source: MondoRescue/branches/3.3/mindi-busybox/miscutils/less.c@ 3621

Last change on this file since 3621 was 3621, checked in by Bruno Cornec, 7 years ago

New 3?3 banch for incorporation of latest busybox 1.25. Changing minor version to handle potential incompatibilities.
File size: 54.1 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * Mini less implementation for busybox
4 *
5 * Copyright (C) 2005 by Rob Sullivan <cogito.ergo.cogito@gmail.com>
6 *
7 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
8 */
9
10/*
11 * TODO:
12 * - Add more regular expression support - search modifiers, certain matches, etc.
13 * - Add more complex bracket searching - currently, nested brackets are
14 * not considered.
15 * - Add support for "F" as an input. This causes less to act in
16 * a similar way to tail -f.
17 * - Allow horizontal scrolling.
18 *
19 * Notes:
20 * - the inp file pointer is used so that keyboard input works after
21 * redirected input has been read from stdin
22 */
23
24//config:config LESS
25//config: bool "less"
26//config: default y
27//config: help
28//config: 'less' is a pager, meaning that it displays text files. It possesses
29//config: a wide array of features, and is an improvement over 'more'.
30//config:
31//config:config FEATURE_LESS_MAXLINES
32//config: int "Max number of input lines less will try to eat"
33//config: default 9999999
34//config: depends on LESS
35//config:
36//config:config FEATURE_LESS_BRACKETS
37//config: bool "Enable bracket searching"
38//config: default y
39//config: depends on LESS
40//config: help
41//config: This option adds the capability to search for matching left and right
42//config: brackets, facilitating programming.
43//config:
44//config:config FEATURE_LESS_FLAGS
45//config: bool "Enable -m/-M"
46//config: default y
47//config: depends on LESS
48//config: help
49//config: The -M/-m flag enables a more sophisticated status line.
50//config:
51//config:config FEATURE_LESS_TRUNCATE
52//config: bool "Enable -S"
53//config: default y
54//config: depends on LESS
55//config: help
56//config: The -S flag causes long lines to be truncated rather than
57//config: wrapped.
58//config:
59//config:config FEATURE_LESS_MARKS
60//config: bool "Enable marks"
61//config: default y
62//config: depends on LESS
63//config: help
64//config: Marks enable positions in a file to be stored for easy reference.
65//config:
66//config:config FEATURE_LESS_REGEXP
67//config: bool "Enable regular expressions"
68//config: default y
69//config: depends on LESS
70//config: help
71//config: Enable regular expressions, allowing complex file searches.
72//config:
73//config:config FEATURE_LESS_WINCH
74//config: bool "Enable automatic resizing on window size changes"
75//config: default y
76//config: depends on LESS
77//config: help
78//config: Makes less track window size changes.
79//config:
80//config:config FEATURE_LESS_ASK_TERMINAL
81//config: bool "Use 'tell me cursor position' ESC sequence to measure window"
82//config: default y
83//config: depends on FEATURE_LESS_WINCH
84//config: help
85//config: Makes less track window size changes.
86//config: If terminal size can't be retrieved and $LINES/$COLUMNS are not set,
87//config: this option makes less perform a last-ditch effort to find it:
88//config: position cursor to 999,999 and ask terminal to report real
89//config: cursor position using "ESC [ 6 n" escape sequence, then read stdin.
90//config:
91//config: This is not clean but helps a lot on serial lines and such.
92//config:
93//config:config FEATURE_LESS_DASHCMD
94//config: bool "Enable flag changes ('-' command)"
95//config: default y
96//config: depends on LESS
97//config: help
98//config: This enables the ability to change command-line flags within
99//config: less itself ('-' keyboard command).
100//config:
101//config:config FEATURE_LESS_LINENUMS
102//config: bool "Enable dynamic switching of line numbers"
103//config: default y
104//config: depends on FEATURE_LESS_DASHCMD
105//config: help
106//config: Enables "-N" command.
107
108//usage:#define less_trivial_usage
109//usage: "[-E" IF_FEATURE_LESS_REGEXP("I")IF_FEATURE_LESS_FLAGS("Mm")
110//usage: "N" IF_FEATURE_LESS_TRUNCATE("S") "h~] [FILE]..."
111//usage:#define less_full_usage "\n\n"
112//usage: "View FILE (or stdin) one screenful at a time\n"
113//usage: "\n -E Quit once the end of a file is reached"
114//usage: IF_FEATURE_LESS_REGEXP(
115//usage: "\n -I Ignore case in all searches"
116//usage: )
117//usage: IF_FEATURE_LESS_FLAGS(
118//usage: "\n -M,-m Display status line with line numbers"
119//usage: "\n and percentage through the file"
120//usage: )
121//usage: "\n -N Prefix line number to each line"
122//usage: IF_FEATURE_LESS_TRUNCATE(
123//usage: "\n -S Truncate long lines"
124//usage: )
125//usage: "\n -~ Suppress ~s displayed past EOF"
126
127#include <sched.h> /* sched_yield() */
128
129#include "libbb.h"
130#include "common_bufsiz.h"
131#if ENABLE_FEATURE_LESS_REGEXP
132#include "xregex.h"
133#endif
134
135
136#define ESC "\033"
137/* The escape codes for highlighted and normal text */
138#define HIGHLIGHT ESC"[7m"
139#define NORMAL ESC"[0m"
140/* The escape code to home and clear to the end of screen */
141#define CLEAR ESC"[H\033[J"
142/* The escape code to clear to the end of line */
143#define CLEAR_2_EOL ESC"[K"
144
145enum {
146/* Absolute max of lines eaten */
147 MAXLINES = CONFIG_FEATURE_LESS_MAXLINES,
148/* This many "after the end" lines we will show (at max) */
149 TILDES = 1,
150};
151
152/* Command line options */
153enum {
154 FLAG_E = 1 << 0,
155 FLAG_M = 1 << 1,
156 FLAG_m = 1 << 2,
157 FLAG_N = 1 << 3,
158 FLAG_TILDE = 1 << 4,
159 FLAG_I = 1 << 5,
160 FLAG_S = (1 << 6) * ENABLE_FEATURE_LESS_TRUNCATE,
161/* hijack command line options variable for internal state vars */
162 LESS_STATE_MATCH_BACKWARDS = 1 << 15,
163};
164
165#if !ENABLE_FEATURE_LESS_REGEXP
166enum { pattern_valid = 0 };
167#endif
168
169struct globals {
170 int cur_fline; /* signed */
171 int kbd_fd; /* fd to get input from */
172 int less_gets_pos;
173/* last position in last line, taking into account tabs */
174 size_t last_line_pos;
175 unsigned max_fline;
176 unsigned max_lineno; /* this one tracks linewrap */
177 unsigned max_displayed_line;
178 unsigned width;
179#if ENABLE_FEATURE_LESS_WINCH
180 unsigned winch_counter;
181#endif
182 ssize_t eof_error; /* eof if 0, error if < 0 */
183 ssize_t readpos;
184 ssize_t readeof; /* must be signed */
185 const char **buffer;
186 const char **flines;
187 const char *empty_line_marker;
188 unsigned num_files;
189 unsigned current_file;
190 char *filename;
191 char **files;
192#if ENABLE_FEATURE_LESS_FLAGS
193 int num_lines; /* a flag if < 0, line count if >= 0 */
194# define REOPEN_AND_COUNT (-1)
195# define REOPEN_STDIN (-2)
196# define NOT_REGULAR_FILE (-3)
197#endif
198#if ENABLE_FEATURE_LESS_MARKS
199 unsigned num_marks;
200 unsigned mark_lines[15][2];
201#endif
202#if ENABLE_FEATURE_LESS_REGEXP
203 unsigned *match_lines;
204 int match_pos; /* signed! */
205 int wanted_match; /* signed! */
206 int num_matches;
207 regex_t pattern;
208 smallint pattern_valid;
209#endif
210#if ENABLE_FEATURE_LESS_ASK_TERMINAL
211 smallint winsize_err;
212#endif
213 smallint terminated;
214 struct termios term_orig, term_less;
215 char kbd_input[KEYCODE_BUFFER_SIZE];
216};
217#define G (*ptr_to_globals)
218#define cur_fline (G.cur_fline )
219#define kbd_fd (G.kbd_fd )
220#define less_gets_pos (G.less_gets_pos )
221#define last_line_pos (G.last_line_pos )
222#define max_fline (G.max_fline )
223#define max_lineno (G.max_lineno )
224#define max_displayed_line (G.max_displayed_line)
225#define width (G.width )
226#define winch_counter (G.winch_counter )
227/* This one is 100% not cached by compiler on read access */
228#define WINCH_COUNTER (*(volatile unsigned *)&winch_counter)
229#define eof_error (G.eof_error )
230#define readpos (G.readpos )
231#define readeof (G.readeof )
232#define buffer (G.buffer )
233#define flines (G.flines )
234#define empty_line_marker (G.empty_line_marker )
235#define num_files (G.num_files )
236#define current_file (G.current_file )
237#define filename (G.filename )
238#define files (G.files )
239#define num_lines (G.num_lines )
240#define num_marks (G.num_marks )
241#define mark_lines (G.mark_lines )
242#if ENABLE_FEATURE_LESS_REGEXP
243#define match_lines (G.match_lines )
244#define match_pos (G.match_pos )
245#define num_matches (G.num_matches )
246#define wanted_match (G.wanted_match )
247#define pattern (G.pattern )
248#define pattern_valid (G.pattern_valid )
249#endif
250#define terminated (G.terminated )
251#define term_orig (G.term_orig )
252#define term_less (G.term_less )
253#define kbd_input (G.kbd_input )
254#define INIT_G() do { \
255 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
256 less_gets_pos = -1; \
257 empty_line_marker = "~"; \
258 num_files = 1; \
259 current_file = 1; \
260 eof_error = 1; \
261 terminated = 1; \
262 IF_FEATURE_LESS_REGEXP(wanted_match = -1;) \
263} while (0)
264
265/* flines[] are lines read from stdin, each in malloc'ed buffer.
