1 /* vi: set sw=4 ts=4: */
3 * Mini less implementation for busybox
5 * Copyright (C) 2005 by Rob Sullivan <cogito.ergo.cogito@gmail.com>
7 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
12 * - Add more regular expression support - search modifiers, certain matches, etc.
13 * - Add more complex bracket searching - currently, nested brackets are
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.
20 * - the inp file pointer is used so that keyboard input works after
21 * redirected input has been read from stdin
24 #include <sched.h> /* sched_yield() */
27 #if ENABLE_FEATURE_LESS_REGEXP
31 /* The escape codes for highlighted and normal text */
32 #define HIGHLIGHT "\033[7m"
33 #define NORMAL "\033[0m"
34 /* The escape code to clear the screen */
35 #define CLEAR "\033[H\033[J"
36 /* The escape code to clear to end of line */
37 #define CLEAR_2_EOL "\033[K"
40 /* Absolute max of lines eaten */
41 MAXLINES
= CONFIG_FEATURE_LESS_MAXLINES
,
42 /* This many "after the end" lines we will show (at max) */
46 /* Command line options */
54 FLAG_S
= (1 << 6) * ENABLE_FEATURE_LESS_DASHCMD
,
55 /* hijack command line options variable for internal state vars */
56 LESS_STATE_MATCH_BACKWARDS
= 1 << 15,
59 #if !ENABLE_FEATURE_LESS_REGEXP
60 enum { pattern_valid
= 0 };
64 int cur_fline
; /* signed */
65 int kbd_fd
; /* fd to get input from */
67 /* last position in last line, taking into account tabs */
70 unsigned max_lineno
; /* this one tracks linewrap */
71 unsigned max_displayed_line
;
73 #if ENABLE_FEATURE_LESS_WINCH
74 unsigned winch_counter
;
76 ssize_t eof_error
; /* eof if 0, error if < 0 */
78 ssize_t readeof
; /* must be signed */
81 const char *empty_line_marker
;
83 unsigned current_file
;
86 #if ENABLE_FEATURE_LESS_MARKS
88 unsigned mark_lines
[15][2];
90 #if ENABLE_FEATURE_LESS_REGEXP
91 unsigned *match_lines
;
92 int match_pos
; /* signed! */
93 int wanted_match
; /* signed! */
96 smallint pattern_valid
;
99 smalluint kbd_input_size
;
100 struct termios term_orig
, term_less
;
101 char kbd_input
[KEYCODE_BUFFER_SIZE
];
103 #define G (*ptr_to_globals)
104 #define cur_fline (G.cur_fline )
105 #define kbd_fd (G.kbd_fd )
106 #define less_gets_pos (G.less_gets_pos )
107 #define last_line_pos (G.last_line_pos )
108 #define max_fline (G.max_fline )
109 #define max_lineno (G.max_lineno )
110 #define max_displayed_line (G.max_displayed_line)
111 #define width (G.width )
112 #define winch_counter (G.winch_counter )
113 /* This one is 100% not cached by compiler on read access */
114 #define WINCH_COUNTER (*(volatile unsigned *)&winch_counter)
115 #define eof_error (G.eof_error )
116 #define readpos (G.readpos )
117 #define readeof (G.readeof )
118 #define buffer (G.buffer )
119 #define flines (G.flines )
120 #define empty_line_marker (G.empty_line_marker )
121 #define num_files (G.num_files )
122 #define current_file (G.current_file )
123 #define filename (G.filename )
124 #define files (G.files )
125 #define num_marks (G.num_marks )
126 #define mark_lines (G.mark_lines )
127 #if ENABLE_FEATURE_LESS_REGEXP
128 #define match_lines (G.match_lines )
129 #define match_pos (G.match_pos )
130 #define num_matches (G.num_matches )
131 #define wanted_match (G.wanted_match )
132 #define pattern (G.pattern )
133 #define pattern_valid (G.pattern_valid )
135 #define terminated (G.terminated )
136 #define term_orig (G.term_orig )
137 #define term_less (G.term_less )
138 #define kbd_input_size (G.kbd_input_size )
139 #define kbd_input (G.kbd_input )
140 #define INIT_G() do { \
141 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
142 less_gets_pos = -1; \
143 empty_line_marker = "~"; \
148 USE_FEATURE_LESS_REGEXP(wanted_match = -1;) \
151 /* flines[] are lines read from stdin, each in malloc'ed buffer.
152 * Line numbers are stored as uint32_t prepended to each line.
153 * Pointer is adjusted so that flines[i] points directly past
154 * line number. Accesor: */
155 #define MEMPTR(p) ((char*)(p) - 4)
156 #define LINENO(p) (*(uint32_t*)((p) - 4))
159 /* Reset terminal input to normal */
160 static void set_tty_cooked(void)
163 tcsetattr(kbd_fd
, TCSANOW
, &term_orig
);
166 /* Move the cursor to a position (x,y), where (0,0) is the
167 top-left corner of the console */
168 static void move_cursor(int line
, int row
)
170 printf("\033[%u;%uH", line
, row
);
173 static void clear_line(void)
175 printf("\033[%u;0H" CLEAR_2_EOL
, max_displayed_line
+ 2);
178 static void print_hilite(const char *str
)
180 printf(HIGHLIGHT
"%s"NORMAL
, str
);
183 static void print_statusline(const char *str
)
186 printf(HIGHLIGHT
"%.*s"NORMAL
, width
- 1, str
);
189 /* Exit the program gracefully */
190 static void less_exit(int code
)
195 kill_myself_with_sig(- code
); /* does not return */
199 #if (ENABLE_FEATURE_LESS_DASHCMD && ENABLE_FEATURE_LESS_LINENUMS) \
200 || ENABLE_FEATURE_LESS_WINCH
201 static void re_wrap(void)
207 int new_cur_fline
= 0;
210 const char **old_flines
= flines
;
212 char **new_flines
= NULL
;
215 if (option_mask32
& FLAG_N
)
228 if (*d
== '\t') /* tab */
232 if (new_line_pos
>= w
) {
234 /* new line is full, create next one */
237 sz
= (d
- linebuf
) + 1; /* + 1: NUL */
238 d
= ((char*)xmalloc(sz
+ 4)) + 4;
240 memcpy(d
, linebuf
, sz
);
241 new_flines
= xrealloc_vector(new_flines
, 8, dst_idx
);
242 new_flines
[dst_idx
] = d
;
244 if (new_line_pos
< w
) {
245 /* if we came here thru "goto next_new" */
246 if (src_idx
> max_fline
)
255 /* *d == NUL: old line ended, go to next old one */
256 free(MEMPTR(old_flines
[src_idx
]));
257 /* btw, convert cur_fline... */
258 if (cur_fline
== src_idx
)
259 new_cur_fline
= dst_idx
;
261 /* no more lines? finish last new line (and exit the loop) */
262 if (src_idx
> max_fline
)
264 s
= old_flines
[src_idx
];
265 if (lineno
!= LINENO(s
)) {
266 /* this is not a continuation line!
