2 * Copyright (C) 1984-2002 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 about less, or for information on how to
8 * contact the author, see the README file.
19 extern char *every_first_cmd;
20 extern int any_display;
21 extern int force_open;
24 extern IFILE curr_ifile;
25 extern IFILE old_ifile;
26 extern struct scrpos initial_scrpos;
27 extern void constant *ml_examine;
28 #if SPACES_IN_FILENAMES
29 extern char openquote;
30 extern char closequote;
35 extern int force_logfile;
36 extern char *namelogfile;
39 char *curr_altfilename = NULL;
40 static void *curr_altpipe;
44 * Textlist functions deal with a list of words separated by spaces.
45 * init_textlist sets up a textlist structure.
46 * forw_textlist uses that structure to iterate thru the list of
47 * words, returning each one as a standard null-terminated string.
48 * back_textlist does the same, but runs thru the list backwards.
51 init_textlist(tlist, str)
52 struct textlist *tlist;
56 #if SPACES_IN_FILENAMES
59 char *esc = get_meta_escape();
60 int esclen = strlen(esc);
63 tlist->string = skipsp(str);
64 tlist->endstring = tlist->string + strlen(tlist->string);
65 for (s = str; s < tlist->endstring; s++)
67 #if SPACES_IN_FILENAMES
71 } else if (esclen > 0 && s + esclen < tlist->endstring &&
72 strncmp(s, esc, esclen) == 0)
76 } else if (delim_quoted)
80 } else /* (!delim_quoted) */
95 forw_textlist(tlist, prev)
96 struct textlist *tlist;
102 * prev == NULL means return the first word in the list.
103 * Otherwise, return the word after "prev".
108 s = prev + strlen(prev);
109 if (s >= tlist->endstring)
113 if (s >= tlist->endstring)
119 back_textlist(tlist, prev)
120 struct textlist *tlist;
126 * prev == NULL means return the last word in the list.
127 * Otherwise, return the word before "prev".
130 s = tlist->endstring;
131 else if (prev <= tlist->string)
137 if (s <= tlist->string)
139 while (s[-1] != '\0' && s > tlist->string)
145 * Close the current input file.
150 struct scrpos scrpos;
152 if (curr_ifile == NULL_IFILE)
156 * Save the current position so that we can return to
157 * the same position if we edit this file again.
160 if (scrpos.pos != NULL_POSITION)
162 store_pos(curr_ifile, &scrpos);
166 * Close the file descriptor, unless it is a pipe.
170 * If we opened a file using an alternate name,
171 * do special stuff to close it.
173 if (curr_altfilename != NULL)
175 close_altfile(curr_altfilename, get_filename(curr_ifile),
177 free(curr_altfilename);
178 curr_altfilename = NULL;
180 curr_ifile = NULL_IFILE;
184 * Edit a new file (given its name).
185 * Filename == "-" means standard input.
186 * Filename == NULL means just close the current file.
192 if (filename == NULL)
193 return (edit_ifile(NULL_IFILE));
194 return (edit_ifile(get_ifile(filename, curr_ifile)));
198 * Edit a new file (given its IFILE).
199 * ifile == NULL means just close the current file.
211 char *qopen_filename;
214 IFILE was_curr_ifile;
217 if (ifile == curr_ifile)
220 * Already have the correct file open.
226 * We must close the currently open file now.
227 * This is necessary to make the open_altfile/close_altfile pairs
228 * nest properly (or rather to avoid nesting at all).
229 * {{ Some stupid implementations of popen() mess up if you do:
230 * fA = popen("A"); fB = popen("B"); pclose(fA); pclose(fB); }}
235 was_curr_ifile = save_curr_ifile();
236 if (curr_ifile != NULL_IFILE)
238 chflags = ch_getflags();
240 if ((chflags & CH_HELPFILE) && held_ifile(was_curr_ifile) <= 1)
243 * Don't keep the help file in the ifile list.
245 del_ifile(was_curr_ifile);
246 was_curr_ifile = old_ifile;
250 if (ifile == NULL_IFILE)
253 * No new file to open.
