1303 files changed, 32187 insertions, 57138 deletions
diff --git a/miscutils/less.c b/miscutils/less.c index 3f4d50f..e90691b 100644 --- a/miscutils/less.c +++ b/miscutils/less.c @@ -48,6 +48,14 @@ //config: help //config: The -M/-m flag enables a more sophisticated status line. //config: +//config:config FEATURE_LESS_TRUNCATE +//config: bool "Enable -S" +//config: default y +//config: depends on LESS +//config: help +//config: The -S flag causes long lines to be truncated rather than +//config: wrapped. +//config: //config:config FEATURE_LESS_MARKS //config: bool "Enable marks" //config: default y @@ -97,22 +105,33 @@ //config: help //config: Enables "-N" command. +//applet:IF_LESS(APPLET(less, BB_DIR_USR_BIN, BB_SUID_DROP)) + +//kbuild:lib-$(CONFIG_LESS) += less.o + //usage:#define less_trivial_usage -//usage: "[-E" IF_FEATURE_LESS_FLAGS("Mm") "Nh~I?] [FILE]..." +//usage: "[-E" IF_FEATURE_LESS_REGEXP("I")IF_FEATURE_LESS_FLAGS("Mm") +//usage: "N" IF_FEATURE_LESS_TRUNCATE("S") "h~] [FILE]..." //usage:#define less_full_usage "\n\n" //usage: "View FILE (or stdin) one screenful at a time\n" //usage: "\n -E Quit once the end of a file is reached" +//usage: IF_FEATURE_LESS_REGEXP( +//usage: "\n -I Ignore case in all searches" +//usage: ) //usage: IF_FEATURE_LESS_FLAGS( //usage: "\n -M,-m Display status line with line numbers" //usage: "\n and percentage through the file" //usage: ) //usage: "\n -N Prefix line number to each line" -//usage: "\n -I Ignore case in all searches" +//usage: IF_FEATURE_LESS_TRUNCATE( +//usage: "\n -S Truncate long lines" +//usage: ) //usage: "\n -~ Suppress ~s displayed past EOF" #include <sched.h> /* sched_yield() */ #include "libbb.h" +#include "common_bufsiz.h" #if ENABLE_FEATURE_LESS_REGEXP #include "xregex.h" #endif @@ -142,7 +161,7 @@ enum { FLAG_N = 1 << 3, FLAG_TILDE = 1 << 4, FLAG_I = 1 << 5, - FLAG_S = (1 << 6) * ENABLE_FEATURE_LESS_DASHCMD, + FLAG_S = (1 << 6) * ENABLE_FEATURE_LESS_TRUNCATE, /* hijack command line options variable for internal state vars */ LESS_STATE_MATCH_BACKWARDS = 1 << 15, }; @@ -154,6 +173,7 @@ enum { pattern_valid = 0 }; struct globals { int cur_fline; /* signed */ int kbd_fd; /* fd to get input from */ + int kbd_fd_orig_flags; int less_gets_pos; /* last position in last line, taking into account tabs */ size_t last_line_pos; @@ -174,6 +194,12 @@ struct globals { unsigned current_file; char *filename; char **files; +#if ENABLE_FEATURE_LESS_FLAGS + int num_lines; /* a flag if < 0, line count if >= 0 */ +# define REOPEN_AND_COUNT (-1) +# define REOPEN_STDIN (-2) +# define NOT_REGULAR_FILE (-3) +#endif #if ENABLE_FEATURE_LESS_MARKS unsigned num_marks; unsigned mark_lines[15][2]; @@ -215,6 +241,7 @@ struct globals { #define current_file (G.current_file ) #define filename (G.filename ) #define files (G.files ) +#define num_lines (G.num_lines ) #define num_marks (G.num_marks ) #define mark_lines (G.mark_lines ) #if ENABLE_FEATURE_LESS_REGEXP @@ -282,6 +309,8 @@ static void print_statusline(const char *str) static void less_exit(int code) { set_tty_cooked(); + if (!