettv->vval.v_number = (buf != NULL && buf->b_ml.ml_mfp != NULL);
353 }
354 
355 /*
356  * "bufname(expr)" function
357  */
358     void
359 f_bufname(typval_T *argvars, typval_T *rettv)
360 {
361     buf_T	*buf;
362     typval_T	*tv = &argvars[0];
363 
364     if (tv->v_type == VAR_UNKNOWN)
365 	buf = curbuf;
366     else
367     {
368 	++emsg_off;
369 	buf = tv_get_buf(tv, FALSE);
370 	--emsg_off;
371 	if (buf == NULL
372 		&& tv->v_type != VAR_NUMBER
373 		&& tv->v_type != VAR_STRING)
374 	    // issue errmsg for type error
375 	    (void)tv_get_number(tv);
376     }
377     rettv->v_type = VAR_STRING;
378     if (buf != NULL && buf->b_fname != NULL)
379 	rettv->vval.v_string = vim_strsave(buf->b_fname);
380     else
381 	rettv->vval.v_string = NULL;
382 }
383 
384 /*
385  * "bufnr(expr)" function
386  */
387     void
388 f_bufnr(typval_T *argvars, typval_T *rettv)
389 {
390     buf_T	*buf;
391     int		error = FALSE;
392     char_u	*name;
393 
394     if (argvars[0].v_type == VAR_UNKNOWN)
395 	buf = curbuf;
396     else
397     {
398 	if (argvars[0].v_type != VAR_STRING)
399 	    (void)tv_get_number(&argvars[0]);    // issue errmsg if type error
400 	++emsg_off;
401 	buf = tv_get_buf(&argvars[0], FALSE);
402 	--emsg_off;
403     }
404 
405     // If the buffer isn't found and the second argument is not zero create a
406     // new buffer.
407     if (buf == NULL
408 	    && argvars[1].v_type != VAR_UNKNOWN
409 	    && tv_get_number_chk(&argvars[1], &error) != 0
410 	    && !error
411 	    && (name = tv_get_string_chk(&argvars[0])) != NULL
412 	    && !error)
413 	buf = buflist_new(name, NULL, (linenr_T)1, 0);
414 
415     if (buf != NULL)
416 	rettv->vval.v_number = buf->b_fnum;
417     else
418 	rettv->vval.v_number = -1;
419 }
420 
421     static void
422 buf_win_common(typval_T *argvars, typval_T *rettv, int get_nr)
423 {
424     win_T	*wp;
425     int		winnr = 0;
426     buf_T	*buf;
427 
428     (void)tv_get_number(&argvars[0]);	    // issue errmsg if type error
429     ++emsg_off;
430     buf = tv_get_buf(&argvars[0], TRUE);
431     FOR_ALL_WINDOWS(wp)
432     {
433 	++winnr;
434 	if (wp->w_buffer == buf)
435 	    break;
436     }
437     rettv->vval.v_number = (wp != NULL ? (get_nr ? winnr : wp->w_id) : -1);
438     --emsg_off;
439 }
440 
441 /*
442  * "bufwinid(nr)" function
443  */
444     void
445 f_bufwinid(typval_T *argvars, typval_T *rettv)
446 {
447     buf_win_common(argvars, rettv, FALSE);
448 }
449 
450 /*
451  * "bufwinnr(nr)" function
452  */
453     void
454 f_bufwinnr(typval_T *argvars, typval_T *rettv)
455 {
456     buf_win_common(argvars, rettv, TRUE);
457 }
458 
459 /*
460  * "deletebufline()" function
461  */
462     void
463 f_deletebufline(typval_T *argvars, typval_T *rettv)
464 {
465     buf_T	*buf;
466     linenr_T	first, last;
467     linenr_T	lnum;
468     long	count;
469     int		is_curbuf;
470     buf_T	*curbuf_save = NULL;
471     win_T	*curwin_save = NULL;
472     tabpage_T	*tp;
473     win_T	*wp;
474 
475     buf = tv_get_buf(&argvars[0], FALSE);
476     if (buf == NULL)
477     {
478 	rettv->vval.v_number = 1; // FAIL
479 	return;
480     }
481     is_curbuf = buf == curbuf;
482 
483     first = tv_get_lnum_buf(&argvars[1], buf);
484     if (argvars[2].v_type != VAR_UNKNOWN)
485 	last = tv_get_lnum_buf(&argvars[2], buf);
486     else
487 	last = first;
488 
489     if (buf->b_ml.ml_mfp == NULL || first < 1
490 			   || first > buf->b_ml.ml_line_count || last < first)
491     {
492 	rettv->vval.v_number = 1;	// FAIL
493 	return;
494     }
495 
496     if (!is_curbuf)
497     {
498 	curbuf_save = curbuf;
499 	curwin_save = curwin;
500 	curbuf = buf;
501 	find_win_for_curbuf();
502     }
503     if (last > curbuf->b_ml.ml_line_count)
504 	last = curbuf->b_ml.ml_line_count;
505     count = last - first + 1;
506 
507     // When coming here from Insert mode, sync undo, so that this can be
508     // undone separately from what was previously inserted.