267 * create next _new_ line too */
273 flines
= (const char **)new_flines
;
275 max_fline
= dst_idx
- 1;
276 last_line_pos
= new_line_pos
;
277 cur_fline
= new_cur_fline
;
278 /* max_lineno is screen-size independent */
279 #if ENABLE_FEATURE_LESS_REGEXP
285 #if ENABLE_FEATURE_LESS_REGEXP
286 static void fill_match_lines(unsigned pos
);
288 #define fill_match_lines(pos) ((void)0)
291 /* Devilishly complex routine.
293 * Has to deal with EOF and EPIPE on input,
294 * with line wrapping, with last line not ending in '\n'
295 * (possibly not ending YET!), with backspace and tabs.
296 * It reads input again if last time we got an EOF (thus supporting
297 * growing files) or EPIPE (watching output of slow process like make).
300 * flines[] - array of lines already read. Linewrap may cause
301 * one source file line to occupy several flines[n].
302 * flines[max_fline] - last line, possibly incomplete.
303 * terminated - 1 if flines[max_fline] is 'terminated'
304 * (if there was '\n' [which isn't stored itself, we just remember
306 * max_lineno - last line's number, this one doesn't increment
307 * on line wrap, only on "real" new lines.
308 * readbuf[0..readeof-1] - small preliminary buffer.
309 * readbuf[readpos] - next character to add to current line.
310 * last_line_pos - screen line position of next char to be read
311 * (takes into account tabs and backspaces)
312 * eof_error - < 0 error, == 0 EOF, > 0 not EOF/error
314 static void read_lines(void)
316 #define readbuf bb_common_bufsiz1
317 char *current_line
, *p
;
319 char last_terminated
= terminated
;
320 #if ENABLE_FEATURE_LESS_REGEXP
321 unsigned old_max_fline
= max_fline
;
322 time_t last_time
= 0;
323 unsigned seconds_p1
= 3; /* seconds_to_loop + 1 */
326 if (option_mask32
& FLAG_N
)
329 USE_FEATURE_LESS_REGEXP(again0
:)
331 p
= current_line
= ((char*)xmalloc(w
+ 4)) + 4;
332 max_fline
+= last_terminated
;
333 if (!last_terminated
) {
334 const char *cp
= flines
[max_fline
];
336 p
+= strlen(current_line
);
337 free(MEMPTR(flines
[max_fline
]));
338 /* last_line_pos is still valid from previous read_lines() */
343 while (1) { /* read lines until we reach cur_fline or wanted_match */
346 while (1) { /* read chars until we have a line */
348 /* if no unprocessed chars left, eat more */
349 if (readpos
>= readeof
) {
351 eof_error
= safe_read(STDIN_FILENO
, readbuf
, sizeof(readbuf
));
358 c
= readbuf
[readpos
];
359 /* backspace? [needed for manpages] */
360 /* <tab><bs> is (a) insane and */
361 /* (b) harder to do correctly, so we refuse to do it */
362 if (c
== '\x8' && last_line_pos
&& p
[-1] != '\t') {
363 readpos
++; /* eat it */
365 /* was buggy (p could end up <= current_line)... */
370 size_t new_last_line_pos
= last_line_pos
+ 1;
372 new_last_line_pos
+= 7;
373 new_last_line_pos
&= (~7);
375 if ((int)new_last_line_pos
>= w
)
377 last_line_pos
= new_last_line_pos
;
379 /* ok, we will eat this char */
386 /* NUL is substituted by '\n'! */
387 if (c
== '\0') c
= '\n';
390 } /* end of "read chars until we have a line" loop */
391 /* Corner case: linewrap with only "" wrapping to next line */
392 /* Looks ugly on screen, so we do not store this empty line */
393 if (!last_terminated
&& !current_line
[0]) {
399 last_terminated
= terminated
;
400 flines
= xrealloc_vector(flines
, 8, max_fline
);
402 flines
[max_fline
] = (char*)xrealloc(MEMPTR(current_line
), strlen(current_line
) + 1 + 4) + 4;
403 LINENO(flines
[max_fline
]) = max_lineno
;
407 if (max_fline
>= MAXLINES
) {
408 eof_error
= 0; /* Pretend we saw EOF */
411 if (!(option_mask32
& FLAG_S
)
412 ? (max_fline
> cur_fline
+ max_displayed_line
)
413 : (max_fline
>= cur_fline
414 && max_lineno
> LINENO(flines
[cur_fline
