xref: /vim-8.2.3635/src/evalbuffer.c (revision 4490ec4e)
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 = empty_option;
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 (in_vim9script() && check_for_string_arg(avar, 0) == FAIL)
92 	return NULL;
93     else if (avar->v_type == VAR_STRING && avar->vval.v_string != NULL)
94     {
95 	buf = buflist_findname_exp(avar->vval.v_string);
96 	if (buf == NULL)
97 	{
98 	    // No full path name match, try a match with a URL or a "nofile"
99 	    // buffer, these don't use the full path.
100 	    FOR_ALL_BUFFERS(buf)
101 		if (buf->b_fname != NULL
102 			&& (path_with_url(buf->b_fname)
103 #ifdef FEAT_QUICKFIX
104 			    || bt_nofilename(buf)
105 #endif
106 			   )
107 			&& STRCMP(buf->b_fname, avar->vval.v_string) == 0)
108 		    break;
109 	}
110     }
111     return buf;
112 }
113 
114 /*
115  * If there is a window for "curbuf", make it the current window.
116  */
117     static void
118 find_win_for_curbuf(void)
119 {
120     wininfo_T *wip;
121 
122     FOR_ALL_BUF_WININFO(curbuf, wip)
123     {
124 	if (wip->wi_win != NULL)
125 	{
126 	    curwin = wip->wi_win;
127 	    break;
128 	}
129     }
130 }
131 
132 /*
133  * Set line or list of lines in buffer "buf" to "lines".
134  * Any type is allowed and converted to a string.
135  */
136     static void
137 set_buffer_lines(
138 	buf_T	    *buf,
139 	linenr_T    lnum_arg,
140 	int	    append,
141 	typval_T    *lines,
142 	typval_T    *rettv)
143 {
144     linenr_T    lnum = lnum_arg + (append ? 1 : 0);
145     char_u	*line = NULL;
146     list_T	*l = NULL;
147     listitem_T	*li = NULL;
148     long	added = 0;
149     linenr_T	append_lnum;
150     buf_T	*curbuf_save = NULL;
151     win_T	*curwin_save = NULL;
152     int		is_curbuf = buf == curbuf;
153 
154     // When using the current buffer ml_mfp will be set if needed.  Useful when
155     // setline() is used on startup.  For other buffers the buffer must be
156     // loaded.
157     if (buf == NULL || (!is_curbuf && buf->b_ml.ml_mfp == NULL) || lnum < 1)
158     {
159 	rettv->vval.v_number = 1;	// FAIL
160 	return;
161     }
162 
163     if (!is_curbuf)
164     {
165 	curbuf_save = curbuf;
166 	curwin_save = curwin;
167 	curbuf = buf;
168 	find_win_for_curbuf();
169     }
170 
171     if (append)
172 	// appendbufline() uses the line number below which we insert
173 	append_lnum = lnum - 1;
174     else
175 	// setbufline() uses the line number above which we insert, we only
176 	// append if it's below the last line
177 	append_lnum = curbuf->b_ml.ml_line_count;
178 
179     if (lines->v_type == VAR_LIST)
180     {
181 	l = lines->vval.v_list;
182 	if (l == NULL || list_len(l) == 0)
183 	{
184 	    // set proper return code
185 	    if (lnum > curbuf->b_ml.ml_line_count)
186 		rettv->vval.v_number = 1;	// FAIL
187 	    goto done;
188 	}
189 	CHECK_LIST_MATERIALIZE(l);
190 	li = l->lv_first;
191     }
192     else
193 	line = typval_tostring(lines, FALSE);
194 
195     // default result is zero == OK
196     for (;;)
197     {
198 	if (l != NULL)
199 	{
200 	    // list argument, get next string
201 	    if (li == NULL)
202 		break;
203 	    vim_free(line);
204 	    line = typval_tostring(&li->li_tv, FALSE);
205 	    li = li->li_next;
206 	}
207 
208 	rettv->vval.v_number = 1;	// FAIL
209 	if (line == NULL || lnum > curbuf->b_ml.ml_line_count + 1)
210 	    break;
211 
212 	// When coming here from Insert mode, sync undo, so that this can be
213 	// undone separately from what was previously inserted.