266 * Line numbers are stored as uint32_t prepended to each line.
267 * Pointer is adjusted so that flines[i] points directly past
268 * line number. Accesor: */
269#define MEMPTR(p) ((char*)(p) - 4)
270#define LINENO(p) (*(uint32_t*)((p) - 4))
271
272
273/* Reset terminal input to normal */
274static void set_tty_cooked(void)
275{
276 fflush_all();
277 tcsetattr(kbd_fd, TCSANOW, &term_orig);
278}
279
280/* Move the cursor to a position (x,y), where (0,0) is the
281 top-left corner of the console */
282static void move_cursor(int line, int row)
283{
284 printf(ESC"[%u;%uH", line, row);
285}
286
287static void clear_line(void)
288{
289 printf(ESC"[%u;0H" CLEAR_2_EOL, max_displayed_line + 2);
290}
291
292static void print_hilite(const char *str)
293{
294 printf(HIGHLIGHT"%s"NORMAL, str);
295}
296
297static void print_statusline(const char *str)
298{
299 clear_line();
300 printf(HIGHLIGHT"%.*s"NORMAL, width - 1, str);
301}
302
303/* Exit the program gracefully */
304static void less_exit(int code)
305{
306 set_tty_cooked();
307 clear_line();
308 if (code < 0)
309 kill_myself_with_sig(- code); /* does not return */
310 exit(code);
311}
312
313#if (ENABLE_FEATURE_LESS_DASHCMD && ENABLE_FEATURE_LESS_LINENUMS) \
314 || ENABLE_FEATURE_LESS_WINCH
315static void re_wrap(void)
316{
317 int w = width;
318 int new_line_pos;
319 int src_idx;
320 int dst_idx;
321 int new_cur_fline = 0;
322 uint32_t lineno;
323 char linebuf[w + 1];
324 const char **old_flines = flines;
325 const char *s;
326 char **new_flines = NULL;
327 char *d;
328
329 if (option_mask32 & FLAG_N)
330 w -= 8;
331
332 src_idx = 0;
333 dst_idx = 0;
334 s = old_flines[0];
335 lineno = LINENO(s);
336 d = linebuf;
337 new_line_pos = 0;
338 while (1) {
339 *d = *s;
340 if (*d != '\0') {
341 new_line_pos++;
342 if (*d == '\t') { /* tab */
343 new_line_pos += 7;
344 new_line_pos &= (~7);
345 }
346 s++;
347 d++;
348 if (new_line_pos >= w) {
349 int sz;
350 /* new line is full, create next one */
351 *d = '\0';
352 next_new:
353 sz = (d - linebuf) + 1; /* + 1: NUL */
354 d = ((char*)xmalloc(sz + 4)) + 4;
355 LINENO(d) = lineno;
356 memcpy(d, linebuf, sz);
357 new_flines = xrealloc_vector(new_flines, 8, dst_idx);
358 new_flines[dst_idx] = d;
359 dst_idx++;
360 if (new_line_pos < w) {
361 /* if we came here thru "goto next_new" */
362 if (src_idx > max_fline)
363 break;
364 lineno = LINENO(s);
365 }
366 d = linebuf;
367 new_line_pos = 0;
368 }
369 continue;
370 }
371 /* *d == NUL: old line ended, go to next old one */
372 free(MEMPTR(old_flines[src_idx]));
373 /* btw, convert cur_fline... */
374 if (cur_fline == src_idx)
375 new_cur_fline = dst_idx;
376 src_idx++;
377 /* no more lines? finish last new line (and exit the loop) */
378 if (src_idx > max_fline)
379 goto next_new;
380 s = old_flines[src_idx];
381 if (lineno != LINENO(s)) {
382 /* this is not a continuation line!
383 * create next _new_ line too */
384 goto next_new;
385 }
386 }
387
388 free(old_flines);
389 flines = (const char **)new_flines;
390
391 max_fline = dst_idx - 1;
392 last_line_pos = new_line_pos;
393 cur_fline = new_cur_fline;
394 /* max_lineno is screen-size independent */
395#if ENABLE_FEATURE_LESS_REGEXP
396 pattern_valid = 0;
397#endif
398}
399#endif
400
401#if ENABLE_FEATURE_LESS_REGEXP
402static void fill_match_lines(unsigned pos);
403#else
404#define fill_match_lines(pos) ((void)0)
405#endif
406
407static int at_end(void)
408{
409 return (option_mask32 & FLAG_S)
410 ? !(cur_fline <= max_fline &&
411 max_lineno > LINENO(flines[cur_fline]) + max_displayed_line)
412 : !(max_fline > cur_fline + max_displayed_line);
413}
414
415/* Devilishly complex routine.
416 *
417 * Has to deal with EOF and EPIPE on input,
418 * with line wrapping, with last line not ending in '\n'
419 * (possibly not ending YET!), with backspace and tabs.
420 * It reads input again if last time we got an EOF (thus supporting
421 * growing files) or EPIPE (watching output of slow process like make).
422 *
423 * Variables used:
424 * flines[] - array of lines already read. Linewrap may cause
425 * one source file line to occupy several flines[n].
426 * flines[max_fline] - last line, possibly incomplete.
427 * terminated - 1 if flines[max_fline] is 'terminated'
428 * (if there was '\n' [which isn't stored itself, we just remember
429 * that it was seen])
430 * max_lineno - last line's number, this one doesn't increment
431 * on line wrap, only on "real" new lines.
432 * readbuf[0..readeof-1] - small preliminary buffer.
433 * readbuf[readpos] - next character to add to current line.
434 * last_line_pos - screen line position of next char to be read
435 * (takes into account tabs and backspaces)
436 * eof_error - < 0 error, == 0 EOF, > 0 not EOF/error
437 *
438 * "git log -p | less -m" on the kernel git tree is a good test for EAGAINs,
439 * "/search on very long input" and "reaching max line count" corner cases.