]) + max_displayed_line
)
416 #if !ENABLE_FEATURE_LESS_REGEXP
419 if (wanted_match
>= num_matches
) { /* goto_match called us */
420 fill_match_lines(old_max_fline
);
421 old_max_fline
= max_fline
;
423 if (wanted_match
< num_matches
)
427 if (eof_error
<= 0) {
429 if (errno
== EAGAIN
) {
430 /* not yet eof or error, reset flag (or else
431 * we will hog CPU - select() will return
435 print_statusline("read error");
438 #if !ENABLE_FEATURE_LESS_REGEXP
441 if (wanted_match
< num_matches
) {
443 } else { /* goto_match called us */
444 time_t t
= time(NULL
);
445 if (t
!= last_time
) {
447 if (--seconds_p1
== 0)
451 goto again0
; /* go loop again (max 2 seconds) */
456 current_line
= ((char*)xmalloc(w
+ 4)) + 4;
459 } /* end of "read lines until we reach cur_fline" loop */
460 fill_match_lines(old_max_fline
);
461 #if ENABLE_FEATURE_LESS_REGEXP
462 /* prevent us from being stuck in search for a match */
468 #if ENABLE_FEATURE_LESS_FLAGS
469 /* Interestingly, writing calc_percent as a function saves around 32 bytes
471 static int calc_percent(void)
473 unsigned p
= (100 * (cur_fline
+max_displayed_line
+1) + max_fline
/2) / (max_fline
+1);
474 return p
<= 100 ? p
: 100;
477 /* Print a status line if -M was specified */
478 static void m_status_print(void)
482 if (less_gets_pos
>= 0) /* don't touch statusline while input is done! */
486 printf(HIGHLIGHT
"%s", filename
);
488 printf(" (file %i of %i)", current_file
, num_files
);
489 printf(" lines %i-%i/%i ",
490 cur_fline
+ 1, cur_fline
+ max_displayed_line
+ 1,
492 if (cur_fline
>= (int)(max_fline
- max_displayed_line
)) {
493 printf("(END)"NORMAL
);
494 if (num_files
> 1 && current_file
!= num_files
)
495 printf(HIGHLIGHT
" - next: %s"NORMAL
, files
[current_file
]);
498 percentage
= calc_percent();
499 printf("%i%%"NORMAL
, percentage
);
503 /* Print the status line */
504 static void status_print(void)
508 if (less_gets_pos
>= 0) /* don't touch statusline while input is done! */
511 /* Change the status if flags have been set */
512 #if ENABLE_FEATURE_LESS_FLAGS
513 if (option_mask32
& (FLAG_M
|FLAG_m
)) {
521 if (cur_fline
&& cur_fline
< (int)(max_fline
- max_displayed_line
)) {
529 printf(HIGHLIGHT
"%s (file %i of %i)"NORMAL
,
530 p
, current_file
, num_files
);
536 static void cap_cur_fline(int nlines
)
541 if (cur_fline
+ max_displayed_line
> max_fline
+ TILDES
) {
545 diff
= max_fline
- (cur_fline
+ max_displayed_line
) + TILDES
;
546 /* As the number of lines requested was too large, we just move
547 to the end of the file */
553 static const char controls
[] ALIGN1
=
554 /* NUL: never encountered; TAB: not converted */
555 /**/"\x01\x02\x03\x04\x05\x06\x07\x08" "\x0a\x0b\x0c\x0d\x0e\x0f"
556 "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f"
557 "\x7f\x9b"; /* DEL and infamous Meta-ESC :( */
558 static const char ctrlconv
[] ALIGN1
=
559 /* '\n': it's a former NUL - subst with '@', not 'J' */
560 "\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x40\x4b\x4c\x4d\x4e\x4f"
561 "\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f";
563 static void lineno_str(char *nbuf9
, const char *line
)
566 if (option_mask32
& FLAG_N
) {
570 if (line
== empty_line_marker
) {
571 memset(nbuf9
, ' ', 8);
575 /* Width of 7 preserves tab spacing in the text */
577 n
= LINENO(line
) + 1;
582 sprintf(nbuf9
, fmt
, n
);
587 #if ENABLE_FEATURE_LESS_REGEXP
588 static void print_found(const char *line
)
593 regmatch_t match_structs
;
597 const char *str
= line
;
602 n
= strcspn(str
, controls
);
609 n
= strspn(str
, controls
);
616 /* buf[] holds quarantined version of str */
618 /* Each part of the line that matches has the HIGHLIGHT
619 and NORMAL escape sequences placed around it.
