/* vi: set sw=4 ts=4: */ /* * Mini less implementation for busybox * * Copyright (C) 2005 by Rob Sullivan * * Licensed under the GPL v2 or later, see the file LICENSE in this tarball. */ /* * TODO: * - Add more regular expression support - search modifiers, certain matches, etc. * - Add more complex bracket searching - currently, nested brackets are * not considered. * - Add support for "F" as an input. This causes less to act in * a similar way to tail -f. * - Allow horizontal scrolling. * * Notes: * - the inp file pointer is used so that keyboard input works after * redirected input has been read from stdin */ #include /* sched_yield() */ #include "libbb.h" #if ENABLE_FEATURE_LESS_REGEXP #include "xregex.h" #endif /* FIXME: currently doesn't work right */ #undef ENABLE_FEATURE_LESS_FLAGCS #define ENABLE_FEATURE_LESS_FLAGCS 0 /* The escape codes for highlighted and normal text */ #define HIGHLIGHT "\033[7m" #define NORMAL "\033[0m" /* The escape code to clear the screen */ #define CLEAR "\033[H\033[J" /* The escape code to clear to end of line */ #define CLEAR_2_EOL "\033[K" /* These are the escape sequences corresponding to special keys */ enum { REAL_KEY_UP = 'A', REAL_KEY_DOWN = 'B', REAL_KEY_RIGHT = 'C', REAL_KEY_LEFT = 'D', REAL_PAGE_UP = '5', REAL_PAGE_DOWN = '6', REAL_KEY_HOME = '7', // vt100? linux vt? or what? REAL_KEY_END = '8', REAL_KEY_HOME_ALT = '1', // ESC [1~ (vt100? linux vt? or what?) REAL_KEY_END_ALT = '4', // ESC [4~ REAL_KEY_HOME_XTERM = 'H', REAL_KEY_END_XTERM = 'F', /* These are the special codes assigned by this program to the special keys */ KEY_UP = 20, KEY_DOWN = 21, KEY_RIGHT = 22, KEY_LEFT = 23, PAGE_UP = 24, PAGE_DOWN = 25, KEY_HOME = 26, KEY_END = 27, /* Absolute max of lines eaten */ MAXLINES = CONFIG_FEATURE_LESS_MAXLINES, /* This many "after the end" lines we will show (at max) */ TILDES = 1, }; /* Command line options */ enum { FLAG_E = 1, FLAG_M = 1 << 1, FLAG_m = 1 << 2, FLAG_N = 1 << 3, FLAG_TILDE = 1 << 4, /* hijack command line options variable for internal state vars */ LESS_STATE_MATCH_BACKWARDS = 1 << 15, }; #if !ENABLE_FEATURE_LESS_REGEXP enum { pattern_valid = 0 }; #endif struct globals { int cur_fline; /* signed */ int kbd_fd; /* fd to get input from */ /* last position in last line, taking into account tabs */ size_t linepos; unsigned max_displayed_line; unsigned max_fline; unsigned max_lineno; /* this one tracks linewrap */ unsigned width; ssize_t eof_error; /* eof if 0, error if < 0 */ size_t readpos; size_t readeof; const char **buffer; const char **flines; const char *empty_line_marker; unsigned num_files; unsigned current_file; char *filename; char **files; #if ENABLE_FEATURE_LESS_MARKS unsigned num_marks; unsigned mark_lines[15][2]; #endif #if ENABLE_FEATURE_LESS_REGEXP unsigned *match_lines; int match_pos; /* signed! */ unsigned num_matches; regex_t pattern; smallint pattern_valid; #endif smallint terminated; struct termios term_orig, term_less; }; #define G (*ptr_to_globals) #define cur_fline (G.cur_fline ) #define kbd_fd (G.kbd_fd ) #define linepos (G.linepos ) #define max_displayed_line (G.max_displayed_line) #define max_fline (G.max_fline ) #define max_lineno (G.max_lineno ) #define width (G.width ) #define eof_error (G.eof_error ) #define readpos (G.readpos ) #define readeof (G.readeof ) #define buffer (G.buffer ) #define flines (G.flines ) #define empty_line_marker (G.empty_line_marker ) #define num_files (G.num_files ) #define current_file (G.current_file ) #define