xref: /freebsd/contrib/less/edit.c (revision fcb560670601b2a4d87bb31d7531c8dcc37ee71b)
1 /*
2  * Copyright (C) 1984-2012  Mark Nudelman
3  *
4  * You may distribute under the terms of either the GNU General Public
5  * License or the Less License, as specified in the README file.
6  *
7  * For more information, see the README file.
8  */
9 
10 
11 #include "less.h"
12 #if HAVE_STAT
13 #include <sys/stat.h>
14 #endif
15 
16 public int fd0 = 0;
17 
18 extern int new_file;
19 extern int errmsgs;
20 extern int cbufs;
21 extern char *every_first_cmd;
22 extern int any_display;
23 extern int force_open;
24 extern int is_tty;
25 extern int sigs;
26 extern IFILE curr_ifile;
27 extern IFILE old_ifile;
28 extern struct scrpos initial_scrpos;
29 extern void constant *ml_examine;
30 #if SPACES_IN_FILENAMES
31 extern char openquote;
32 extern char closequote;
33 #endif
34 
35 #if LOGFILE
36 extern int logfile;
37 extern int force_logfile;
38 extern char *namelogfile;
39 #endif
40 
41 #if HAVE_STAT_INO
42 public dev_t curr_dev;
43 public ino_t curr_ino;
44 #endif
45 
46 char *curr_altfilename = NULL;
47 static void *curr_altpipe;
48 
49 
50 /*
51  * Textlist functions deal with a list of words separated by spaces.
52  * init_textlist sets up a textlist structure.
53  * forw_textlist uses that structure to iterate thru the list of
54  * words, returning each one as a standard null-terminated string.
55  * back_textlist does the same, but runs thru the list backwards.
56  */
57 	public void
58 init_textlist(tlist, str)
59 	struct textlist *tlist;
60 	char *str;
61 {
62 	char *s;
63 #if SPACES_IN_FILENAMES
64 	int meta_quoted = 0;
65 	int delim_quoted = 0;
66 	char *esc = get_meta_escape();
67 	int esclen = strlen(esc);
68 #endif
69 
70 	tlist->string = skipsp(str);
71 	tlist->endstring = tlist->string + strlen(tlist->string);
72 	for (s = str;  s < tlist->endstring;  s++)
73 	{
74 #if SPACES_IN_FILENAMES
75 		if (meta_quoted)
76 		{
77 			meta_quoted = 0;
78 		} else if (esclen > 0 && s + esclen < tlist->endstring &&
79 		           strncmp(s, esc, esclen) == 0)
80 		{
81 			meta_quoted = 1;
82 			s += esclen - 1;
83 		} else if (delim_quoted)
84 		{
85 			if (*s == closequote)
86 				delim_quoted = 0;
87 		} else /* (!delim_quoted) */
88 		{
89 			if (*s == openquote)
90 				delim_quoted = 1;
91 			else if (*s == ' ')
92 				*s = '\0';
93 		}
94 #else
95 		if (*s == ' ')
96 			*s = '\0';
97 #endif
98 	}
99 }
100 
101 	public char *
102 forw_textlist(tlist, prev)
103 	struct textlist *tlist;
104 	char *prev;
105 {
106 	char *s;
107 
108 	/*
109 	 * prev == NULL means return the first word in the list.
110 	 * Otherwise, return the word after "prev".
111 	 */
112 	if (prev == NULL)
113 		s = tlist->string;
114 	else
115 		s = prev + strlen(prev);
116 	if (s >= tlist->endstring)
117 		return (NULL);
118 	while (*s == '\0')
119 		s++;
120 	if (s >= tlist->endstring)
121 		return (NULL);
122 	return (s);
123 }
124 
125 	public char *
126 back_textlist(tlist, prev)
127 	struct textlist *tlist;
128 	char *prev;
129 {
130 	char *s;
131 
132 	/*
133 	 * prev == NULL means return the last word in the list.
134 	 * Otherwise, return the word before "prev".
