source: MondoRescue/branches/3.2/mindi-busybox/miscutils/less.c@ 3232

Last change on this file since 3232 was 3232, checked in by Bruno Cornec, 10 years ago
  • Update mindi-busybox to 1.21.1
File size: 50.6 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_MARKS
52//config: bool "Enable marks"
53//config: default y
54//config: depends on LESS
55//config: help
56//config: Marks enable positions in a file to be stored for easy reference.
57//config:
58//config:config FEATURE_LESS_REGEXP
59//config: bool "Enable regular expressions"
60//config: default y
61//config: depends on LESS
62//config: help
63//config: Enable regular expressions, allowing complex file searches.
64//config:
65//config:config FEATURE_LESS_WINCH
66//config: bool "Enable automatic resizing on window size changes"
67//config: default y
68//config: depends on LESS
69//config: help
70//config: Makes less track window size changes.
71//config:
72//config:config FEATURE_LESS_ASK_TERMINAL
73//config: bool "Use 'tell me cursor position' ESC sequence to measure window"
74//config: default y
75//config: depends on FEATURE_LESS_WINCH
76//config: help
77//config: Makes less track window size changes.
78//config: If terminal size can't be retrieved and $LINES/$COLUMNS are not set,
79//config: this option makes less perform a last-ditch effort to find it:
80//config: position cursor to 999,999 and ask terminal to report real
81//config: cursor position using "ESC [ 6 n" escape sequence, then read stdin.
82//config:
83//config: This is not clean but helps a lot on serial lines and such.
84//config:
85//config:config FEATURE_LESS_DASHCMD
86//config: bool "Enable flag changes ('-' command)"
87//config: default y
88//config: depends on LESS
89//config: help
90//config: This enables the ability to change command-line flags within
91//config: less itself ('-' keyboard command).
92//config:
93//config:config FEATURE_LESS_LINENUMS
94//config: bool "Enable dynamic switching of line numbers"
95//config: default y
96//config: depends on FEATURE_LESS_DASHCMD
97//config: help
98//config: Enables "-N" command.
99
100//usage:#define less_trivial_usage
101//usage: "[-E" IF_FEATURE_LESS_FLAGS("Mm") "Nh~I?] [FILE]..."
102//usage:#define less_full_usage "\n\n"
103//usage: "View FILE (or stdin) one screenful at a time\n"
104//usage: "\n -E Quit once the end of a file is reached"
105//usage: IF_FEATURE_LESS_FLAGS(
106//usage: "\n -M,-m Display status line with line numbers"
107//usage: "\n and percentage through the file"
108//usage: )
109//usage: "\n -N Prefix line number to each line"
110//usage: "\n -I Ignore case in all searches"
111//usage: "\n -~ Suppress ~s displayed past EOF"
112
113#include <sched.h> /* sched_yield() */
114
115#include "libbb.h"
116#if ENABLE_FEATURE_LESS_REGEXP
117#include "xregex.h"
118#endif
119
120
121#define ESC "\033"
122/* The escape codes for highlighted and normal text */
123#define HIGHLIGHT ESC"[7m"
124#define NORMAL ESC"[0m"
125/* The escape code to home and clear to the end of screen */
126#define CLEAR ESC"[H\033[J"
127/* The escape code to clear to the end of line */
128#define CLEAR_2_EOL ESC"[K"
129
130enum {
131/* Absolute max of lines eaten */
132 MAXLINES = CONFIG_FEATURE_LESS_MAXLINES,
133/* This many "after the end" lines we will show (at max) */
134 TILDES = 1,
135};
136
137/* Command line options */
138enum {
139 FLAG_E = 1 << 0,
140 FLAG_M = 1 << 1,
141 FLAG_m = 1 << 2,
142 FLAG_N = 1 << 3,
143 FLAG_TILDE = 1 << 4,
144 FLAG_I = 1 << 5,
145 FLAG_S = (1 << 6) * ENABLE_FEATURE_LESS_DASHCMD,
146/* hijack command line options variable for internal state vars */
147 LESS_STATE_MATCH_BACKWARDS = 1 << 15,
148};
149
150#if !ENABLE_FEATURE_LESS_REGEXP
151enum { pattern_valid = 0 };
152#endif
153
154struct globals {
155 int cur_fline; /* signed */
156 int kbd_fd; /* fd to get input from */
157 int less_gets_pos;
158/* last position in last line, taking into account tabs */
159 size_t last_line_pos;
160 unsigned max_fline;
161 unsigned max_lineno; /* this one tracks linewrap */
162 unsigned max_displayed_line;
163 unsigned width;
164#if ENABLE_FEATURE_LESS_WINCH
165 unsigned winch_counter;
166#endif
167 ssize_t eof_error; /* eof if 0, error if < 0 */
168 ssize_t readpos;
169 ssize_t readeof; /* must be signed */
170 const char **buffer;
171 const char **flines;
172 const char *empty_line_marker;
173 unsigned num_files;
174 unsigned current_file;
175 char *filename;
176 char **files;
177#if ENABLE_FEATURE_LESS_MARKS
178 unsigned num_marks;
179 unsigned mark_lines[15][2];
180#endif
181#if ENABLE_FEATURE_LESS_REGEXP
182 unsigned *match_lines;
183 int match_pos; /* signed! */
184 int wanted_match; /* signed! */
185 int num_matches;
186 regex_t pattern;
187 smallint pattern_valid;
188#endif
189#if ENABLE_FEATURE_LESS_ASK_TERMINAL
190 smallint winsize_err;
191#endif
192 smallint terminated;
193 struct termios term_orig, term_less;
194 char kbd_input[KEYCODE_BUFFER_SIZE];
195};
196#define G (*ptr_to_globals)
197#define cur_fline (G.cur_fline )
198#define kbd_fd (G.kbd_fd )
199#define less_gets_pos (G.less_gets_pos )
200#define last_line_pos (G.last_line_pos )
201#define max_fline (G.max_fline )
202#define max_lineno (G.max_lineno )
203#define max_displayed_line (G.max_displayed_line)
204#define width (G.width )
205#define winch_counter (G.winch_counter )
206/* This one is 100% not cached by compiler on read access */
207#define WINCH_COUNTER (*(volatile unsigned *)&winch_counter)
208#define eof_error (G.eof_error )
209#define readpos (G.readpos )
210#define readeof (G.readeof )
211#define buffer (G.buffer )
212#define flines (G.flines )
213#define empty_line_marker (G.empty_line_marker )
214#define num_files (G.num_files )
215#define current_file (G.current_file )
216#define filename (G.filename )
217#define files (G.files )
218#define num_marks (G.num_marks )
219#define mark_lines (G.mark_lines )
220#if ENABLE_FEATURE_LESS_REGEXP
221#define match_lines (G.match_lines )
222#define match_pos (G.match_pos )
223#define num_matches (G.num_matches )
224#define wanted_match (G.wanted_match )
225#define pattern (G.pattern )
226#define pattern_valid (G.pattern_valid )
227#endif
228#define terminated (G.terminated )
229#define term_orig (G.term_orig )
230#define term_less (G.term_less )
231#define kbd_input (G.kbd_input )
232#define INIT_G() do { \
233 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
234 less_gets_pos = -1; \
235 empty_line_marker = "~"; \
236 num_files = 1; \
237 current_file = 1; \
238 eof_error = 1; \
239 terminated = 1; \
240 IF_FEATURE_LESS_REGEXP(wanted_match = -1;) \
241} while (0)
242
243/* flines[] are lines read from stdin, each in malloc'ed buffer.
244 * Line numbers are stored as uint32_t prepended to each line.