filename (G.filename ) #define files (G.files ) #define num_marks (G.num_marks ) #define mark_lines (G.mark_lines ) #if ENABLE_FEATURE_LESS_REGEXP #define match_lines (G.match_lines ) #define match_pos (G.match_pos ) #define num_matches (G.num_matches ) #define pattern (G.pattern ) #define pattern_valid (G.pattern_valid ) #endif #define terminated (G.terminated ) #define term_orig (G.term_orig ) #define term_less (G.term_less ) #define INIT_G() do { \ PTR_TO_GLOBALS = xzalloc(sizeof(G)); \ empty_line_marker = "~"; \ num_files = 1; \ current_file = 1; \ eof_error = 1; \ terminated = 1; \ } while (0) /* Reset terminal input to normal */ static void set_tty_cooked(void) { fflush(stdout); tcsetattr(kbd_fd, TCSANOW, &term_orig); } /* Exit the program gracefully */ static void less_exit(int code) { /* TODO: We really should save the terminal state when we start, * and restore it when we exit. Less does this with the * "ti" and "te" termcap commands; can this be done with * only termios.h? */ putchar('\n'); fflush_stdout_and_exit(code); } /* Move the cursor to a position (x,y), where (0,0) is the top-left corner of the console */ static void move_cursor(int line, int row) { printf("\033[%u;%uH", line, row); } static void clear_line(void) { printf("\033[%u;0H" CLEAR_2_EOL, max_displayed_line + 2); } static void print_hilite(const char *str) { printf(HIGHLIGHT"%s"NORMAL, str); } static void print_statusline(const char *str) { clear_line(); printf(HIGHLIGHT"%.*s"NORMAL, width - 1, str); } #if ENABLE_FEATURE_LESS_REGEXP static void fill_match_lines(unsigned pos); #else #define fill_match_lines(pos) ((void)0) #endif /* Devilishly complex routine. * * Has to deal with EOF and EPIPE on input, * with line wrapping, with last line not ending in '\n' * (possibly not ending YET!), with backspace and tabs. * It reads input again if last time we got an EOF (thus supporting * growing files) or EPIPE (watching output of slow process like make). * * Variables used: * flines[] - array of lines already read. Linewrap may cause * one source file line to occupy several flines[n]. * flines[max_fline] - last line, possibly incomplete. * terminated - 1 if flines[max_fline] is 'terminated' * (if there was '\n' [which isn't stored itself, we just remember * that it was seen]) * max_lineno - last line's number, this one doesn't increment * on line wrap, only on "real" new lines. * readbuf[0..readeof-1] - small preliminary buffer. * readbuf[readpos] - next character to add to current line. * linepos - 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 */ static void read_lines(void) { #define readbuf bb_common_bufsiz1 char *current_line, *p; USE_FEATURE_LESS_REGEXP(unsigned old_max_fline = max_fline;) int w = width; char last_terminated = terminated; if (option_mask32 & FLAG_N) w -= 8; current_line = xmalloc(w); p = current_line; max_fline += last_terminated; if (!last_terminated) { const char *cp = flines[max_fline]; if (option_mask32 & FLAG_N) cp += 8; strcpy(current_line, cp); p += strlen(current_line); /* linepos is still valid from previous read_lines() */ } else { linepos = 0; } while (1) { again: *p = '\0'; terminated = 0; while (1) { char c; /* if no unprocessed chars left, eat more */ if (readpos >= readeof) { smallint yielded = 0; ndelay_on(0); read_again: eof_error = safe_read(0, readbuf, sizeof(readbuf)); readpos = 0; readeof = eof_error; if (eof_error < 0) { if (errno == EAGAIN && !yielded) { /* We can hit EAGAIN while searching for regexp match. * Yield