2 * Copyright (C) 1984-2020 Mark Nudelman
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.
7 * For more information, see the README file.
25 extern char *every_first_cmd;
26 extern int any_display;
27 extern int force_open;
30 extern IFILE curr_ifile;
31 extern IFILE old_ifile;
32 extern struct scrpos initial_scrpos;
33 extern void *ml_examine;
34 #if SPACES_IN_FILENAMES
35 extern char openquote;
36 extern char closequote;
41 extern int force_logfile;
42 extern char *namelogfile;
46 public dev_t curr_dev;
47 public ino_t curr_ino;
52 * Textlist functions deal with a list of words separated by spaces.
53 * init_textlist sets up a textlist structure.
54 * forw_textlist uses that structure to iterate thru the list of
55 * words, returning each one as a standard null-terminated string.
56 * back_textlist does the same, but runs thru the list backwards.
59 init_textlist(tlist, str)
60 struct textlist *tlist;
64 #if SPACES_IN_FILENAMES
67 char *esc = get_meta_escape();
68 int esclen = (int) strlen(esc);
71 tlist->string = skipsp(str);
72 tlist->endstring = tlist->string + strlen(tlist->string);
73 for (s = str; s < tlist->endstring; s++)
75 #if SPACES_IN_FILENAMES
79 } else if (esclen > 0 && s + esclen < tlist->endstring &&
80 strncmp(s, esc, esclen) == 0)
84 } else if (delim_quoted)
88 } else /* (!delim_quoted) */
103 forw_textlist(tlist, prev)
104 struct textlist *tlist;
110 * prev == NULL means return the first word in the list.
111 * Otherwise, return the word after "prev".
116 s = prev + strlen(prev);
117 if (s >= tlist->endstring)
121 if (s >= tlist->endstring)
127 back_textlist(tlist, prev)
128 struct textlist *tlist;
134 * prev == NULL means return the last word in the list.
135 * Otherwise, return the word before "prev".
138 s = tlist->endstring;
139 else if (prev <= tlist->string)
145 if (s <= tlist->string)
147 while (s[-1] != '\0' && s > tlist->string)
153 * Close a pipe opened via popen.
156 close_pipe(FILE *pipefd)
162 * The pclose function of OS/2 emx sometimes fails.
163 * Send SIGINT to the piped process before closing it.
165 kill(pipefd->_pid, SIGINT);
171 * Close the current input file.
174 close_file(VOID_PARAM)
176 struct scrpos scrpos;
181 if (curr_ifile == NULL_IFILE)
185 * Save the current position so that we can return to
186 * the same position if we edit this file again.
188 get_scrpos(&scrpos, TOP);
189 if (scrpos.pos != NULL_POSITION)
191 store_pos(curr_ifile, &scrpos);
195 * Close the file descriptor, unless it is a pipe.
197 chflags = ch_getflags();
200 * If we opened a file using an alternate name,
201 * do special stuff to close it.
203 altfilename = get_altfilename(curr_ifile);
204 if (altfilename != NULL)
206 altpipe = get_altpipe(curr_ifile);
207 if (altpipe != NULL && !(chflags & CH_KEEPOPEN))
210 set_altpipe(curr_ifile, NULL);
212 close_altfile(altfilename, get_filename(curr_ifile));
213 set_altfilename(curr_ifile, NULL);
215 curr_ifile = NULL_IFILE;
217 curr_ino = curr_dev = 0;
222 * Edit a new file (given its name).
223 * Filename == "-" means standard input.
224 * Filename == NULL means just close the current file.
230 if (filename == NULL)
231 return (edit_ifile(NULL_IFILE));
232 return (edit_ifile(get_ifile(filename, curr_ifile)));
236 * Edit a new file (given its IFILE).
237 * ifile == NULL means just close the current file.
251 IFILE was_curr_ifile;
254 if (ifile == curr_ifile)
257 * Already have the correct file open.
263 * We must close the currently open file now.
264 * This is necessary to make the open_altfile/close_altfile pairs
265 * nest properly (or rather to avoid nesting at all).
266 * {{ Some stupid implementations of popen() mess up if you do:
267 * fA = popen("A"); fB = popen("B"); pclose(fA); pclose(fB); }}
272 was_curr_ifile = save_curr_ifile();
273 if (curr_ifile != NULL_IFILE)
275 chflags = ch_getflags();
277 if ((chflags & CH_HELPFILE) && held_ifile(was_curr_ifile) <= 1)
280 * Don't keep the help file in the ifile list.
282 del_ifile(was_curr_ifile);
283 was_curr_ifile = old_ifile;
287 if (ifile == NULL_IFILE)
290 * No new file to open.
291 * (Don't set old_ifile, because if you call edit_ifile(NULL),
292 * you're supposed to have saved curr_ifile yourself,
293 * and you'll restore it if necessary.)