(G.kbd_fd_orig_flags & O_NONBLOCK)) + ndelay_off(kbd_fd); clear_line(); if (code < 0) kill_myself_with_sig(- code); /* does not return */ @@ -317,8 +346,10 @@ static void re_wrap(void) *d = *s; if (*d != '\0') { new_line_pos++; - if (*d == '\t') /* tab */ + if (*d == '\t') { /* tab */ new_line_pos += 7; + new_line_pos &= (~7); + } s++; d++; if (new_line_pos >= w) { @@ -335,7 +366,7 @@ static void re_wrap(void) dst_idx++; if (new_line_pos < w) { /* if we came here thru "goto next_new" */ - if (src_idx > (int) max_fline) + if (src_idx > max_fline) break; lineno = LINENO(s); } @@ -351,7 +382,7 @@ static void re_wrap(void) new_cur_fline = dst_idx; src_idx++; /* no more lines? finish last new line (and exit the loop) */ - if (src_idx > (int) max_fline) + if (src_idx > max_fline) goto next_new; s = old_flines[src_idx]; if (lineno != LINENO(s)) { @@ -380,6 +411,14 @@ static void fill_match_lines(unsigned pos); #define fill_match_lines(pos) ((void)0) #endif +static int at_end(void) +{ + return (option_mask32 & FLAG_S) + ? !(cur_fline <= max_fline && + max_lineno > LINENO(flines[cur_fline]) + max_displayed_line) + : !(max_fline > cur_fline + max_displayed_line); +} + /* Devilishly complex routine. * * Has to deal with EOF and EPIPE on input, @@ -402,33 +441,39 @@ static void fill_match_lines(unsigned pos); * last_line_pos - screen line position of next char to be read * (takes into account tabs and backspaces) * eof_error - < 0 error, == 0 EOF, > 0 not EOF/error + * + * "git log -p | less -m" on the kernel git tree is a good test for EAGAINs, + * "/search on very long input" and "reaching max line count" corner cases. */ static void read_lines(void) { -#define readbuf bb_common_bufsiz1 char *current_line, *p; int w = width; char last_terminated = terminated; + time_t last_time = 0; + int retry_EAGAIN = 2; #if ENABLE_FEATURE_LESS_REGEXP unsigned old_max_fline = max_fline; - time_t last_time = 0; - unsigned seconds_p1 = 3; /* seconds_to_loop + 1 */ #endif +#define readbuf bb_common_bufsiz1 + setup_common_bufsiz(); + + /* (careful: max_fline can be -1) */ + if (max_fline + 1 > MAXLINES) + return; + if (option_mask32 & FLAG_N) w -= 8; - IF_FEATURE_LESS_REGEXP(again0:) - - p = current_line = ((char*)xmalloc(w + 4)) + 4; - max_fline += last_terminated; + p = current_line = ((char*)xmalloc(w + 5)) + 4; if (!last_terminated) { const char *cp = flines[max_fline]; - strcpy(p, cp); - p += strlen(current_line); - free(MEMPTR(flines[max_fline])); + p = stpcpy(p, cp); + free(MEMPTR(cp)); /* last_line_pos is still valid from previous read_lines() */ } else { + max_fline++; last_line_pos = 0; } @@ -439,13 +484,29 @@ static void read_lines(void) char c; /* if no unprocessed chars left, eat more */ if (readpos >= readeof) { - ndelay_on(0); - eof_error = safe_read(STDIN_FILENO, readbuf, sizeof(readbuf)); - ndelay_off(0); + int flags = ndelay_on(0); + + while (1) { + time_t t; + + errno = 0; + eof_error = safe_read(STDIN_FILENO, readbuf, COMMON_BUFSIZE); + if (errno != EAGAIN) + break; + t = time(NULL); + if (t != last_time) { + last_time = t; + if (--retry_EAGAIN < 0) + break; + } + sched_yield(); + } + fcntl(0, F_SETFL, flags); /* ndelay_off(0) */ readpos = 0; readeof = eof_error; if (eof_error <= 0) goto reached_eof; + retry_EAGAIN = 1; } c = readbuf[readpos]; /* backspace? [needed for manpages] */ @@ -464,7 +525,7 @@ static void read_lines(void) new_last_line_pos += 7; new_last_line_pos &= (~7); } - if ((int)new_last_line_pos >= w) + if ((int)new_last_line_pos > w) break; last_line_pos = new_last_line_pos; } @@ -480,6 +541,11 @@ static void read_lines(void) *p++ = c; *p = '\0'; } /* end of "read chars until we have a line" loop */ +#if 0 +//BUG: also triggers on this: +// { printf "\nfoo\n"; sleep 1; printf "\nbar\n"; } | less +// (resulting in lost empty line between "foo" and "bar" lines) +// the "terminated" logic needs fixing (or explaining) /* Corner case: linewrap with only "" wrapping to next line */ /* Looks ugly on screen, so we do not store this empty line */ if (!last_terminated && !current_line[0]) { @@ -487,6 +553,7 @@ static void read_lines(void) max_lineno++; continue; } +#endif reached_eof: last_terminated = terminated; flines = xrealloc_vector(flines, 8, max_fline); @@ -500,11 +567,7 @@ static void read_lines(void) eof_error = 0; /* Pretend we saw EOF */ break; } - if (!(option_mask32 & FLAG_S) - ? (max_fline > cur_fline + max_displayed_line) - : (max_fline >= (unsigned) cur_fline - && max_lineno > LINENO(flines[cur_fline]) + max_displayed_line) - ) { + if (!at_end()) { #if !ENABLE_FEATURE_LESS_REGEXP break; #else @@ -517,38 +580,26 @@ static void read_lines(void) #endif } if (eof_error <= 0) { - if (eof_error < 0) { - if (errno == EAGAIN) { - /* not yet eof or error, reset flag (or else - * we will hog CPU - select() will return - * immediately */ - eof_error = 1; - } else { - print_statusline(bb_msg_read_error); - } - } -#if !ENABLE_FEATURE_LESS_REGEXP break; -#else - if (wanted_match < num_matches) { - break; - } else { /* goto_match called us */ - time_t t = time(NULL); - if (t != last_time) { - last_time = t; - if (--seconds_p1 == 0) - break; - } - sched_yield(); - goto again0; /* go loop again (max 2 seconds) */ - } -#endif } max_fline++; - current_line = ((char*)xmalloc(w + 4)) + 4; + current_line = ((char*)xmalloc(w + 5)) + 4; p = current_line; last_line_pos = 0; } /* end of "read lines until we reach cur_fline" loop */ + + if (eof_error < 0) { + if (errno == EAGAIN) { + eof_error = 1; + } else { + print_statusline(bb_msg_read_error); + } + } +#if ENABLE_FEATURE_LESS_FLAGS + else if (eof_error == 0) + num_lines = max_lineno; +#endif + fill_match_lines(old_max_fline); #if ENABLE_FEATURE_LESS_REGEXP /* prevent us from being stuck in search for a match */ @@ -558,18 +609,61 @@ static void read_lines(void) } #if ENABLE_FEATURE_LESS_FLAGS -/* Interestingly, writing calc_percent as a function saves around 32 bytes - * on my build. */ -static int calc_percent(void) +static int safe_lineno(int fline) +{ + if (fline >= max_fline) + fline = max_fline - 1; + + /* also catches empty file (max_fline == 0) */ + if (fline < 0) + return 0; + + return LINENO(flines[fline]) + 1; +} + +/* count number of lines in file */ +static void update_num_lines(void) { - unsigned p = (100 * (cur_fline+max_displayed_line+1) + max_fline/2) / (max_fline+1); - return p <= 100 ? p : 100; + int count, fd; + struct stat stbuf; + ssize_t len, i; + char buf[4096]; + + /* only do this for regular files */ + if (num_lines == REOPEN_AND_COUNT || num_lines == REOPEN_STDIN) { + count = 0; + fd = open("/proc/self/fd/0", O_RDONLY); + if (fd < 0 && num_lines == REOPEN_AND_COUNT) { + /* "filename" is valid only if REOPEN_AND_COUNT */ + fd = open(filename, O_RDONLY); + } + if (fd < 0) { + /* somebody stole my file! */ + num_lines = NOT_REGULAR_FILE; + return; + } + if (fstat(fd, &stbuf) != 0 || !S_ISREG(stbuf.st_mode)) { + num_lines = NOT_REGULAR_FILE; + goto do_close; + } + while ((len = safe_read(fd, buf, sizeof(buf))) > 0) { + for (i = 0; i < len; ++i) { + if (buf[i] == '\n' && ++count == MAXLINES) + goto done; + } + } + done: + num_lines = count; + do_close: + close(fd); + } } /* Print a status line if -M was specified */ static void m_status_print(void) { - int percentage; + int first, last; + unsigned percent; if (less_gets_pos >= 0) /* don't touch statusline while input is done! */ return; @@ -578,17 +672,26 @@ static void m_status_print(void) printf(HIGHLIGHT"%s", filename); if (num_files > 1) printf(" (file %i of %i)", current_file, num_files); - printf(" lines %i-%i/%i ", - cur_fline + 1, cur_fline + max_displayed_line + 1, - max_fline + 1); - if (cur_fline >= (int)(max_fline - max_displayed_line)) { - printf("(END)"NORMAL); + + first = safe_lineno(cur_fline); + last = (option_mask32 & FLAG_S) + ? MIN(first + max_displayed_line, max_lineno) + : safe_lineno(cur_fline + max_displayed_line); + printf(" lines %i-%i", first, last); + + update_num_lines(); + if (num_lines >= 0) + printf("/%i", num_lines); + + if (at_end()) { + printf(" (END)"); if (num_files > 1 && current_file != num_files) - printf(HIGHLIGHT" - next: %s"NORMAL, files[current_file]); - return; + printf(" - next: %s", files[current_file]); + } else if (num_lines > 0) { + percent = (100 * last + num_lines/2) / num_lines; + printf(" %i%%", percent <= 100 ? percent : 100); } - percentage = calc_percent(); - printf("%i%%"NORMAL, percentage); + printf(NORMAL); } #endif @@ -610,7 +713,7 @@ static void status_print(void) #endif clear_line(); - if (cur_fline && cur_fline < (int)(max_fline - max_displayed_line)) { + if (cur_fline && !at_end()) { bb_putchar(':'); return; } @@ -625,23 +728,6 @@ static void status_print(void) print_hilite(p); } -static void cap_cur_fline(int nlines) -{ - int diff; - if (cur_fline < 0) - cur_fline = 0; - if (cur_fline + max_displayed_line > max_fline + TILDES) { - cur_fline -= nlines; - if (cur_fline < 0) - cur_fline = 0; - diff = max_fline - (cur_fline + max_displayed_line) + TILDES; - /* As the number of lines requested was too large, we just move - * to the end of the file */ - if (diff > 0) - cur_fline += diff; - } -} - static const char controls[] ALIGN1 = /* NUL: never encountered; TAB: not converted */ /**/"\x01\x02\x03\x04\x05\x06\x07\x08" "\x0a\x0b\x0c\x0d\x0e\x0f" @@ -653,27 +739,21 @@ static const char ctrlconv[] ALIGN1 = "\x40\x41\x42\x43\x44\x45\x46\x47\x48\x49\x40\x4b\x4c\x4d\x4e\x4f" "\x50\x51\x52\x53\x54\x55\x56\x57\x58\x59\x5a\x5b\x5c\x5d\x5e\x5f"; -static void lineno_str(char *nbuf9, const char *line) +static void print_lineno(const char *line) { - nbuf9[0] = '\0'; - if (option_mask32 & FLAG_N) { - const char *fmt; - unsigned n; - - if (line == empty_line_marker) { - memset(nbuf9, ' ', 8); - nbuf9[8] = '\0'; - return; - } + const char *fmt = " "; + unsigned n = n; /* for compiler */ + + if (line != empty_line_marker) { /* Width of 7 preserves tab spacing in the text */ fmt = "%7u "; n = LINENO(line) + 1; - if (n > 9999999) { + if (n > 9999999 && MAXLINES > 9999999) { n %= 10000000; fmt = "%07u "; } - sprintf(nbuf9, fmt, n); } + printf(fmt, n); } @@ -685,8 +765,7 @@ static void print_found(const