440 */
441static void read_lines(void)
442{
443 char *current_line, *p;
444 int w = width;
445 char last_terminated = terminated;
446 time_t last_time = 0;
447 int retry_EAGAIN = 2;
448#if ENABLE_FEATURE_LESS_REGEXP
449 unsigned old_max_fline = max_fline;
450#endif
451
452#define readbuf bb_common_bufsiz1
453 setup_common_bufsiz();
454
455 /* (careful: max_fline can be -1) */
456 if (max_fline + 1 > MAXLINES)
457 return;
458
459 if (option_mask32 & FLAG_N)
460 w -= 8;
461
462 p = current_line = ((char*)xmalloc(w + 5)) + 4;
463 if (!last_terminated) {
464 const char *cp = flines[max_fline];
465 p = stpcpy(p, cp);
466 free(MEMPTR(cp));
467 /* last_line_pos is still valid from previous read_lines() */
468 } else {
469 max_fline++;
470 last_line_pos = 0;
471 }
472
473 while (1) { /* read lines until we reach cur_fline or wanted_match */
474 *p = '\0';
475 terminated = 0;
476 while (1) { /* read chars until we have a line */
477 char c;
478 /* if no unprocessed chars left, eat more */
479 if (readpos >= readeof) {
480 int flags = ndelay_on(0);
481
482 while (1) {
483 time_t t;
484
485 errno = 0;
486 eof_error = safe_read(STDIN_FILENO, readbuf, COMMON_BUFSIZE);
487 if (errno != EAGAIN)
488 break;
489 t = time(NULL);
490 if (t != last_time) {
491 last_time = t;
492 if (--retry_EAGAIN < 0)
493 break;
494 }
495 sched_yield();
496 }
497 fcntl(0, F_SETFL, flags); /* ndelay_off(0) */
498 readpos = 0;
499 readeof = eof_error;
500 if (eof_error <= 0)
501 goto reached_eof;
502 retry_EAGAIN = 1;
503 }
504 c = readbuf[readpos];
505 /* backspace? [needed for manpages] */
506 /* <tab><bs> is (a) insane and */
507 /* (b) harder to do correctly, so we refuse to do it */
508 if (c == '\x8' && last_line_pos && p[-1] != '\t') {
509 readpos++; /* eat it */
510 last_line_pos--;
511 /* was buggy (p could end up <= current_line)... */
512 *--p = '\0';
513 continue;
514 }
515 {
516 size_t new_last_line_pos = last_line_pos + 1;
517 if (c == '\t') {
518 new_last_line_pos += 7;
519 new_last_line_pos &= (~7);
520 }
521 if ((int)new_last_line_pos > w)
522 break;
523 last_line_pos = new_last_line_pos;
524 }
525 /* ok, we will eat this char */
526 readpos++;
527 if (c == '\n') {
528 terminated = 1;
529 last_line_pos = 0;
530 break;
531 }
532 /* NUL is substituted by '\n'! */
533 if (c == '\0') c = '\n';
534 *p++ = c;
535 *p = '\0';
536 } /* end of "read chars until we have a line" loop */
537#if 0
538//BUG: also triggers on this:
539// { printf "\nfoo\n"; sleep 1; printf "\nbar\n"; } | less
540// (resulting in lost empty line between "foo" and "bar" lines)
541// the "terminated" logic needs fixing (or explaining)
542 /* Corner case: linewrap with only "" wrapping to next line */
543 /* Looks ugly on screen, so we do not store this empty line */
544 if (!last_terminated && !current_line[0]) {
545 last_terminated = 1;
546 max_lineno++;
547 continue;
548 }
549#endif
550 reached_eof:
551 last_terminated = terminated;
552 flines = xrealloc_vector(flines, 8, max_fline);
553
554 flines[max_fline] = (char*)xrealloc(MEMPTR(current_line), strlen(current_line) + 1 + 4) + 4;
555 LINENO(flines[max_fline]) = max_lineno;
556 if (terminated)
557 max_lineno++;
558
559 if (max_fline >= MAXLINES) {
560 eof_error = 0; /* Pretend we saw EOF */
561 break;
562 }
563 if (!at_end()) {
564#if !ENABLE_FEATURE_LESS_REGEXP
565 break;
566#else
567 if (wanted_match >= num_matches) { /* goto_match called us */
568 fill_match_lines(old_max_fline);
569 old_max_fline = max_fline;
570 }
571 if (wanted_match < num_matches)
572 break;
573#endif
574 }
575 if (eof_error <= 0) {
576 break;
577 }
578 max_fline++;
579 current_line = ((char*)xmalloc(w + 5)) + 4;
580 p = current_line;
581 last_line_pos = 0;
582 } /* end of "read lines until we reach cur_fline" loop */
583
584 if (eof_error < 0) {
585 if (errno == EAGAIN) {
586 eof_error = 1;
587 } else {
588 print_statusline(bb_msg_read_error);
589 }
590 }
591#if ENABLE_FEATURE_LESS_FLAGS
592 else if (eof_error == 0)
593 num_lines = max_lineno;
594#endif
595
596 fill_match_lines(old_max_fline);
597#if ENABLE_FEATURE_LESS_REGEXP
598 /* prevent us from being stuck in search for a match */
599 wanted_match = -1;
600#endif
601#undef readbuf
602}
603
604#if ENABLE_FEATURE_LESS_FLAGS
605static int safe_lineno(int fline)
606{
607 if (fline >= max_fline)
608 fline = max_fline - 1;
609
610 /* also catches empty file (max_fline == 0) */
611 if (fline < 0)
612 return 0;
613
614 return LINENO(flines[fline]) + 1;
615}
616
617/* count number of lines in file */
618static void update_num_lines(void)
619{
620 int count, fd;
621 struct stat stbuf;
622 ssize_t len, i;
623 char buf[4096];
624
625 /* only do this for regular files */
626 if (num_lines == REOPEN_AND_COUNT || num_lines == REOPEN_STDIN) {
627 count = 0;
628 fd = open("/proc/self/fd/0", O_RDONLY);
629 if (fd < 0 && num_lines == REOPEN_AND_COUNT) {
630 /* "filename" is valid only if REOPEN_AND_COUNT */
631 fd = open(filename, O_RDONLY);
632 }
633 if (fd < 0) {
634 /* somebody stole my file! */
635 num_lines = NOT_REGULAR_FILE;
636 return;
637 }
638 if (fstat(fd, &stbuf) != 0 || !S_ISREG(stbuf.st_mode)) {
639 num_lines = NOT_REGULAR_FILE;
640 goto do_close;
641 }
642 while ((len = safe_read(fd, buf, sizeof(buf))) > 0) {
643 for (i = 0; i < len; ++i) {
644 if (buf[i] == '\n' && ++count == MAXLINES)
645 goto done;
646 }
647 }
648 done:
649 num_lines = count;
650 do_close:
651 close(fd);
652 }
653}
654
655/* Print a status line if -M was specified */
656static void m_status_print(void)
657{
658 int first, last;
659 unsigned percent;
660
661 if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
662 return;
663
664 clear_line();
665 printf(HIGHLIGHT"%s", filename);
666 if (num_files > 1)
667 printf(" (file %i of %i)", current_file, num_files);
668
669 first = safe_lineno(cur_fline);
670 last = (option_mask32 & FLAG_S)
671 ? MIN(first + max_displayed_line, max_lineno)
672 : safe_lineno(cur_fline + max_displayed_line);
673 printf(" lines %i-%i", first, last);
674
675 update_num_lines();
676 if (num_lines >= 0)
677 printf("/%i", num_lines);
678
679 if (at_end()) {
680 printf(" (END)");
681 if (num_files > 1 && current_file != num_files)
682 printf(" - next: %s", files[current_file]);
683 } else if (num_lines > 0) {
684 percent = (100 * last + num_lines/2) / num_lines;
685 printf(" %i%%", percent <= 100 ? percent : 100);
686 }
687 printf(NORMAL);
688}
689#endif
690
691/* Print the status line */
692static void status_print(void)
693{
694 const char *p;
695
696 if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
697 return;
698
699 /* Change the status if flags have been set */
700#if ENABLE_FEATURE_LESS_FLAGS
701 if (option_mask32 & (FLAG_M|FLAG_m)) {
702 m_status_print();
703 return;
704 }
705 /* No flags set */
706#endif
707
708 clear_line();
709 if (cur_fline && !at_end()) {
710 bb_putchar(':');
711 return;
712 }
713 p = "(END)";
714 if (!cur_fline)
715 p = filename;
716 if (num_files > 1) {
717 printf(HIGHLIGHT"%s (file %i of %i)"NORMAL,
718 p, current_file, num_files);
719 return;
720 }
721 print_hilite(p);
722}
723
724static const char controls[] ALIGN1 =
725 /* NUL: never encountered; TAB: not converted */
726 /**/"\x01\x02\x03\x04\x05\x06\x07\x08" "\x0a\x0b\x0c\x0d\x0e\x0f"
727 "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
728 "\x7f\x9b"; /* DEL and infamous Meta-ESC :( */
729static const char ctrlconv[] ALIGN1 =
730 /* why 40 instead of 4a below? - it is a replacement for '\n'.
731 * '\n' is a former NUL - we subst it with @, not J */
732 "\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x40\x4b\x4c\x4d\x4e\x4f"
733 "\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f";
734
735static void print_lineno(const char *line)
736{
737 const char *fmt = " ";
738 unsigned n = n; /* for compiler */
739
740 if (line != empty_line_marker) {
741 /* Width of 7 preserves tab spacing in the text */
742 fmt = "%7u ";
743 n = LINENO(line) + 1;
744 if (n > 9999999 && MAXLINES > 9999999) {
745 n %= 10000000;
746 fmt = "%07u ";
747 }
748 }
749 printf(fmt, n);
750}
751
752
753#if ENABLE_FEATURE_LESS_REGEXP
754static void print_found(const char *line)
755{
756 int match_status;
757 int eflags;
758 char *growline;
759 regmatch_t match_structs;
760
761 char buf[width+1];
762 const char *str = line;
763 char *p = buf;
764 size_t n;
765
766 while (*str) {
767 n = strcspn(str, controls);
768 if (n) {
769 if (!str[n]) break;
770 memcpy(p, str, n);
771 p += n;
772 str += n;
773 }
774 n = strspn(str, controls);
775 memset(p, '.', n);
776 p += n;
777 str += n;
778 }
779 strcpy(p, str);
780
781 /* buf[] holds quarantined version of str */
782
783 /* Each part of the line that matches has the HIGHLIGHT
784 * and NORMAL escape sequences placed around it.