509     if (u_sync_once == 2)
510     {
511 	u_sync_once = 1; // notify that u_sync() was called
512 	u_sync(TRUE);
513     }
514 
515     if (u_save(first - 1, last + 1) == FAIL)
516     {
517 	rettv->vval.v_number = 1;	// FAIL
518 	return;
519     }
520 
521     for (lnum = first; lnum <= last; ++lnum)
522 	ml_delete_flags(first, ML_DEL_MESSAGE);
523 
524     FOR_ALL_TAB_WINDOWS(tp, wp)
525 	if (wp->w_buffer == buf)
526 	{
527 	    if (wp->w_cursor.lnum > last)
528 		wp->w_cursor.lnum -= count;
529 	    else if (wp->w_cursor.lnum> first)
530 		wp->w_cursor.lnum = first;
531 	    if (wp->w_cursor.lnum > wp->w_buffer->b_ml.ml_line_count)
532 		wp->w_cursor.lnum = wp->w_buffer->b_ml.ml_line_count;
533 	}
534     check_cursor_col();
535     deleted_lines_mark(first, count);
536 
537     if (!is_curbuf)
538     {
539 	curbuf = curbuf_save;
540 	curwin = curwin_save;
541     }
542 }
543 
544 /*
545  * Returns buffer options, variables and other attributes in a dictionary.
546  */
547     static dict_T *
548 get_buffer_info(buf_T *buf)
549 {
550     dict_T	*dict;
551     tabpage_T	*tp;
552     win_T	*wp;
553     list_T	*windows;
554 
555     dict = dict_alloc();
556     if (dict == NULL)
557 	return NULL;
558 
559     dict_add_number(dict, "bufnr", buf->b_fnum);
560     dict_add_string(dict, "name", buf->b_ffname);
561     dict_add_number(dict, "lnum", buf == curbuf ? curwin->w_cursor.lnum
562 						     : buflist_findlnum(buf));
563     dict_add_number(dict, "linecount", buf->b_ml.ml_line_count);
564     dict_add_number(dict, "loaded", buf->b_ml.ml_mfp != NULL);
565     dict_add_number(dict, "listed", buf->b_p_bl);
566     dict_add_number(dict, "changed", bufIsChanged(buf));
567     dict_add_number(dict, "changedtick", CHANGEDTICK(buf));
568     dict_add_number(dict, "hidden",
569 			    buf->b_ml.ml_mfp != NULL && buf->b_nwindows == 0);
570 
571     // Get a reference to buffer variables
572     dict_add_dict(dict, "variables", buf->b_vars);
573 
574     // List of windows displaying this buffer
575     windows = list_alloc();
576     if (windows != NULL)
577     {
578 	FOR_ALL_TAB_WINDOWS(tp, wp)
579 	    if (wp->w_buffer == buf)
580 		list_append_number(windows, (varnumber_T)wp->w_id);
581 	dict_add_list(dict, "windows", windows);
582     }
583 
584 #ifdef FEAT_PROP_POPUP
585     // List of popup windows displaying this buffer
586     windows = list_alloc();
587     if (windows != NULL)
588     {
589 	FOR_ALL_POPUPWINS(wp)
590 	    if (wp->w_buffer == buf)
591 		list_append_number(windows, (varnumber_T)wp->w_id);
592 	FOR_ALL_TABPAGES(tp)
593 	    FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
594 		if (wp->w_buffer == buf)
595 		    list_append_number(windows, (varnumber_T)wp->w_id);
596 
597 	dict_add_list(dict, "popups", windows);
598     }
599 #endif
600 
601 #ifdef FEAT_SIGNS
602     if (buf->b_signlist != NULL)
603     {
604 	// List of signs placed in this buffer
605 	list_T	*signs = list_alloc();
606 	if (signs != NULL)
607 	{
608 	    get_buffer_signs(buf, signs);
609 	    dict_add_list(dict, "signs", signs);
610 	}
611     }
612 #endif
613 
614 #ifdef FEAT_VIMINFO
615     dict_add_number(dict, "lastused", buf->b_last_used);
616 #endif
617 
618     return dict;
619 }
620 
621 /*
622  * "getbufinfo()" function
623  */
624     void
625 f_getbufinfo(typval_T *argvars, typval_T *rettv)
626 {
627     buf_T	*buf = NULL;
628     buf_T	*argbuf = NULL;
629     dict_T	*d;
630     int		filtered = FALSE;
631     int		sel_buflisted = FALSE;
632     int		sel_bufloaded = FALSE;
633     int		sel_bufmodified = FALSE;
634 
635     if (rettv_list_alloc(rettv) != OK)