char *line) char *growline; regmatch_t match_structs; - char buf[width]; - char nbuf9[9]; + char buf[width+1]; const char *str = line; char *p = buf; size_t n; @@ -736,12 +815,7 @@ static void print_found(const char *line) match_status = 1; } - lineno_str(nbuf9, line); - if (!growline) { - printf(CLEAR_2_EOL"%s%s\n", nbuf9, str); - return; - } - printf(CLEAR_2_EOL"%s%s%s\n", nbuf9, growline, str); + printf("%s%s\n", growline ? growline : "", str); free(growline); } #else @@ -750,14 +824,10 @@ void print_found(const char *line); static void print_ascii(const char *str) { - char buf[width]; - char nbuf9[9]; + char buf[width+1]; char *p; size_t n; - lineno_str(nbuf9, str); - printf(CLEAR_2_EOL"%s", nbuf9); - while (*str) { n = strcspn(str, controls); if (n) { @@ -790,18 +860,28 @@ static void buffer_print(void) unsigned i; move_cursor(0, 0); - for (i = 0; i <= max_displayed_line; i++) + for (i = 0; i <= max_displayed_line; i++) { + printf(CLEAR_2_EOL); + if (option_mask32 & FLAG_N) + print_lineno(buffer[i]); if (pattern_valid) print_found(buffer[i]); else print_ascii(buffer[i]); + } + if ((option_mask32 & FLAG_E) + && eof_error <= 0 + && (max_fline - cur_fline) <= max_displayed_line + ) { + less_exit(EXIT_SUCCESS); + } status_print(); } static void buffer_fill_and_print(void) { unsigned i; -#if ENABLE_FEATURE_LESS_DASHCMD +#if ENABLE_FEATURE_LESS_TRUNCATE int fpos = cur_fline; if (option_mask32 & FLAG_S) { @@ -833,45 +913,112 @@ static void buffer_fill_and_print(void) buffer_print(); } +/* move cur_fline to a given line number, reading lines if necessary */ +static void goto_lineno(int target) +{ + if (target <= 0 ) { + cur_fline = 0; + } + else if (target > LINENO(flines[cur_fline])) { + retry: + while (LINENO(flines[cur_fline]) != target && cur_fline < max_fline) + ++cur_fline; + /* target not reached but more input is available */ + if (LINENO(flines[cur_fline]) != target && eof_error > 0) { + read_lines(); + goto retry; + } + } + else { + /* search backwards through already-read lines */ + while (LINENO(flines[cur_fline]) != target && cur_fline > 0) + --cur_fline; + } +} + +static void cap_cur_fline(void) +{ + if ((option_mask32 & FLAG_S)) { + if (cur_fline > max_fline) + cur_fline = max_fline; + if (LINENO(flines[cur_fline]) + max_displayed_line > max_lineno + TILDES) { + goto_lineno(max_lineno - max_displayed_line + TILDES); + read_lines(); + } + } + else { + if (cur_fline + max_displayed_line > max_fline + TILDES) + cur_fline = max_fline - max_displayed_line + TILDES; + if (cur_fline < 0) + cur_fline = 0; + } +} + /* Move the buffer up and down in the file in order to scroll */ static void buffer_down(int nlines) { - cur_fline += nlines; + if ((option_mask32 & FLAG_S)) + goto_lineno(LINENO(flines[cur_fline]) + nlines); + else + cur_fline += nlines; read_lines(); - cap_cur_fline(nlines); + cap_cur_fline(); buffer_fill_and_print(); } static void buffer_up(int nlines) { - cur_fline -= nlines; - if (cur_fline < 0) cur_fline = 0; + if ((option_mask32 & FLAG_S)) { + goto_lineno(LINENO(flines[cur_fline]) - nlines); + } + else { + cur_fline -= nlines; + if (cur_fline < 0) + cur_fline = 0; + } read_lines(); buffer_fill_and_print(); } -static void buffer_line(int linenum) +/* display a given line where the argument can be either an index into + * the