214 	if (u_sync_once == 2)
215 	{
216 	    u_sync_once = 1; // notify that u_sync() was called
217 	    u_sync(TRUE);
218 	}
219 
220 	if (!append && lnum <= curbuf->b_ml.ml_line_count)
221 	{
222 	    // Existing line, replace it.
223 	    // Removes any existing text properties.
224 	    if (u_savesub(lnum) == OK && ml_replace_len(
225 		      lnum, line, (colnr_T)STRLEN(line) + 1, TRUE, TRUE) == OK)
226 	    {
227 		changed_bytes(lnum, 0);
228 		if (is_curbuf && lnum == curwin->w_cursor.lnum)
229 		    check_cursor_col();
230 		rettv->vval.v_number = 0;	// OK
231 	    }
232 	}
233 	else if (added > 0 || u_save(lnum - 1, lnum) == OK)
234 	{
235 	    // append the line
236 	    ++added;
237 	    if (ml_append(lnum - 1, line, (colnr_T)0, FALSE) == OK)
238 		rettv->vval.v_number = 0;	// OK
239 	}
240 
241 	if (l == NULL)			// only one string argument
242 	    break;
243 	++lnum;
244     }
245     vim_free(line);
246 
247     if (added > 0)
248     {
249 	win_T	    *wp;
250 	tabpage_T   *tp;
251 
252 	appended_lines_mark(append_lnum, added);
253 
254 	// Only adjust the cursor for buffers other than the current, unless it
255 	// is the current window.  For curbuf and other windows it has been
256 	// done in mark_adjust_internal().
257 	FOR_ALL_TAB_WINDOWS(tp, wp)
258 	    if (wp->w_buffer == buf
259 		    && (wp->w_buffer != curbuf || wp == curwin)
260 		    && wp->w_cursor.lnum > append_lnum)
261 		wp->w_cursor.lnum += added;
262 	check_cursor_col();
263 	update_topline();
264     }
265 
266 done:
267     if (!is_curbuf)
268     {
269 	curbuf = curbuf_save;
270 	curwin = curwin_save;
271     }
272 }
273 
274 /*
275  * "append(lnum, string/list)" function
276  */
277     void
278 f_append(typval_T *argvars, typval_T *rettv)
279 {
280     linenr_T	lnum;
281 
282     if (in_vim9script() && check_for_lnum_arg(argvars, 0) == FAIL)
283 	return;
284 
285     lnum = tv_get_lnum(&argvars[0]);
286     set_buffer_lines(curbuf, lnum, TRUE, &argvars[1], rettv);
287 }
288 
289 /*
290  * "appendbufline(buf, lnum, string/list)" function
291  */
292     void
293 f_appendbufline(typval_T *argvars, typval_T *rettv)
294 {
295     linenr_T	lnum;
296     buf_T	*buf;
297 
298     if (in_vim9script()
299 	    && (check_for_buffer_arg(argvars, 0) == FAIL
300 		|| check_for_lnum_arg(argvars, 1) == FAIL
301 		|| check_for_string_or_number_or_list_arg(argvars, 2) == FAIL))
302 	return;
303 
304     buf = tv_get_buf(&argvars[0], FALSE);
305     if (buf == NULL)
306 	rettv->vval.v_number = 1; // FAIL
307     else
308     {
309 	lnum = tv_get_lnum_buf(&argvars[1], buf);
310 	set_buffer_lines(buf, lnum, TRUE, &argvars[2], rettv);
311     }
312 }
313 
314 /*
315  * "bufadd(expr)" function
316  */
317     void
318 f_bufadd(typval_T *argvars, typval_T *rettv)
319 {
320     char_u *name;
321 
322     if (in_vim9script() && check_for_string_arg(argvars, 0) == FAIL)
323 	return;
324 
325     name = tv_get_string(&argvars[0]);
326     rettv->vval.v_number = buflist_add(*name == NUL ? NULL : name, 0);
327 }
328 
329 /*
330  * "bufexists(expr)" function
331  */
332     void
