xref: /vim-8.2.3635/src/evalbuffer.c (revision 10893741)
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 
363     if (argvars[0].v_type == VAR_UNKNOWN)
364 	buf = curbuf;
365     else
366     {
367 	(void)tv_get_number(&argvars[0]);	// issue errmsg if type error
368 	++emsg_off;
369 	buf = tv_get_buf(&argvars[0], FALSE);
370 	--emsg_off;
371     }
372     rettv->v_type = VAR_STRING;
373     if (buf != NULL && buf->b_fname != NULL)
374 	rettv->vval.v_string = vim_strsave(buf->b_fname);
375     else
376 	rettv->vval.v_string = NULL;
377 }
378 
379 /*
380  * "bufnr(expr)" function
381  */
382     void
383 f_bufnr(typval_T *argvars, typval_T *rettv)
384 {
385     buf_T	*buf;
386     int		error = FALSE;
387     char_u	*name;
388 
389     if (argvars[0].v_type == VAR_UNKNOWN)
390 	buf = curbuf;
391     else
392     {
393 	(void)tv_get_number(&argvars[0]);    // issue errmsg if type error
394 	++emsg_off;
395 	buf = tv_get_buf(&argvars[0], FALSE);
396 	--emsg_off;
397     }
398 
399     // If the buffer isn't found and the second argument is not zero create a
400     // new buffer.
401     if (buf == NULL
402 	    && argvars[1].v_type != VAR_UNKNOWN
403 	    && tv_get_number_chk(&argvars[1], &error) != 0
404 	    && !error
405 	    && (name = tv_get_string_chk(&argvars[0])) != NULL
406 	    && !error)
407 	buf = buflist_new(name, NULL, (linenr_T)1, 0);
408 
409     if (buf != NULL)
410 	rettv->vval.v_number = buf->b_fnum;
411     else
412 	rettv->vval.v_number = -1;
413 }
414 
415     static void
416 buf_win_common(typval_T *argvars, typval_T *rettv, int get_nr)
417 {
418     win_T	*wp;
419     int		winnr = 0;
420     buf_T	*buf;
421 
422     (void)tv_get_number(&argvars[0]);	    // issue errmsg if type error
423     ++emsg_off;
424     buf = tv_get_buf(&argvars[0], TRUE);
425     FOR_ALL_WINDOWS(wp)
426     {
427 	++winnr;
428 	if (wp->w_buffer == buf)
429 	    break;
430     }
431     rettv->vval.v_number = (wp != NULL ? (get_nr ? winnr : wp->w_id) : -1);
432     --emsg_off;
433 }
434 
435 /*
436  * "bufwinid(nr)" function
437  */
438     void
439 f_bufwinid(typval_T *argvars, typval_T *rettv)
440 {
441     buf_win_common(argvars, rettv, FALSE);
442 }
443 
444 /*
445  * "bufwinnr(nr)" function
446  */
447     void
448 f_bufwinnr(typval_T *argvars, typval_T *rettv)
449 {
450     buf_win_common(argvars, rettv, TRUE);
451 }
452 
453 /*
454  * "deletebufline()" function
455  */
456     void
457 f_deletebufline(typval_T *argvars, typval_T *rettv)
458 {
459     buf_T	*buf;
460     linenr_T	first, last;
461     linenr_T	lnum;
462     long	count;
463     int		is_curbuf;
464     buf_T	*curbuf_save = NULL;
465     win_T	*curwin_save = NULL;
466     tabpage_T	*tp;
467     win_T	*wp;
468 
469     buf = tv_get_buf(&argvars[0], FALSE);
470     if (buf == NULL)
471     {
472 	rettv->vval.v_number = 1; // FAIL
473 	return;
474     }
475     is_curbuf = buf == curbuf;
476 
477     first = tv_get_lnum_buf(&argvars[1], buf);
478     if (argvars[2].v_type != VAR_UNKNOWN)
479 	last = tv_get_lnum_buf(&argvars[2], buf);
480     else
481 	last = first;
482 
483     if (buf->b_ml.ml_mfp == NULL || first < 1
484 			   || first > buf->b_ml.ml_line_count || last < first)
485     {
486 	rettv->vval.v_number = 1;	// FAIL
487 	return;
488     }
489 
490     if (!is_curbuf)
491     {
492 	curbuf_save = curbuf;
493 	curwin_save = curwin;
494 	curbuf = buf;
495 	find_win_for_curbuf();
496     }
497     if (last > curbuf->b_ml.ml_line_count)
498 	last = curbuf->b_ml.ml_line_count;
499     count = last - first + 1;
500 
501     // When coming here from Insert mode, sync undo, so that this can be
502     // undone separately from what was previously inserted.
