f4dff7735

Denis Vlasenko

2006-12-24

FAILED Duration: 5s

Subject

less: implement waiting for input using select(). Rather tricky business. But we do not read entire input anymore up-front.

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

miscutils/less.c +516 -454 shell/ash.c +1 -1

miscutils/less.c+516 -454

@@ -26,26 +26,9 @@
	#include "xregex.h"
	#endif

-
-	/* These are the escape sequences corresponding to special keys */
-	#define REAL_KEY_UP 'A'
-	#define REAL_KEY_DOWN 'B'
-	#define REAL_KEY_RIGHT 'C'
-	#define REAL_KEY_LEFT 'D'
-	#define REAL_PAGE_UP '5'
-	#define REAL_PAGE_DOWN '6'
-	#define REAL_KEY_HOME '7'
-	#define REAL_KEY_END '8'
-
-	/* These are the special codes assigned by this program to the special keys */
-	#define KEY_UP 20
-	#define KEY_DOWN 21
-	#define KEY_RIGHT 22
-	#define KEY_LEFT 23
-	#define PAGE_UP 24
-	#define PAGE_DOWN 25
-	#define KEY_HOME 26
-	#define KEY_END 27
+	/* 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"
@@ -55,124 +38,103 @@
	/* The escape code to clear to end of line */
	#define CLEAR_2_EOL "\033[K"

-	#define MAXLINES CONFIG_FEATURE_LESS_MAXLINES
+	/* 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',
+	REAL_KEY_END = '8',
+
+	/* 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,
+	};
+
+	static unsigned max_displayed_line;
+	static unsigned width;
+	static const char *empty_line_marker = "~";

-	static int height;
-	static int width;
-	static char **files;
	static char *filename;
+	static char **files;
+	static unsigned num_files = 1;
+	static unsigned current_file = 1;
	static const char **buffer;
-	static char **flines;
-	static int current_file = 1;
-	static int line_pos;
-	static int num_flines;
-	static int num_files = 1;
-	static const char *empty_line_marker = "~";
+	static const char **flines;
+	static int cur_fline; /* signed */
+	static unsigned max_fline;
+	static unsigned max_lineno; /* this one tracks linewrap */
+
+	static ssize_t eof_error = 1; /* eof if 0, error if < 0 */
+	static char terminated = 1;
+	static size_t readpos;
+	static size_t readeof;
+	/* last position in last line, taking into account tabs */
+	static size_t linepos;

	/* Command line options */
-	#define FLAG_E 1
-	#define FLAG_M (1<<1)
-	#define FLAG_m (1<<2)
-	#define FLAG_N (1<<3)
-	#define FLAG_TILDE (1<<4)
+	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 */
-	#define LESS_STATE_MATCH_BACKWARDS (1<<6)
+	LESS_STATE_MATCH_BACKWARDS = 1 << 15,
+	};

	#if ENABLE_FEATURE_LESS_MARKS
-	static int mark_lines[15][2];
-	static int num_marks;
+	static unsigned mark_lines[15][2];
+	static unsigned num_marks;
	#endif

	#if ENABLE_FEATURE_LESS_REGEXP
-	static int *match_lines;
-	static int match_pos;
-	static int num_matches;
+	static unsigned *match_lines;
+	static int match_pos; /* signed! */
+	static unsigned num_matches;
	static regex_t pattern;
-	static int pattern_valid;
+	static unsigned pattern_valid;
	#endif

-	/* Needed termios structures */
	static struct termios term_orig, term_vi;

	/* File pointer to get input from */
-	static FILE *inp;
+	static int kbd_fd;

	/* Reset terminal input to normal */
	static void set_tty_cooked(void)
	{
	fflush(stdout);
-	tcsetattr(fileno(inp), TCSANOW, &term_orig);
+	tcsetattr(kbd_fd, TCSANOW, &term_orig);
	}

	/* Exit the program gracefully */
-	static void tless_exit(int code)
+	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? */
+	* 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);
	}