333 f_bufexists(typval_T *argvars, typval_T *rettv)
334 {
335     if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
336 	return;
337 
338     rettv->vval.v_number = (find_buffer(&argvars[0]) != NULL);
339 }
340 
341 /*
342  * "buflisted(expr)" function
343  */
344     void
345 f_buflisted(typval_T *argvars, typval_T *rettv)
346 {
347     buf_T	*buf;
348 
349     if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
350 	return;
351 
352     buf = find_buffer(&argvars[0]);
353     rettv->vval.v_number = (buf != NULL && buf->b_p_bl);
354 }
355 
356 /*
357  * "bufload(expr)" function
358  */
359     void
360 f_bufload(typval_T *argvars, typval_T *rettv UNUSED)
361 {
362     buf_T	*buf;
363 
364     if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
365 	return;
366 
367     buf = get_buf_arg(&argvars[0]);
368     if (buf != NULL)
369 	buffer_ensure_loaded(buf);
370 }
371 
372 /*
373  * "bufloaded(expr)" function
374  */
375     void
376 f_bufloaded(typval_T *argvars, typval_T *rettv)
377 {
378     buf_T	*buf;
379 
380     if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
381 	return;
382 
383     buf = find_buffer(&argvars[0]);
384     rettv->vval.v_number = (buf != NULL && buf->b_ml.ml_mfp != NULL);
385 }
386 
387 /*
388  * "bufname(expr)" function
389  */
390     void
391 f_bufname(typval_T *argvars, typval_T *rettv)
392 {
393     buf_T	*buf;
394     typval_T	*tv = &argvars[0];
395 
396     if (in_vim9script() && check_for_opt_buffer_arg(argvars, 0) == FAIL)
397 	return;
398 
399     if (tv->v_type == VAR_UNKNOWN)
400 	buf = curbuf;
401     else
402 	buf = tv_get_buf_from_arg(tv);
403     rettv->v_type = VAR_STRING;
404     if (buf != NULL && buf->b_fname != NULL)
405 	rettv->vval.v_string = vim_strsave(buf->b_fname);
406     else
407 	rettv->vval.v_string = NULL;
408 }
409 
410 /*
411  * "bufnr(expr)" function
412  */
413     void
414 f_bufnr(typval_T *argvars, typval_T *rettv)
415 {
416     buf_T	*buf;
417     int		error = FALSE;
418     char_u	*name;
419 
420     if (in_vim9script()
421 	    && (check_for_opt_buffer_arg(argvars, 0) == FAIL
422 		|| (argvars[0].v_type != VAR_UNKNOWN
423 		    && check_for_opt_bool_arg(argvars, 1) == FAIL)))
424 	return;
425 
426     if (argvars[0].v_type == VAR_UNKNOWN)
427 	buf = curbuf;
428     else
429 	buf = tv_get_buf_from_arg(&argvars[0]);
430 
431     // If the buffer isn't found and the second argument is not zero create a
432     // new buffer.
433     if (buf == NULL
434 	    && argvars[1].v_type != VAR_UNKNOWN
435 	    && tv_get_bool_chk(&argvars[1], &error) != 0
436 	    && !error
437 	    && (name = tv_get_string_chk(&argvars[0])) != NULL
438 	    && !error)
439 	buf = buflist_new(name, NULL, (linenr_T)1, 0);
440 
441     if (buf != NULL)
442 	rettv->vval.v_number = buf->b_fnum;
443     else
444 	rettv->vval.v_number = -1;
445 }
446 
447     static void
448 buf_win_common(typval_T *argvars, typval_T *rettv, int get_nr)
449 {
450     win_T	*wp;
451     int		winnr = 0;
452     buf_T	*buf;
453 
454     if (in_vim9script() && check_for_buffer_arg(argvars, 0) == FAIL)
455 	return;
456 