is not 100% reliable solution in general, * but for less it should be good enough - * we give stdin supplier some CPU time to produce * more input. We do it just once. * Currently, we do not stop when we found the Nth * occurrence we were looking for. We read till end * (or double EAGAIN). TODO? */ sched_yield(); yielded = 1; goto read_again; } readeof = 0; if (errno != EAGAIN) print_statusline("read error"); } ndelay_off(0); if (eof_error <= 0) { goto reached_eof; } } c = readbuf[readpos]; /* backspace? [needed for manpages] */ /* is (a) insane and */ /* (b) harder to do correctly, so we refuse to do it */ if (c == '\x8' && linepos && p[-1] != '\t') { readpos++; /* eat it */ linepos--; /* was buggy (p could end up <= current_line)... */ *--p = '\0'; continue; } { size_t new_linepos = linepos + 1; if (c == '\t') { new_linepos += 7; new_linepos &= (~7); } if (new_linepos >= w) break; linepos = new_linepos; } /* ok, we will eat this char */ readpos++; if (c == '\n') { terminated = 1; linepos = 0; break; } /* NUL is substituted by '\n'! */ if (c == '\0') c = '\n'; *p++ = c; *p = '\0'; } /* 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]) { last_terminated = 1; max_lineno++; goto again; } reached_eof: last_terminated = terminated; flines = xrealloc(flines, (max_fline+1) * sizeof(char *)); if (option_mask32 & FLAG_N) { /* Width of 7 preserves tab spacing in the text */ flines[max_fline] = xasprintf( (max_lineno <= 9999999) ? "%7u %s" : "%07u %s", max_lineno % 10000000, current_line); free(current_line); if (terminated) max_lineno++; } else { flines[max_fline] = xrealloc(current_line, strlen(current_line)+1); } if (max_fline >= MAXLINES) { eof_error = 0; /* Pretend we saw EOF */ break; } if (max_fline > cur_fline + max_displayed_line) break; if (eof_error <= 0) { if (eof_error < 0 && errno == EAGAIN) { /* not yet eof or error, reset flag (or else * we will hog CPU - select() will return * immediately */ eof_error = 1; } break; } max_fline++; current_line = xmalloc(w); p = current_line; linepos = 0; } fill_match_lines(old_max_fline); #undef readbuf } #if ENABLE_FEATURE_LESS_FLAGS /* Interestingly, writing calc_percent as a function saves around 32 bytes * on my build. */ static int calc_percent(void) { unsigned p = (100 * (cur_fline+max_displayed_line+1) + max_fline/2) / (max_fline+1); return p <= 100 ? p : 100; } /* Print a status line if -M was specified */ static void m_status_print(void) { int percentage; clear_line(); 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 >= max_fline - max_displayed_line) { printf("(END)"NORMAL); if (num_files > 1 && current_file != num_files) printf(HIGHLIGHT" - next: %s"NORMAL, files[current_file]); return; } percentage = calc_percent(); printf("%i%%"NORMAL, percentage); } #endif /* Print the status line */ static void status_print(void) { const char *p; /* Change the status if flags have been set */ #if ENABLE_FEATURE_LESS_FLAGS if (option_mask32 & (FLAG_M|FLAG_m)) { m_status_print(); return; } /* No flags set */ #endif clear_line(); if (cur_fline && cur_fline < max_fline - max_displayed_line) { putchar(':'); return; } p = "(END)"; if (!cur_fline) p = filename; if (num_files > 1) { printf(HIGHLIGHT"%s (file %i of %i)"NORMAL, p, current_file, num_files); return; } 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" "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" "\x7f\x9b"; /* DEL and infamous Meta-ESC :( */ static const char ctrlconv[] ALIGN1 = /* '\n': it's a former NUL - subst with '@', not 'J' */ "\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"; #if ENABLE_FEATURE_LESS_REGEXP static void print_found(const char *line) { int match_status; int eflags; char *growline; regmatch_t match_structs; char buf[width]; const char *str = line; char *p = buf; size_t n; while (*str) { n = strcspn(str, controls); if (n) { if (!str[n]) break; memcpy(p, str, n); p += n; str += n; } n = strspn(str, controls); memset(p, '.', n); p += n; str += n; } strcpy(p, str); /* buf[] holds quarantined version of str */ /* Each part of the line that matches has the HIGHLIGHT and NORMAL escape sequences placed around it. NB: we regex against line, but insert text from quarantined copy (buf[]) */ str = buf; growline = NULL; eflags = 0; goto start; while (match_status == 0) { char *new = xasprintf("%s%.*s"HIGHLIGHT"%.*s"NORMAL, growline ? : "", match_structs.rm_so, str, match_structs.rm_eo - match_structs.rm_so, str + match_structs.rm_so); free(growline); growline = new; str += match_structs.rm_eo; line += match_structs.rm_eo; eflags = REG_NOTBOL; start: /* Most of the time doesn't find the regex, optimize for that */ match_status = regexec(&pattern, line, 1, &match_structs, eflags); } if (!growline) { printf(CLEAR_2_EOL"%s\n", str); return; } printf(CLEAR_2_EOL"%s%s\n", growline, str); free(growline); } #else void print_found(const char *line); #endif static void print_ascii(const char *str) { char buf[width]; char *p; size_t n; printf(CLEAR_2_EOL); while (*str) { n = strcspn(str, controls); if (n) { if (!str[n]) break; printf("%.*s", (int) n, str); str += n; } n = strspn(str, controls); p = buf; do { if (*str == 0x7f) *p++ = '?'; else if (*str == (char)0x9b) /* VT100's CSI, aka Meta-ESC. Who's inventor? */ /* I want to know who committed this sin */ *p++ = '{'; else *p++ = ctrlconv[(unsigned char)*str]; str++; } while (--n); *p = '\0'; print_hilite(buf); } puts(str); } /* Print the buffer */ static void buffer_print(void) { int i; move_cursor(0, 0); for (i = 0; i <= max_displayed_line; i++) if (pattern_valid) print_found(buffer[i]); else print_ascii(buffer[i]); status_print(); } static void buffer_fill_and_print(void) { int i; for (i = 0; i <= max_displayed_line && cur_fline + i <= max_fline; i++) { buffer[i] = flines[cur_fline + i]; } for (; i <= max_displayed_line; i++) { buffer[i] = empty_line_marker; } buffer_print(); } /* Move the buffer up and down in the file in order to scroll */ static void buffer_down(int nlines) { cur_fline += nlines; read_lines(); cap_cur_fline(nlines); buffer_fill_and_print(); } static void buffer_up(int nlines) { cur_fline -= nlines; if (cur_fline < 0) cur_fline = 0; read_lines(); buffer_fill_and_print(); } static void buffer_line(int linenum) { if (linenum < 0) linenum = 0; 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; buffer_fill_and_print(); } static void open_file_and_read_lines(void) { if (filename) { int fd = xopen(filename, O_RDONLY); dup2(fd, 0); if (fd) close(fd); } else { /* "less" with no arguments in argv[] */ /* For status line only */ filename = xstrdup(bb_msg_standard_input); } readpos = 0; readeof = 0; linepos = 0; terminated = 1; read_lines(); } /* Reinitialize everything for a new file - free the memory and start over */ static void reinitialize(void) { int i; if (flines) { for (i = 0; i <= max_fline; i++) free((void*)(flines[i])); free(flines); flines = NULL; } max_fline = -1; cur_fline = 0; max_lineno = 0; open_file_and_read_lines(); buffer_fill_and_print(); } static