245 * Pointer is adjusted so that flines[i] points directly past
246 * line number. Accesor: */
247#define MEMPTR(p) ((char*)(p) - 4)
248#define LINENO(p) (*(uint32_t*)((p) - 4))
249
250
251/* Reset terminal input to normal */
252static void set_tty_cooked(void)
253{
254 fflush_all();
255 tcsetattr(kbd_fd, TCSANOW, &term_orig);
256}
257
258/* Move the cursor to a position (x,y), where (0,0) is the
259 top-left corner of the console */
260static void move_cursor(int line, int row)
261{
262 printf(ESC"[%u;%uH", line, row);
263}
264
265static void clear_line(void)
266{
267 printf(ESC"[%u;0H" CLEAR_2_EOL, max_displayed_line + 2);
268}
269
270static void print_hilite(const char *str)
271{
272 printf(HIGHLIGHT"%s"NORMAL, str);
273}
274
275static void print_statusline(const char *str)
276{
277 clear_line();
278 printf(HIGHLIGHT"%.*s"NORMAL, width - 1, str);
279}
280
281/* Exit the program gracefully */
282static void less_exit(int code)
283{
284 set_tty_cooked();
285 clear_line();
286 if (code < 0)
287 kill_myself_with_sig(- code); /* does not return */
288 exit(code);
289}
290
291#if (ENABLE_FEATURE_LESS_DASHCMD && ENABLE_FEATURE_LESS_LINENUMS) \
292 || ENABLE_FEATURE_LESS_WINCH
293static void re_wrap(void)
294{
295 int w = width;
296 int new_line_pos;
297 int src_idx;
298 int dst_idx;
299 int new_cur_fline = 0;
300 uint32_t lineno;
301 char linebuf[w + 1];
302 const char **old_flines = flines;
303 const char *s;
304 char **new_flines = NULL;
305 char *d;
306
307 if (option_mask32 & FLAG_N)
308 w -= 8;
309
310 src_idx = 0;
311 dst_idx = 0;
312 s = old_flines[0];
313 lineno = LINENO(s);
314 d = linebuf;
315 new_line_pos = 0;
316 while (1) {
317 *d = *s;
318 if (*d != '\0') {
319 new_line_pos++;
320 if (*d == '\t') /* tab */
321 new_line_pos += 7;
322 s++;
323 d++;
324 if (new_line_pos >= w) {
325 int sz;
326 /* new line is full, create next one */
327 *d = '\0';
328 next_new:
329 sz = (d - linebuf) + 1; /* + 1: NUL */
330 d = ((char*)xmalloc(sz + 4)) + 4;
331 LINENO(d) = lineno;
332 memcpy(d, linebuf, sz);
333 new_flines = xrealloc_vector(new_flines, 8, dst_idx);
334 new_flines[dst_idx] = d;
335 dst_idx++;
336 if (new_line_pos < w) {
337 /* if we came here thru "goto next_new" */
338 if (src_idx > max_fline)
339 break;
340 lineno = LINENO(s);
341 }
342 d = linebuf;
343 new_line_pos = 0;
344 }
345 continue;
346 }
347 /* *d == NUL: old line ended, go to next old one */
348 free(MEMPTR(old_flines[src_idx]));
349 /* btw, convert cur_fline... */
350 if (cur_fline == src_idx)
351 new_cur_fline = dst_idx;
352 src_idx++;
353 /* no more lines? finish last new line (and exit the loop) */
354 if (src_idx > max_fline)
355 goto next_new;
356 s = old_flines[src_idx];
357 if (lineno != LINENO(s)) {
358 /* this is not a continuation line!
359 * create next _new_ line too */
360 goto next_new;
361 }
362 }
363
364 free(old_flines);
365 flines = (const char **)new_flines;
366
367 max_fline = dst_idx - 1;
368 last_line_pos = new_line_pos;
369 cur_fline = new_cur_fline;
370 /* max_lineno is screen-size independent */
371#if ENABLE_FEATURE_LESS_REGEXP
372 pattern_valid = 0;
373#endif
374}
375#endif
376
377#if ENABLE_FEATURE_LESS_REGEXP
378static void fill_match_lines(unsigned pos);
379#else
380#define fill_match_lines(pos) ((void)0)
381#endif
382
383/* Devilishly complex routine.
384 *
385 * Has to deal with EOF and EPIPE on input,
386 * with line wrapping, with last line not ending in '\n'
387 * (possibly not ending YET!), with backspace and tabs.
388 * It reads input again if last time we got an EOF (thus supporting
389 * growing files) or EPIPE (watching output of slow process like make).
390 *
391 * Variables used:
392 * flines[] - array of lines already read. Linewrap may cause
393 * one source file line to occupy several flines[n].
394 * flines[max_fline] - last line, possibly incomplete.
395 * terminated - 1 if flines[max_fline] is 'terminated'
396 * (if there was '\n' [which isn't stored itself, we just remember
397 * that it was seen])
398 * max_lineno - last line's number, this one doesn't increment
399 * on line wrap, only on "real" new lines.
400 * readbuf[0..readeof-1] - small preliminary buffer.
401 * readbuf[readpos] - next character to add to current line.
402 * last_line_pos - screen line position of next char to be read
403 * (takes into account tabs and backspaces)
404 * eof_error - < 0 error, == 0 EOF, > 0 not EOF/error
405 */
406static void read_lines(void)
407{
408#define readbuf bb_common_bufsiz1
409 char *current_line, *p;
410 int w = width;
411 char last_terminated = terminated;
412#if ENABLE_FEATURE_LESS_REGEXP
413 unsigned old_max_fline = max_fline;
414 time_t last_time = 0;
415 unsigned seconds_p1 = 3; /* seconds_to_loop + 1 */
416#endif
417
418 if (option_mask32 & FLAG_N)
419 w -= 8;
420
421 IF_FEATURE_LESS_REGEXP(again0:)
422
423 p = current_line = ((char*)xmalloc(w + 4)) + 4;
424 max_fline += last_terminated;
425 if (!last_terminated) {
426 const char *cp = flines[max_fline];
427 strcpy(p, cp);
428 p += strlen(current_line);
429 free(MEMPTR(flines[max_fline]));
430 /* last_line_pos is still valid from previous read_lines() */
431 } else {
432 last_line_pos = 0;
433 }
434
435 while (1) { /* read lines until we reach cur_fline or wanted_match */
436 *p = '\0';
437 terminated = 0;
438 while (1) { /* read chars until we have a line */
439 char c;
440 /* if no unprocessed chars left, eat more */
441 if (readpos >= readeof) {
442 ndelay_on(0);
443 eof_error = safe_read(STDIN_FILENO, readbuf, sizeof(readbuf));
444 ndelay_off(0);
445 readpos = 0;
446 readeof = eof_error;
447 if (eof_error <= 0)
448 goto reached_eof;
449 }
450 c = readbuf[readpos];
451 /* backspace? [needed for manpages] */
452 /* <tab><bs> is (a) insane and */
453 /* (b) harder to do correctly, so we refuse to do it */
454 if (c == '\x8' && last_line_pos && p[-1] != '\t') {
455 readpos++; /* eat it */
456 last_line_pos--;
457 /* was buggy (p could end up <= current_line)... */
458 *--p = '\0';
459 continue;
460 }
461 {
462 size_t new_last_line_pos = last_line_pos + 1;
463 if (c == '\t') {
464 new_last_line_pos += 7;
465 new_last_line_pos &= (~7);
466 }
467 if ((int)new_last_line_pos >= w)
468 break;
469 last_line_pos = new_last_line_pos;
470 }
471 /* ok, we will eat this char */
472 readpos++;
473 if (c == '\n') {