785 * NB: we regex against line, but insert text
786 * from quarantined copy (buf[]) */
787 str = buf;
788 growline = NULL;
789 eflags = 0;
790 goto start;
791
792 while (match_status == 0) {
793 char *new = xasprintf("%s%.*s"HIGHLIGHT"%.*s"NORMAL,
794 growline ? growline : "",
795 (int)match_structs.rm_so, str,
796 (int)(match_structs.rm_eo - match_structs.rm_so),
797 str + match_structs.rm_so);
798 free(growline);
799 growline = new;
800 str += match_structs.rm_eo;
801 line += match_structs.rm_eo;
802 eflags = REG_NOTBOL;
803 start:
804 /* Most of the time doesn't find the regex, optimize for that */
805 match_status = regexec(&pattern, line, 1, &match_structs, eflags);
806 /* if even "" matches, treat it as "not a match" */
807 if (match_structs.rm_so >= match_structs.rm_eo)
808 match_status = 1;
809 }
810
811 printf("%s%s\n", growline ? growline : "", str);
812 free(growline);
813}
814#else
815void print_found(const char *line);
816#endif
817
818static void print_ascii(const char *str)
819{
820 char buf[width+1];
821 char *p;
822 size_t n;
823
824 while (*str) {
825 n = strcspn(str, controls);
826 if (n) {
827 if (!str[n]) break;
828 printf("%.*s", (int) n, str);
829 str += n;
830 }
831 n = strspn(str, controls);
832 p = buf;
833 do {
834 if (*str == 0x7f)
835 *p++ = '?';
836 else if (*str == (char)0x9b)
837 /* VT100's CSI, aka Meta-ESC. Who's inventor? */
838 /* I want to know who committed this sin */
839 *p++ = '{';
840 else
841 *p++ = ctrlconv[(unsigned char)*str];
842 str++;
843 } while (--n);
844 *p = '\0';
845 print_hilite(buf);
846 }
847 puts(str);
848}
849
850/* Print the buffer */
851static void buffer_print(void)
852{
853 unsigned i;
854
855 move_cursor(0, 0);
856 for (i = 0; i <= max_displayed_line; i++) {
857 printf(CLEAR_2_EOL);
858 if (option_mask32 & FLAG_N)
859 print_lineno(buffer[i]);
860 if (pattern_valid)
861 print_found(buffer[i]);
862 else
863 print_ascii(buffer[i]);
864 }
865 if ((option_mask32 & FLAG_E)
866 && eof_error <= 0
867 && (max_fline - cur_fline) <= max_displayed_line
868 ) {
869 less_exit(EXIT_SUCCESS);
870 }
871 status_print();
872}
873
874static void buffer_fill_and_print(void)
875{
876 unsigned i;
877#if ENABLE_FEATURE_LESS_TRUNCATE
878 int fpos = cur_fline;
879
880 if (option_mask32 & FLAG_S) {
881 /* Go back to the beginning of this line */
882 while (fpos && LINENO(flines[fpos]) == LINENO(flines[fpos-1]))
883 fpos--;
884 }
885
886 i = 0;
887 while (i <= max_displayed_line && fpos <= max_fline) {
888 int lineno = LINENO(flines[fpos]);
889 buffer[i] = flines[fpos];
890 i++;
891 do {
892 fpos++;
893 } while ((fpos <= max_fline)
894 && (option_mask32 & FLAG_S)
895 && lineno == LINENO(flines[fpos])
896 );
897 }
898#else
899 for (i = 0; i <= max_displayed_line && cur_fline + i <= max_fline; i++) {
900 buffer[i] = flines[cur_fline + i];
901 }
902#endif
903 for (; i <= max_displayed_line; i++) {
904 buffer[i] = empty_line_marker;
905 }
906 buffer_print();
907}
908
909/* move cur_fline to a given line number, reading lines if necessary */
910static void goto_lineno(int target)
911{
912 if (target <= 0 ) {
913 cur_fline = 0;
914 }
915 else if (target > LINENO(flines[cur_fline])) {
916 retry:
917 while (LINENO(flines[cur_fline]) != target && cur_fline < max_fline)
918 ++cur_fline;
919 /* target not reached but more input is available */
920 if (LINENO(flines[cur_fline]) != target && eof_error > 0) {
921 read_lines();
922 goto retry;
923 }
924 }
925 else {
926 /* search backwards through already-read lines */
927 while (LINENO(flines[cur_fline]) != target && cur_fline > 0)
928 --cur_fline;
929 }
930}
931
932static void cap_cur_fline(void)
933{
934 if ((option_mask32 & FLAG_S)) {
935 if (cur_fline > max_fline)
936 cur_fline = max_fline;
937 if (LINENO(flines[cur_fline]) + max_displayed_line > max_lineno + TILDES) {
938 goto_lineno(max_lineno - max_displayed_line + TILDES);
939 read_lines();
940 }
941 }
942 else {
943 if (cur_fline + max_displayed_line > max_fline + TILDES)
944 cur_fline = max_fline - max_displayed_line + TILDES;
945 if (cur_fline < 0)
946 cur_fline = 0;
947 }
948}
949
950/* Move the buffer up and down in the file in order to scroll */
951static void buffer_down(int nlines)
952{
953 if ((option_mask32 & FLAG_S))
954 goto_lineno(LINENO(flines[cur_fline]) + nlines);
955 else
956 cur_fline += nlines;
957 read_lines();
958 cap_cur_fline();
959 buffer_fill_and_print();
960}
961
962static void buffer_up(int nlines)
963{
964 if ((option_mask32 & FLAG_S)) {
965 goto_lineno(LINENO(flines[cur_fline]) - nlines);
966 }
967 else {
968 cur_fline -= nlines;
969 if (cur_fline < 0)
970 cur_fline = 0;
971 }
972 read_lines();
973 buffer_fill_and_print();
974}
975
976/* display a given line where the argument can be either an index into
977 * the flines array or a line number */
978static void buffer_to_line(int linenum, int is_lineno)
979{
980 if (linenum <= 0)
981 cur_fline = 0;
982 else if (is_lineno)
983 goto_lineno(linenum);
984 else
985 cur_fline = linenum;
986 read_lines();
987 cap_cur_fline();
988 buffer_fill_and_print();
989}
990
991static void buffer_line(int linenum)
992{
993 buffer_to_line(linenum, FALSE);
994}
995
996static void buffer_lineno(int lineno)
997{
998 buffer_to_line(lineno, TRUE);
999}
1000
1001static void open_file_and_read_lines(void)
1002{
1003 if (filename) {
1004 xmove_fd(xopen(filename, O_RDONLY), STDIN_FILENO);
1005#if ENABLE_FEATURE_LESS_FLAGS
1006 num_lines = REOPEN_AND_COUNT;
1007#endif
1008 } else {
1009 /* "less" with no arguments in argv[] */
1010 /* For status line only */
1011 filename = xstrdup(bb_msg_standard_input);
1012#if ENABLE_FEATURE_LESS_FLAGS
1013 num_lines = REOPEN_STDIN;
1014#endif
1015 }
1016 readpos = 0;
1017 readeof = 0;
1018 last_line_pos = 0;
1019 terminated = 1;
1020 read_lines();
1021}
1022
1023/* Reinitialize everything for a new file - free the memory and start over */
1024static void reinitialize(void)
1025{
1026 unsigned i;
1027
1028 if (flines) {
1029 for (i = 0; i <= max_fline; i++)
1030 free(MEMPTR(flines[i]));
1031 free(flines);
1032 flines = NULL;
1033 }
1034
1035 max_fline = -1;
1036 cur_fline = 0;
1037 max_lineno = 0;
1038 open_file_and_read_lines();
1039#if ENABLE_FEATURE_LESS_ASK_TERMINAL
1040 if (G.winsize_err)
1041 printf("\033[999;999H" "\033[6n");
1042#endif
1043 buffer_fill_and_print();
1044}
1045
1046static int64_t getch_nowait(void)
1047{
1048 int rd;
1049 int64_t key64;
1050 struct pollfd pfd[2];
1051
1052 pfd[0].fd = STDIN_FILENO;
1053 pfd[0].events = POLLIN;
1054 pfd[1].fd = kbd_fd;
1055 pfd[1].events = POLLIN;
1056 again:
1057 tcsetattr(kbd_fd, TCSANOW, &term_less);
1058 /* NB: select/poll returns whenever read will not block. Therefore:
1059 * if eof is reached, select/poll will return immediately
1060 * because read will immediately return 0 bytes.