457     buf = tv_get_buf_from_arg(&argvars[0]);
458     FOR_ALL_WINDOWS(wp)
459     {
460 	++winnr;
461 	if (wp->w_buffer == buf)
462 	    break;
463     }
464     rettv->vval.v_number = (wp != NULL ? (get_nr ? winnr : wp->w_id) : -1);
465 }
466 
467 /*
468  * "bufwinid(nr)" function
469  */
470     void
471 f_bufwinid(typval_T *argvars, typval_T *rettv)
472 {
473     buf_win_common(argvars, rettv, FALSE);
474 }
475 
476 /*
477  * "bufwinnr(nr)" function
478  */
479     void
480 f_bufwinnr(typval_T *argvars, typval_T *rettv)
481 {
482     buf_win_common(argvars, rettv, TRUE);
483 }
484 
485 /*
486  * "deletebufline()" function
487  */
488     void
489 f_deletebufline(typval_T *argvars, typval_T *rettv)
490 {
491     buf_T	*buf;
492     linenr_T	first, last;
493     linenr_T	lnum;
494     long	count;
495     int		is_curbuf;
496     buf_T	*curbuf_save = NULL;
497     win_T	*curwin_save = NULL;
498     tabpage_T	*tp;
499     win_T	*wp;
500 
501     if (in_vim9script()
502 	    && (check_for_buffer_arg(argvars, 0) == FAIL
503 		|| check_for_lnum_arg(argvars, 1) == FAIL
504 		|| check_for_opt_lnum_arg(argvars, 2) == FAIL))
505 	return;
506 
507     buf = tv_get_buf(&argvars[0], FALSE);
508     if (buf == NULL)
509     {
510 	rettv->vval.v_number = 1; // FAIL
511 	return;
512     }
513     is_curbuf = buf == curbuf;
514 
515     first = tv_get_lnum_buf(&argvars[1], buf);
516     if (argvars[2].v_type != VAR_UNKNOWN)
517 	last = tv_get_lnum_buf(&argvars[2], buf);
518     else
519 	last = first;
520 
521     if (buf->b_ml.ml_mfp == NULL || first < 1
522 			   || first > buf->b_ml.ml_line_count || last < first)
523     {
524 	rettv->vval.v_number = 1;	// FAIL
525 	return;
526     }
527 
528     if (!is_curbuf)
529     {
530 	curbuf_save = curbuf;
531 	curwin_save = curwin;
532 	curbuf = buf;
533 	find_win_for_curbuf();
534     }
535     if (last > curbuf->b_ml.ml_line_count)
536 	last = curbuf->b_ml.ml_line_count;
537     count = last - first + 1;
538 
539     // When coming here from Insert mode, sync undo, so that this can be
540     // undone separately from what was previously inserted.
541     if (u_sync_once == 2)
542     {
543 	u_sync_once = 1; // notify that u_sync() was called
544 	u_sync(TRUE);
545     }
546 
547     if (u_save(first - 1, last + 1) == FAIL)
548     {
549 	rettv->vval.v_number = 1;	// FAIL
550     }
551     else
552     {
553 	for (lnum = first; lnum <= last; ++lnum)
554 	    ml_delete_flags(first, ML_DEL_MESSAGE);
555 
556 	FOR_ALL_TAB_WINDOWS(tp, wp)
557 	    if (wp->w_buffer == buf)
558 	    {
559 		if (wp->w_cursor.lnum > last)
560 		    wp->w_cursor.lnum -= count;
561 		else if (wp->w_cursor.lnum> first)
562 		    wp->w_cursor.lnum = first;
563 		if (wp->w_cursor.lnum > wp->w_buffer->b_ml.ml_line_count)
564 		    wp->w_cursor.lnum = wp->w_buffer->b_ml.ml_line_count;
565 	    }
566 	check_cursor_col();
567 	deleted_lines_mark(first, count);
568     }
569 
570     if (!is_curbuf)
571     {
572 	curbuf = curbuf_save;
573 	curwin = curwin_save;
574     }
575 }
576 
577 /*
578  * Returns buffer options, variables and other attributes in a dictionary.