flines array or a line number */ +static void buffer_to_line(int linenum, int is_lineno) { - if (linenum < 0) - linenum = 0; - cur_fline = linenum; + if (linenum <= 0) + cur_fline = 0; + else if (is_lineno) + goto_lineno(linenum); + else + cur_fline = linenum; read_lines(); - if (linenum + max_displayed_line > max_fline) - linenum = max_fline - max_displayed_line + TILDES; - if (linenum < 0) - linenum = 0; - cur_fline = linenum; + cap_cur_fline(); buffer_fill_and_print(); } +static void buffer_line(int linenum) +{ + buffer_to_line(linenum, FALSE); +} + +static void buffer_lineno(int lineno) +{ + buffer_to_line(lineno, TRUE); +} + static void open_file_and_read_lines(void) { if (filename) { xmove_fd(xopen(filename, O_RDONLY), STDIN_FILENO); +#if ENABLE_FEATURE_LESS_FLAGS + num_lines = REOPEN_AND_COUNT; +#endif } else { /* "less" with no arguments in argv[] */ /* For status line only */ filename = xstrdup(bb_msg_standard_input); +#if ENABLE_FEATURE_LESS_FLAGS + num_lines = REOPEN_STDIN; +#endif } readpos = 0; readeof = 0; @@ -923,12 +1070,7 @@ static int64_t getch_nowait(void) */ rd = 1; /* Are we interested in stdin? */ -//TODO: reuse code for determining this - if (!(option_mask32 & FLAG_S) - ? !(max_fline > cur_fline + max_displayed_line) - : !(max_fline >= (unsigned) cur_fline - && max_lineno > LINENO(flines[cur_fline]) + max_displayed_line) - ) { + if (at_end()) { if (eof_error > 0) /* did NOT reach eof yet */ rd = 0; /* yes, we are interested in stdin */ } @@ -1239,7 +1381,7 @@ static void number_process(int first_digit) i = 1; while (i < sizeof(num_input)-1) { keypress = less_getch(i + 1); - if ((unsigned)keypress > 255 || !isdigit(num_input[i])) + if ((unsigned)keypress > 255 || !isdigit(keypress)) break; num_input[i] = keypress; bb_putchar(keypress); @@ -1263,15 +1405,16 @@ static void number_process(int first_digit) buffer_up(num); break; case 'g': case '<': case 'G': case '>': - cur_fline = num + max_displayed_line; - read_lines(); - buffer_line(num - 1); + buffer_lineno(num - 1); break; case 'p': case '%': - num = num * (max_fline / 100); /* + max_fline / 2; */ - cur_fline = num + max_displayed_line; - read_lines(); - buffer_line(num); +#if ENABLE_FEATURE_LESS_FLAGS + update_num_lines(); + num = num * (num_lines > 0 ? num_lines : max_lineno) / 100; +#else + num = num * max_lineno / 100; +#endif + buffer_lineno(num); break; #if ENABLE_FEATURE_LESS_REGEXP case 'n': @@ -1311,10 +1454,12 @@ static void flag_change(void) case '~': option_mask32 ^= FLAG_TILDE; break; +#if ENABLE_FEATURE_LESS_TRUNCATE case 'S': option_mask32 ^= FLAG_S; buffer_fill_and_print(); break; +#endif #if ENABLE_FEATURE_LESS_LINENUMS case 'N': option_mask32 ^= FLAG_N; @@ -1412,7 +1557,7 @@ static void add_mark(void) static void goto_mark(void) { int letter; - unsigned i; + int i; print_statusline("Go to mark: "); letter = less_getch(sizeof("Go to mark: ") - 1); @@ -1420,11 +1565,11 @@ static void goto_mark(void) if (isalpha(letter)) { for (i = 0; i <= num_marks; i++) - if ((unsigned) letter == mark_lines[i][0]) { + if (letter == mark_lines[i][0]) { buffer_line(mark_lines[i][1]); break; } - if (num_marks == 14 && (unsigned) letter != mark_lines[14][0]) + if (num_marks == 14 && letter != mark_lines[14][0]) print_statusline("Mark not set"); } else print_statusline("Invalid