1061 * Even if select/poll says that input is available, read CAN block
1062 * (switch fd into O_NONBLOCK'ed mode to avoid it)
1063 */
1064 rd = 1;
1065 /* Are we interested in stdin? */
1066 if (at_end()) {
1067 if (eof_error > 0) /* did NOT reach eof yet */
1068 rd = 0; /* yes, we are interested in stdin */
1069 }
1070 /* Position cursor if line input is done */
1071 if (less_gets_pos >= 0)
1072 move_cursor(max_displayed_line + 2, less_gets_pos + 1);
1073 fflush_all();
1074
1075 if (kbd_input[0] == 0) { /* if nothing is buffered */
1076#if ENABLE_FEATURE_LESS_WINCH
1077 while (1) {
1078 int r;
1079 /* NB: SIGWINCH interrupts poll() */
1080 r = poll(pfd + rd, 2 - rd, -1);
1081 if (/*r < 0 && errno == EINTR &&*/ winch_counter)
1082 return '\\'; /* anything which has no defined function */
1083 if (r) break;
1084 }
1085#else
1086 safe_poll(pfd + rd, 2 - rd, -1);
1087#endif
1088 }
1089
1090 /* We have kbd_fd in O_NONBLOCK mode, read inside read_key()
1091 * would not block even if there is no input available */
1092 key64 = read_key(kbd_fd, kbd_input, /*timeout off:*/ -2);
1093 if ((int)key64 == -1) {
1094 if (errno == EAGAIN) {
1095 /* No keyboard input available. Since poll() did return,
1096 * we should have input on stdin */
1097 read_lines();
1098 buffer_fill_and_print();
1099 goto again;
1100 }
1101 /* EOF/error (ssh session got killed etc) */
1102 less_exit(0);
1103 }
1104 set_tty_cooked();
1105 return key64;
1106}
1107
1108/* Grab a character from input without requiring the return key.
1109 * May return KEYCODE_xxx values.
1110 * Note that this function works best with raw input. */
1111static int64_t less_getch(int pos)
1112{
1113 int64_t key64;
1114 int key;
1115
1116 again:
1117 less_gets_pos = pos;
1118 key = key64 = getch_nowait();
1119 less_gets_pos = -1;
1120
1121 /* Discard Ctrl-something chars.
1122 * (checking only lower 32 bits is a size optimization:
1123 * upper 32 bits are used only by KEYCODE_CURSOR_POS)
1124 */
1125 if (key >= 0 && key < ' ' && key != 0x0d && key != 8)
1126 goto again;
1127
1128 return key64;
1129}
1130
1131static char* less_gets(int sz)
1132{
1133 int c;
1134 unsigned i = 0;
1135 char *result = xzalloc(1);
1136
1137 while (1) {
1138 c = '\0';
1139 less_gets_pos = sz + i;
1140 c = getch_nowait();
1141 if (c == 0x0d) {
1142 result[i] = '\0';
1143 less_gets_pos = -1;
1144 return result;
1145 }
1146 if (c == 0x7f)
1147 c = 8;
1148 if (c == 8 && i) {
1149 printf("\x8 \x8");
1150 i--;
1151 }
1152 if (c < ' ') /* filters out KEYCODE_xxx too (<0) */
1153 continue;
1154 if (i >= width - sz - 1)
1155 continue; /* len limit */
1156 bb_putchar(c);
1157 result[i++] = c;
1158 result = xrealloc(result, i+1);
1159 }
1160}
1161
1162static void examine_file(void)
1163{
1164 char *new_fname;
1165
1166 print_statusline("Examine: ");
1167 new_fname = less_gets(sizeof("Examine: ") - 1);
1168 if (!new_fname[0]) {
1169 status_print();
1170 err:
1171 free(new_fname);
1172 return;
1173 }
1174 if (access(new_fname, R_OK) != 0) {
1175 print_statusline("Cannot read this file");
1176 goto err;
1177 }
1178 free(filename);
1179 filename = new_fname;
1180 /* files start by = argv. why we assume that argv is infinitely long??
1181 files[num_files] = filename;
1182 current_file = num_files + 1;
1183 num_files++; */
1184 files[0] = filename;
1185 num_files = current_file = 1;
1186 reinitialize();
1187}
1188
1189/* This function changes the file currently being paged. direction can be one of the following:
1190 * -1: go back one file
1191 * 0: go to the first file
1192 * 1: go forward one file */
1193static void change_file(int direction)
1194{
1195 if (current_file != ((direction > 0) ? num_files : 1)) {
1196 current_file = direction ? current_file + direction : 1;
1197 free(filename);
1198 filename = xstrdup(files[current_file - 1]);
1199 reinitialize();
1200 } else {
1201 print_statusline(direction > 0 ? "No next file" : "No previous file");
1202 }
1203}
1204
1205static void remove_current_file(void)
1206{
1207 unsigned i;
1208
1209 if (num_files < 2)
1210 return;
1211
1212 if (current_file != 1) {
1213 change_file(-1);
1214 for (i = 3; i <= num_files; i++)
1215 files[i - 2] = files[i - 1];
1216 num_files--;
1217 } else {
1218 change_file(1);
1219 for (i = 2; i <= num_files; i++)
1220 files[i - 2] = files[i - 1];
1221 num_files--;
1222 current_file--;
1223 }
1224}
1225
1226static void colon_process(void)
1227{
1228 int keypress;
1229
1230 /* Clear the current line and print a prompt */
1231 print_statusline(" :");
1232
1233 keypress = less_getch(2);
1234 switch (keypress) {
1235 case 'd':
1236 remove_current_file();
1237 break;
1238 case 'e':
1239 examine_file();
1240 break;
1241#if ENABLE_FEATURE_LESS_FLAGS
1242 case 'f':
1243 m_status_print();
1244 break;
1245#endif
1246 case 'n':
1247 change_file(1);
1248 break;
1249 case 'p':
1250 change_file(-1);
1251 break;
1252 case 'q':
1253 less_exit(EXIT_SUCCESS);
1254 break;
1255 case 'x':
1256 change_file(0);
1257 break;
1258 }
1259}
1260
1261#if ENABLE_FEATURE_LESS_REGEXP
1262static void normalize_match_pos(int match)
1263{
1264 if (match >= num_matches)
1265 match = num_matches - 1;
1266 if (match < 0)
1267 match = 0;
1268 match_pos = match;
1269}
1270
1271static void goto_match(int match)
1272{
1273 if (!pattern_valid)
1274 return;
1275 if (match < 0)
1276 match = 0;
1277 /* Try to find next match if eof isn't reached yet */
1278 if (match >= num_matches && eof_error > 0) {
1279 wanted_match = match; /* "I want to read until I see N'th match" */
1280 read_lines();
1281 }
1282 if (num_matches) {
1283 normalize_match_pos(match);
1284 buffer_line(match_lines[match_pos]);
1285 } else {
1286 print_statusline("No matches found");
1287 }
1288}
1289
1290static void fill_match_lines(unsigned pos)
1291{
1292 if (!pattern_valid)
1293 return;
1294 /* Run the regex on each line of the current file */
1295 while (pos <= max_fline) {
1296 /* If this line matches */
1297 if (regexec(&pattern, flines[pos], 0, NULL, 0) == 0
1298 /* and we didn't match it last time */
1299 && !(num_matches && match_lines[num_matches-1] == pos)
1300 ) {
1301 match_lines = xrealloc_vector(match_lines, 4, num_matches);
1302 match_lines[num_matches++] = pos;
1303 }
1304 pos++;
1305 }
1306}
1307
1308static void regex_process(void)
1309{
1310 char *uncomp_regex, *err;
1311
1312 /* Reset variables */
1313 free(match_lines);
1314 match_lines = NULL;
1315 match_pos = 0;
1316 num_matches = 0;
1317 if (pattern_valid) {
1318 regfree(&pattern);
1319 pattern_valid = 0;
1320 }
1321
1322 /* Get the uncompiled regular expression from the user */
1323 clear_line();
1324 bb_putchar((option_mask32 & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
1325 uncomp_regex = less_gets(1);
1326 if (!uncomp_regex[0]) {
1327 free(uncomp_regex);
1328 buffer_print();
1329 return;
1330 }
1331
1332 /* Compile the regex and check for errors */
1333 err = regcomp_or_errmsg(&pattern, uncomp_regex,
1334 (option_mask32 & FLAG_I) ? REG_ICASE : 0);
1335 free(uncomp_regex);
1336 if (err) {
1337 print_statusline(err);
1338 free(err);
1339 return;
1340 }
1341
1342 pattern_valid = 1;
1343 match_pos = 0;
1344 fill_match_lines(0);
1345 while (match_pos < num_matches) {
1346 if ((int)match_lines[match_pos] > cur_fline)
1347 break;
1348 match_pos++;
1349 }
1350 if (option_mask32 & LESS_STATE_MATCH_BACKWARDS)
1351 match_pos--;
1352
1353 /* It's possible that no matches are found yet.