474 terminated = 1;
475 last_line_pos = 0;
476 break;
477 }
478 /* NUL is substituted by '\n'! */
479 if (c == '\0') c = '\n';
480 *p++ = c;
481 *p = '\0';
482 } /* end of "read chars until we have a line" loop */
483 /* Corner case: linewrap with only "" wrapping to next line */
484 /* Looks ugly on screen, so we do not store this empty line */
485 if (!last_terminated && !current_line[0]) {
486 last_terminated = 1;
487 max_lineno++;
488 continue;
489 }
490 reached_eof:
491 last_terminated = terminated;
492 flines = xrealloc_vector(flines, 8, max_fline);
493
494 flines[max_fline] = (char*)xrealloc(MEMPTR(current_line), strlen(current_line) + 1 + 4) + 4;
495 LINENO(flines[max_fline]) = max_lineno;
496 if (terminated)
497 max_lineno++;
498
499 if (max_fline >= MAXLINES) {
500 eof_error = 0; /* Pretend we saw EOF */
501 break;
502 }
503 if (!(option_mask32 & FLAG_S)
504 ? (max_fline > cur_fline + max_displayed_line)
505 : (max_fline >= cur_fline
506 && max_lineno > LINENO(flines[cur_fline]) + max_displayed_line)
507 ) {
508#if !ENABLE_FEATURE_LESS_REGEXP
509 break;
510#else
511 if (wanted_match >= num_matches) { /* goto_match called us */
512 fill_match_lines(old_max_fline);
513 old_max_fline = max_fline;
514 }
515 if (wanted_match < num_matches)
516 break;
517#endif
518 }
519 if (eof_error <= 0) {
520 if (eof_error < 0) {
521 if (errno == EAGAIN) {
522 /* not yet eof or error, reset flag (or else
523 * we will hog CPU - select() will return
524 * immediately */
525 eof_error = 1;
526 } else {
527 print_statusline(bb_msg_read_error);
528 }
529 }
530#if !ENABLE_FEATURE_LESS_REGEXP
531 break;
532#else
533 if (wanted_match < num_matches) {
534 break;
535 } else { /* goto_match called us */
536 time_t t = time(NULL);
537 if (t != last_time) {
538 last_time = t;
539 if (--seconds_p1 == 0)
540 break;
541 }
542 sched_yield();
543 goto again0; /* go loop again (max 2 seconds) */
544 }
545#endif
546 }
547 max_fline++;
548 current_line = ((char*)xmalloc(w + 4)) + 4;
549 p = current_line;
550 last_line_pos = 0;
551 } /* end of "read lines until we reach cur_fline" loop */
552 fill_match_lines(old_max_fline);
553#if ENABLE_FEATURE_LESS_REGEXP
554 /* prevent us from being stuck in search for a match */
555 wanted_match = -1;
556#endif
557#undef readbuf
558}
559
560#if ENABLE_FEATURE_LESS_FLAGS
561/* Interestingly, writing calc_percent as a function saves around 32 bytes
562 * on my build. */
563static int calc_percent(void)
564{
565 unsigned p = (100 * (cur_fline+max_displayed_line+1) + max_fline/2) / (max_fline+1);
566 return p <= 100 ? p : 100;
567}
568
569/* Print a status line if -M was specified */
570static void m_status_print(void)
571{
572 int percentage;
573
574 if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
575 return;
576
577 clear_line();
578 printf(HIGHLIGHT"%s", filename);
579 if (num_files > 1)
580 printf(" (file %i of %i)", current_file, num_files);
581 printf(" lines %i-%i/%i ",
582 cur_fline + 1, cur_fline + max_displayed_line + 1,
583 max_fline + 1);
584 if (cur_fline >= (int)(max_fline - max_displayed_line)) {
585 printf("(END)"NORMAL);
586 if (num_files > 1 && current_file != num_files)
587 printf(HIGHLIGHT" - next: %s"NORMAL, files[current_file]);
588 return;
589 }
590 percentage = calc_percent();
591 printf("%i%%"NORMAL, percentage);
592}
593#endif
594
595/* Print the status line */
596static void status_print(void)
597{
598 const char *p;
599
600 if (less_gets_pos >= 0) /* don't touch statusline while input is done! */
601 return;
602
603 /* Change the status if flags have been set */
604#if ENABLE_FEATURE_LESS_FLAGS
605 if (option_mask32 & (FLAG_M|FLAG_m)) {
606 m_status_print();
607 return;
608 }
609 /* No flags set */
610#endif
611
612 clear_line();
613 if (cur_fline && cur_fline < (int)(max_fline - max_displayed_line)) {
614 bb_putchar(':');
615 return;
616 }
617 p = "(END)";
618 if (!cur_fline)
619 p = filename;
620 if (num_files > 1) {
621 printf(HIGHLIGHT"%s (file %i of %i)"NORMAL,
622 p, current_file, num_files);
623 return;
624 }
625 print_hilite(p);
626}
627
628static void cap_cur_fline(int nlines)
629{
630 int diff;
631 if (cur_fline < 0)
632 cur_fline = 0;
633 if (cur_fline + max_displayed_line > max_fline + TILDES) {
634 cur_fline -= nlines;
635 if (cur_fline < 0)
636 cur_fline = 0;
637 diff = max_fline - (cur_fline + max_displayed_line) + TILDES;
638 /* As the number of lines requested was too large, we just move
639 * to the end of the file */
640 if (diff > 0)
641 cur_fline += diff;
642 }
643}
644
645static const char controls[] ALIGN1 =
646 /* NUL: never encountered; TAB: not converted */
647 /**/"\x01\x02\x03\x04\x05\x06\x07\x08" "\x0a\x0b\x0c\x0d\x0e\x0f"
648 "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
649 "\x7f\x9b"; /* DEL and infamous Meta-ESC :( */
650static const char ctrlconv[] ALIGN1 =
651 /* why 40 instead of 4a below? - it is a replacement for '\n'.
652 * '\n' is a former NUL - we subst it with @, not J */
653 "\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x40\x4b\x4c\x4d\x4e\x4f"
654 "\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f";
655
656static void lineno_str(char *nbuf9, const char *line)
657{
658 nbuf9[0] = '\0';
659 if (option_mask32 & FLAG_N) {
660 const char *fmt;
661 unsigned n;
662
663 if (line == empty_line_marker) {
664 memset(nbuf9, ' ', 8);
665 nbuf9[8] = '\0';
666 return;
667 }
668 /* Width of 7 preserves tab spacing in the text */
669 fmt = "%7u ";
670 n = LINENO(line) + 1;
671 if (n > 9999999) {
672 n %= 10000000;
673 fmt = "%07u ";
674 }
675 sprintf(nbuf9, fmt, n);
676 }
677}
678
679
680#if ENABLE_FEATURE_LESS_REGEXP
681static void print_found(const char *line)
682{
683 int match_status;
684 int eflags;
685 char *growline;
686 regmatch_t match_structs;
687
688 char buf[width];
689 char nbuf9[9];
690 const char *str = line;
691 char *p = buf;
692 size_t n;
693
694 while (*str) {
695 n = strcspn(str, controls);
696 if (n) {
697 if (!str[n]) break;
698 memcpy(p, str, n);
699 p += n;
700 str += n;
701 }
702 n = strspn(str, controls);
703 memset(p, '.', n);
704 p += n;
705 str += n;
706 }
707 strcpy(p, str);
708
709 /* buf[] holds quarantined version of str */
710
711 /* Each part of the line that matches has the HIGHLIGHT
712 * and NORMAL escape sequences placed around it.