503     if (u_sync_once == 2)
504     {
505 	u_sync_once = 1; // notify that u_sync() was called
506 	u_sync(TRUE);
507     }
508 
509     if (u_save(first - 1, last + 1) == FAIL)
510     {
511 	rettv->vval.v_number = 1;	// FAIL
512 	return;
513     }
514 
515     for (lnum = first; lnum <= last; ++lnum)
516 	ml_delete_flags(first, ML_DEL_MESSAGE);
517 
518     FOR_ALL_TAB_WINDOWS(tp, wp)
519 	if (wp->w_buffer == buf)
520 	{
521 	    if (wp->w_cursor.lnum > last)
522 		wp->w_cursor.lnum -= count;
523 	    else if (wp->w_cursor.lnum> first)
524 		wp->w_cursor.lnum = first;
525 	    if (wp->w_cursor.lnum > wp->w_buffer->b_ml.ml_line_count)
526 		wp->w_cursor.lnum = wp->w_buffer->b_ml.ml_line_count;
527 	}
528     check_cursor_col();
529     deleted_lines_mark(first, count);
530 
531     if (!is_curbuf)
532     {
533 	curbuf = curbuf_save;
534 	curwin = curwin_save;
535     }
536 }
537 
538 /*
539  * Returns buffer options, variables and other attributes in a dictionary.
540  */
541     static dict_T *
542 get_buffer_info(buf_T *buf)
543 {
544     dict_T	*dict;
545     tabpage_T	*tp;
546     win_T	*wp;
547     list_T	*windows;
548 
549     dict = dict_alloc();
550     if (dict == NULL)
551 	return NULL;
552 
553     dict_add_number(dict, "bufnr", buf->b_fnum);
554     dict_add_string(dict, "name", buf->b_ffname);
555     dict_add_number(dict, "lnum", buf == curbuf ? curwin->w_cursor.lnum
556 						     : buflist_findlnum(buf));
557     dict_add_number(dict, "linecount", buf->b_ml.ml_line_count);
558     dict_add_number(dict, "loaded", buf->b_ml.ml_mfp != NULL);
559     dict_add_number(dict, "listed", buf->b_p_bl);
560     dict_add_number(dict, "changed", bufIsChanged(buf));
561     dict_add_number(dict, "changedtick", CHANGEDTICK(buf));
562     dict_add_number(dict, "hidden",
563 			    buf->b_ml.ml_mfp != NULL && buf->b_nwindows == 0);
564 
565     // Get a reference to buffer variables
566     dict_add_dict(dict, "variables", buf->b_vars);
567 
568     // List of windows displaying this buffer
569     windows = list_alloc();
570     if (windows != NULL)
571     {
572 	FOR_ALL_TAB_WINDOWS(tp, wp)
573 	    if (wp->w_buffer == buf)
574 		list_append_number(windows, (varnumber_T)wp->w_id);
575 	dict_add_list(dict, "windows", windows);
576     }
577 
578 #ifdef FEAT_PROP_POPUP
579     // List of popup windows displaying this buffer
580     windows = list_alloc();
581     if (windows != NULL)
582     {
583 	FOR_ALL_POPUPWINS(wp)
584 	    if (wp->w_buffer == buf)
585 		list_append_number(windows, (varnumber_T)wp->w_id);
586 	FOR_ALL_TABPAGES(tp)
587 	    FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
588 		if (wp->w_buffer == buf)
589 		    list_append_number(windows, (varnumber_T)wp->w_id);
590 
591 	dict_add_list(dict, "popups", windows);
592     }
593 #endif
594 
595 #ifdef FEAT_SIGNS
596     if (buf->b_signlist != NULL)
597     {
598 	// List of signs placed in this buffer
599 	list_T	*signs = list_alloc();
600 	if (signs != NULL)
601 	{
602 	    get_buffer_signs(buf, signs);
603 	    dict_add_list(dict, "signs", signs);
604 	}
605     }
606 #endif
607 
608 #ifdef FEAT_VIMINFO
609     dict_add_number(dict, "lastused", buf->b_last_used);
610 #endif
611 
612     return dict;
613 }
614 
615 /*
616  * "getbufinfo()" function
617  */
618     void
619 f_getbufinfo(typval_T *argvars, typval_T *rettv)
620 {
621     buf_T	*buf = NULL;
622     buf_T	*argbuf = NULL;
623     dict_T	*d;
624     int		filtered = FALSE;
625     int		sel_buflisted = FALSE;
626     int		sel_bufloaded = FALSE;
627     int		sel_bufmodified = FALSE;
628 
629     if (rettv_list_alloc(rettv) != OK)