620 NB: we regex against line, but insert text
621 from quarantined copy (buf[]) */
627 while (match_status
== 0) {
628 char *new = xasprintf("%s%.*s"HIGHLIGHT
"%.*s"NORMAL
,
630 match_structs
.rm_so
, str
,
631 match_structs
.rm_eo
- match_structs
.rm_so
,
632 str
+ match_structs
.rm_so
);
635 str
+= match_structs
.rm_eo
;
636 line
+= match_structs
.rm_eo
;
639 /* Most of the time doesn't find the regex, optimize for that */
640 match_status
= regexec(&pattern
, line
, 1, &match_structs
, eflags
);
641 /* if even "" matches, treat it as "not a match" */
642 if (match_structs
.rm_so
>= match_structs
.rm_eo
)
646 lineno_str(nbuf9
, line
);
648 printf(CLEAR_2_EOL
"%s%s\n", nbuf9
, str
);
651 printf(CLEAR_2_EOL
"%s%s%s\n", nbuf9
, growline
, str
);
655 void print_found(const char *line
);
658 static void print_ascii(const char *str
)
665 lineno_str(nbuf9
, str
);
666 printf(CLEAR_2_EOL
"%s", nbuf9
);
669 n
= strcspn(str
, controls
);
672 printf("%.*s", (int) n
, str
);
675 n
= strspn(str
, controls
);
680 else if (*str
== (char)0x9b)
681 /* VT100's CSI, aka Meta-ESC. Who's inventor? */
682 /* I want to know who committed this sin */
685 *p
++ = ctrlconv
[(unsigned char)*str
];
694 /* Print the buffer */
695 static void buffer_print(void)
700 for (i
= 0; i
<= max_displayed_line
; i
++)
702 print_found(buffer
[i
]);
704 print_ascii(buffer
[i
]);
708 static void buffer_fill_and_print(void)
711 #if ENABLE_FEATURE_LESS_DASHCMD
712 int fpos
= cur_fline
;
714 if (option_mask32
& FLAG_S
) {
715 /* Go back to the beginning of this line */
716 while (fpos
&& LINENO(flines
[fpos
]) == LINENO(flines
[fpos
-1]))
721 while (i
<= max_displayed_line
&& fpos
<= max_fline
) {
722 int lineno
= LINENO(flines
[fpos
]);
723 buffer
[i
] = flines
[fpos
];
727 } while ((fpos
<= max_fline
)
728 && (option_mask32
& FLAG_S
)
729 && lineno
== LINENO(flines
[fpos
])
733 for (i
= 0; i
<= max_displayed_line
&& cur_fline
+ i
<= max_fline
; i
++) {
734 buffer
[i
] = flines
[cur_fline
+ i
];
737 for (; i
<= max_displayed_line
; i
++) {
738 buffer
[i
] = empty_line_marker
;
743 /* Move the buffer up and down in the file in order to scroll */
744 static void buffer_down(int nlines
)
748 cap_cur_fline(nlines
);
749 buffer_fill_and_print();
752 static void buffer_up(int nlines
)
755 if (cur_fline
< 0) cur_fline
= 0;
757 buffer_fill_and_print();
760 static void buffer_line(int linenum
)
766 if (linenum
+ max_displayed_line
> max_fline
)
767 linenum
= max_fline
- max_displayed_line
+ TILDES
;
771 buffer_fill_and_print();
774 static void open_file_and_read_lines(void)
777 xmove_fd(xopen(filename
, O_RDONLY
), STDIN_FILENO
);
779 /* "less" with no arguments in argv[] */
780 /* For status line only */
781 filename
= xstrdup(bb_msg_standard_input
);
790 /* Reinitialize everything for a new file - free the memory and start over */
791 static void reinitialize(void)
796 for (i
= 0; i
<= max_fline
; i
++)
797 free(MEMPTR(flines
[i
]));
805 open_file_and_read_lines();
806 buffer_fill_and_print();
809 static ssize_t
getch_nowait(void)
812 struct pollfd pfd
[2];
814 pfd
[0].fd
= STDIN_FILENO
;
815 pfd
[0].events
= POLLIN
;
817 pfd
[1].events
= POLLIN
;
819 tcsetattr(kbd_fd
, TCSANOW
, &term_less
);
820 /* NB: select/poll returns whenever read will not block. Therefore:
821 * if eof is reached, select/poll will return immediately
822 * because read will immediately return 0 bytes.
823 * Even if select/poll says that input is available, read CAN block
824 * (switch fd into O_NONBLOCK'ed mode to avoid it)
827 /* Are we interested in stdin? */
828 //TODO: reuse code for determining this
829 if (!(option_mask32
& FLAG_S
)
830 ? !(max_fline
> cur_fline
+ max_displayed_line
)
831 : !(max_fline
>= cur_fline
832 && max_lineno
> LINENO(flines
[cur_fline
]) + max_displayed_line
)
834 if (eof_error
> 0) /* did NOT reach eof yet */
835 rd
= 0; /* yes, we are interested in stdin */
837 /* Position cursor if line input is done */
838 if (less_gets_pos
>= 0)
839 move_cursor(max_displayed_line
+ 2, less_gets_pos
+ 1);
842 if (kbd_input_size
== 0) {
843 #if ENABLE_FEATURE_LESS_WINCH
846 /* NB: SIGWINCH interrupts poll() */
847 r
= poll(pfd
+ rd
, 2 - rd
, -1);
848 if (/*r < 0 && errno == EINTR &&*/ winch_counter
)
849 return '\\'; /* anything which has no defined function */
853 safe_poll(pfd
+ rd
, 2 - rd
, -1);
857 /* We have kbd_fd in O_NONBLOCK mode, read inside read_key()
858 * would not block even if there is no input available */
859 rd
= read_key(kbd_fd
, &kbd_input_size
, kbd_input
);
861 if (errno
== EAGAIN
) {
862 /* No keyboard input available. Since poll() did return,
863 * we should have input on stdin */
865 buffer_fill_and_print();
868 /* EOF/error (ssh session got killed etc) */
875 /* Grab a character from input without requiring the return key. If the
876 * character is ASCII \033, get more characters and assign certain sequences
877 * special return codes. Note that this function works best with raw input. */
878 static int less_getch(int pos
)
887 /* Discard Ctrl-something chars */
888 if (i
>= 0 && i
< ' ' && i
!= 0x0d && i
!= 8)
893 static char* less_gets(int sz
)
897 char *result
= xzalloc(1);
901 less_gets_pos
= sz
+ i
;
914 if (c
< ' ') /* filters out KEYCODE_xxx too (<0) */
916 if (i
>= width
- sz
- 1)
917 continue; /* len limit */
920 result
= xrealloc(result
, i
+1);
924 static void examine_file(void)
928 print_statusline("Examine: ");
929 new_fname
= less_gets(sizeof("Examine: ") - 1);
936 if (access(new_fname
, R_OK
) != 0) {
937 print_statusline("Cannot read this file");
941 filename
= new_fname
;
942 /* files start by = argv. why we assume that argv is infinitely long??