713 * NB: we regex against line, but insert text
714 * from quarantined copy (buf[]) */
715 str = buf;
716 growline = NULL;
717 eflags = 0;
718 goto start;
719
720 while (match_status == 0) {
721 char *new = xasprintf("%s%.*s"HIGHLIGHT"%.*s"NORMAL,
722 growline ? growline : "",
723 (int)match_structs.rm_so, str,
724 (int)(match_structs.rm_eo - match_structs.rm_so),
725 str + match_structs.rm_so);
726 free(growline);
727 growline = new;
728 str += match_structs.rm_eo;
729 line += match_structs.rm_eo;
730 eflags = REG_NOTBOL;
731 start:
732 /* Most of the time doesn't find the regex, optimize for that */
733 match_status = regexec(&pattern, line, 1, &match_structs, eflags);
734 /* if even "" matches, treat it as "not a match" */
735 if (match_structs.rm_so >= match_structs.rm_eo)
736 match_status = 1;
737 }
738
739 lineno_str(nbuf9, line);
740 if (!growline) {
741 printf(CLEAR_2_EOL"%s%s\n", nbuf9, str);
742 return;
743 }
744 printf(CLEAR_2_EOL"%s%s%s\n", nbuf9, growline, str);
745 free(growline);
746}
747#else
748void print_found(const char *line);
749#endif
750
751static void print_ascii(const char *str)
752{
753 char buf[width];
754 char nbuf9[9];
755 char *p;
756 size_t n;
757
758 lineno_str(nbuf9, str);
759 printf(CLEAR_2_EOL"%s", nbuf9);
760
761 while (*str) {
762 n = strcspn(str, controls);
763 if (n) {
764 if (!str[n]) break;
765 printf("%.*s", (int) n, str);
766 str += n;
767 }
768 n = strspn(str, controls);
769 p = buf;
770 do {
771 if (*str == 0x7f)
772 *p++ = '?';
773 else if (*str == (char)0x9b)
774 /* VT100's CSI, aka Meta-ESC. Who's inventor? */
775 /* I want to know who committed this sin */
776 *p++ = '{';
777 else
778 *p++ = ctrlconv[(unsigned char)*str];
779 str++;
780 } while (--n);
781 *p = '\0';
782 print_hilite(buf);
783 }
784 puts(str);
785}
786
787/* Print the buffer */
788static void buffer_print(void)
789{
790 unsigned i;
791
792 move_cursor(0, 0);
793 for (i = 0; i <= max_displayed_line; i++)
794 if (pattern_valid)
795 print_found(buffer[i]);
796 else
797 print_ascii(buffer[i]);
798 status_print();
799}
800
801static void buffer_fill_and_print(void)
802{
803 unsigned i;
804#if ENABLE_FEATURE_LESS_DASHCMD
805 int fpos = cur_fline;
806
807 if (option_mask32 & FLAG_S) {
808 /* Go back to the beginning of this line */
809 while (fpos && LINENO(flines[fpos]) == LINENO(flines[fpos-1]))
810 fpos--;
811 }
812
813 i = 0;
814 while (i <= max_displayed_line && fpos <= max_fline) {
815 int lineno = LINENO(flines[fpos]);
816 buffer[i] = flines[fpos];
817 i++;
818 do {
819 fpos++;
820 } while ((fpos <= max_fline)
821 && (option_mask32 & FLAG_S)
822 && lineno == LINENO(flines[fpos])
823 );
824 }
825#else
826 for (i = 0; i <= max_displayed_line && cur_fline + i <= max_fline; i++) {
827 buffer[i] = flines[cur_fline + i];
828 }
829#endif
830 for (; i <= max_displayed_line; i++) {
831 buffer[i] = empty_line_marker;
832 }
833 buffer_print();
834}
835
836/* Move the buffer up and down in the file in order to scroll */
837static void buffer_down(int nlines)
838{
839 cur_fline += nlines;
840 read_lines();
841 cap_cur_fline(nlines);
842 buffer_fill_and_print();
843}
844
845static void buffer_up(int nlines)
846{
847 cur_fline -= nlines;
848 if (cur_fline < 0) cur_fline = 0;
849 read_lines();
850 buffer_fill_and_print();
851}
852
853static void buffer_line(int linenum)
854{
855 if (linenum < 0)
856 linenum = 0;
857 cur_fline = linenum;
858 read_lines();
859 if (linenum + max_displayed_line > max_fline)
860 linenum = max_fline - max_displayed_line + TILDES;
861 if (linenum < 0)
862 linenum = 0;
863 cur_fline = linenum;
864 buffer_fill_and_print();
865}
866
867static void open_file_and_read_lines(void)
868{
869 if (filename) {
870 xmove_fd(xopen(filename, O_RDONLY), STDIN_FILENO);
871 } else {
872 /* "less" with no arguments in argv[] */
873 /* For status line only */
874 filename = xstrdup(bb_msg_standard_input);
875 }
876 readpos = 0;
877 readeof = 0;
878 last_line_pos = 0;
879 terminated = 1;
880 read_lines();
881}
882
883/* Reinitialize everything for a new file - free the memory and start over */
884static void reinitialize(void)
885{
886 unsigned i;
887
888 if (flines) {
889 for (i = 0; i <= max_fline; i++)
890 free(MEMPTR(flines[i]));
891 free(flines);
892 flines = NULL;
893 }
894
895 max_fline = -1;
896 cur_fline = 0;
897 max_lineno = 0;
898 open_file_and_read_lines();
899#if ENABLE_FEATURE_LESS_ASK_TERMINAL
900 if (G.winsize_err)
901 printf("\033[999;999H" "\033[6n");
902#endif
903 buffer_fill_and_print();
904}
905
906static int64_t getch_nowait(void)
907{
908 int rd;
909 int64_t key64;
910 struct pollfd pfd[2];
911
912 pfd[0].fd = STDIN_FILENO;
913 pfd[0].events = POLLIN;
914 pfd[1].fd = kbd_fd;
915 pfd[1].events = POLLIN;
916 again:
917 tcsetattr(kbd_fd, TCSANOW, &term_less);
918 /* NB: select/poll returns whenever read will not block. Therefore:
919 * if eof is reached, select/poll will return immediately
920 * because read will immediately return 0 bytes.
921 * Even if select/poll says that input is available, read CAN block
922 * (switch fd into O_NONBLOCK'ed mode to avoid it)
923 */
924 rd = 1;
925 /* Are we interested in stdin? */
926//TODO: reuse code for determining this
927 if (!(option_mask32 & FLAG_S)
928 ? !(max_fline > cur_fline + max_displayed_line)
929 : !(max_fline >= cur_fline
930 && max_lineno > LINENO(flines[cur_fline]) + max_displayed_line)
931 ) {
932 if (eof_error > 0) /* did NOT reach eof yet */
933 rd = 0; /* yes, we are interested in stdin */
934 }
935 /* Position cursor if line input is done */
936 if (less_gets_pos >= 0)
937 move_cursor(max_displayed_line + 2, less_gets_pos + 1);
938 fflush_all();
939
940 if (kbd_input[0] == 0) { /* if nothing is buffered */
941#if ENABLE_FEATURE_LESS_WINCH
942 while (1) {
943 int r;
944 /* NB: SIGWINCH interrupts poll() */
945 r = poll(pfd + rd, 2 - rd, -1);
946 if (/*r < 0 && errno == EINTR &&*/ winch_counter)
947 return '\\'; /* anything which has no defined function */
948 if (r) break;
949 }
950#else
951 safe_poll(pfd + rd, 2 - rd, -1);
952#endif
953 }
954
955 /* We have kbd_fd in O_NONBLOCK mode, read inside read_key()
956 * would not block even if there is no input available */
957 key64 = read_key(kbd_fd, kbd_input, /*timeout off:*/ -2);
958 if ((int)key64 == -1) {
959 if (errno == EAGAIN) {
960 /* No keyboard input available. Since poll() did return,
961 * we should have input on stdin */
962 read_lines();
963 buffer_fill_and_print();
964 goto again;
965 }
966 /* EOF/error (ssh session got killed etc) */
967 less_exit(0);
968 }
969 set_tty_cooked();
970 return key64;
971}
972
973/* Grab a character from input without requiring the return key.
974 * May return KEYCODE_xxx values.
975 * Note that this function works best with raw input. */
976static int64_t less_getch(int pos)
977{
978 int64_t key64;
979 int key;
980
981 again:
982 less_gets_pos = pos;
983 key = key64 = getch_nowait();
984 less_gets_pos = -1;
985
986 /* Discard Ctrl-something chars.