630 	return;
631 
632     // List of all the buffers or selected buffers
633     if (argvars[0].v_type == VAR_DICT)
634     {
635 	dict_T	*sel_d = argvars[0].vval.v_dict;
636 
637 	if (sel_d != NULL)
638 	{
639 	    dictitem_T	*di;
640 
641 	    filtered = TRUE;
642 
643 	    di = dict_find(sel_d, (char_u *)"buflisted", -1);
644 	    if (di != NULL && tv_get_number(&di->di_tv))
645 		sel_buflisted = TRUE;
646 
647 	    di = dict_find(sel_d, (char_u *)"bufloaded", -1);
648 	    if (di != NULL && tv_get_number(&di->di_tv))
649 		sel_bufloaded = TRUE;
650 
651 	    di = dict_find(sel_d, (char_u *)"bufmodified", -1);
652 	    if (di != NULL && tv_get_number(&di->di_tv))
653 		sel_bufmodified = TRUE;
654 	}
655     }
656     else if (argvars[0].v_type != VAR_UNKNOWN)
657     {
658 	// Information about one buffer.  Argument specifies the buffer
659 	(void)tv_get_number(&argvars[0]);   // issue errmsg if type error
660 	++emsg_off;
661 	argbuf = tv_get_buf(&argvars[0], FALSE);
662 	--emsg_off;
663 	if (argbuf == NULL)
664 	    return;
665     }
666 
667     // Return information about all the buffers or a specified buffer
668     FOR_ALL_BUFFERS(buf)
669     {
670 	if (argbuf != NULL && argbuf != buf)
671 	    continue;
672 	if (filtered && ((sel_bufloaded && buf->b_ml.ml_mfp == NULL)
673 			|| (sel_buflisted && !buf->b_p_bl)
674 			|| (sel_bufmodified && !buf->b_changed)))
675 	    continue;
676 
677 	d = get_buffer_info(buf);
678 	if (d != NULL)
679 	    list_append_dict(rettv->vval.v_list, d);
680 	if (argbuf != NULL)
681 	    return;
682     }
683 }
684 
685 /*
686  * Get line or list of lines from buffer "buf" into "rettv".
687  * Return a range (from start to end) of lines in rettv from the specified
688  * buffer.
689  * If 'retlist' is TRUE, then the lines are returned as a Vim List.
690  */
691     static void
692 get_buffer_lines(
693     buf_T	*buf,
694     linenr_T	start,
695     linenr_T	end,
696     int		retlist,
697     typval_T	*rettv)
698 {
699     char_u	*p;
700 
701     if (retlist)
702     {
703 	if (rettv_list_alloc(rettv) == FAIL)
704 	    return;
705     }
706     else
707     {
708 	rettv->v_type = VAR_STRING;
709 	rettv->vval.v_string = NULL;
710     }
711 
712     if (buf == NULL || buf->b_ml.ml_mfp == NULL || start < 0)
713 	return;
714 
715     if (!retlist)
716     {
717 	if (start >= 1 && start <= buf->b_ml.ml_line_count)
718 	    p = ml_get_buf(buf, start, FALSE);
719 	else
720 	    p = (char_u *)"";
721 	rettv->vval.v_string = vim_strsave(p);
722     }
723     else
724     {
725 	if (end < start)
726 	    return;
727 
728 	if (start < 1)
729 	    start = 1;
730 	if (end > buf->b_ml.ml_line_count)
731 	    end = buf->b_ml.ml_line_count;
732 	while (start <= end)
733 	    if (list_append_string(rettv->vval.v_list,
734 				 ml_get_buf(buf, start++, FALSE), -1) == FAIL)
735 		break;
736     }
737 }
738 
739 /*
740  * "getbufline()" function
741  */
742     void
743 f_getbufline(typval_T *argvars, typval_T *rettv)
744 {
745     linenr_T	lnum;
746     linenr_T	end;
747     buf_T	*buf;
748 
749     (void)tv_get_number(&argvars[0]);	    // issue errmsg if type error
750     ++emsg_off;
751     buf = tv_get_buf(&argvars[0], FALSE);
752     --emsg_off;
753 
754     lnum = tv_get_lnum_buf(&argvars[1], buf);
755     if (argvars[2].v_type == VAR_UNKNOWN)
756 	end = lnum;
757     else
758 	end = tv_get_lnum_buf(&argvars[2], buf);
759 
760     get_buffer_lines(buf, lnum, end, TRUE, rettv);
761 }
762 
763     type_T *
764 ret_f_getline(int argcount, type_T **argtypes UNUSED)
765 {
766     return argcount == 1 ? &t_string : &t_list_string;