void getch_nowait(char* input, int sz) { ssize_t rd; fd_set readfds; again: fflush(stdout); /* NB: select returns whenever read will not block. Therefore: * (a) with O_NONBLOCK'ed fds select will return immediately * (b) if eof is reached, select will also return * because read will immediately return 0 bytes. * Even if select says that input is available, read CAN block * (switch fd into O_NONBLOCK'ed mode to avoid it) */ FD_ZERO(&readfds); if (max_fline <= cur_fline + max_displayed_line && eof_error > 0 /* did NOT reach eof yet */ ) { /* We are interested in stdin */ FD_SET(0, &readfds); } FD_SET(kbd_fd, &readfds); tcsetattr(kbd_fd, TCSANOW, &term_less); select(kbd_fd + 1, &readfds, NULL, NULL, NULL); input[0] = '\0'; ndelay_on(kbd_fd); rd = read(kbd_fd, input, sz); ndelay_off(kbd_fd); if (rd < 0) { /* No keyboard input, but we have input on stdin! */ if (errno != EAGAIN) /* Huh?? */ return; read_lines(); buffer_fill_and_print(); goto again; } } /* Grab a character from input without requiring the return key. If the * character is ASCII \033, get more characters and assign certain sequences * special return codes. Note that this function works best with raw input. */ static int less_getch(void) { char input[16]; unsigned i; again: memset(input, 0, sizeof(input)); getch_nowait(input, sizeof(input)); /* Detect escape sequences (i.e. arrow keys) and handle * them accordingly */ if (input[0] == '\033' && input[1] == '[') { set_tty_cooked(); i = input[2] - REAL_KEY_UP; if (i < 4) return 20 + i; i = input[2] - REAL_PAGE_UP; if (i < 4) return 24 + i; if (input[2] == REAL_KEY_HOME_XTERM) return KEY_HOME; if (input[2] == REAL_KEY_HOME_ALT) return KEY_HOME; if (input[2] == REAL_KEY_END_XTERM) return KEY_END; if (input[2] == REAL_KEY_END_ALT) return KEY_END; return 0; } /* Reject almost all control chars */ i = input[0]; if (i < ' ' && i != 0x0d && i != 8) goto again; set_tty_cooked(); return i; } static char* less_gets(int sz) { char c; int i = 0; char *result = xzalloc(1); while (1) { fflush(stdout); /* I be damned if I know why is it needed *repeatedly*, * but it is needed. Is it because of stdio? */ tcsetattr(kbd_fd, TCSANOW, &term_less); c = '\0'; read(kbd_fd, &c, 1); if (c == 0x0d) return result; if (c == 0x7f) c = 8; if (c == 8 && i) { printf("\x8 \x8"); i--; } if (c < ' ') continue; if (i >= width - sz - 1) continue; /* len limit */ putchar(c); result[i++] = c; result = xrealloc(result, i+1); result[i] = '\0'; } } static void examine_file(void) { print_statusline("Examine: "); free(filename); filename = less_gets(sizeof("Examine: ")-1); /* files start by = argv. why we assume that argv is infinitely long?? files[num_files] = filename; current_file = num_files + 1; num_files++; */ files[0] = filename; num_files = current_file = 1; reinitialize(); } /* This function changes the file currently being paged. direction can be one of the following: * -1: go back one file * 0: go to the first file * 1: go forward one file */ static void change_file(int direction) { if (current_file != ((direction > 0) ? num_files : 1)) { current_file = direction ? current_file + direction : 1; free(filename); filename = xstrdup(files[current_file - 1]); reinitialize(); } else { print_statusline(direction > 0 ? "No next file" : "No previous file"); } } static void remove_current_file(void) { int i; if (num_files < 2) return; if (current_file != 1) { change_file(-1); for (i = 3; i <= num_files; i++) files[i - 2] = files[i - 1]; num_files--; } else { change_file(1); for (i = 2; i <= num_files; i++) files[i - 2] = files[i - 1]; num_files--; current_file--; } } static void colon_process(void) { int keypress; /* Clear the current line and print a prompt */ print_statusline(" :"); keypress = less_getch(); switch (keypress) { case 'd': remove_current_file(); break; case 'e': examine_file(); break; #if ENABLE_FEATURE_LESS_FLAGS case 'f': m_status_print(); break; #endif case 'n': change_file(1); break; case 'p': change_file(-1); break; case 'q': less_exit(0); break; case 'x': change_file(0); break; } } #if ENABLE_FEATURE_LESS_REGEXP static void normalize_match_pos(int match) { if (match >= num_matches) match = num_matches - 1; if (match < 0) match = 0; match_pos = match; } static void goto_match(int match) { int sv; if (!pattern_valid) return; if (match < 0) match = 0; sv = cur_fline; /* Try to find next match if eof isn't reached yet */ if (match >= num_matches && eof_error > 0) { cur_fline = MAXLINES; /* look as far as needed */ read_lines(); } if (num_matches) { cap_cur_fline(cur_fline); normalize_match_pos(match); buffer_line(match_lines[match_pos]); } else { cur_fline = sv; print_statusline("No matches found"); } } static void fill_match_lines(unsigned pos) { if (!pattern_valid) return; /* Run the regex on each line of the current file */ while (pos <= max_fline) { /* If this line matches */ if (regexec(&pattern, flines[pos], 0, NULL, 0) == 0 /* and we didn't match it last time */ && !(num_matches && match_lines[num_matches-1] == pos) ) { match_lines = xrealloc(match_lines, (num_matches+1) * sizeof(int)); match_lines[num_matches++] = pos; } pos++; } } static void regex_process(void) { char *uncomp_regex, *err; /* Reset variables */ free(match_lines); match_lines = NULL; match_pos = 0; num_matches = 0; if (pattern_valid) { regfree(&pattern); pattern_valid = 0; } /* Get the uncompiled regular expression from the user */ clear_line(); putchar((option_mask32 & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/'); uncomp_regex = less_gets(1); if (!uncomp_regex[0]) { free(uncomp_regex); buffer_print(); return; } /* Compile the regex and check for errors */ err = regcomp_or_errmsg(&pattern, uncomp_regex, 0); free(uncomp_regex); if (err) { print_statusline(err); free(err); return; } pattern_valid = 1; match_pos = 0; fill_match_lines(0); while (match_pos < num_matches) { if (match_lines[match_pos] > cur_fline) break; match_pos++; } if (option_mask32 & LESS_STATE_MATCH_BACKWARDS) match_pos--; /* It's possible that no matches are found yet. * goto_match() will read input looking for match, * if needed */ goto_match(match_pos); } #endif static void number_process(int first_digit) { int i = 1; int num; char num_input[sizeof(int)*4]; /* more than enough */ char keypress; num_input[0] = first_digit; /* Clear the current line, print a prompt, and then print the digit */ clear_line(); printf(":%c", first_digit); /* Receive input until a letter is given */ while (i < sizeof(num_input)-1) { num_input[i] = less_getch(); if (!num_input[i] || !isdigit(num_input[i])) break; putchar(num_input[i]); i++; } /* Take the final letter out of the digits string */ keypress = num_input[i]; num_input[i] = '\0'; num = bb_strtou(num_input, NULL, 10); /* on format error, num == -1 */ if (num < 1 || num > MAXLINES) { buffer_print(); return; } /* We now know the number and the letter entered, so we process them */ switch (keypress) { case KEY_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015': buffer_down(num); break; case