987 * (checking only lower 32 bits is a size optimization:
988 * upper 32 bits are used only by KEYCODE_CURSOR_POS)
989 */
990 if (key >= 0 && key < ' ' && key != 0x0d && key != 8)
991 goto again;
992
993 return key64;
994}
995
996static char* less_gets(int sz)
997{
998 int c;
999 unsigned i = 0;
1000 char *result = xzalloc(1);
1001
1002 while (1) {
1003 c = '\0';
1004 less_gets_pos = sz + i;
1005 c = getch_nowait();
1006 if (c == 0x0d) {
1007 result[i] = '\0';
1008 less_gets_pos = -1;
1009 return result;
1010 }
1011 if (c == 0x7f)
1012 c = 8;
1013 if (c == 8 && i) {
1014 printf("\x8 \x8");
1015 i--;
1016 }
1017 if (c < ' ') /* filters out KEYCODE_xxx too (<0) */
1018 continue;
1019 if (i >= width - sz - 1)
1020 continue; /* len limit */
1021 bb_putchar(c);
1022 result[i++] = c;
1023 result = xrealloc(result, i+1);
1024 }
1025}
1026
1027static void examine_file(void)
1028{
1029 char *new_fname;
1030
1031 print_statusline("Examine: ");
1032 new_fname = less_gets(sizeof("Examine: ") - 1);
1033 if (!new_fname[0]) {
1034 status_print();
1035 err:
1036 free(new_fname);
1037 return;
1038 }
1039 if (access(new_fname, R_OK) != 0) {
1040 print_statusline("Cannot read this file");
1041 goto err;
1042 }
1043 free(filename);
1044 filename = new_fname;
1045 /* files start by = argv. why we assume that argv is infinitely long??
1046 files[num_files] = filename;
1047 current_file = num_files + 1;
1048 num_files++; */
1049 files[0] = filename;
1050 num_files = current_file = 1;
1051 reinitialize();
1052}
1053
1054/* This function changes the file currently being paged. direction can be one of the following:
1055 * -1: go back one file
1056 * 0: go to the first file
1057 * 1: go forward one file */
1058static void change_file(int direction)
1059{
1060 if (current_file != ((direction > 0) ? num_files : 1)) {
1061 current_file = direction ? current_file + direction : 1;
1062 free(filename);
1063 filename = xstrdup(files[current_file - 1]);
1064 reinitialize();
1065 } else {
1066 print_statusline(direction > 0 ? "No next file" : "No previous file");
1067 }
1068}
1069
1070static void remove_current_file(void)
1071{
1072 unsigned i;
1073
1074 if (num_files < 2)
1075 return;
1076
1077 if (current_file != 1) {
1078 change_file(-1);
1079 for (i = 3; i <= num_files; i++)
1080 files[i - 2] = files[i - 1];
1081 num_files--;
1082 } else {
1083 change_file(1);
1084 for (i = 2; i <= num_files; i++)
1085 files[i - 2] = files[i - 1];
1086 num_files--;
1087 current_file--;
1088 }
1089}
1090
1091static void colon_process(void)
1092{
1093 int keypress;
1094
1095 /* Clear the current line and print a prompt */
1096 print_statusline(" :");
1097
1098 keypress = less_getch(2);
1099 switch (keypress) {
1100 case 'd':
1101 remove_current_file();
1102 break;
1103 case 'e':
1104 examine_file();
1105 break;
1106#if ENABLE_FEATURE_LESS_FLAGS
1107 case 'f':
1108 m_status_print();
1109 break;
1110#endif
1111 case 'n':
1112 change_file(1);
1113 break;
1114 case 'p':
1115 change_file(-1);
1116 break;
1117 case 'q':
1118 less_exit(EXIT_SUCCESS);
1119 break;
1120 case 'x':
1121 change_file(0);
1122 break;
1123 }
1124}
1125
1126#if ENABLE_FEATURE_LESS_REGEXP
1127static void normalize_match_pos(int match)
1128{
1129 if (match >= num_matches)
1130 match = num_matches - 1;
1131 if (match < 0)
1132 match = 0;
1133 match_pos = match;
1134}
1135
1136static void goto_match(int match)
1137{
1138 if (!pattern_valid)
1139 return;
1140 if (match < 0)
1141 match = 0;
1142 /* Try to find next match if eof isn't reached yet */
1143 if (match >= num_matches && eof_error > 0) {
1144 wanted_match = match; /* "I want to read until I see N'th match" */
1145 read_lines();
1146 }
1147 if (num_matches) {
1148 normalize_match_pos(match);
1149 buffer_line(match_lines[match_pos]);
1150 } else {
1151 print_statusline("No matches found");
1152 }
1153}
1154
1155static void fill_match_lines(unsigned pos)
1156{
1157 if (!pattern_valid)
1158 return;
1159 /* Run the regex on each line of the current file */
1160 while (pos <= max_fline) {
1161 /* If this line matches */
1162 if (regexec(&pattern, flines[pos], 0, NULL, 0) == 0
1163 /* and we didn't match it last time */
1164 && !(num_matches && match_lines[num_matches-1] == pos)
1165 ) {
1166 match_lines = xrealloc_vector(match_lines, 4, num_matches);
1167 match_lines[num_matches++] = pos;
1168 }
1169 pos++;
1170 }
1171}
1172
1173static void regex_process(void)
1174{
1175 char *uncomp_regex, *err;
1176
1177 /* Reset variables */
1178 free(match_lines);
1179 match_lines = NULL;
1180 match_pos = 0;
1181 num_matches = 0;
1182 if (pattern_valid) {
1183 regfree(&pattern);
1184 pattern_valid = 0;
1185 }
1186
1187 /* Get the uncompiled regular expression from the user */
1188 clear_line();
1189 bb_putchar((option_mask32 & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
1190 uncomp_regex = less_gets(1);
1191 if (!uncomp_regex[0]) {
1192 free(uncomp_regex);
1193 buffer_print();
1194 return;
1195 }
1196
1197 /* Compile the regex and check for errors */
1198 err = regcomp_or_errmsg(&pattern, uncomp_regex,
1199 (option_mask32 & FLAG_I) ? REG_ICASE : 0);
1200 free(uncomp_regex);
1201 if (err) {
1202 print_statusline(err);
1203 free(err);
1204 return;
1205 }
1206
1207 pattern_valid = 1;
1208 match_pos = 0;
1209 fill_match_lines(0);
1210 while (match_pos < num_matches) {
1211 if ((int)match_lines[match_pos] > cur_fline)
1212 break;
1213 match_pos++;
1214 }
1215 if (option_mask32 & LESS_STATE_MATCH_BACKWARDS)
1216 match_pos--;
1217
1218 /* It's possible that no matches are found yet.