943 files[num_files] = filename;
944 current_file = num_files + 1;
947 num_files
= current_file
= 1;
951 /* This function changes the file currently being paged. direction can be one of the following:
952 * -1: go back one file
953 * 0: go to the first file
954 * 1: go forward one file */
955 static void change_file(int direction
)
957 if (current_file
!= ((direction
> 0) ? num_files
: 1)) {
958 current_file
= direction
? current_file
+ direction
: 1;
960 filename
= xstrdup(files
[current_file
- 1]);
963 print_statusline(direction
> 0 ? "No next file" : "No previous file");
967 static void remove_current_file(void)
974 if (current_file
!= 1) {
976 for (i
= 3; i
<= num_files
; i
++)
977 files
[i
- 2] = files
[i
- 1];
981 for (i
= 2; i
<= num_files
; i
++)
982 files
[i
- 2] = files
[i
- 1];
988 static void colon_process(void)
992 /* Clear the current line and print a prompt */
993 print_statusline(" :");
995 keypress
= less_getch(2);
998 remove_current_file();
1003 #if ENABLE_FEATURE_LESS_FLAGS
1015 less_exit(EXIT_SUCCESS
);
1023 #if ENABLE_FEATURE_LESS_REGEXP
1024 static void normalize_match_pos(int match
)
1026 if (match
>= num_matches
)
1027 match
= num_matches
- 1;
1033 static void goto_match(int match
)
1039 /* Try to find next match if eof isn't reached yet */
1040 if (match
>= num_matches
&& eof_error
> 0) {
1041 wanted_match
= match
; /* "I want to read until I see N'th match" */
1045 normalize_match_pos(match
);
1046 buffer_line(match_lines
[match_pos
]);
1048 print_statusline("No matches found");
1052 static void fill_match_lines(unsigned pos
)
1056 /* Run the regex on each line of the current file */
1057 while (pos
<= max_fline
) {
1058 /* If this line matches */
1059 if (regexec(&pattern
, flines
[pos
], 0, NULL
, 0) == 0
1060 /* and we didn't match it last time */
1061 && !(num_matches
&& match_lines
[num_matches
-1] == pos
)
1063 match_lines
= xrealloc_vector(match_lines
, 4, num_matches
);
1064 match_lines
[num_matches
++] = pos
;
1070 static void regex_process(void)
1072 char *uncomp_regex
, *err
;
1074 /* Reset variables */
1079 if (pattern_valid
) {
1084 /* Get the uncompiled regular expression from the user */
1086 bb_putchar((option_mask32
& LESS_STATE_MATCH_BACKWARDS
) ? '?' : '/');
1087 uncomp_regex
= less_gets(1);
1088 if (!uncomp_regex
[0]) {
1094 /* Compile the regex and check for errors */
1095 err
= regcomp_or_errmsg(&pattern
, uncomp_regex
,
1096 (option_mask32
& FLAG_I
) ? REG_ICASE
: 0);
1099 print_statusline(err
);
1106 fill_match_lines(0);
1107 while (match_pos
< num_matches
) {
1108 if ((int)match_lines
[match_pos
] > cur_fline
)
1112 if (option_mask32
& LESS_STATE_MATCH_BACKWARDS
)
1115 /* It's possible that no matches are found yet.
1116 * goto_match() will read input looking for match,
1118 goto_match(match_pos
);
1122 static void number_process(int first_digit
)
1127 char num_input
[sizeof(int)*4]; /* more than enough */
1129 num_input
[0] = first_digit
;
1131 /* Clear the current line, print a prompt, and then print the digit */
1133 printf(":%c", first_digit
);
1135 /* Receive input until a letter is given */
1137 while (i
< sizeof(num_input
)-1) {
1138 keypress
= less_getch(i
+ 1);
1139 if ((unsigned)keypress
> 255 || !isdigit(num_input
[i
]))
1141 num_input
[i
] = keypress
;
1142 bb_putchar(keypress
);
1146 num_input
[i
] = '\0';
1147 num
= bb_strtou(num_input
, NULL
, 10);
1148 /* on format error, num == -1 */
1149 if (num
< 1 || num
> MAXLINES
) {
1154 /* We now know the number and the letter entered, so we process them */
1156 case KEYCODE_DOWN
: case 'z': case 'd': case 'e': case ' ': case '\015':
1159 case KEYCODE_UP
: case 'b': case 'w': case 'y': case 'u':
1162 case 'g': case '<': case 'G': case '>':
1163 cur_fline
= num
+ max_displayed_line
;
1165 buffer_line(num
- 1);
1168 num
= num
* (max_fline
/ 100); /* + max_fline / 2; */
1169 cur_fline
= num
+ max_displayed_line
;
1173 #if ENABLE_FEATURE_LESS_REGEXP
1175 goto_match(match_pos
+ num
);
1178 option_mask32
&= ~LESS_STATE_MATCH_BACKWARDS
;
1182 option_mask32
|= LESS_STATE_MATCH_BACKWARDS
;
1189 #if ENABLE_FEATURE_LESS_DASHCMD
1190 static void flag_change(void)
1196 keypress
= less_getch(1);
1200 option_mask32
^= FLAG_M
;
1203 option_mask32
^= FLAG_m
;
1206 option_mask32
^= FLAG_E
;
1209 option_mask32
^= FLAG_TILDE
;
1212 option_mask32
^= FLAG_S
;
1213 buffer_fill_and_print();
1215 #if ENABLE_FEATURE_LESS_LINENUMS
1217 option_mask32
^= FLAG_N
;
1219 buffer_fill_and_print();
1226 static void show_flag_status(void)
1233 keypress
= less_getch(1);
1237 flag_val
= option_mask32
& FLAG_M
;
1240 flag_val
= option_mask32
& FLAG_m
;
1243 flag_val
= option_mask32
& FLAG_TILDE
;
1246 flag_val