579  */
580     static dict_T *
581 get_buffer_info(buf_T *buf)
582 {
583     dict_T	*dict;
584     tabpage_T	*tp;
585     win_T	*wp;
586     list_T	*windows;
587 
588     dict = dict_alloc();
589     if (dict == NULL)
590 	return NULL;
591 
592     dict_add_number(dict, "bufnr", buf->b_fnum);
593     dict_add_string(dict, "name", buf->b_ffname);
594     dict_add_number(dict, "lnum", buf == curbuf ? curwin->w_cursor.lnum
595 						     : buflist_findlnum(buf));
596     dict_add_number(dict, "linecount", buf->b_ml.ml_line_count);
597     dict_add_number(dict, "loaded", buf->b_ml.ml_mfp != NULL);
598     dict_add_number(dict, "listed", buf->b_p_bl);
599     dict_add_number(dict, "changed", bufIsChanged(buf));
600     dict_add_number(dict, "changedtick", CHANGEDTICK(buf));
601     dict_add_number(dict, "hidden",
602 			    buf->b_ml.ml_mfp != NULL && buf->b_nwindows == 0);
603 
604     // Get a reference to buffer variables
605     dict_add_dict(dict, "variables", buf->b_vars);
606 
607     // List of windows displaying this buffer
608     windows = list_alloc();
609     if (windows != NULL)
610     {
611 	FOR_ALL_TAB_WINDOWS(tp, wp)
612 	    if (wp->w_buffer == buf)
613 		list_append_number(windows, (varnumber_T)wp->w_id);
614 	dict_add_list(dict, "windows", windows);
615     }
616 
617 #ifdef FEAT_PROP_POPUP
618     // List of popup windows displaying this buffer
619     windows = list_alloc();
620     if (windows != NULL)
621     {
622 	FOR_ALL_POPUPWINS(wp)
623 	    if (wp->w_buffer == buf)
624 		list_append_number(windows, (varnumber_T)wp->w_id);
625 	FOR_ALL_TABPAGES(tp)
626 	    FOR_ALL_POPUPWINS_IN_TAB(tp, wp)
627 		if (wp->w_buffer == buf)
628 		    list_append_number(windows, (varnumber_T)wp->w_id);
629 
630 	dict_add_list(dict, "popups", windows);
631     }
632 #endif
633 
634 #ifdef FEAT_SIGNS
635     if (buf->b_signlist != NULL)
636     {
637 	// List of signs placed in this buffer
638 	list_T	*signs = list_alloc();
639 	if (signs != NULL)
640 	{
641 	    get_buffer_signs(buf, signs);
642 	    dict_add_list(dict, "signs", signs);
643 	}
644     }
645 #endif
646 
647 #ifdef FEAT_VIMINFO
648     dict_add_number(dict, "lastused", buf->b_last_used);
649 #endif
650 
651     return dict;
652 }
653 
654 /*
655  * "getbufinfo()" function
656  */
657     void
658 f_getbufinfo(typval_T *argvars, typval_T *rettv)
659 {
660     buf_T	*buf = NULL;
661     buf_T	*argbuf = NULL;
662     dict_T	*d;
663     int		filtered = FALSE;
664     int		sel_buflisted = FALSE;
665     int		sel_bufloaded = FALSE;
666     int		sel_bufmodified = FALSE;
667 
668     if (rettv_list_alloc(rettv) != OK)
669 	return;
670 
671     if (in_vim9script()
672 	    && check_for_opt_buffer_or_dict_arg(argvars, 0) == FAIL)
673 	return;
674 
675     // List of all the buffers or selected buffers
676     if (argvars[0].v_type == VAR_DICT)
677     {
678 	dict_T	*sel_d = argvars[0].vval.v_dict;
679 
680 	if (sel_d != NULL)
681 	{
682 	    filtered = TRUE;
683 	    sel_buflisted = dict_get_bool(sel_d, (char_u *)"buflisted", FALSE);
684 	    sel_bufloaded = dict_get_bool(sel_d, (char_u *)"bufloaded", FALSE);
685 	    sel_bufmodified = dict_get_bool(sel_d, (char_u *)"bufmodified",
686 									FALSE);
687 	}
688     }
689     else if (argvars[0].v_type != VAR_UNKNOWN)
690     {
691 	// Information about one buffer.  Argument specifies the buffer
692 	argbuf = tv_get_buf_from_arg(&argvars[0]);
693 	if (argbuf == NULL)
694 	    return;
695     }
696 
697     // Return information about all the buffers or a specified buffer
698     FOR_ALL_BUFFERS(buf)
699     {
700 	if (argbuf != NULL && argbuf != buf)
701 	    continue;
702 	if (filtered && ((sel_bufloaded && buf->b_ml.ml_mfp == NULL)
703 			|| (sel_buflisted && !buf->b_p_bl)
704 			|| (sel_bufmodified && !buf->b_changed)))
705 	    continue;
706 
707 	d = get_buffer_info(buf);
708 	if (d != NULL)
709 	    list_append_dict(rettv->vval.v_list, d);
710 	if (argbuf != NULL)
711 	    return;
712     }
713 }
714 
715 /*
716  * Get line or list of lines from buffer "buf" into "rettv".