767 }
768 
769 /*
770  * "getline(lnum, [end])" function
771  */
772     void
773 f_getline(typval_T *argvars, typval_T *rettv)
774 {
775     linenr_T	lnum;
776     linenr_T	end;
777     int		retlist;
778 
779     lnum = tv_get_lnum(argvars);
780     if (argvars[1].v_type == VAR_UNKNOWN)
781     {
782 	end = 0;
783 	retlist = FALSE;
784     }
785     else
786     {
787 	end = tv_get_lnum(&argvars[1]);
788 	retlist = TRUE;
789     }
790 
791     get_buffer_lines(curbuf, lnum, end, retlist, rettv);
792 }
793 
794 /*
795  * "setbufline()" function
796  */
797     void
798 f_setbufline(typval_T *argvars, typval_T *rettv)
799 {
800     linenr_T	lnum;
801     buf_T	*buf;
802 
803     buf = tv_get_buf(&argvars[0], FALSE);
804     if (buf == NULL)
805 	rettv->vval.v_number = 1; // FAIL
806     else
807     {
808 	lnum = tv_get_lnum_buf(&argvars[1], buf);
809 	set_buffer_lines(buf, lnum, FALSE, &argvars[2], rettv);
810     }
811 }
812 
813 /*
814  * "setline()" function
815  */
816     void
817 f_setline(typval_T *argvars, typval_T *rettv)
818 {
819     linenr_T	lnum = tv_get_lnum(&argvars[0]);
820 
821     set_buffer_lines(curbuf, lnum, FALSE, &argvars[1], rettv);
822 }
823 #endif  // FEAT_EVAL
824 
825 #if defined(FEAT_JOB_CHANNEL) \
826 	|| defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
827 	|| defined(PROTO)
828 /*
829  * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
830  * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
831  */
832     void
833 switch_buffer(bufref_T *save_curbuf, buf_T *buf)
834 {
835     block_autocmds();
836     set_bufref(save_curbuf, curbuf);
837     --curbuf->b_nwindows;
838     curbuf = buf;
839     curwin->w_buffer = buf;
840     ++curbuf->b_nwindows;
841 }
842 
843 /*
844  * Restore the current buffer after using switch_buffer().
845  */
846     void
847 restore_buffer(bufref_T *save_curbuf)
848 {
849     unblock_autocmds();
850     // Check for valid buffer, just in case.
851     if (bufref_valid(save_curbuf))
852     {
853 	--curbuf->b_nwindows;
854 	curwin->w_buffer = save_curbuf->br_buf;
855 	curbuf = save_curbuf->br_buf;
856 	++curbuf->b_nwindows;
857     }
858 }
859 
860 /*
861  * Find a window for buffer "buf".
862  * If found OK is returned and "wp" and "tp" are set to the window and tabpage.
863  * If not found FAIL is returned.
864  */
865     static int
866 find_win_for_buf(
867     buf_T     *buf,
868     win_T     **wp,
869     tabpage_T **tp)
870 {
871     FOR_ALL_TAB_WINDOWS(*tp, *wp)
872 	if ((*wp)->w_buffer == buf)
873 	    return OK;
874     return FAIL;
875 }
876 
877 /*
878  * Find a window that contains "buf" and switch to it.
879  * If there is no such window, use the current window and change "curbuf".
880  * Caller must initialize save_curbuf to NULL.
881  * restore_win_for_buf() MUST be called later!
882  */
883     void
884 switch_to_win_for_buf(
885     buf_T	*buf,
886     win_T	**save_curwinp,
887     tabpage_T	**save_curtabp,
888     bufref_T	*save_curbuf)
889 {
890     win_T	*wp;
891     tabpage_T	*tp;
892 
893     if (find_win_for_buf(buf, &wp, &tp) == FAIL)
894 	switch_buffer(save_curbuf, buf);
895     else if (switch_win(save_curwinp, save_curtabp, wp, tp, TRUE) == FAIL)
896     {
897 	restore_win(*save_curwinp, *save_curtabp, TRUE);
898 	switch_buffer(save_curbuf, buf);
899     }
900 }
901 
902     void
903 restore_win_for_buf(
904     win_T	*save_curwin,
905     tabpage_T	*save_curtab,
906     bufref_T	*save_curbuf)
907 {
908     if (save_curbuf->br_buf == NULL)
909 	restore_win(save_curwin, save_curtab, TRUE);
910     else
911 	restore_buffer(save_curbuf);
912 }
913 #endif
914