KEY_UP: case 'b': case 'w': case 'y': case 'u': buffer_up(num); break; case 'g': case '<': case 'G': case '>': cur_fline = num + max_displayed_line; read_lines(); buffer_line(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); break; #if ENABLE_FEATURE_LESS_REGEXP case 'n': goto_match(match_pos + num); break; case '/': option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS; regex_process(); break; case '?': option_mask32 |= LESS_STATE_MATCH_BACKWARDS; regex_process(); break; #endif } } #if ENABLE_FEATURE_LESS_FLAGCS static void flag_change(void) { int keypress; clear_line(); putchar('-'); keypress = less_getch(); switch (keypress) { case 'M': option_mask32 ^= FLAG_M; break; case 'm': option_mask32 ^= FLAG_m; break; case 'E': option_mask32 ^= FLAG_E; break; case '~': option_mask32 ^= FLAG_TILDE; break; } } static void show_flag_status(void) { int keypress; int flag_val; clear_line(); putchar('_'); keypress = less_getch(); switch (keypress) { case 'M': flag_val = option_mask32 & FLAG_M; break; case 'm': flag_val = option_mask32 & FLAG_m; break; case '~': flag_val = option_mask32 & FLAG_TILDE; break; case 'N': flag_val = option_mask32 & FLAG_N; break; case 'E': flag_val = option_mask32 & FLAG_E; break; default: flag_val = 0; break; } clear_line(); printf(HIGHLIGHT"The status of the flag is: %u"NORMAL, flag_val != 0); } #endif static void save_input_to_file(void) { const char *msg = ""; char *current_line; int i; FILE *fp; print_statusline("Log file: "); current_line = less_gets(sizeof("Log file: ")-1); if (strlen(current_line) > 0) { fp = fopen(current_line, "w"); if (!fp) { msg = "Error opening log file"; goto ret; } for (i = 0; i <= max_fline; i++) fprintf(fp, "%s\n", flines[i]); fclose(fp); msg = "Done"; } ret: print_statusline(msg); free(current_line); } #if ENABLE_FEATURE_LESS_MARKS static void add_mark(void) { int letter; print_statusline("Mark: "); letter = less_getch(); if (isalpha(letter)) { /* If we exceed 15 marks, start overwriting previous ones */ if (num_marks == 14) num_marks = 0; mark_lines[num_marks][0] = letter; mark_lines[num_marks][1] = cur_fline; num_marks++; } else { print_statusline("Invalid mark letter"); } } static void goto_mark(void) { int letter; int i; print_statusline("Go to mark: "); letter = less_getch(); clear_line(); if (isalpha(letter)) { for (i = 0; i <= num_marks; i++) if (letter == mark_lines[i][0]) { buffer_line(mark_lines[i][1]); break; } if (num_marks == 14 && letter != mark_lines[14][0]) print_statusline("Mark not set"); } else print_statusline("Invalid mark letter"); } #endif #if ENABLE_FEATURE_LESS_BRACKETS static char opp_bracket(char bracket) { switch (bracket) { case '{': case '[': return bracket + 2; case '(': return ')'; case '}': case ']': return bracket - 2; case ')': return '('; } return 0; } static void match_right_bracket(char bracket) { int bracket_line = -1; int i; if (strchr(flines[cur_fline], bracket) == NULL) { print_statusline("No bracket in top line"); return; } for (i = cur_fline + 1; i < max_fline; i++) { if (strchr(flines[i], opp_bracket(bracket)) != NULL) { bracket_line = i; break; } } if (bracket_line == -1) print_statusline("No matching bracket found"); buffer_line(bracket_line - max_displayed_line); } static void match_left_bracket(char bracket) { int bracket_line = -1; int i; if (strchr(flines[cur_fline + max_displayed_line], bracket) == NULL) { print_statusline("No bracket in bottom line"); return; } for (i = cur_fline + max_displayed_line; i >= 0; i--) { if (strchr(flines[i], opp_bracket(bracket)) != NULL) { bracket_line = i; break; } } if (bracket_line == -1) print_statusline("No matching bracket found"); buffer_line(bracket_line); } #endif /* FEATURE_LESS_BRACKETS */ static void keypress_process(int keypress) { switch (keypress) { case KEY_DOWN: case 'e': case 'j': case 0x0d: buffer_down(1); break; case KEY_UP: case 'y': case 'k': buffer_up(1); break; case PAGE_DOWN: case ' ': case 'z': buffer_down(max_displayed_line + 1); break; case PAGE_UP: case 'w': case 'b': buffer_up(max_displayed_line + 1); break; case 'd': buffer_down((max_displayed_line + 1) / 2); break; case 'u': buffer_up((max_displayed_line + 1) / 2); break; case KEY_HOME: case 'g': case 'p': case '<': case '%': buffer_line(0); break; case KEY_END: case 'G': case '>': cur_fline = MAXLINES; read_lines(); buffer_line(cur_fline); break; case 'q': case 'Q': less_exit(0); break; #if ENABLE_FEATURE_LESS_MARKS case 'm': add_mark(); buffer_print(); break; case '\'': goto_mark(); buffer_print(); break; #endif case 'r': case 'R': buffer_print(); break; /*case 'R': full_repaint(); break;*/ case 's': save_input_to_file(); break; case 'E': examine_file(); break; #if ENABLE_FEATURE_LESS_FLAGS case '=': m_status_print(); break; #endif #if ENABLE_FEATURE_LESS_REGEXP case '/': option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS; regex_process(); break; case 'n': goto_match(match_pos + 1); break; case 'N': goto_match(match_pos - 1); break; case '?': option_mask32 |= LESS_STATE_MATCH_BACKWARDS; regex_process(); break; #endif #if ENABLE_FEATURE_LESS_FLAGCS case '-': flag_change(); buffer_print(); break; case '_': show_flag_status(); break; #endif #if ENABLE_FEATURE_LESS_BRACKETS case '{': case '(': case '[': match_right_bracket(keypress); break; case '}': case ')': case ']': match_left_bracket(keypress); break; #endif case ':': colon_process(); break; } if (isdigit(keypress)) number_process(keypress); } static void sig_catcher(int sig ATTRIBUTE_UNUSED) { set_tty_cooked(); exit(1); } int less_main(int argc, char **argv); int less_main(int argc, char **argv) { int keypress; 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~"); argc -= optind; argv += optind; num_files = argc; files = argv; /* Another popular pager, most, detects when stdout * is not a tty and turns into cat. This makes sense. */ if (!isatty(STDOUT_FILENO)) return bb_cat(argv); kbd_fd = open(CURRENT_TTY, O_RDONLY); if (kbd_fd < 0) return bb_cat(argv); if (!num_files) { if (isatty(STDIN_FILENO)) { /* Just "less"? No args and no redirection? */ bb_error_msg("missing filename"); bb_show_usage(); } } else filename = xstrdup(files[0]); get_terminal_width_height(kbd_fd, &width, &max_displayed_line); /* 20: two tabstops + 4 */ if (width < 20 || max_displayed_line < 3) bb_error_msg_and_die("too narrow here"); max_displayed_line -= 2; buffer = xmalloc((max_displayed_line+1) * sizeof(char *)); if (option_mask32 & FLAG_TILDE) empty_line_marker = ""; tcgetattr(kbd_fd, &term_orig); signal(SIGTERM, sig_catcher); signal(SIGINT, sig_catcher); term_less = term_orig; term_less.c_lflag &= ~(ICANON | ECHO); term_less.c_iflag &= ~(IXON | ICRNL); /*term_less.c_oflag &= ~ONLCR;*/ term_less.c_cc[VMIN] = 1; term_less.c_cc[VTIME] = 0; /* Want to do it just once, but it doesn't work, */ /* so we are redoing it (see code above). Mystery... */ /*tcsetattr(kbd_fd, TCSANOW, &term_less);*/ reinitialize(); while (1) { keypress = less_getch(); keypress_process(keypress); } }