= option_mask32
& FLAG_N
;
1249 flag_val
= option_mask32
& FLAG_E
;
1257 printf(HIGHLIGHT
"The status of the flag is: %u"NORMAL
, flag_val
!= 0);
1261 #endif /* ENABLE_FEATURE_LESS_DASHCMD */
1263 static void save_input_to_file(void)
1265 const char *msg
= "";
1270 print_statusline("Log file: ");
1271 current_line
= less_gets(sizeof("Log file: ")-1);
1272 if (current_line
[0]) {
1273 fp
= fopen_for_write(current_line
);
1275 msg
= "Error opening log file";
1278 for (i
= 0; i
<= max_fline
; i
++)
1279 fprintf(fp
, "%s\n", flines
[i
]);
1284 print_statusline(msg
);
1288 #if ENABLE_FEATURE_LESS_MARKS
1289 static void add_mark(void)
1293 print_statusline("Mark: ");
1294 letter
= less_getch(sizeof("Mark: ") - 1);
1296 if (isalpha(letter
)) {
1297 /* If we exceed 15 marks, start overwriting previous ones */
1298 if (num_marks
== 14)
1301 mark_lines
[num_marks
][0] = letter
;
1302 mark_lines
[num_marks
][1] = cur_fline
;
1305 print_statusline("Invalid mark letter");
1309 static void goto_mark(void)
1314 print_statusline("Go to mark: ");
1315 letter
= less_getch(sizeof("Go to mark: ") - 1);
1318 if (isalpha(letter
)) {
1319 for (i
= 0; i
<= num_marks
; i
++)
1320 if (letter
== mark_lines
[i
][0]) {
1321 buffer_line(mark_lines
[i
][1]);
1324 if (num_marks
== 14 && letter
!= mark_lines
[14][0])
1325 print_statusline("Mark not set");
1327 print_statusline("Invalid mark letter");
1331 #if ENABLE_FEATURE_LESS_BRACKETS
1332 static char opp_bracket(char bracket
)
1335 case '{': case '[': /* '}' == '{' + 2. Same for '[' */
1337 case '(': /* ')' == '(' + 1 */
1349 static void match_right_bracket(char bracket
)
1353 if (strchr(flines
[cur_fline
], bracket
) == NULL
) {
1354 print_statusline("No bracket in top line");
1357 bracket
= opp_bracket(bracket
);
1358 for (i
= cur_fline
+ 1; i
< max_fline
; i
++) {
1359 if (strchr(flines
[i
], bracket
) != NULL
) {
1364 print_statusline("No matching bracket found");
1367 static void match_left_bracket(char bracket
)
1371 if (strchr(flines
[cur_fline
+ max_displayed_line
], bracket
) == NULL
) {
1372 print_statusline("No bracket in bottom line");
1376 bracket
= opp_bracket(bracket
);
1377 for (i
= cur_fline
+ max_displayed_line
; i
>= 0; i
--) {
1378 if (strchr(flines
[i
], bracket
) != NULL
) {
1383 print_statusline("No matching bracket found");
1385 #endif /* FEATURE_LESS_BRACKETS */
1387 static void keypress_process(int keypress
)
1390 case KEYCODE_DOWN
: case 'e': case 'j': case 0x0d:
1393 case KEYCODE_UP
: case 'y': case 'k':
1396 case KEYCODE_PAGEDOWN
: case ' ': case 'z': case 'f':
1397 buffer_down(max_displayed_line
+ 1);
1399 case KEYCODE_PAGEUP
: case 'w': case 'b':
1400 buffer_up(max_displayed_line
+ 1);
1403 buffer_down((max_displayed_line
+ 1) / 2);
1406 buffer_up((max_displayed_line
+ 1) / 2);
1408 case KEYCODE_HOME
: case 'g': case 'p': case '<': case '%':
1411 case KEYCODE_END
: case 'G': case '>':
1412 cur_fline
= MAXLINES
;
1414 buffer_line(cur_fline
);
1417 less_exit(EXIT_SUCCESS
);
1419 #if ENABLE_FEATURE_LESS_MARKS
1436 save_input_to_file();
1441 #if ENABLE_FEATURE_LESS_FLAGS
1446 #if ENABLE_FEATURE_LESS_REGEXP
1448 option_mask32
&= ~LESS_STATE_MATCH_BACKWARDS
;
1452 goto_match(match_pos
+ 1);
1455 goto_match(match_pos
- 1);
1458 option_mask32
|= LESS_STATE_MATCH_BACKWARDS
;
1462 #if ENABLE_FEATURE_LESS_DASHCMD
1473 #if ENABLE_FEATURE_LESS_BRACKETS
1474 case '{': case '(': case '[':
1475 match_right_bracket(keypress
);
1477 case '}': case ')': case ']':
1478 match_left_bracket(keypress
);
1486 if (isdigit(keypress
))
1487 number_process(keypress
);
1490 static void sig_catcher(int sig
)
1495 #if ENABLE_FEATURE_LESS_WINCH
1496 static void sigwinch_handler(int sig UNUSED_PARAM
)
1502 int less_main(int argc
, char **argv
) MAIN_EXTERNALLY_VISIBLE
;
1503 int less_main(int argc
, char **argv
)
1509 /* TODO: -x: do not interpret backspace, -xx: tab also */
1510 /* -xxx: newline also */
1511 /* -w N: assume width N (-xxx -w 32: hex viewer of sorts) */
1512 getopt32(argv
, "EMmN~I" USE_FEATURE_LESS_DASHCMD("S"));
1518 /* Another popular pager, most, detects when stdout
1519 * is not a tty and turns into cat. This makes sense. */
1520 if (!isatty(STDOUT_FILENO
))
1521 return bb_cat(argv
);
1524 if (isatty(STDIN_FILENO
)) {
1525 /* Just "less"? No args and no redirection? */
1526 bb_error_msg("missing filename");
1530 filename
= xstrdup(files
[0]);
1533 if (option_mask32
& FLAG_TILDE
)
1534 empty_line_marker
= "";
1536 kbd_fd
= open(CURRENT_TTY
, O_RDONLY
);
1538 return bb_cat(argv
);
1541 tcgetattr(kbd_fd
, &term_orig
);
1542 term_less
= term_orig
;
1543 term_less
.c_lflag
&= ~(ICANON
| ECHO
);
1544 term_less
.c_iflag
&= ~(IXON
| ICRNL
);
1545 /*term_less.c_oflag &= ~ONLCR;*/