295 unsave_ifile(was_curr_ifile);
299 filename = save(get_filename(ifile));
302 * See if LESSOPEN specifies an "alternate" file to open.
304 altpipe = get_altpipe(ifile);
308 * File is already open.
309 * chflags and f are not used by ch_init if ifile has
310 * filestate which should be the case if we're here.
311 * Set them here to avoid uninitialized variable warnings.
315 alt_filename = get_altfilename(ifile);
316 open_filename = (alt_filename != NULL) ? alt_filename : filename;
319 if (strcmp(filename, FAKE_HELPFILE) == 0 ||
320 strcmp(filename, FAKE_EMPTYFILE) == 0)
323 alt_filename = open_altfile(filename, &f, &altpipe);
325 open_filename = (alt_filename != NULL) ? alt_filename : filename;
331 * The alternate "file" is actually a pipe.
332 * f has already been set to the file descriptor of the pipe
333 * in the call to open_altfile above.
334 * Keep the file descriptor open because it was opened
335 * via popen(), and pclose() wants to close it.
337 chflags |= CH_POPENED;
338 if (strcmp(filename, "-") == 0)
339 chflags |= CH_KEEPOPEN;
340 } else if (strcmp(filename, "-") == 0)
343 * Use standard input.
344 * Keep the file descriptor open because we can't reopen it.
347 chflags |= CH_KEEPOPEN;
349 * Must switch stdin to BINARY mode.
352 #if MSDOS_COMPILER==DJGPPC
354 * Setting stdin to binary by default causes
355 * Ctrl-C to not raise SIGINT. We must undo
358 __djgpp_set_ctrl_c(1);
360 } else if (strcmp(open_filename, FAKE_EMPTYFILE) == 0)
363 chflags |= CH_NODATA;
364 } else if (strcmp(open_filename, FAKE_HELPFILE) == 0)
367 chflags |= CH_HELPFILE;
368 } else if ((parg.p_string = bad_file(open_filename)) != NULL)
371 * It looks like a bad file. Don't try to open it.
376 if (alt_filename != NULL)
379 close_altfile(alt_filename, filename);
385 * Re-open the current file.
387 if (was_curr_ifile == ifile)
390 * Whoops. The "current" ifile is the one we just deleted.
395 reedit_ifile(was_curr_ifile);
397 } else if ((f = open(open_filename, OPEN_READ)) < 0)
400 * Got an error trying to open it.
402 parg.p_string = errno_message(filename);
408 chflags |= CH_CANSEEK;
409 if (!force_open && !opened(ifile) && bin_file(f))
412 * Looks like a binary file.
413 * Ask user if we should proceed.
415 parg.p_string = filename;
416 answer = query("\"%s\" may be a binary file. See it anyway? ",
418 if (answer != 'y' && answer != 'Y')
429 * Get the saved position for the file.
431 if (was_curr_ifile != NULL_IFILE)
433 old_ifile = was_curr_ifile;
434 unsave_ifile(was_curr_ifile);
437 set_altfilename(curr_ifile, alt_filename);
438 set_altpipe(curr_ifile, altpipe);
439 set_open(curr_ifile); /* File has been opened */
440 get_pos(curr_ifile, &initial_scrpos);
444 if (!(chflags & CH_HELPFILE))
447 if (namelogfile != NULL && is_tty)
448 use_logfile(namelogfile);
451 /* Remember the i-number and device of the opened file. */
452 if (strcmp(open_filename, "-") != 0)
455 int r = stat(open_filename, &statbuf);
458 curr_ino = statbuf.st_ino;
459 curr_dev = statbuf.st_dev;
463 if (every_first_cmd != NULL)
465 ungetcc(CHAR_END_COMMAND);
466 ungetsc(every_first_cmd);
470 no_display = !any_display;
477 * Output is to a real tty.
481 * Indicate there is nothing displayed yet.
488 if (strcmp(filename, FAKE_HELPFILE) && strcmp(filename, FAKE_EMPTYFILE))
490 char *qfilename = shell_quote(filename);
491 cmd_addhist(ml_examine, qfilename, 1);
495 if (no_display && errmsgs > 0)
498 * We displayed some messages on error output
499 * (file descriptor 2; see error() function).
500 * Before erasing the screen contents,
501 * display the file name and wait for a keystroke.
503 parg.p_string = filename;
512 * Edit a space-separated list of files.
513 * For each filename in the list, enter it into the ifile list.
514 * Then edit the first one.
526 struct textlist tl_files;
527 struct textlist tl_gfiles;
529 save_ifile = save_curr_ifile();
530 good_filename = NULL;
533 * Run thru each filename in the list.
534 * Try to glob the filename.
535 * If it doesn't expand, just try to open the filename.
536 * If it does expand, try to open each name in that list.