636 	return;
637 
638     // List of all the buffers or selected buffers
639     if (argvars[0].v_type == VAR_DICT)
640     {
641 	dict_T	*sel_d = argvars[0].vval.v_dict;
642 
643 	if (sel_d != NULL)
644 	{
645 	    dictitem_T	*di;
646 
647 	    filtered = TRUE;
648 
649 	    di = dict_find(sel_d, (char_u *)"buflisted", -1);
650 	    if (di != NULL && tv_get_number(&di->di_tv))
651 		sel_buflisted = TRUE;
652 
653 	    di = dict_find(sel_d, (char_u *)"bufloaded", -1);
654 	    if (di != NULL && tv_get_number(&di->di_tv))
655 		sel_bufloaded = TRUE;
656 
657 	    di = dict_find(sel_d, (char_u *)"bufmodified", -1);
658 	    if (di != NULL && tv_get_number(&di->di_tv))
659 		sel_bufmodified = TRUE;
660 	}
661     }
662     else if (argvars[0].v_type != VAR_UNKNOWN)
663     {
664 	// Information about one buffer.  Argument specifies the buffer
665 	(void)tv_get_number(&argvars[0]);   // issue errmsg if type error
666 	++emsg_off;
667 	argbuf = tv_get_buf(&argvars[0], FALSE);
668 	--emsg_off;
669 	if (argbuf == NULL)
670 	    return;
671     }
672 
673     // Return information about all the buffers or a specified buffer
674     FOR_ALL_BUFFERS(buf)
675     {
676 	if (argbuf != NULL && argbuf != buf)
677 	    continue;
678 	if (filtered && ((sel_bufloaded && buf->b_ml.ml_mfp == NULL)
679 			|| (sel_buflisted && !buf->b_p_bl)
680 			|| (sel_bufmodified && !buf->b_changed)))
681 	    continue;
682 
683 	d = get_buffer_info(buf);
684 	if (d != NULL)
685 	    list_append_dict(rettv->vval.v_list, d);
686 	if (argbuf != NULL)
687 	    return;
688     }
689 }
690 
691 /*
692  * Get line or list of lines from buffer "buf" into "rettv".
693  * Return a range (from start to end) of lines in rettv from the specified
694  * buffer.
695  * If 'retlist' is TRUE, then the lines are returned as a Vim List.
696  */
697     static void
698 get_buffer_lines(
699     buf_T	*buf,
700     linenr_T	start,
701     linenr_T	end,
702     int		retlist,
703     typval_T	*rettv)
704 {
705     char_u	*p;
706 
707     if (retlist)
708     {
709 	if (rettv_list_alloc(rettv) == FAIL)
710 	    return;
711     }
712     else
713     {
714 	rettv->v_type = VAR_STRING;
715 	rettv->vval.v_string = NULL;
716     }
717 
718     if (buf == NULL || buf->b_ml.ml_mfp == NULL || start < 0)
719 	return;
720 
721     if (!retlist)
722     {
723 	if (start >= 1 && start <= buf->b_ml.ml_line_count)
724 	    p = ml_get_buf(buf, start, FALSE);
725 	else
726 	    p = (char_u *)"";
727 	rettv->vval.v_string = vim_strsave(p);
728     }
729     else
730     {
731 	if (end < start)
732 	    return;
733 
734 	if (start < 1)
735 	    start = 1;
736 	if (end > buf->b_ml.ml_line_count)
737 	    end = buf->b_ml.ml_line_count;
738 	while (start <= end)
739 	    if (list_append_string(rettv->vval.v_list,
740 				 ml_get_buf(buf, start++, FALSE), -1) == FAIL)
741 		break;
742     }
743 }
744 
745 /*
746  * "getbufline()" function
747  */
748     void
749 f_getbufline(typval_T *argvars, typval_T *rettv)
750 {
751     linenr_T	lnum;
752     linenr_T	end;
753     buf_T	*buf;
754 
755     (void)tv_get_number(&argvars[0]);	    // issue errmsg if type error
756     ++emsg_off;
757     buf = tv_get_buf(&argvars[0], FALSE);
758     --emsg_off;
759 
760     lnum = tv_get_lnum_buf(&argvars[1], buf);
761     if (argvars[2].v_type == VAR_UNKNOWN)
762 	end = lnum;
763     else
764 	end = tv_get_lnum_buf(&argvars[2], buf);
765 
766     get_buffer_lines(buf, lnum, end, TRUE, rettv);
767 }
768 
769     type_T *
770 ret_f_getline(int argcount, type_T **argtypes UNUSED)
771 {
772     return argcount == 1 ? &t_string : &t_list_string;