135 	 */
136 	if (prev == NULL)
137 		s = tlist->endstring;
138 	else if (prev <= tlist->string)
139 		return (NULL);
140 	else
141 		s = prev - 1;
142 	while (*s == '\0')
143 		s--;
144 	if (s <= tlist->string)
145 		return (NULL);
146 	while (s[-1] != '\0' && s > tlist->string)
147 		s--;
148 	return (s);
149 }
150 
151 /*
152  * Close the current input file.
153  */
154 	static void
155 close_file()
156 {
157 	struct scrpos scrpos;
158 
159 	if (curr_ifile == NULL_IFILE)
160 		return;
161 
162 	/*
163 	 * Save the current position so that we can return to
164 	 * the same position if we edit this file again.
165 	 */
166 	get_scrpos(&scrpos);
167 	if (scrpos.pos != NULL_POSITION)
168 	{
169 		store_pos(curr_ifile, &scrpos);
170 		lastmark();
171 	}
172 	/*
173 	 * Close the file descriptor, unless it is a pipe.
174 	 */
175 	ch_close();
176 	/*
177 	 * If we opened a file using an alternate name,
178 	 * do special stuff to close it.
179 	 */
180 	if (curr_altfilename != NULL)
181 	{
182 		close_altfile(curr_altfilename, get_filename(curr_ifile),
183 				curr_altpipe);
184 		free(curr_altfilename);
185 		curr_altfilename = NULL;
186 	}
187 	curr_ifile = NULL_IFILE;
188 #if HAVE_STAT_INO
189 	curr_ino = curr_dev = 0;
190 #endif
191 }
192 
193 /*
194  * Edit a new file (given its name).
195  * Filename == "-" means standard input.
196  * Filename == NULL means just close the current file.
197  */
198 	public int
199 edit(filename)
200 	char *filename;
201 {
202 	if (filename == NULL)
203 		return (edit_ifile(NULL_IFILE));
204 	return (edit_ifile(get_ifile(filename, curr_ifile)));
205 }
206 
207 /*
208  * Edit a new file (given its IFILE).
209  * ifile == NULL means just close the current file.
210  */
211 	public int
212 edit_ifile(ifile)
213 	IFILE ifile;
214 {
215 	int f;
216 	int answer;
217 	int no_display;
218 	int chflags;
219 	char *filename;
220 	char *open_filename;
221 	char *qopen_filename;
222 	char *alt_filename;
223 	void *alt_pipe;
224 	IFILE was_curr_ifile;
225 	PARG parg;
226 
227 	if (ifile == curr_ifile)
228 	{
229 		/*
230 		 * Already have the correct file open.
231 		 */
232 		return (0);
233 	}
234 
235 	/*
236 	 * We must close the currently open file now.
237 	 * This is necessary to make the open_altfile/close_altfile pairs
238 	 * nest properly (or rather to avoid nesting at all).
239 	 * {{ Some stupid implementations of popen() mess up if you do:
240 	 *    fA = popen("A"); fB = popen("B"); pclose(fA); pclose(fB); }}
241 	 */
242 #if LOGFILE
243 	end_logfile();
244 #endif
245 	was_curr_ifile = save_curr_ifile();
246 	if (curr_ifile != NULL_IFILE)
247 	{
248 		chflags = ch_getflags();
249 		close_file();
250 		if ((chflags & CH_HELPFILE) && held_ifile(was_curr_ifile) <= 1)
251 		{
252 			/*
253 			 * Don't keep the help file in the ifile list.
254 			 */
255 			del_ifile(was_curr_ifile);
256 			was_curr_ifile = old_ifile;
257 		}
258 	}
259 
260 	if (ifile == NULL_IFILE)
261 	{
262 		/*
263 		 * No new file to open.
264 		 * (Don't set old_ifile, because if you call edit_ifile(NULL),
265 		 *  you're supposed to have saved curr_ifile yourself,
266 		 *  and you'll restore it if necessary.)