1219 * goto_match() will read input looking for match,
1220 * if needed */
1221 goto_match(match_pos);
1222}
1223#endif
1224
1225static void number_process(int first_digit)
1226{
1227 unsigned i;
1228 int num;
1229 int keypress;
1230 char num_input[sizeof(int)*4]; /* more than enough */
1231
1232 num_input[0] = first_digit;
1233
1234 /* Clear the current line, print a prompt, and then print the digit */
1235 clear_line();
1236 printf(":%c", first_digit);
1237
1238 /* Receive input until a letter is given */
1239 i = 1;
1240 while (i < sizeof(num_input)-1) {
1241 keypress = less_getch(i + 1);
1242 if ((unsigned)keypress > 255 || !isdigit(num_input[i]))
1243 break;
1244 num_input[i] = keypress;
1245 bb_putchar(keypress);
1246 i++;
1247 }
1248
1249 num_input[i] = '\0';
1250 num = bb_strtou(num_input, NULL, 10);
1251 /* on format error, num == -1 */
1252 if (num < 1 || num > MAXLINES) {
1253 buffer_print();
1254 return;
1255 }
1256
1257 /* We now know the number and the letter entered, so we process them */
1258 switch (keypress) {
1259 case KEYCODE_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015':
1260 buffer_down(num);
1261 break;
1262 case KEYCODE_UP: case 'b': case 'w': case 'y': case 'u':
1263 buffer_up(num);
1264 break;
1265 case 'g': case '<': case 'G': case '>':
1266 cur_fline = num + max_displayed_line;
1267 read_lines();
1268 buffer_line(num - 1);
1269 break;
1270 case 'p': case '%':
1271 num = num * (max_fline / 100); /* + max_fline / 2; */
1272 cur_fline = num + max_displayed_line;
1273 read_lines();
1274 buffer_line(num);
1275 break;
1276#if ENABLE_FEATURE_LESS_REGEXP
1277 case 'n':
1278 goto_match(match_pos + num);
1279 break;
1280 case '/':
1281 option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
1282 regex_process();
1283 break;
1284 case '?':
1285 option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
1286 regex_process();
1287 break;
1288#endif
1289 }
1290}
1291
1292#if ENABLE_FEATURE_LESS_DASHCMD
1293static void flag_change(void)
1294{
1295 int keypress;
1296
1297 clear_line();
1298 bb_putchar('-');
1299 keypress = less_getch(1);
1300
1301 switch (keypress) {
1302 case 'M':
1303 option_mask32 ^= FLAG_M;
1304 break;
1305 case 'm':
1306 option_mask32 ^= FLAG_m;
1307 break;
1308 case 'E':
1309 option_mask32 ^= FLAG_E;
1310 break;
1311 case '~':
1312 option_mask32 ^= FLAG_TILDE;
1313 break;
1314 case 'S':
1315 option_mask32 ^= FLAG_S;
1316 buffer_fill_and_print();
1317 break;
1318#if ENABLE_FEATURE_LESS_LINENUMS
1319 case 'N':
1320 option_mask32 ^= FLAG_N;
1321 re_wrap();
1322 buffer_fill_and_print();
1323 break;
1324#endif
1325 }
1326}
1327
1328#ifdef BLOAT
1329static void show_flag_status(void)
1330{
1331 int keypress;
1332 int flag_val;
1333
1334 clear_line();
1335 bb_putchar('_');
1336 keypress = less_getch(1);
1337
1338 switch (keypress) {
1339 case 'M':
1340 flag_val = option_mask32 & FLAG_M;
1341 break;
1342 case 'm':
1343 flag_val = option_mask32 & FLAG_m;
1344 break;
1345 case '~':
1346 flag_val = option_mask32 & FLAG_TILDE;
1347 break;
1348 case 'N':
1349 flag_val = option_mask32 & FLAG_N;
1350 break;
1351 case 'E':
1352 flag_val = option_mask32 & FLAG_E;
1353 break;
1354 default:
1355 flag_val = 0;
1356 break;
1357 }
1358
1359 clear_line();
1360 printf(HIGHLIGHT"The status of the flag is: %u"NORMAL, flag_val != 0);
1361}
1362#endif
1363
1364#endif /* ENABLE_FEATURE_LESS_DASHCMD */
1365
1366static void save_input_to_file(void)
1367{
1368 const char *msg = "";
1369 char *current_line;
1370 unsigned i;
1371 FILE *fp;
1372
1373 print_statusline("Log file: ");
1374 current_line = less_gets(sizeof("Log file: ")-1);
1375 if (current_line[0]) {
1376 fp = fopen_for_write(current_line);
1377 if (!fp) {
1378 msg = "Error opening log file";
1379 goto ret;
1380 }
1381 for (i = 0; i <= max_fline; i++)
1382 fprintf(fp, "%s\n", flines[i]);
1383 fclose(fp);
1384 msg = "Done";
1385 }
1386 ret:
1387 print_statusline(msg);
1388 free(current_line);
1389}
1390
1391#if ENABLE_FEATURE_LESS_MARKS
1392static void add_mark(void)
1393{
1394 int letter;
1395
1396 print_statusline("Mark: ");
1397 letter = less_getch(sizeof("Mark: ") - 1);
1398
1399 if (isalpha(letter)) {
1400 /* If we exceed 15 marks, start overwriting previous ones */
1401 if (num_marks == 14)
1402 num_marks = 0;
1403
1404 mark_lines[num_marks][0] = letter;
1405 mark_lines[num_marks][1] = cur_fline;
1406 num_marks++;
1407 } else {
1408 print_statusline("Invalid mark letter");
1409 }
1410}
1411
1412static void goto_mark(void)
1413{
1414 int letter;
1415 int i;
1416
1417 print_statusline("Go to mark: ");
1418 letter = less_getch(sizeof("Go to mark: ") - 1);
1419 clear_line();
1420
1421 if (isalpha(letter)) {
1422 for (i = 0; i <= num_marks; i++)
1423 if (letter == mark_lines[i][0]) {
1424 buffer_line(mark_lines[i][1]);
1425 break;
1426 }
1427 if (num_marks == 14 && letter != mark_lines[14][0])
1428 print_statusline("Mark not set");
1429 } else
1430 print_statusline("Invalid mark letter");
1431}
1432#endif
1433
1434#if ENABLE_FEATURE_LESS_BRACKETS
1435static char opp_bracket(char bracket)
1436{
1437 switch (bracket) {
1438 case '{': case '[': /* '}' == '{' + 2. Same for '[' */
1439 bracket++;
1440 case '(': /* ')' == '(' + 1 */
1441 bracket++;
1442 break;
1443 case '}': case ']':
1444 bracket--;
1445 case ')':
1446 bracket--;
1447 break;
1448 };
1449 return bracket;
1450}
1451
1452static void match_right_bracket(char bracket)
1453{
1454 unsigned i;
1455
1456 if (strchr(flines[cur_fline], bracket) == NULL) {
1457 print_statusline("No bracket in top line");
1458 return;
1459 }
1460 bracket = opp_bracket(bracket);
1461 for (i = cur_fline + 1; i < max_fline; i++) {
1462 if (strchr(flines[i], bracket) != NULL) {
1463 buffer_line(i);
1464 return;
1465 }
1466 }
1467 print_statusline("No matching bracket found");
1468}
1469
1470static void match_left_bracket(char bracket)
1471{
1472 int i;
1473
1474 if (strchr(flines[cur_fline + max_displayed_line], bracket) == NULL) {
1475 print_statusline("No bracket in bottom line");
1476 return;
1477 }
1478
1479 bracket = opp_bracket(bracket);
1480 for (i = cur_fline + max_displayed_line; i >= 0; i--) {
1481 if (strchr(flines[i], bracket) != NULL) {
1482 buffer_line(i);
1483 return;
1484 }
1485 }
1486 print_statusline("No matching bracket found");
1487}
1488#endif /* FEATURE_LESS_BRACKETS */
1489
1490static void keypress_process(int keypress)
1491{
1492 switch (keypress) {
1493 case KEYCODE_DOWN: case 'e': case 'j': case 0x0d:
1494 buffer_down(1);
1495 break;
1496 case KEYCODE_UP: case 'y': case 'k':
1497 buffer_up(1);
1498 break;
1499 case KEYCODE_PAGEDOWN: case ' ': case 'z': case 'f':
1500 buffer_down(max_displayed_line + 1);
1501 break;
1502 case KEYCODE_PAGEUP: case 'w': case 'b':
1503 buffer_up(max_displayed_line + 1);
1504 break;
1505 case 'd':
1506 buffer_down((max_displayed_line + 1) / 2);
1507 break;
1508 case 'u':
1509 buffer_up((max_displayed_line + 1) / 2);
1510 break;
1511 case KEYCODE_HOME: case 'g': case 'p': case '<': case '%':
1512 buffer_line(0);
1513 break;
1514 case KEYCODE_END: case 'G': case '>':
1515 cur_fline = MAXLINES;
1516 read_lines();
1517 buffer_line(cur_fline);
1518 break;
1519 case 'q': case 'Q':
1520 less_exit(EXIT_SUCCESS);
1521 break;
1522#if ENABLE_FEATURE_LESS_MARKS
1523 case 'm':
1524 add_mark();
1525 buffer_print();
1526 break;
1527 case '\'':
1528 goto_mark();
1529 buffer_print();
1530 break;
1531#endif
1532 case 'r': case 'R':
1533 /* TODO: (1) also bind ^R, ^L to this?