717  * Return a range (from start to end) of lines in rettv from the specified
718  * buffer.
719  * If 'retlist' is TRUE, then the lines are returned as a Vim List.
720  */
721     static void
722 get_buffer_lines(
723     buf_T	*buf,
724     linenr_T	start,
725     linenr_T	end,
726     int		retlist,
727     typval_T	*rettv)
728 {
729     char_u	*p;
730 
731     if (retlist)
732     {
733 	if (rettv_list_alloc(rettv) == FAIL)
734 	    return;
735     }
736     else
737     {
738 	rettv->v_type = VAR_STRING;
739 	rettv->vval.v_string = NULL;
740     }
741 
742     if (buf == NULL || buf->b_ml.ml_mfp == NULL || start < 0)
743 	return;
744 
745     if (!retlist)
746     {
747 	if (start >= 1 && start <= buf->b_ml.ml_line_count)
748 	    p = ml_get_buf(buf, start, FALSE);
749 	else
750 	    p = (char_u *)"";
751 	rettv->vval.v_string = vim_strsave(p);
752     }
753     else
754     {
755 	if (end < start)
756 	    return;
757 
758 	if (start < 1)
759 	    start = 1;
760 	if (end > buf->b_ml.ml_line_count)
761 	    end = buf->b_ml.ml_line_count;
762 	while (start <= end)
763 	    if (list_append_string(rettv->vval.v_list,
764 				 ml_get_buf(buf, start++, FALSE), -1) == FAIL)
765 		break;
766     }
767 }
768 
769 /*
770  * "getbufline()" function
771  */
772     void
773 f_getbufline(typval_T *argvars, typval_T *rettv)
774 {
775     linenr_T	lnum = 1;
776     linenr_T	end = 1;
777     buf_T	*buf;
778 
779     if (in_vim9script()
780 	    && (check_for_buffer_arg(argvars, 0) == FAIL
781 		|| check_for_lnum_arg(argvars, 1) == FAIL
782 		|| check_for_opt_lnum_arg(argvars, 2) == FAIL))
783 	return;
784 
785     buf = tv_get_buf_from_arg(&argvars[0]);
786     if (buf != NULL)
787     {
788 	lnum = tv_get_lnum_buf(&argvars[1], buf);
789 	if (argvars[2].v_type == VAR_UNKNOWN)
790 	    end = lnum;
791 	else
792 	    end = tv_get_lnum_buf(&argvars[2], buf);
793     }
794 
795     get_buffer_lines(buf, lnum, end, TRUE, rettv);
796 }
797 
798     type_T *
799 ret_f_getline(int argcount, type_T **argtypes UNUSED)
800 {
801     return argcount == 1 ? &t_string : &t_list_string;
802 }
803 
804 /*
805  * "getline(lnum, [end])" function
806  */
807     void
808 f_getline(typval_T *argvars, typval_T *rettv)
809 {
810     linenr_T	lnum;
811     linenr_T	end;
812     int		retlist;
813 
814     if (in_vim9script()
815 	    && (check_for_lnum_arg(argvars, 0) == FAIL
816 		|| check_for_opt_lnum_arg(argvars, 1) == FAIL))
817 	return;
818 
819     lnum = tv_get_lnum(argvars);
820     if (argvars[1].v_type == VAR_UNKNOWN)
821     {
822 	end = 0;
823 	retlist = FALSE;
824     }
825     else
826     {
827 	end = tv_get_lnum(&argvars[1]);
828 	retlist = TRUE;
829     }
830 
831     get_buffer_lines(curbuf, lnum, end, retlist, rettv);
832 }
833 
834 /*
835  * "setbufline()" function
836  */
837     void
838 f_setbufline(typval_T *argvars, typval_T *rettv)
839 {
840     linenr_T	lnum;
841     buf_T	*buf;
842 
843     if (in_vim9script()
844 	    && (check_for_buffer_arg(argvars, 0) == FAIL
845 		|| check_for_lnum_arg(argvars, 1) == FAIL
846 		|| check_for_string_or_number_or_list_arg(argvars, 2) == FAIL))
847 	return;
848 
849     buf = tv_get_buf(&argvars[0], FALSE);
850     if (buf == NULL)
851 	rettv->vval.v_number = 1; // FAIL
852     else
853     {
854 	lnum = tv_get_lnum_buf(&argvars[1], buf);
855 	set_buffer_lines(buf, lnum, FALSE, &argvars[2], rettv);
856     }
857 }
858 
859 /*
860  * "setline()" function
861  */
862     void
863 f_setline(typval_T *argvars, typval_T *rettv)
864 {
865     linenr_T	lnum;
866 
867     if (in_vim9script() && check_for_lnum_arg(argvars, 0) == FAIL)
868 	return;
869 
870     lnum = tv_get_lnum(&argvars[0]);
871     set_buffer_lines(curbuf, lnum, FALSE, &argvars[1], rettv);
872 }
873 #endif  // FEAT_EVAL
874 
875 #if defined(FEAT_JOB_CHANNEL) \
876 	|| defined(FEAT_PYTHON) || defined(FEAT_PYTHON3) \
877 	|| defined(PROTO)
878 /*
879  * Make "buf" the current buffer.  restore_buffer() MUST be called to undo.