254 * (Don't set old_ifile, because if you call edit_ifile(NULL),
255 * you're supposed to have saved curr_ifile yourself,
256 * and you'll restore it if necessary.)
258 unsave_ifile(was_curr_ifile);
262 filename = save(get_filename(ifile));
264 * See if LESSOPEN specifies an "alternate" file to open.
267 alt_filename = open_altfile(filename, &f, &alt_pipe);
268 open_filename = (alt_filename != NULL) ? alt_filename : filename;
269 qopen_filename = shell_unquote(open_filename);
272 if (alt_pipe != NULL)
275 * The alternate "file" is actually a pipe.
276 * f has already been set to the file descriptor of the pipe
277 * in the call to open_altfile above.
278 * Keep the file descriptor open because it was opened
279 * via popen(), and pclose() wants to close it.
281 chflags |= CH_POPENED;
282 } else if (strcmp(open_filename, "-") == 0)
285 * Use standard input.
286 * Keep the file descriptor open because we can't reopen it.
289 chflags |= CH_KEEPOPEN;
291 * Must switch stdin to BINARY mode.
294 #if MSDOS_COMPILER==DJGPPC
296 * Setting stdin to binary by default causes
297 * Ctrl-C to not raise SIGINT. We must undo
300 __djgpp_set_ctrl_c(1);
302 } else if (strcmp(open_filename, FAKE_HELPFILE) == 0)
305 chflags |= CH_HELPFILE;
306 } else if ((parg.p_string = bad_file(open_filename)) != NULL)
309 * It looks like a bad file. Don't try to open it.
314 if (alt_filename != NULL)
316 close_altfile(alt_filename, filename, alt_pipe);
320 free(qopen_filename);
323 * Re-open the current file.
325 reedit_ifile(was_curr_ifile);
327 } else if ((f = open(qopen_filename, OPEN_READ)) < 0)
330 * Got an error trying to open it.
332 parg.p_string = errno_message(filename);
338 chflags |= CH_CANSEEK;
339 if (!force_open && !opened(ifile) && bin_file(f))
342 * Looks like a binary file.
343 * Ask user if we should proceed.
345 parg.p_string = filename;
346 answer = query("\"%s\" may be a binary file. See it anyway? ",
348 if (answer != 'y' && answer != 'Y')
355 free(qopen_filename);
359 * Get the saved position for the file.
361 if (was_curr_ifile != NULL_IFILE)
363 old_ifile = was_curr_ifile;
364 unsave_ifile(was_curr_ifile);
367 curr_altfilename = alt_filename;
368 curr_altpipe = alt_pipe;
369 set_open(curr_ifile); /* File has been opened */
370 get_pos(curr_ifile, &initial_scrpos);
374 if (!(chflags & CH_HELPFILE))
377 if (namelogfile != NULL && is_tty)
378 use_logfile(namelogfile);
380 if (every_first_cmd != NULL)
381 ungetsc(every_first_cmd);
384 no_display = !any_display;
391 * Output is to a real tty.
395 * Indicate there is nothing displayed yet.
402 cmd_addhist(ml_examine, filename);
403 if (no_display && errmsgs > 0)
406 * We displayed some messages on error output
407 * (file descriptor 2; see error() function).
408 * Before erasing the screen contents,
409 * display the file name and wait for a keystroke.
411 parg.p_string = filename;
420 * Edit a space-separated list of files.
421 * For each filename in the list, enter it into the ifile list.
422 * Then edit the first one.
433 struct textlist tl_files;
434 struct textlist tl_gfiles;
436 save_ifile = save_curr_ifile();
437 good_filename = NULL;
440 * Run thru each filename in the list.
441 * Try to glob the filename.
442 * If it doesn't expand, just try to open the filename.
443 * If it does expand, try to open each name in that list.
445 init_textlist(&tl_files, filelist);
447 while ((filename = forw_textlist(&tl_files, filename)) != NULL)
449 gfilelist = lglob(filename);
450 init_textlist(&tl_gfiles, gfilelist);
452 while ((gfilename = forw_textlist(&tl_gfiles, gfilename)) != NULL)
454 if (edit(gfilename) == 0 && good_filename == NULL)
455 good_filename = get_filename(curr_ifile);
460 * Edit the first valid filename in the list.