1354 * goto_match() will read input looking for match,
1355 * if needed */
1356 goto_match(match_pos);
1357}
1358#endif
1359
1360static void number_process(int first_digit)
1361{
1362 unsigned i;
1363 int num;
1364 int keypress;
1365 char num_input[sizeof(int)*4]; /* more than enough */
1366
1367 num_input[0] = first_digit;
1368
1369 /* Clear the current line, print a prompt, and then print the digit */
1370 clear_line();
1371 printf(":%c", first_digit);
1372
1373 /* Receive input until a letter is given */
1374 i = 1;
1375 while (i < sizeof(num_input)-1) {
1376 keypress = less_getch(i + 1);
1377 if ((unsigned)keypress > 255 || !isdigit(keypress))
1378 break;
1379 num_input[i] = keypress;
1380 bb_putchar(keypress);
1381 i++;
1382 }
1383
1384 num_input[i] = '\0';
1385 num = bb_strtou(num_input, NULL, 10);
1386 /* on format error, num == -1 */
1387 if (num < 1 || num > MAXLINES) {
1388 buffer_print();
1389 return;
1390 }
1391
1392 /* We now know the number and the letter entered, so we process them */
1393 switch (keypress) {
1394 case KEYCODE_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015':
1395 buffer_down(num);
1396 break;
1397 case KEYCODE_UP: case 'b': case 'w': case 'y': case 'u':
1398 buffer_up(num);
1399 break;
1400 case 'g': case '<': case 'G': case '>':
1401 buffer_lineno(num - 1);
1402 break;
1403 case 'p': case '%':
1404#if ENABLE_FEATURE_LESS_FLAGS
1405 update_num_lines();
1406 num = num * (num_lines > 0 ? num_lines : max_lineno) / 100;
1407#else
1408 num = num * max_lineno / 100;
1409#endif
1410 buffer_lineno(num);
1411 break;
1412#if ENABLE_FEATURE_LESS_REGEXP
1413 case 'n':
1414 goto_match(match_pos + num);
1415 break;
1416 case '/':
1417 option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
1418 regex_process();
1419 break;
1420 case '?':
1421 option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
1422 regex_process();
1423 break;
1424#endif
1425 }
1426}
1427
1428#if ENABLE_FEATURE_LESS_DASHCMD
1429static void flag_change(void)
1430{
1431 int keypress;
1432
1433 clear_line();
1434 bb_putchar('-');
1435 keypress = less_getch(1);
1436
1437 switch (keypress) {
1438 case 'M':
1439 option_mask32 ^= FLAG_M;
1440 break;
1441 case 'm':
1442 option_mask32 ^= FLAG_m;
1443 break;
1444 case 'E':
1445 option_mask32 ^= FLAG_E;
1446 break;
1447 case '~':
1448 option_mask32 ^= FLAG_TILDE;
1449 break;
1450#if ENABLE_FEATURE_LESS_TRUNCATE
1451 case 'S':
1452 option_mask32 ^= FLAG_S;
1453 buffer_fill_and_print();
1454 break;
1455#endif
1456#if ENABLE_FEATURE_LESS_LINENUMS
1457 case 'N':
1458 option_mask32 ^= FLAG_N;
1459 re_wrap();
1460 buffer_fill_and_print();
1461 break;
1462#endif
1463 }
1464}
1465
1466#ifdef BLOAT
1467static void show_flag_status(void)
1468{
1469 int keypress;
1470 int flag_val;
1471
1472 clear_line();
1473 bb_putchar('_');
1474 keypress = less_getch(1);
1475
1476 switch (keypress) {
1477 case 'M':
1478 flag_val = option_mask32 & FLAG_M;
1479 break;
1480 case 'm':
1481 flag_val = option_mask32 & FLAG_m;
1482 break;
1483 case '~':
1484 flag_val = option_mask32 & FLAG_TILDE;
1485 break;
1486 case 'N':
1487 flag_val = option_mask32 & FLAG_N;
1488 break;
1489 case 'E':
1490 flag_val = option_mask32 & FLAG_E;
1491 break;
1492 default:
1493 flag_val = 0;
1494 break;
1495 }
1496
1497 clear_line();
1498 printf(HIGHLIGHT"The status of the flag is: %u"NORMAL, flag_val != 0);
1499}
1500#endif
1501
1502#endif /* ENABLE_FEATURE_LESS_DASHCMD */
1503
1504static void save_input_to_file(void)
1505{
1506 const char *msg = "";
1507 char *current_line;
1508 unsigned i;
1509 FILE *fp;
1510
1511 print_statusline("Log file: ");
1512 current_line = less_gets(sizeof("Log file: ")-1);
1513 if (current_line[0]) {
1514 fp = fopen_for_write(current_line);
1515 if (!fp) {
1516 msg = "Error opening log file";
1517 goto ret;
1518 }
1519 for (i = 0; i <= max_fline; i++)
1520 fprintf(fp, "%s\n", flines[i]);
1521 fclose(fp);
1522 msg = "Done";
1523 }
1524 ret:
1525 print_statusline(msg);
1526 free(current_line);
1527}
1528
1529#if ENABLE_FEATURE_LESS_MARKS
1530static void add_mark(void)
1531{
1532 int letter;
1533
1534 print_statusline("Mark: ");
1535 letter = less_getch(sizeof("Mark: ") - 1);
1536
1537 if (isalpha(letter)) {
1538 /* If we exceed 15 marks, start overwriting previous ones */
1539 if (num_marks == 14)
1540 num_marks = 0;
1541
1542 mark_lines[num_marks][0] = letter;
1543 mark_lines[num_marks][1] = cur_fline;
1544 num_marks++;
1545 } else {
1546 print_statusline("Invalid mark letter");
1547 }
1548}
1549
1550static void goto_mark(void)
1551{
1552 int letter;
1553 int i;
1554
1555 print_statusline("Go to mark: ");
1556 letter = less_getch(sizeof("Go to mark: ") - 1);
1557 clear_line();
1558
1559 if (isalpha(letter)) {
1560 for (i = 0; i <= num_marks; i++)
1561 if (letter == mark_lines[i][0]) {
1562 buffer_line(mark_lines[i][1]);
1563 break;
1564 }
1565 if (num_marks == 14 && letter != mark_lines[14][0])
1566 print_statusline("Mark not set");
1567 } else
1568 print_statusline("Invalid mark letter");
1569}
1570#endif
1571
1572#if ENABLE_FEATURE_LESS_BRACKETS
1573static char opp_bracket(char bracket)
1574{
1575 switch (bracket) {
1576 case '{': case '[': /* '}' == '{' + 2. Same for '[' */
1577 bracket++;
1578 case '(': /* ')' == '(' + 1 */
1579 bracket++;
1580 break;
1581 case '}': case ']':
1582 bracket--;
1583 case ')':
1584 bracket--;
1585 break;
1586 };
1587 return bracket;
1588}
1589
1590static void match_right_bracket(char bracket)
1591{
1592 unsigned i;
1593
1594 if (strchr(flines[cur_fline], bracket) == NULL) {
1595 print_statusline("No bracket in top line");
1596 return;
1597 }
1598 bracket = opp_bracket(bracket);
1599 for (i = cur_fline + 1; i < max_fline; i++) {
1600 if (strchr(flines[i], bracket) != NULL) {
1601 buffer_line(i);
1602 return;
1603 }
1604 }
1605 print_statusline("No matching bracket found");
1606}
1607
1608static void match_left_bracket(char bracket)
1609{
1610 int i;
1611
1612 if (strchr(flines[cur_fline + max_displayed_line], bracket) == NULL) {
1613 print_statusline("No bracket in bottom line");
1614 return;
1615 }
1616
1617 bracket = opp_bracket(bracket);
1618 for (i = cur_fline + max_displayed_line; i >= 0; i--) {
1619 if (strchr(flines[i], bracket) != NULL) {
1620 buffer_line(i);
1621 return;
1622 }
1623 }
1624 print_statusline("No matching bracket found");
1625}
1626#endif /* FEATURE_LESS_BRACKETS */
1627
1628static void keypress_process(int keypress)
1629{
1630 switch (keypress) {
1631 case KEYCODE_DOWN: case 'e': case 'j': case 0x0d:
1632 buffer_down(1);
1633 break;
1634 case KEYCODE_UP: case 'y': case 'k':
1635 buffer_up(1);
1636 break;
1637 case KEYCODE_PAGEDOWN: case ' ': case 'z': case 'f':
1638 buffer_down(max_displayed_line + 1);
1639 break;
1640 case KEYCODE_PAGEUP: case 'w': case 'b':
1641 buffer_up(max_displayed_line + 1);
1642 break;
1643 case 'd':
1644 buffer_down((max_displayed_line + 1) / 2);
1645 break;
1646 case 'u':
1647 buffer_up((max_displayed_line + 1) / 2);
1648 break;
1649 case KEYCODE_HOME: case 'g': case 'p': case '<': case '%':
1650 buffer_line(0);
1651 break;
1652 case KEYCODE_END: case 'G': case '>':
1653 cur_fline = MAXLINES;
1654 read_lines();
1655 buffer_line(cur_fline);
1656 break;
1657 case 'q': case 'Q':
1658 less_exit(EXIT_SUCCESS);
1659 break;
1660#if ENABLE_FEATURE_LESS_MARKS
1661 case 'm':
1662 add_mark();
1663 buffer_print();
1664 break;
1665 case '\'':
1666 goto_mark();
1667 buffer_print();
1668 break;
1669#endif
1670 case 'r': case 'R':
1671 /* TODO: (1) also bind ^R, ^L to this?