267 		 */
268 		unsave_ifile(was_curr_ifile);
269 		return (0);
270 	}
271 
272 	filename = save(get_filename(ifile));
273 	/*
274 	 * See if LESSOPEN specifies an "alternate" file to open.
275 	 */
276 	alt_pipe = NULL;
277 	alt_filename = open_altfile(filename, &f, &alt_pipe);
278 	open_filename = (alt_filename != NULL) ? alt_filename : filename;
279 	qopen_filename = shell_unquote(open_filename);
280 
281 	chflags = 0;
282 	if (alt_pipe != NULL)
283 	{
284 		/*
285 		 * The alternate "file" is actually a pipe.
286 		 * f has already been set to the file descriptor of the pipe
287 		 * in the call to open_altfile above.
288 		 * Keep the file descriptor open because it was opened
289 		 * via popen(), and pclose() wants to close it.
290 		 */
291 		chflags |= CH_POPENED;
292 	} else if (strcmp(open_filename, "-") == 0)
293 	{
294 		/*
295 		 * Use standard input.
296 		 * Keep the file descriptor open because we can't reopen it.
297 		 */
298 		f = fd0;
299 		chflags |= CH_KEEPOPEN;
300 		/*
301 		 * Must switch stdin to BINARY mode.
302 		 */
303 		SET_BINARY(f);
304 #if MSDOS_COMPILER==DJGPPC
305 		/*
306 		 * Setting stdin to binary by default causes
307 		 * Ctrl-C to not raise SIGINT.  We must undo
308 		 * that side-effect.
309 		 */
310 		__djgpp_set_ctrl_c(1);
311 #endif
312 	} else if (strcmp(open_filename, FAKE_EMPTYFILE) == 0)
313 	{
314 		f = -1;
315 		chflags |= CH_NODATA;
316 	} else if (strcmp(open_filename, FAKE_HELPFILE) == 0)
317 	{
318 		f = -1;
319 		chflags |= CH_HELPFILE;
320 	} else if ((parg.p_string = bad_file(open_filename)) != NULL)
321 	{
322 		/*
323 		 * It looks like a bad file.  Don't try to open it.
324 		 */
325 		error("%s", &parg);
326 		free(parg.p_string);
327 	    err1:
328 		if (alt_filename != NULL)
329 		{
330 			close_altfile(alt_filename, filename, alt_pipe);
331 			free(alt_filename);
332 		}
333 		del_ifile(ifile);
334 		free(qopen_filename);
335 		free(filename);
336 		/*
337 		 * Re-open the current file.
338 		 */
339 		if (was_curr_ifile == ifile)
340 		{
341 			/*
342 			 * Whoops.  The "current" ifile is the one we just deleted.
343 			 * Just give up.
344 			 */
345 			quit(QUIT_ERROR);
346 		}
347 		reedit_ifile(was_curr_ifile);
348 		return (1);
349 	} else if ((f = open(qopen_filename, OPEN_READ)) < 0)
350 	{
351 		/*
352 		 * Got an error trying to open it.
353 		 */
354 		parg.p_string = errno_message(filename);
355 		error("%s", &parg);
356 		free(parg.p_string);
357 	    	goto err1;
358 	} else
359 	{
360 		chflags |= CH_CANSEEK;
361 		if (!force_open && !opened(ifile) && bin_file(f))
362 		{
363 			/*
364 			 * Looks like a binary file.
365 			 * Ask user if we should proceed.
366 			 */
367 			parg.p_string = filename;
368 			answer = query("\"%s\" may be a binary file.  See it anyway? ",
369 				&parg);
370 			if (answer != 'y' && answer != 'Y')
371 			{
372 				close(f);
373 				goto err1;
374 			}
375 		}
376 	}
377 
378 	/*
379 	 * Get the new ifile.
380 	 * Get the saved position for the file.