538 init_textlist(&tl_files, filelist);
540 while ((filename = forw_textlist(&tl_files, filename)) != NULL)
542 gfilelist = lglob(filename);
543 init_textlist(&tl_gfiles, gfilelist);
545 while ((gfilename = forw_textlist(&tl_gfiles, gfilename)) != NULL)
547 qfilename = shell_unquote(gfilename);
548 if (edit(qfilename) == 0 && good_filename == NULL)
549 good_filename = get_filename(curr_ifile);
555 * Edit the first valid filename in the list.
557 if (good_filename == NULL)
559 unsave_ifile(save_ifile);
562 if (get_ifile(good_filename, curr_ifile) == curr_ifile)
565 * Trying to edit the current file; don't reopen it.
567 unsave_ifile(save_ifile);
570 reedit_ifile(save_ifile);
571 return (edit(good_filename));
575 * Edit the first file in the command line (ifile) list.
578 edit_first(VOID_PARAM)
581 return (edit_stdin());
582 curr_ifile = NULL_IFILE;
583 return (edit_next(1));
587 * Edit the last file in the command line (ifile) list.
590 edit_last(VOID_PARAM)
592 curr_ifile = NULL_IFILE;
593 return (edit_prev(1));
598 * Edit the n-th next or previous file in the command line (ifile) list.
601 edit_istep(h, n, dir)
609 * Skip n filenames, then try to edit each filename.
613 next = (dir > 0) ? next_ifile(h) : prev_ifile(h);
616 if (edit_ifile(h) == 0)
619 if (next == NULL_IFILE)
622 * Reached end of the ifile list.
629 * Interrupt breaks out, if we're in a long
630 * list of files that can't be opened.
637 * Found a file that we can edit.
647 return (edit_istep(h, n, +1));
654 return edit_istep(curr_ifile, n, +1);
662 return (edit_istep(h, n, -1));
669 return edit_istep(curr_ifile, n, -1);
673 * Edit a specific file in the command line (ifile) list.
684 if ((h = next_ifile(h)) == NULL_IFILE)
687 * Reached end of the list without finding it.
691 } while (get_index(h) != n);
693 return (edit_ifile(h));
697 save_curr_ifile(VOID_PARAM)
699 if (curr_ifile != NULL_IFILE)
700 hold_ifile(curr_ifile, 1);
705 unsave_ifile(save_ifile)
708 if (save_ifile != NULL_IFILE)
709 hold_ifile(save_ifile, -1);
713 * Reedit the ifile which was previously open.
716 reedit_ifile(save_ifile)
723 * Try to reopen the ifile.
724 * Note that opening it may fail (maybe the file was removed),
725 * in which case the ifile will be deleted from the list.
726 * So save the next and prev ifiles first.
728 unsave_ifile(save_ifile);
729 next = next_ifile(save_ifile);
730 prev = prev_ifile(save_ifile);
731 if (edit_ifile(save_ifile) == 0)
734 * If can't reopen it, open the next input file in the list.
736 if (next != NULL_IFILE && edit_inext(next, 0) == 0)
739 * If can't open THAT one, open the previous input file in the list.
741 if (prev != NULL_IFILE && edit_iprev(prev, 0) == 0)
744 * If can't even open that, we're stuck. Just quit.
750 reopen_curr_ifile(VOID_PARAM)
752 IFILE save_ifile = save_curr_ifile();
754 reedit_ifile(save_ifile);
758 * Edit standard input.
761 edit_stdin(VOID_PARAM)
765 error("Missing filename (\"less --help\" for help)", NULL_PARG);
772 * Copy a file directly to standard output.
773 * Used if standard output is not a tty.
780 while ((c = ch_forw_get()) != EOI)
788 * If the user asked for a log file and our input file
789 * is standard input, create the log file.
790 * We take care not to blindly overwrite an existing file.
793 use_logfile(filename)
800 if (ch_getflags() & CH_CANSEEK)
802 * Can't currently use a log file on a file that can seek.
807 * {{ We could use access() here. }}
809 exists = open(filename, OPEN_READ);
812 exists = (exists >= 0);
815 * Decide whether to overwrite the log file or append to it.
816 * If it doesn't exist we "overwrite" it.
818 if (!exists || force_logfile)
821 * Overwrite (or create) the log file.
827 * Ask user what to do.
829 parg.p_string = filename;
830 answer = query("Warning: \"%s\" exists; Overwrite, Append or Don't log? ", &parg);
838 * Overwrite: create the file.
840 logfile = creat(filename, 0644);
844 * Append: open the file and seek to the end.
846 logfile = open(filename, OPEN_APPEND);
847 if (lseek(logfile, (off_t)0, SEEK_END) == BAD_LSEEK)
865 answer = query("Overwrite, Append, or Don't log? (Type \"O\", \"A\", \"D\" or \"q\") ", NULL_PARG);
872 * Error in opening logfile.
874 parg.p_string = filename;
875 error("Cannot write to \"%s\"", &parg);