1546 term_less
.c_cc
[VMIN
] = 1;
1547 term_less
.c_cc
[VTIME
] = 0;
1549 get_terminal_width_height(kbd_fd
, &width
, &max_displayed_line
);
1550 /* 20: two tabstops + 4 */
1551 if (width
< 20 || max_displayed_line
< 3)
1552 return bb_cat(argv
);
1553 max_displayed_line
-= 2;
1555 /* We want to restore term_orig on exit */
1556 bb_signals(BB_FATAL_SIGS
, sig_catcher
);
1557 #if ENABLE_FEATURE_LESS_WINCH
1558 signal(SIGWINCH
, sigwinch_handler
);
1561 buffer
= xmalloc((max_displayed_line
+1) * sizeof(char *));
1564 #if ENABLE_FEATURE_LESS_WINCH
1565 while (WINCH_COUNTER
) {
1568 get_terminal_width_height(kbd_fd
, &width
, &max_displayed_line
);
1569 /* 20: two tabstops + 4 */
1572 if (max_displayed_line
< 3)
1573 max_displayed_line
= 3;
1574 max_displayed_line
-= 2;
1576 buffer
= xmalloc((max_displayed_line
+1) * sizeof(char *));
1577 /* Avoid re-wrap and/or redraw if we already know
1578 * we need to do it again. These ops are expensive */
1584 buffer_fill_and_print();
1585 /* This took some time. Loop back and check,
1586 * were there another SIGWINCH? */
1589 keypress
= less_getch(-1); /* -1: do not position cursor */
1590 keypress_process(keypress
);
1595 Help text of less version 418 is below.
1596 If you are implementing something, keeping
1597 key and/or command line switch compatibility is a good idea:
1600 SUMMARY OF LESS COMMANDS
1602 Commands marked with * may be preceded by a number, N.
1603 Notes in parentheses indicate the behavior if N is given.
1604 h H Display this help.
1606 ---------------------------------------------------------------------------
1608 e ^E j ^N CR * Forward one line (or N lines).
1609 y ^Y k ^K ^P * Backward one line (or N lines).
1610 f ^F ^V SPACE * Forward one window (or N lines).
1611 b ^B ESC-v * Backward one window (or N lines).
1612 z * Forward one window (and set window to N).
1613 w * Backward one window (and set window to N).
1614 ESC-SPACE * Forward one window, but don't stop at end-of-file.
1615 d ^D * Forward one half-window (and set half-window to N).
1616 u ^U * Backward one half-window (and set half-window to N).
1617 ESC-) RightArrow * Left one half screen width (or N positions).
1618 ESC-( LeftArrow * Right one half screen width (or N positions).
1619 F Forward forever; like "tail -f".
1620 r ^R ^L Repaint screen.
1621 R Repaint screen, discarding buffered input.
1622 ---------------------------------------------------
1623 Default "window" is the screen height.
1624 Default "half-window" is half of the screen height.
1625 ---------------------------------------------------------------------------
1627 /pattern * Search forward for (N-th) matching line.
1628 ?pattern * Search backward for (N-th) matching line.
1629 n * Repeat previous search (for N-th occurrence).
1630 N * Repeat previous search in reverse direction.
1631 ESC-n * Repeat previous search, spanning files.
1632 ESC-N * Repeat previous search, reverse dir. & spanning files.
1633 ESC-u Undo (toggle) search highlighting.
1634 ---------------------------------------------------
1635 Search patterns may be modified by one or more of:
1636 ^N or ! Search for NON-matching lines.
1637 ^E or * Search multiple files (pass thru END OF FILE).
1638 ^F or @ Start search at FIRST file (for /) or last file (for ?).
1639 ^K Highlight matches, but don't move (KEEP position).
1640 ^R Don't use REGULAR EXPRESSIONS.
1641 ---------------------------------------------------------------------------
1643 g < ESC-< * Go to first line in file (or line N).
1644 G > ESC-> * Go to last line in file (or line N).
1645 p % * Go to beginning of file (or N percent into file).
1646 t * Go to the (N-th) next tag.
1647 T * Go to the (N-th) previous tag.
1648 { ( [ * Find close bracket } ) ].
1649 } ) ] * Find open bracket { ( [.
1650 ESC-^F <c1> <c2> * Find close bracket <c2>.
1651 ESC-^B <c1> <c2> * Find open bracket <c1>
1652 ---------------------------------------------------
1653 Each "find close bracket" command goes forward to the close bracket
1654 matching the (N-th) open bracket in the top line.
1655 Each "find open bracket" command goes backward to the open bracket
1656 matching the (N-th) close bracket in the bottom line.
1657 m<letter> Mark the current position with <letter>.
1658 '<letter> Go to a previously marked position.
1659 '' Go to the previous position.
1661 ---------------------------------------------------
1662 A mark is any upper-case or lower-case letter.
1663 Certain marks are predefined:
1664 ^ means beginning of the file
1665 $ means end of the file
1666 ---------------------------------------------------------------------------
1668 :e [file] Examine a new file.