1534 * (2) re-measure window size?
1535 */
1536 buffer_print();
1537 break;
1538 /*case 'R':
1539 full_repaint();
1540 break;*/
1541 case 's':
1542 save_input_to_file();
1543 break;
1544 case 'E':
1545 examine_file();
1546 break;
1547#if ENABLE_FEATURE_LESS_FLAGS
1548 case '=':
1549 m_status_print();
1550 break;
1551#endif
1552#if ENABLE_FEATURE_LESS_REGEXP
1553 case '/':
1554 option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
1555 regex_process();
1556 break;
1557 case 'n':
1558 goto_match(match_pos + 1);
1559 break;
1560 case 'N':
1561 goto_match(match_pos - 1);
1562 break;
1563 case '?':
1564 option_mask32 |= LESS_STATE_MATCH_BACKWARDS;
1565 regex_process();
1566 break;
1567#endif
1568#if ENABLE_FEATURE_LESS_DASHCMD
1569 case '-':
1570 flag_change();
1571 buffer_print();
1572 break;
1573#ifdef BLOAT
1574 case '_':
1575 show_flag_status();
1576 break;
1577#endif
1578#endif
1579#if ENABLE_FEATURE_LESS_BRACKETS
1580 case '{': case '(': case '[':
1581 match_right_bracket(keypress);
1582 break;
1583 case '}': case ')': case ']':
1584 match_left_bracket(keypress);
1585 break;
1586#endif
1587 case ':':
1588 colon_process();
1589 break;
1590 }
1591
1592 if (isdigit(keypress))
1593 number_process(keypress);
1594}
1595
1596static void sig_catcher(int sig)
1597{
1598 less_exit(- sig);
1599}
1600
1601#if ENABLE_FEATURE_LESS_WINCH
1602static void sigwinch_handler(int sig UNUSED_PARAM)
1603{
1604 winch_counter++;
1605}
1606#endif
1607
1608int less_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1609int less_main(int argc, char **argv)
1610{
1611 INIT_G();
1612
1613 /* TODO: -x: do not interpret backspace, -xx: tab also */
1614 /* -xxx: newline also */
1615 /* -w N: assume width N (-xxx -w 32: hex viewer of sorts) */
1616 getopt32(argv, "EMmN~I" IF_FEATURE_LESS_DASHCMD("S"));
1617 argc -= optind;
1618 argv += optind;
1619 num_files = argc;
1620 files = argv;
1621
1622 /* Another popular pager, most, detects when stdout
1623 * is not a tty and turns into cat. This makes sense. */
1624 if (!isatty(STDOUT_FILENO))
1625 return bb_cat(argv);
1626
1627 if (!num_files) {
1628 if (isatty(STDIN_FILENO)) {
1629 /* Just "less"? No args and no redirection? */
1630 bb_error_msg("missing filename");
1631 bb_show_usage();
1632 }
1633 } else {
1634 filename = xstrdup(files[0]);
1635 }
1636
1637 if (option_mask32 & FLAG_TILDE)
1638 empty_line_marker = "";
1639
1640 kbd_fd = open(CURRENT_TTY, O_RDONLY);
1641 if (kbd_fd < 0)
1642 return bb_cat(argv);
1643 ndelay_on(kbd_fd);
1644
1645 tcgetattr(kbd_fd, &term_orig);
1646 term_less = term_orig;
1647 term_less.c_lflag &= ~(ICANON | ECHO);
1648 term_less.c_iflag &= ~(IXON | ICRNL);
1649 /*term_less.c_oflag &= ~ONLCR;*/
1650 term_less.c_cc[VMIN] = 1;
1651 term_less.c_cc[VTIME] = 0;
1652
1653 IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
1654 /* 20: two tabstops + 4 */
1655 if (width < 20 || max_displayed_line < 3)
1656 return bb_cat(argv);
1657 max_displayed_line -= 2;
1658
1659 /* We want to restore term_orig on exit */
1660 bb_signals(BB_FATAL_SIGS, sig_catcher);
1661#if ENABLE_FEATURE_LESS_WINCH
1662 signal(SIGWINCH, sigwinch_handler);
1663#endif
1664
1665 buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
1666 reinitialize();
1667 while (1) {
1668 int64_t keypress;
1669
1670#if ENABLE_FEATURE_LESS_WINCH
1671 while (WINCH_COUNTER) {
1672 again:
1673 winch_counter--;
1674 IF_FEATURE_LESS_ASK_TERMINAL(G.winsize_err =) get_terminal_width_height(kbd_fd, &width, &max_displayed_line);
1675 IF_FEATURE_LESS_ASK_TERMINAL(got_size:)
1676 /* 20: two tabstops + 4 */
1677 if (width < 20)
1678 width = 20;
1679 if (max_displayed_line < 3)
1680 max_displayed_line = 3;
1681 max_displayed_line -= 2;
1682 free(buffer);
1683 buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
1684 /* Avoid re-wrap and/or redraw if we already know
1685 * we need to do it again. These ops are expensive */
1686 if (WINCH_COUNTER)
1687 goto again;
1688 re_wrap();
1689 if (WINCH_COUNTER)
1690 goto again;
1691 buffer_fill_and_print();
1692 /* This took some time. Loop back and check,
1693 * were there another SIGWINCH? */
1694 }
1695 keypress = less_getch(-1); /* -1: do not position cursor */
1696# if ENABLE_FEATURE_LESS_ASK_TERMINAL
1697 if ((int32_t)keypress == KEYCODE_CURSOR_POS) {
1698 uint32_t rc = (keypress >> 32);
1699 width = (rc & 0x7fff);
1700 max_displayed_line = ((rc >> 16) & 0x7fff);
1701 goto got_size;
1702 }
1703# endif
1704#else
1705 keypress = less_getch(-1); /* -1: do not position cursor */
1706#endif
1707 keypress_process(keypress);
1708 }
1709}
1710
1711/*
1712Help text of less version 418 is below.
1713If you are implementing something, keeping
1714key and/or command line switch compatibility is a good idea:
1715
1716
1717 SUMMARY OF LESS COMMANDS
1718
1719 Commands marked with * may be preceded by a number, N.
1720 Notes in parentheses indicate the behavior if N is given.
1721 h H Display this help.
1722 q :q Q :Q ZZ Exit.
1723 ---------------------------------------------------------------------------
1724 MOVING
1725 e ^E j ^N CR * Forward one line (or N lines).
1726 y ^Y k ^K ^P * Backward one line (or N lines).
1727 f ^F ^V SPACE * Forward one window (or N lines).
1728 b ^B ESC-v * Backward one window (or N lines).
1729 z * Forward one window (and set window to N).
1730 w * Backward one window (and set window to N).
1731 ESC-SPACE * Forward one window, but don't stop at end-of-file.
1732 d ^D * Forward one half-window (and set half-window to N).
1733 u ^U * Backward one half-window (and set half-window to N).
1734 ESC-) RightArrow * Left one half screen width (or N positions).
1735 ESC-( LeftArrow * Right one half screen width (or N positions).
1736 F Forward forever; like "tail -f".
1737 r ^R ^L Repaint screen.
1738 R Repaint screen, discarding buffered input.
1739 ---------------------------------------------------
1740 Default "window" is the screen height.
1741 Default "half-window" is half of the screen height.
1742 ---------------------------------------------------------------------------
1743 SEARCHING
1744 /pattern * Search forward for (N-th) matching line.
1745 ?pattern * Search backward for (N-th) matching line.
1746 n * Repeat previous search (for N-th occurrence).
1747 N * Repeat previous search in reverse direction.
1748 ESC-n * Repeat previous search, spanning files.
1749 ESC-N * Repeat previous search, reverse dir. & spanning files.
1750 ESC-u Undo (toggle) search highlighting.
1751 ---------------------------------------------------
1752 Search patterns may be modified by one or more of:
1753 ^N or ! Search for NON-matching lines.