mark letter"); @@ -1451,16 +1596,23 @@ static char opp_bracket(char bracket) static void match_right_bracket(char bracket) { - unsigned i; + unsigned i = cur_fline; - if (strchr(flines[cur_fline], bracket) == NULL) { + if (i >= max_fline + || strchr(flines[i], bracket) == NULL + ) { print_statusline("No bracket in top line"); return; } + bracket = opp_bracket(bracket); - for (i = cur_fline + 1; i < max_fline; i++) { + for (; i < max_fline; i++) { if (strchr(flines[i], bracket) != NULL) { - buffer_line(i); + /* + * Line with matched right bracket becomes + * last visible line + */ + buffer_line(i - max_displayed_line); return; } } @@ -1469,16 +1621,22 @@ static void match_right_bracket(char bracket) static void match_left_bracket(char bracket) { - int i; + int i = cur_fline + max_displayed_line; - if (strchr(flines[cur_fline + max_displayed_line], bracket) == NULL) { + if (i >= max_fline + || strchr(flines[i], bracket) == NULL + ) { print_statusline("No bracket in bottom line"); return; } bracket = opp_bracket(bracket); - for (i = cur_fline + max_displayed_line; i >= 0; i--) { + for (; i >= 0; i--) { if (strchr(flines[i], bracket) != NULL) { + /* + * Line with matched left bracket becomes + * first visible line + */ buffer_line(i); return; } @@ -1613,10 +1771,13 @@ int less_main(int argc, char **argv) INIT_G(); - /* TODO: -x: do not interpret backspace, -xx: tab also */ - /* -xxx: newline also */ - /* -w N: assume width N (-xxx -w 32: hex viewer of sorts) */ - getopt32(argv, "EMmN~I" IF_FEATURE_LESS_DASHCMD("S")); + /* TODO: -x: do not interpret backspace, -xx: tab also + * -xxx: newline also + * -w N: assume width N (-xxx -w 32: hex viewer of sorts) + * -s: condense many empty lines to one + * (used by some setups for manpage display) + */ + getopt32(argv, "EMmN~I" IF_FEATURE_LESS_TRUNCATE("S") /*ignored:*/"s"); argc -= optind; argv += optind; num_files = argc; @@ -1643,9 +1804,10 @@ int less_main(int argc, char **argv) /* Some versions of less can survive w/o controlling tty, * try to do the same. This also allows to specify an alternative * tty via "less 1<>TTY". - * We don't try to use STDOUT_FILENO directly, + * + * We prefer not to use STDOUT_FILENO directly, * since we want to set this fd to non-blocking mode, - * and not bother with restoring it on exit. + * and not interfere with other processes which share stdout with us. */ tty_name = xmalloc_ttyname(STDOUT_FILENO); if (tty_name) { @@ -1657,10 +1819,12 @@ int less_main(int argc, char **argv) /* Try controlling tty */ try_ctty: tty_fd = open(CURRENT_TTY, O_RDONLY); - if (tty_fd < 0) - return bb_cat(argv); + if (tty_fd < 0) { + /* If all else fails, less 481 uses stdout. Mimic that */ + tty_fd = STDOUT_FILENO; + } } - ndelay_on(tty_fd); + G.kbd_fd_orig_flags = ndelay_on(tty_fd); kbd_fd = tty_fd; /* save in a global */ tcgetattr(kbd_fd, &term_orig); @@ -1826,7 +1990,7 @@ key and/or command line switch compatibility is a good idea: Most options may be changed either on the command line, or from within less by using the - or -- command. Options may be given in one of two forms: either a single - character preceded by a -, or a name preceeded by --. + character preceded by a -, or a name preceded by --. -? ........ --help Display help (from command line). -a ........ --search-skip-screen |