880  * No autocommands will be executed.  Use aucmd_prepbuf() if there are any.
881  */
882     void
883 switch_buffer(bufref_T *save_curbuf, buf_T *buf)
884 {
885     block_autocmds();
886 #ifdef FEAT_FOLDING
887     ++disable_fold_update;
888 #endif
889     set_bufref(save_curbuf, curbuf);
890     --curbuf->b_nwindows;
891     curbuf = buf;
892     curwin->w_buffer = buf;
893     ++curbuf->b_nwindows;
894 }
895 
896 /*
897  * Restore the current buffer after using switch_buffer().
898  */
899     void
900 restore_buffer(bufref_T *save_curbuf)
901 {
902     unblock_autocmds();
903 #ifdef FEAT_FOLDING
904     --disable_fold_update;
905 #endif
906     // Check for valid buffer, just in case.
907     if (bufref_valid(save_curbuf))
908     {
909 	--curbuf->b_nwindows;
910 	curwin->w_buffer = save_curbuf->br_buf;
911 	curbuf = save_curbuf->br_buf;
912 	++curbuf->b_nwindows;
913     }
914 }
915 
916 /*
917  * Find a window for buffer "buf".
918  * If found OK is returned and "wp" and "tp" are set to the window and tabpage.
919  * If not found FAIL is returned.
920  */
921     static int
922 find_win_for_buf(
923     buf_T     *buf,
924     win_T     **wp,
925     tabpage_T **tp)
926 {
927     FOR_ALL_TAB_WINDOWS(*tp, *wp)
928 	if ((*wp)->w_buffer == buf)
929 	    return OK;
930     return FAIL;
931 }
932 
933 /*
934  * Find a window that contains "buf" and switch to it.
935  * If there is no such window, use the current window and change "curbuf".
936  * Caller must initialize save_curbuf to NULL.
937  * restore_win_for_buf() MUST be called later!
938  */
939     void
940 switch_to_win_for_buf(
941     buf_T	*buf,
942     win_T	**save_curwinp,
943     tabpage_T	**save_curtabp,
944     bufref_T	*save_curbuf)
945 {
946     win_T	*wp;
947     tabpage_T	*tp;
948 
949     if (find_win_for_buf(buf, &wp, &tp) == FAIL)
950 	switch_buffer(save_curbuf, buf);
951     else if (switch_win(save_curwinp, save_curtabp, wp, tp, TRUE) == FAIL)
952     {
953 	restore_win(*save_curwinp, *save_curtabp, TRUE);
954 	switch_buffer(save_curbuf, buf);
955     }
956 }
957 
958     void
959 restore_win_for_buf(
960     win_T	*save_curwin,
961     tabpage_T	*save_curtab,
962     bufref_T	*save_curbuf)
963 {
964     if (save_curbuf->br_buf == NULL)
965 	restore_win(save_curwin, save_curtab, TRUE);
966     else
967 	restore_buffer(save_curbuf);
968 }
969 #endif
970