381 	 */
382 	if (was_curr_ifile != NULL_IFILE)
383 	{
384 		old_ifile = was_curr_ifile;
385 		unsave_ifile(was_curr_ifile);
386 	}
387 	curr_ifile = ifile;
388 	curr_altfilename = alt_filename;
389 	curr_altpipe = alt_pipe;
390 	set_open(curr_ifile); /* File has been opened */
391 	get_pos(curr_ifile, &initial_scrpos);
392 	new_file = TRUE;
393 	ch_init(f, chflags);
394 
395 	if (!(chflags & CH_HELPFILE))
396 	{
397 #if LOGFILE
398 		if (namelogfile != NULL && is_tty)
399 			use_logfile(namelogfile);
400 #endif
401 #if HAVE_STAT_INO
402 		/* Remember the i-number and device of the opened file. */
403 		{
404 			struct stat statbuf;
405 			int r = stat(qopen_filename, &statbuf);
406 			if (r == 0)
407 			{
408 				curr_ino = statbuf.st_ino;
409 				curr_dev = statbuf.st_dev;
410 			}
411 		}
412 #endif
413 		if (every_first_cmd != NULL)
414 			ungetsc(every_first_cmd);
415 	}
416 
417 	free(qopen_filename);
418 	no_display = !any_display;
419 	flush();
420 	any_display = TRUE;
421 
422 	if (is_tty)
423 	{
424 		/*
425 		 * Output is to a real tty.
426 		 */
427 
428 		/*
429 		 * Indicate there is nothing displayed yet.
430 		 */
431 		pos_clear();
432 		clr_linenum();
433 #if HILITE_SEARCH
434 		clr_hilite();
435 #endif
436 		cmd_addhist(ml_examine, filename);
437 		if (no_display && errmsgs > 0)
438 		{
439 			/*
440 			 * We displayed some messages on error output
441 			 * (file descriptor 2; see error() function).
442 			 * Before erasing the screen contents,
443 			 * display the file name and wait for a keystroke.
444 			 */
445 			parg.p_string = filename;
446 			error("%s", &parg);
447 		}
448 	}
449 	free(filename);
450 	return (0);
451 }
452 
453 /*
454  * Edit a space-separated list of files.
455  * For each filename in the list, enter it into the ifile list.
456  * Then edit the first one.
457  */
458 	public int
459 edit_list(filelist)
460 	char *filelist;
461 {
462 	IFILE save_ifile;
463 	char *good_filename;
464 	char *filename;
465 	char *gfilelist;
466 	char *gfilename;
467 	struct textlist tl_files;
468 	struct textlist tl_gfiles;
469 
470 	save_ifile = save_curr_ifile();
471 	good_filename = NULL;
472 
473 	/*
474 	 * Run thru each filename in the list.
475 	 * Try to glob the filename.
476 	 * If it doesn't expand, just try to open the filename.
477 	 * If it does expand, try to open each name in that list.
478 	 */
479 	init_textlist(&tl_files, filelist);
480 	filename = NULL;
481 	while ((filename = forw_textlist(&tl_files, filename)) != NULL)
482 	{
483 		gfilelist = lglob(filename);
484 		init_textlist(&tl_gfiles, gfilelist);
485 		gfilename = NULL;
486 		while ((gfilename = forw_textlist(&tl_gfiles, gfilename)) != NULL)
487 		{
488 			if (edit(gfilename) == 0 && good_filename == NULL)
489 				good_filename = get_filename(curr_ifile);
490 		}
491 		free(gfilelist);
492 	}
493 	/*
494 	 * Edit the first valid filename in the list.
495 	 */
496 	if (good_filename == NULL)
497 	{
498 		unsave_ifile(save_ifile);
499 		return (1);
500 	}
501 	if (get_ifile(good_filename, curr_ifile) == curr_ifile)
502 	{
503 		/*
504 		 * Trying to edit the current file; don't reopen it.
505 		 */
506 		unsave_ifile(save_ifile);
507 		return (0);
508 	}
509 	reedit_ifile(save_ifile);
510 	return (edit(good_filename));
511 }
512 
513 /*
514  * Edit the first file in the command line (ifile) list.