1670 :n * Examine the (N-th) next file from the command line.
1671 :p * Examine the (N-th) previous file from the command line.
1672 :x * Examine the first (or N-th) file from the command line.
1673 :d Delete the current file from the command line list.
1674 = ^G :f Print current file name.
1675 ---------------------------------------------------------------------------
1676 MISCELLANEOUS COMMANDS
1677 -<flag> Toggle a command line option [see OPTIONS below].
1678 --<name> Toggle a command line option, by name.
1679 _<flag> Display the setting of a command line option.
1680 __<name> Display the setting of an option, by name.
1681 +cmd Execute the less cmd each time a new file is examined.
1682 !command Execute the shell command with $SHELL.
1683 |Xcommand Pipe file between current pos & mark X to shell command.
1684 v Edit the current file with $VISUAL or $EDITOR.
1685 V Print version number of "less".
1686 ---------------------------------------------------------------------------
1688 Most options may be changed either on the command line,
1689 or from within less by using the - or -- command.
1690 Options may be given in one of two forms: either a single
1691 character preceded by a -, or a name preceeded by --.
1693 Display help (from command line).
1694 -a ........ --search-skip-screen
1695 Forward search skips current screen.
1696 -b [N] .... --buffers=[N]
1698 -B ........ --auto-buffers
1699 Don't automatically allocate buffers for pipes.
1700 -c ........ --clear-screen
1701 Repaint by clearing rather than scrolling.
1704 -D [xn.n] . --color=xn.n
1705 Set screen colors. (MS-DOS only)
1706 -e -E .... --quit-at-eof --QUIT-AT-EOF
1707 Quit at end of file.
1709 Force open non-regular files.
1710 -F ........ --quit-if-one-screen
1711 Quit if entire file fits on first screen.
1712 -g ........ --hilite-search
1713 Highlight only last match for searches.
1714 -G ........ --HILITE-SEARCH
1715 Don't highlight any matches for searches.
1716 -h [N] .... --max-back-scroll=[N]
1717 Backward scroll limit.
1718 -i ........ --ignore-case
1719 Ignore case in searches that do not contain uppercase.
1720 -I ........ --IGNORE-CASE
1721 Ignore case in all searches.
1722 -j [N] .... --jump-target=[N]
1723 Screen position of target lines.
1724 -J ........ --status-column
1725 Display a status column at left edge of screen.
1726 -k [file] . --lesskey-file=[file]
1728 -L ........ --no-lessopen
1729 Ignore the LESSOPEN environment variable.
1730 -m -M .... --long-prompt --LONG-PROMPT
1732 -n -N .... --line-numbers --LINE-NUMBERS
1733 Don't use line numbers.
1734 -o [file] . --log-file=[file]
1735 Copy to log file (standard input only).
1736 -O [file] . --LOG-FILE=[file]
1737 Copy to log file (unconditionally overwrite).
1738 -p [pattern] --pattern=[pattern]
1739 Start at pattern (from command line).
1740 -P [prompt] --prompt=[prompt]
1742 -q -Q .... --quiet --QUIET --silent --SILENT
1743 Quiet the terminal bell.
1744 -r -R .... --raw-control-chars --RAW-CONTROL-CHARS
1745 Output "raw" control characters.
1746 -s ........ --squeeze-blank-lines
1747 Squeeze multiple blank lines.
1748 -S ........ --chop-long-lines
1750 -t [tag] .. --tag=[tag]
1752 -T [tagsfile] --tag-file=[tagsfile]
1753 Use an alternate tags file.
1754 -u -U .... --underline-special --UNDERLINE-SPECIAL
1755 Change handling of backspaces.
1756 -V ........ --version
1757 Display the version number of "less".
1758 -w ........ --hilite-unread
1759 Highlight first new line after forward-screen.
1760 -W ........ --HILITE-UNREAD
1761 Highlight first new line after any forward movement.
1762 -x [N[,...]] --tabs=[N[,...]]
1764 -X ........ --no-init
1765 Don't use termcap init/deinit strings.
1767 Don't use termcap keypad init/deinit strings.
1768 -y [N] .... --max-forw-scroll=[N]
1769 Forward scroll limit.
1770 -z [N] .... --window=[N]
1772 -" [c[c]] . --quotes=[c[c]]
1773 Set shell quote characters.
1775 Don't display tildes after end of file.
1776 -# [N] .... --shift=[N]
1777 Horizontal scroll amount (0 = one half screen width)
1779 ---------------------------------------------------------------------------
1781 These keys can be used to edit text being entered
1782 on the "command line" at the bottom of the screen.
1783 RightArrow ESC-l Move cursor right one character.
1784 LeftArrow ESC-h Move cursor left one character.
1785 CNTL-RightArrow ESC-RightArrow ESC-w Move cursor right one word.
1786 CNTL-LeftArrow ESC-LeftArrow ESC-b Move cursor left one word.
1787 HOME ESC-0 Move cursor to start of line.
1788 END ESC-$ Move cursor to end of line.
1789 BACKSPACE Delete char to left of cursor.
1790 DELETE ESC-x Delete char under cursor.
1791 CNTL-BACKSPACE ESC-BACKSPACE Delete word to left of cursor.
1792 CNTL-DELETE ESC-DELETE ESC-X Delete word under cursor.
1793 CNTL-U ESC (MS-DOS only) Delete entire line.
1794 UpArrow ESC-k Retrieve previous command line.
1795 DownArrow ESC-j Retrieve next command line.
1796 TAB Complete filename & cycle.
1797 SHIFT-TAB ESC-TAB Complete filename & reverse cycle.
1798 CNTL-L Complete filename, list all.