1672 * (2) re-measure window size?
1673 */
1674 buffer_print();
1675 break;
1676 /*case 'R':
1677 full_repaint();
1678 break;*/
1679 case 's':
1680 save_input_to_file();
1681 break;
1682 case 'E':
1683 examine_file();
1684 break;
1685#if ENABLE_FEATURE_LESS_FLAGS
1686 case '=':
1687 m_status_print();
1688 break;
1689#endif
1690#if ENABLE_FEATURE_LESS_REGEXP
1691 case '/':
1692 option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
1693 regex_process();
1694 break;
1695 case 'n':
1696 goto_match(match_pos + 1);
1697 break;
1698 case 'N':
1699 goto_match(match_pos - 1);
1700 break;
1701 case '?':
1702 option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
1703 regex_process();
1704 break;
1705#endif
1706#if ENABLE_FEATURE_LESS_DASHCMD
1707 case '-':
1708 flag_change();
1709 buffer_print();
1710 break;
1711#ifdef BLOAT
1712 case '_':
1713 show_flag_status();
1714 break;
1715#endif
1716#endif
1717#if ENABLE_FEATURE_LESS_BRACKETS
1718 case '{': case '(': case '[':
1719 match_right_bracket(keypress);
1720 break;
1721 case '}': case ')': case ']':
1722 match_left_bracket(keypress);
1723 break;
1724#endif
1725 case ':':
1726 colon_process();
1727 break;
1728 }
1729
1730 if (isdigit(keypress))
1731 number_process(keypress);
1732}
1733
1734static void sig_catcher(int sig)
1735{
1736 less_exit(- sig);
1737}
1738
1739#if ENABLE_FEATURE_LESS_WINCH
1740static void sigwinch_handler(int sig UNUSED_PARAM)
1741{
1742 winch_counter++;
1743}
1744#endif
1745
1746int less_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1747int less_main(int argc, char **argv)
1748{
1749 char *tty_name;
1750 int tty_fd;
1751
1752 INIT_G();
1753
1754 /* TODO: -x: do not interpret backspace, -xx: tab also
1755 * -xxx: newline also
1756 * -w N: assume width N (-xxx -w 32: hex viewer of sorts)
1757 * -s: condense many empty lines to one
1758 * (used by some setups for manpage display)
1759 */
1760 getopt32(argv, "EMmN~I" IF_FEATURE_LESS_TRUNCATE("S") /*ignored:*/"s");
1761 argc -= optind;
1762 argv += optind;
1763 num_files = argc;
1764 files = argv;
1765
1766 /* Another popular pager, most, detects when stdout
1767 * is not a tty and turns into cat. This makes sense. */
1768 if (!isatty(STDOUT_FILENO))
1769 return bb_cat(argv);
1770
1771 if (!num_files) {
1772 if (isatty(STDIN_FILENO)) {
1773 /* Just "less"? No args and no redirection? */
1774 bb_error_msg("missing filename");
1775 bb_show_usage();
1776 }
1777 } else {
1778 filename = xstrdup(files[0]);
1779 }
1780
1781 if (option_mask32 & FLAG_TILDE)
1782 empty_line_marker = "";
1783
1784 /* Some versions of less can survive w/o controlling tty,
1785 * try to do the same. This also allows to specify an alternative
1786 * tty via "less 1<>TTY".
1787 * We don't try to use STDOUT_FILENO directly,
1788 * since we want to set this fd to non-blocking mode,
1789 * and not bother with restoring it on exit.
1790 */
1791 tty_name = xmalloc_ttyname(STDOUT_FILENO);
1792 if (tty_name) {
1793 tty_fd = open(tty_name, O_RDONLY);
1794 free(tty_name);
1795 if (tty_fd < 0)
1796 goto try_ctty;
1797 } else {
1798 /* Try controlling tty */
1799 try_ctty:
1800 tty_fd = open(CURRENT_TTY, O_RDONLY);
1801 if (tty_fd < 0)
1802 return bb_cat(argv);
1803 }
1804 ndelay_on(tty_fd);
1805 kbd_fd = tty_fd; /* save in a global */
1806
1807 tcgetattr(kbd_fd, &term_orig);
1808 term_less = term_orig;
1809 term_less.c_lflag &= ~(ICANON | ECHO);
1810 term_less.c_iflag &= ~(IXON | ICRNL);
1811 /*term_less.c_oflag &= ~ONLCR;*/
1812 term_less.c_cc[VMIN] = 1;
1813 term_less.c_cc[VTIME] = 0;
1814
1815 IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
1816 /* 20: two tabstops + 4 */
1817 if (width < 20 || max_displayed_line < 3)
1818 return bb_cat(argv);
1819 max_displayed_line -= 2;
1820
1821 /* We want to restore term_orig on exit */
1822 bb_signals(BB_FATAL_SIGS, sig_catcher);
1823#if ENABLE_FEATURE_LESS_WINCH
1824 signal(SIGWINCH, sigwinch_handler);
1825#endif
1826
1827 buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
1828 reinitialize();
1829 while (1) {
1830 int64_t keypress;
1831
1832#if ENABLE_FEATURE_LESS_WINCH
1833 while (WINCH_COUNTER) {
1834 again:
1835 winch_counter--;
1836 IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
1837 IF_FEATURE_LESS_ASK_TERMINAL(got_size:)
1838 /* 20: two tabstops + 4 */
1839 if (width < 20)
1840 width = 20;
1841 if (max_displayed_line < 3)
1842 max_displayed_line = 3;
1843 max_displayed_line -= 2;
1844 free(buffer);
1845 buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
1846 /* Avoid re-wrap and/or redraw if we already know
1847 * we need to do it again. These ops are expensive */
1848 if (WINCH_COUNTER)
1849 goto again;
1850 re_wrap();
1851 if (WINCH_COUNTER)
1852 goto again;
1853 buffer_fill_and_print();
1854 /* This took some time. Loop back and check,
1855 * were there another SIGWINCH? */
1856 }
1857 keypress = less_getch(-1); /* -1: do not position cursor */
1858# if ENABLE_FEATURE_LESS_ASK_TERMINAL
1859 if ((int32_t)keypress == KEYCODE_CURSOR_POS) {
1860 uint32_t rc = (keypress >> 32);
1861 width = (rc & 0x7fff);
1862 max_displayed_line = ((rc >> 16) & 0x7fff);
1863 goto got_size;
1864 }
1865# endif
1866#else
1867 keypress = less_getch(-1); /* -1: do not position cursor */
1868#endif
1869 keypress_process(keypress);
1870 }
1871}
1872
1873/*
1874Help text of less version 418 is below.
1875If you are implementing something, keeping
1876key and/or command line switch compatibility is a good idea:
1877
1878
1879 SUMMARY OF LESS COMMANDS
1880
1881 Commands marked with * may be preceded by a number, N.
1882 Notes in parentheses indicate the behavior if N is given.
1883 h H Display this help.
1884 q :q Q :Q ZZ Exit.
1885 ---------------------------------------------------------------------------
1886 MOVING
1887 e ^E j ^N CR * Forward one line (or N lines).
1888 y ^Y k ^K ^P * Backward one line (or N lines).
1889 f ^F ^V SPACE * Forward one window (or N lines).
1890 b ^B ESC-v * Backward one window (or N lines).
1891 z * Forward one window (and set window to N).
1892 w * Backward one window (and set window to N).
1893 ESC-SPACE * Forward one window, but don't stop at end-of-file.
1894 d ^D * Forward one half-window (and set half-window to N).
1895 u ^U * Backward one half-window (and set half-window to N).