515  */
516 	public int
517 edit_first()
518 {
519 	curr_ifile = NULL_IFILE;
520 	return (edit_next(1));
521 }
522 
523 /*
524  * Edit the last file in the command line (ifile) list.
525  */
526 	public int
527 edit_last()
528 {
529 	curr_ifile = NULL_IFILE;
530 	return (edit_prev(1));
531 }
532 
533 
534 /*
535  * Edit the n-th next or previous file in the command line (ifile) list.
536  */
537 	static int
538 edit_istep(h, n, dir)
539 	IFILE h;
540 	int n;
541 	int dir;
542 {
543 	IFILE next;
544 
545 	/*
546 	 * Skip n filenames, then try to edit each filename.
547 	 */
548 	for (;;)
549 	{
550 		next = (dir > 0) ? next_ifile(h) : prev_ifile(h);
551 		if (--n < 0)
552 		{
553 			if (edit_ifile(h) == 0)
554 				break;
555 		}
556 		if (next == NULL_IFILE)
557 		{
558 			/*
559 			 * Reached end of the ifile list.
560 			 */
561 			return (1);
562 		}
563 		if (ABORT_SIGS())
564 		{
565 			/*
566 			 * Interrupt breaks out, if we're in a long
567 			 * list of files that can't be opened.
568 			 */
569 			return (1);
570 		}
571 		h = next;
572 	}
573 	/*
574 	 * Found a file that we can edit.
575 	 */
576 	return (0);
577 }
578 
579 	static int
580 edit_inext(h, n)
581 	IFILE h;
582 	int n;
583 {
584 	return (edit_istep(h, n, +1));
585 }
586 
587 	public int
588 edit_next(n)
589 	int n;
590 {
591 	return edit_istep(curr_ifile, n, +1);
592 }
593 
594 	static int
595 edit_iprev(h, n)
596 	IFILE h;
597 	int n;
598 {
599 	return (edit_istep(h, n, -1));
600 }
601 
602 	public int
603 edit_prev(n)
604 	int n;
605 {
606 	return edit_istep(curr_ifile, n, -1);
607 }
608 
609 /*
610  * Edit a specific file in the command line (ifile) list.
611  */
612 	public int
613 edit_index(n)
614 	int n;
615 {
616 	IFILE h;
617 
618 	h = NULL_IFILE;
619 	do
620 	{
621 		if ((h = next_ifile(h)) == NULL_IFILE)
622 		{
623 			/*
624 			 * Reached end of the list without finding it.
625 			 */
626 			return (1);
627 		}
628 	} while (get_index(h) != n);
629 
630 	return (edit_ifile(h));
631 }
632 
633 	public IFILE
634 save_curr_ifile()
635 {
636 	if (curr_ifile != NULL_IFILE)
637 		hold_ifile(curr_ifile, 1);
638 	return (curr_ifile);
639 }
640 
641 	public void
642 unsave_ifile(save_ifile)
643 	IFILE save_ifile;
644 {
645 	if (save_ifile != NULL_IFILE)
646 		hold_ifile(save_ifile, -1);
647 }
648 
649 /*
650  * Reedit the ifile which was previously open.
651  */
652 	public void
653 reedit_ifile(save_ifile)
654 	IFILE save_ifile;
655 {
656 	IFILE next;
657 	IFILE prev;
658 
659 	/*
660 	 * Try to reopen the ifile.
661 	 * Note that opening it may fail (maybe the file was removed),
662 	 * in which case the ifile will be deleted from the list.
663 	 * So save the next and prev ifiles first.
664 	 */
665 	unsave_ifile(save_ifile);
666 	next = next_ifile(save_ifile);
667 	prev = prev_ifile(save_ifile);
668 	if (edit_ifile(save_ifile) == 0)
669 		return;
670 	/*
671 	 * If can't reopen it, open the next input file in the list.