773 }
774 
775 /*
776  * "getline(lnum, [end])" function
777  */
778     void
779 f_getline(typval_T *argvars, typval_T *rettv)
780 {
781     linenr_T	lnum;
782     linenr_T	end;
783     int		retlist;
784 
785     lnum = tv_get_lnum(argvars);
786     if (argvars[1].v_type == VAR_UNKNOWN)
787     {
788 	end = 0;
789 	retlist = FALSE;
790     }
791     else
792     {
793 	end = tv_get_lnum(&argvars[1]);
794 	retlist = TRUE;
795     }
796 
797     get_buffer_lines(curbuf, lnum, end, retlist, rettv);
798 }
799 
800 /*
801  * "setbufline()" function
802  */
803     void
804 f_setbufline(typval_T *argvars, typval_T *rettv)
805 {
806     linenr_T	lnum;
807     buf_T	*buf;
808 
809     buf = tv_get_buf(&argvars[0], FALSE);
810     if (buf == NULL)
811 	rettv->vval.v_number = 1; // FAIL
812     else
813     {
814 	lnum = tv_get_lnum_buf(&argvars[1], buf);
815 	set_buffer_lines(buf, lnum, FALSE, &argvars[2], rettv);
816     }
817 }
818 
819 /*
820  * "setline()" function
821  */
822     void
823 f_setline(typval_T *argvars, typval_T *rettv)
824 {
825     linenr_T	lnum = tv_get_lnum(&argvars[0]);
826 
827     set_buffer_lines(curbuf, lnum, FALSE, &argvars[1], rettv);
828 }
829 #endif  // FEAT_EVAL
830 
831 #if defined(FEAT_JOB_CHANNEL) \
832 	|| defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
833 	|| defined(PROTO)
834 /*
835  * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
836  * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
837  */
838     void
839 switch_buffer(bufref_T *save_curbuf, buf_T *buf)
840 {
841     block_autocmds();
842     set_bufref(save_curbuf, curbuf);
843     --curbuf->b_nwindows;
844     curbuf = buf;
845     curwin->w_buffer = buf;
846     ++curbuf->b_nwindows;
847 }
848 
849 /*
850  * Restore the current buffer after using switch_buffer().
851  */
852     void
853 restore_buffer(bufref_T *save_curbuf)
854 {
855     unblock_autocmds();
856     // Check for valid buffer, just in case.
857     if (bufref_valid(save_curbuf))
858     {
859 	--curbuf->b_nwindows;
860 	curwin->w_buffer = save_curbuf->br_buf;
861 	curbuf = save_curbuf->br_buf;
862 	++curbuf->b_nwindows;
863     }
864 }
865 
866 /*
867  * Find a window for buffer "buf".
868  * If found OK is returned and "wp" and "tp" are set to the window and tabpage.
869  * If not found FAIL is returned.
870  */
871     static int
872 find_win_for_buf(
873     buf_T     *buf,
874     win_T     **wp,
875     tabpage_T **tp)
876 {
877     FOR_ALL_TAB_WINDOWS(*tp, *wp)
878 	if ((*wp)->w_buffer == buf)
879 	    return OK;
880     return FAIL;
881 }
882 
883 /*
884  * Find a window that contains "buf" and switch to it.
885  * If there is no such window, use the current window and change "curbuf".
886  * Caller must initialize save_curbuf to NULL.
887  * restore_win_for_buf() MUST be called later!
888  */
889     void
890 switch_to_win_for_buf(
891     buf_T	*buf,
892     win_T	**save_curwinp,
893     tabpage_T	**save_curtabp,
894     bufref_T	*save_curbuf)
895 {
896     win_T	*wp;
897     tabpage_T	*tp;
898 
899     if (find_win_for_buf(buf, &wp, &tp) == FAIL)
900 	switch_buffer(save_curbuf, buf);
901     else if (switch_win(save_curwinp, save_curtabp, wp, tp, TRUE) == FAIL)
902     {
903 	restore_win(*save_curwinp, *save_curtabp, TRUE);
904 	switch_buffer(save_curbuf, buf);
905     }
906 }
907 
908     void
909 restore_win_for_buf(
910     win_T	*save_curwin,
911     tabpage_T	*save_curtab,
912     bufref_T	*save_curbuf)
913 {
914     if (save_curbuf->br_buf == NULL)
915 	restore_win(save_curwin, save_curtab, TRUE);
916     else
917 	restore_buffer(save_curbuf);
918 }
919 #endif
920