462 if (good_filename == NULL)
464 unsave_ifile(save_ifile);
467 if (get_ifile(good_filename, curr_ifile) == curr_ifile)
470 * Trying to edit the current file; don't reopen it.
472 unsave_ifile(save_ifile);
475 reedit_ifile(save_ifile);
476 return (edit(good_filename));
480 * Edit the first file in the command line (ifile) list.
485 curr_ifile = NULL_IFILE;
486 return (edit_next(1));
490 * Edit the last file in the command line (ifile) list.
495 curr_ifile = NULL_IFILE;
496 return (edit_prev(1));
501 * Edit the next or previous file in the command line (ifile) list.
504 edit_istep(h, n, dir)
512 * Skip n filenames, then try to edit each filename.
516 next = (dir > 0) ? next_ifile(h) : prev_ifile(h);
519 if (edit_ifile(h) == 0)
522 if (next == NULL_IFILE)
525 * Reached end of the ifile list.
532 * Interrupt breaks out, if we're in a long
533 * list of files that can't be opened.
540 * Found a file that we can edit.
550 return (edit_istep(h, n, 1));
557 return edit_istep(curr_ifile, n, 1);
565 return (edit_istep(h, n, -1));
572 return edit_istep(curr_ifile, n, -1);
576 * Edit a specific file in the command line (ifile) list.
587 if ((h = next_ifile(h)) == NULL_IFILE)
590 * Reached end of the list without finding it.
594 } while (get_index(h) != n);
596 return (edit_ifile(h));
602 if (curr_ifile != NULL_IFILE)
603 hold_ifile(curr_ifile, 1);
608 unsave_ifile(save_ifile)
611 if (save_ifile != NULL_IFILE)
612 hold_ifile(save_ifile, -1);
616 * Reedit the ifile which was previously open.
619 reedit_ifile(save_ifile)
626 * Try to reopen the ifile.
627 * Note that opening it may fail (maybe the file was removed),
628 * in which case the ifile will be deleted from the list.
629 * So save the next and prev ifiles first.
631 unsave_ifile(save_ifile);
632 next = next_ifile(save_ifile);
633 prev = prev_ifile(save_ifile);
634 if (edit_ifile(save_ifile) == 0)
637 * If can't reopen it, open the next input file in the list.
639 if (next != NULL_IFILE && edit_inext(next, 0) == 0)
642 * If can't open THAT one, open the previous input file in the list.
644 if (prev != NULL_IFILE && edit_iprev(prev, 0) == 0)
647 * If can't even open that, we're stuck. Just quit.
653 * Edit standard input.
660 error("Missing filename (\"less --help\" for help)", NULL_PARG);
667 * Copy a file directly to standard output.
668 * Used if standard output is not a tty.
675 while ((c = ch_forw_get()) != EOI)
683 * If the user asked for a log file and our input file
684 * is standard input, create the log file.
685 * We take care not to blindly overwrite an existing file.
688 use_logfile(filename)
695 if (ch_getflags() & CH_CANSEEK)
697 * Can't currently use a log file on a file that can seek.
702 * {{ We could use access() here. }}
704 filename = shell_unquote(filename);
705 exists = open(filename, OPEN_READ);
707 exists = (exists >= 0);
710 * Decide whether to overwrite the log file or append to it.
711 * If it doesn't exist we "overwrite" it.
713 if (!exists || force_logfile)
716 * Overwrite (or create) the log file.
722 * Ask user what to do.
724 parg.p_string = filename;
725 answer = query("Warning: \"%s\" exists; Overwrite, Append or Don't log? ", &parg);
733 * Overwrite: create the file.
735 logfile = creat(filename, 0644);
739 * Append: open the file and seek to the end.
741 logfile = open(filename, OPEN_APPEND);
742 if (lseek(logfile, (off_t)0, 2) == BAD_LSEEK)
761 answer = query("Overwrite, Append, or Don't log? (Type \"O\", \"A\", \"D\" or \"q\") ", NULL_PARG);
768 * Error in opening logfile.
770 parg.p_string = filename;
771 error("Cannot write to \"%s\"", &parg);