672 	 */
673 	if (next != NULL_IFILE && edit_inext(next, 0) == 0)
674 		return;
675 	/*
676 	 * If can't open THAT one, open the previous input file in the list.
677 	 */
678 	if (prev != NULL_IFILE && edit_iprev(prev, 0) == 0)
679 		return;
680 	/*
681 	 * If can't even open that, we're stuck.  Just quit.
682 	 */
683 	quit(QUIT_ERROR);
684 }
685 
686 	public void
687 reopen_curr_ifile()
688 {
689 	IFILE save_ifile = save_curr_ifile();
690 	close_file();
691 	reedit_ifile(save_ifile);
692 }
693 
694 /*
695  * Edit standard input.
696  */
697 	public int
698 edit_stdin()
699 {
700 	if (isatty(fd0))
701 	{
702 		error("Missing filename (\"less --help\" for help)", NULL_PARG);
703 		quit(QUIT_OK);
704 	}
705 	return (edit("-"));
706 }
707 
708 /*
709  * Copy a file directly to standard output.
710  * Used if standard output is not a tty.
711  */
712 	public void
713 cat_file()
714 {
715 	register int c;
716 
717 	while ((c = ch_forw_get()) != EOI)
718 		putchr(c);
719 	flush();
720 }
721 
722 #if LOGFILE
723 
724 /*
725  * If the user asked for a log file and our input file
726  * is standard input, create the log file.
727  * We take care not to blindly overwrite an existing file.
728  */
729 	public void
730 use_logfile(filename)
731 	char *filename;
732 {
733 	register int exists;
734 	register int answer;
735 	PARG parg;
736 
737 	if (ch_getflags() & CH_CANSEEK)
738 		/*
739 		 * Can't currently use a log file on a file that can seek.
740 		 */
741 		return;
742 
743 	/*
744 	 * {{ We could use access() here. }}
745 	 */
746 	filename = shell_unquote(filename);
747 	exists = open(filename, OPEN_READ);
748 	close(exists);
749 	exists = (exists >= 0);
750 
751 	/*
752 	 * Decide whether to overwrite the log file or append to it.
753 	 * If it doesn't exist we "overwrite" it.
754 	 */
755 	if (!exists || force_logfile)
756 	{
757 		/*
758 		 * Overwrite (or create) the log file.
759 		 */
760 		answer = 'O';
761 	} else
762 	{
763 		/*
764 		 * Ask user what to do.
765 		 */
766 		parg.p_string = filename;
767 		answer = query("Warning: \"%s\" exists; Overwrite, Append or Don't log? ", &parg);
768 	}
769 
770 loop:
771 	switch (answer)
772 	{
773 	case 'O': case 'o':
774 		/*
775 		 * Overwrite: create the file.
776 		 */
777 		logfile = creat(filename, 0644);
778 		break;
779 	case 'A': case 'a':
780 		/*
781 		 * Append: open the file and seek to the end.
782 		 */
783 		logfile = open(filename, OPEN_APPEND);
784 		if (lseek(logfile, (off_t)0, SEEK_END) == BAD_LSEEK)
785 		{
786 			close(logfile);
787 			logfile = -1;
788 		}
789 		break;
790 	case 'D': case 'd':
791 		/*
792 		 * Don't do anything.
793 		 */
794 		free(filename);
795 		return;
796 	case 'q':
797 		quit(QUIT_OK);
798 		/*NOTREACHED*/
799 	default:
800 		/*
801 		 * Eh?
802 		 */
803 		answer = query("Overwrite, Append, or Don't log? (Type \"O\", \"A\", \"D\" or \"q\") ", NULL_PARG);
804 		goto loop;
805 	}
806 
807 	if (logfile < 0)
808 	{
809 		/*
810 		 * Error in opening logfile.
811 		 */
812 		parg.p_string = filename;
813 		error("Cannot write to \"%s\"", &parg);
814 		free(filename);
815 		return;
816 	}
817 	free(filename);
818 	SET_BINARY(logfile);
819 }
820 
821 #endif
822