1896 ESC-) RightArrow * Left one half screen width (or N positions).
1897 ESC-( LeftArrow * Right one half screen width (or N positions).
1898 F Forward forever; like "tail -f".
1899 r ^R ^L Repaint screen.
1900 R Repaint screen, discarding buffered input.
1901 ---------------------------------------------------
1902 Default "window" is the screen height.
1903 Default "half-window" is half of the screen height.
1904 ---------------------------------------------------------------------------
1905 SEARCHING
1906 /pattern * Search forward for (N-th) matching line.
1907 ?pattern * Search backward for (N-th) matching line.
1908 n * Repeat previous search (for N-th occurrence).
1909 N * Repeat previous search in reverse direction.
1910 ESC-n * Repeat previous search, spanning files.
1911 ESC-N * Repeat previous search, reverse dir. & spanning files.
1912 ESC-u Undo (toggle) search highlighting.
1913 ---------------------------------------------------
1914 Search patterns may be modified by one or more of:
1915 ^N or ! Search for NON-matching lines.
1916 ^E or * Search multiple files (pass thru END OF FILE).
1917 ^F or @ Start search at FIRST file (for /) or last file (for ?).
1918 ^K Highlight matches, but don't move (KEEP position).
1919 ^R Don't use REGULAR EXPRESSIONS.
1920 ---------------------------------------------------------------------------
1921 JUMPING
1922 g < ESC-< * Go to first line in file (or line N).
1923 G > ESC-> * Go to last line in file (or line N).
1924 p % * Go to beginning of file (or N percent into file).
1925 t * Go to the (N-th) next tag.
1926 T * Go to the (N-th) previous tag.
1927 { ( [ * Find close bracket } ) ].
1928 } ) ] * Find open bracket { ( [.
1929 ESC-^F <c1> <c2> * Find close bracket <c2>.
1930 ESC-^B <c1> <c2> * Find open bracket <c1>
1931 ---------------------------------------------------
1932 Each "find close bracket" command goes forward to the close bracket
1933 matching the (N-th) open bracket in the top line.
1934 Each "find open bracket" command goes backward to the open bracket
1935 matching the (N-th) close bracket in the bottom line.
1936 m<letter> Mark the current position with <letter>.
1937 '<letter> Go to a previously marked position.
1938 '' Go to the previous position.
1939 ^X^X Same as '.
1940 ---------------------------------------------------
1941 A mark is any upper-case or lower-case letter.
1942 Certain marks are predefined:
1943 ^ means beginning of the file
1944 $ means end of the file
1945 ---------------------------------------------------------------------------
1946 CHANGING FILES
1947 :e [file] Examine a new file.
1948 ^X^V Same as :e.
1949 :n * Examine the (N-th) next file from the command line.
1950 :p * Examine the (N-th) previous file from the command line.
1951 :x * Examine the first (or N-th) file from the command line.
1952 :d Delete the current file from the command line list.
1953 = ^G :f Print current file name.
1954 ---------------------------------------------------------------------------
1955 MISCELLANEOUS COMMANDS
1956 -<flag> Toggle a command line option [see OPTIONS below].
1957 --<name> Toggle a command line option, by name.
1958 _<flag> Display the setting of a command line option.
1959 __<name> Display the setting of an option, by name.
1960 +cmd Execute the less cmd each time a new file is examined.
1961 !command Execute the shell command with $SHELL.
1962 |Xcommand Pipe file between current pos & mark X to shell command.
1963 v Edit the current file with $VISUAL or $EDITOR.
1964 V Print version number of "less".
1965 ---------------------------------------------------------------------------
1966 OPTIONS
1967 Most options may be changed either on the command line,
1968 or from within less by using the - or -- command.
1969 Options may be given in one of two forms: either a single
1970 character preceded by a -, or a name preceded by --.
1971 -? ........ --help
1972 Display help (from command line).
1973 -a ........ --search-skip-screen
1974 Forward search skips current screen.
1975 -b [N] .... --buffers=[N]
1976 Number of buffers.
1977 -B ........ --auto-buffers
1978 Don't automatically allocate buffers for pipes.
1979 -c ........ --clear-screen
1980 Repaint by clearing rather than scrolling.
1981 -d ........ --dumb
1982 Dumb terminal.
1983 -D [xn.n] . --color=xn.n
1984 Set screen colors. (MS-DOS only)
1985 -e -E .... --quit-at-eof --QUIT-AT-EOF
1986 Quit at end of file.
1987 -f ........ --force
1988 Force open non-regular files.
1989 -F ........ --quit-if-one-screen
1990 Quit if entire file fits on first screen.
1991 -g ........ --hilite-search
1992 Highlight only last match for searches.
1993 -G ........ --HILITE-SEARCH
1994 Don't highlight any matches for searches.
1995 -h [N] .... --max-back-scroll=[N]
1996 Backward scroll limit.
1997 -i ........ --ignore-case
1998 Ignore case in searches that do not contain uppercase.
1999 -I ........ --IGNORE-CASE
2000 Ignore case in all searches.
2001 -j [N] .... --jump-target=[N]
2002 Screen position of target lines.
2003 -J ........ --status-column
2004 Display a status column at left edge of screen.
2005 -k [file] . --lesskey-file=[file]
2006 Use a lesskey file.
2007 -L ........ --no-lessopen
2008 Ignore the LESSOPEN environment variable.
2009 -m -M .... --long-prompt --LONG-PROMPT
2010 Set prompt style.
2011 -n -N .... --line-numbers --LINE-NUMBERS
2012 Don't use line numbers.
2013 -o [file] . --log-file=[file]
2014 Copy to log file (standard input only).
2015 -O [file] . --LOG-FILE=[file]
2016 Copy to log file (unconditionally overwrite).
2017 -p [pattern] --pattern=[pattern]
2018 Start at pattern (from command line).
2019 -P [prompt] --prompt=[prompt]
2020 Define new prompt.
2021 -q -Q .... --quiet --QUIET --silent --SILENT
2022 Quiet the terminal bell.
2023 -r -R .... --raw-control-chars --RAW-CONTROL-CHARS
2024 Output "raw" control characters.
2025 -s ........ --squeeze-blank-lines
2026 Squeeze multiple blank lines.
2027 -S ........ --chop-long-lines
2028 Chop long lines.
2029 -t [tag] .. --tag=[tag]
2030 Find a tag.
2031 -T [tagsfile] --tag-file=[tagsfile]
2032 Use an alternate tags file.
2033 -u -U .... --underline-special --UNDERLINE-SPECIAL
2034 Change handling of backspaces.
2035 -V ........ --version
2036 Display the version number of "less".
2037 -w ........ --hilite-unread
2038 Highlight first new line after forward-screen.
2039 -W ........ --HILITE-UNREAD
2040 Highlight first new line after any forward movement.
2041 -x [N[,...]] --tabs=[N[,...]]
2042 Set tab stops.
2043 -X ........ --no-init
2044 Don't use termcap init/deinit strings.
2045 --no-keypad
2046 Don't use termcap keypad init/deinit strings.
2047 -y [N] .... --max-forw-scroll=[N]
2048 Forward scroll limit.
2049 -z [N] .... --window=[N]
2050 Set size of window.
2051 -" [c[c]] . --quotes=[c[c]]
2052 Set shell quote characters.
2053 -~ ........ --tilde
2054 Don't display tildes after end of file.
2055 -# [N] .... --shift=[N]
2056 Horizontal scroll amount (0 = one half screen width)
2057
2058 ---------------------------------------------------------------------------
2059 LINE EDITING
2060 These keys can be used to edit text being entered
2061 on the "command line" at the bottom of the screen.
2062 RightArrow ESC-l Move cursor right one character.
2063 LeftArrow ESC-h Move cursor left one character.
2064 CNTL-RightArrow ESC-RightArrow ESC-w Move cursor right one word.
2065 CNTL-LeftArrow ESC-LeftArrow ESC-b Move cursor left one word.
2066 HOME ESC-0 Move cursor to start of line.
2067 END ESC-$ Move cursor to end of line.
2068 BACKSPACE Delete char to left of cursor.
2069 DELETE ESC-x Delete char under cursor.
2070 CNTL-BACKSPACE ESC-BACKSPACE Delete word to left of cursor.
2071 CNTL-DELETE ESC-DELETE ESC-X Delete word under cursor.
2072 CNTL-U ESC (MS-DOS only) Delete entire line.
2073 UpArrow ESC-k Retrieve previous command line.
2074 DownArrow ESC-j Retrieve next command line.
2075 TAB Complete filename & cycle.
2076 SHIFT-TAB ESC-TAB Complete filename & reverse cycle.
2077 CNTL-L Complete filename, list all.
2078*/
Note: See TracBrowser for help on using the repository browser.