1754 ^E or * Search multiple files (pass thru END OF FILE).
1755 ^F or @ Start search at FIRST file (for /) or last file (for ?).
1756 ^K Highlight matches, but don't move (KEEP position).
1757 ^R Don't use REGULAR EXPRESSIONS.
1758 ---------------------------------------------------------------------------
1759 JUMPING
1760 g < ESC-< * Go to first line in file (or line N).
1761 G > ESC-> * Go to last line in file (or line N).
1762 p % * Go to beginning of file (or N percent into file).
1763 t * Go to the (N-th) next tag.
1764 T * Go to the (N-th) previous tag.
1765 { ( [ * Find close bracket } ) ].
1766 } ) ] * Find open bracket { ( [.
1767 ESC-^F <c1> <c2> * Find close bracket <c2>.
1768 ESC-^B <c1> <c2> * Find open bracket <c1>
1769 ---------------------------------------------------
1770 Each "find close bracket" command goes forward to the close bracket
1771 matching the (N-th) open bracket in the top line.
1772 Each "find open bracket" command goes backward to the open bracket
1773 matching the (N-th) close bracket in the bottom line.
1774 m<letter> Mark the current position with <letter>.
1775 '<letter> Go to a previously marked position.
1776 '' Go to the previous position.
1777 ^X^X Same as '.
1778 ---------------------------------------------------
1779 A mark is any upper-case or lower-case letter.
1780 Certain marks are predefined:
1781 ^ means beginning of the file
1782 $ means end of the file
1783 ---------------------------------------------------------------------------
1784 CHANGING FILES
1785 :e [file] Examine a new file.
1786 ^X^V Same as :e.
1787 :n * Examine the (N-th) next file from the command line.
1788 :p * Examine the (N-th) previous file from the command line.
1789 :x * Examine the first (or N-th) file from the command line.
1790 :d Delete the current file from the command line list.
1791 = ^G :f Print current file name.
1792 ---------------------------------------------------------------------------
1793 MISCELLANEOUS COMMANDS
1794 -<flag> Toggle a command line option [see OPTIONS below].
1795 --<name> Toggle a command line option, by name.
1796 _<flag> Display the setting of a command line option.
1797 __<name> Display the setting of an option, by name.
1798 +cmd Execute the less cmd each time a new file is examined.
1799 !command Execute the shell command with $SHELL.
1800 |Xcommand Pipe file between current pos & mark X to shell command.
1801 v Edit the current file with $VISUAL or $EDITOR.
1802 V Print version number of "less".
1803 ---------------------------------------------------------------------------
1804 OPTIONS
1805 Most options may be changed either on the command line,
1806 or from within less by using the - or -- command.
1807 Options may be given in one of two forms: either a single
1808 character preceded by a -, or a name preceeded by --.
1809 -? ........ --help
1810 Display help (from command line).
1811 -a ........ --search-skip-screen
1812 Forward search skips current screen.
1813 -b [N] .... --buffers=[N]
1814 Number of buffers.
1815 -B ........ --auto-buffers
1816 Don't automatically allocate buffers for pipes.
1817 -c ........ --clear-screen
1818 Repaint by clearing rather than scrolling.
1819 -d ........ --dumb
1820 Dumb terminal.
1821 -D [xn.n] . --color=xn.n
1822 Set screen colors. (MS-DOS only)
1823 -e -E .... --quit-at-eof --QUIT-AT-EOF
1824 Quit at end of file.
1825 -f ........ --force
1826 Force open non-regular files.
1827 -F ........ --quit-if-one-screen
1828 Quit if entire file fits on first screen.
1829 -g ........ --hilite-search
1830 Highlight only last match for searches.
1831 -G ........ --HILITE-SEARCH
1832 Don't highlight any matches for searches.
1833 -h [N] .... --max-back-scroll=[N]
1834 Backward scroll limit.
1835 -i ........ --ignore-case
1836 Ignore case in searches that do not contain uppercase.
1837 -I ........ --IGNORE-CASE
1838 Ignore case in all searches.
1839 -j [N] .... --jump-target=[N]
1840 Screen position of target lines.
1841 -J ........ --status-column
1842 Display a status column at left edge of screen.
1843 -k [file] . --lesskey-file=[file]
1844 Use a lesskey file.
1845 -L ........ --no-lessopen
1846 Ignore the LESSOPEN environment variable.
1847 -m -M .... --long-prompt --LONG-PROMPT
1848 Set prompt style.
1849 -n -N .... --line-numbers --LINE-NUMBERS
1850 Don't use line numbers.
1851 -o [file] . --log-file=[file]
1852 Copy to log file (standard input only).
1853 -O [file] . --LOG-FILE=[file]
1854 Copy to log file (unconditionally overwrite).
1855 -p [pattern] --pattern=[pattern]
1856 Start at pattern (from command line).
1857 -P [prompt] --prompt=[prompt]
1858 Define new prompt.
1859 -q -Q .... --quiet --QUIET --silent --SILENT
1860 Quiet the terminal bell.
1861 -r -R .... --raw-control-chars --RAW-CONTROL-CHARS
1862 Output "raw" control characters.
1863 -s ........ --squeeze-blank-lines
1864 Squeeze multiple blank lines.
1865 -S ........ --chop-long-lines
1866 Chop long lines.
1867 -t [tag] .. --tag=[tag]
1868 Find a tag.
1869 -T [tagsfile] --tag-file=[tagsfile]
1870 Use an alternate tags file.
1871 -u -U .... --underline-special --UNDERLINE-SPECIAL
1872 Change handling of backspaces.
1873 -V ........ --version
1874 Display the version number of "less".
1875 -w ........ --hilite-unread
1876 Highlight first new line after forward-screen.
1877 -W ........ --HILITE-UNREAD
1878 Highlight first new line after any forward movement.
1879 -x [N[,...]] --tabs=[N[,...]]
1880 Set tab stops.
1881 -X ........ --no-init
1882 Don't use termcap init/deinit strings.
1883 --no-keypad
1884 Don't use termcap keypad init/deinit strings.
1885 -y [N] .... --max-forw-scroll=[N]
1886 Forward scroll limit.
1887 -z [N] .... --window=[N]
1888 Set size of window.
1889 -" [c[c]] . --quotes=[c[c]]
1890 Set shell quote characters.
1891 -~ ........ --tilde
1892 Don't display tildes after end of file.
1893 -# [N] .... --shift=[N]
1894 Horizontal scroll amount (0 = one half screen width)
1895
1896 ---------------------------------------------------------------------------
1897 LINE EDITING
1898 These keys can be used to edit text being entered
1899 on the "command line" at the bottom of the screen.
1900 RightArrow ESC-l Move cursor right one character.
1901 LeftArrow ESC-h Move cursor left one character.
1902 CNTL-RightArrow ESC-RightArrow ESC-w Move cursor right one word.
1903 CNTL-LeftArrow ESC-LeftArrow ESC-b Move cursor left one word.
1904 HOME ESC-0 Move cursor to start of line.
1905 END ESC-$ Move cursor to end of line.
1906 BACKSPACE Delete char to left of cursor.
1907 DELETE ESC-x Delete char under cursor.
1908 CNTL-BACKSPACE ESC-BACKSPACE Delete word to left of cursor.
1909 CNTL-DELETE ESC-DELETE ESC-X Delete word under cursor.
1910 CNTL-U ESC (MS-DOS only) Delete entire line.
1911 UpArrow ESC-k Retrieve previous command line.
1912 DownArrow ESC-j Retrieve next command line.
1913 TAB Complete filename & cycle.
1914 SHIFT-TAB ESC-TAB Complete filename & reverse cycle.
1915 CNTL-L Complete filename, list all.
1916*/
Note: See TracBrowser for help on using the repository browser.