-	/* 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 tless_getch(void)
-	{
-	int input;
-	/* Set terminal input to raw mode (taken from vi.c) */
-	tcsetattr(fileno(inp), TCSANOW, &term_vi);
-	again:
-	input = getc(inp);
-	/* Detect escape sequences (i.e. arrow keys) and handle
-	them accordingly */
-
-	if (input == '\033' && getc(inp) == '[') {
-	unsigned i;
-	input = getc(inp);
-	set_tty_cooked();
-
-	i = input - REAL_KEY_UP;
-	if (i < 4)
-	return 20 + i;
-	i = input - REAL_PAGE_UP;
-	if (i < 4)
-	return 24 + i;
-	return 0; /* ?? */
-	}
-	/* Reject almost all control chars */
-	if (input < ' ' && input != 0x0d && input != 8) goto again;
-	set_tty_cooked();
-	return input;
-	}
-
-	static char* tless_gets(int sz)
-	{
-	int c;
-	int i = 0;
-	char *result = xzalloc(1);
-	while (1) {
-	c = tless_getch();
-	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';
-	}
-	}
-
	/* 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)
@@ -182,7 +144,7 @@ static void move_cursor(int line, int row)

	static void clear_line(void)
	{
-	printf("\033[%u;0H" CLEAR_2_EOL, height);
+	printf("\033[%u;0H" CLEAR_2_EOL, max_displayed_line + 2);
	}

	static void print_hilite(const char *str)
@@ -193,90 +155,116 @@ static void print_hilite(const char *str)
	static void print_statusline(const char *str)
	{
	clear_line();
-	printf(HIGHLIGHT"%.*s"NORMAL, width-1, str);
+	printf(HIGHLIGHT"%.*s"NORMAL, width - 1, str);
	}

-	static void data_readlines(void)
+	static void read_lines(void)
	{
-	unsigned i, pos;
-	unsigned lineno = 1;
-	int w = width;
-	char terminated, last_terminated = 1;
-	char current_line, p;
-	FILE *fp;
+	/* TODO: regexp match array should be updated too */

-	if (filename)
-	fp = xfopen(filename, "r");
-	else {
-	/* "less" with no arguments in argv[] */
-	fp = stdin;
-	/* For status line only */
-	filename = xstrdup(bb_msg_standard_input);
-	}
+	#define readbuf bb_common_bufsiz1
+	char current_line, p;
+	int w = width;
+	char last_terminated = terminated;

-	flines = NULL;
-	if (option_mask32 & FLAG_N) {
+	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);
	}
-	for (i = 0; !feof(fp) && i <= MAXLINES; i++) {
-	flines = xrealloc(flines, (i+1) * sizeof(char *));
-	current_line = xmalloc(w);
+
+	while (1) {
	again:
-	p = current_line;
-	pos = 0;
+	*p = '\0';
	terminated = 0;
	while (1) {
-	int c = getc(fp);
-	if (c == '\t') pos += (pos^7) & 7;
-	pos++;
-	if (pos >= w) { ungetc(c, fp); break; }
-	if (c == EOF) break;
+	char c;
+	if (readpos >= readeof) {
+	ndelay_on(0);
+	eof_error = safe_read(0, readbuf, sizeof(readbuf));
+	ndelay_off(0);
+	readpos = 0;
+	readeof = eof_error;
+	if (eof_error < 0) {
+	readeof = 0;
+	if (errno != EAGAIN)
+	print_statusline("read error");
+	}
+	if (eof_error <= 0) {
+	goto reached_eof;
+	}
+	}
+	c = readbuf[readpos];
+	if (c == '\t')
+	linepos += (linepos^7) & 7;
+	linepos++;
+	if (linepos >= w)
+	break;
+	readpos++;
	if (c == '\n') { terminated = 1; break; }
	/* NUL is substituted by '\n'! */
	if (c == '\0') c = '\n';
	*p++ = c;
+	*p = '\0';
	}
-	*p = '\0';
-	if (fp != stdin)
-	die_if_ferror(fp, filename);
-
	/* 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;
-	lineno++;
+	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[i] = xasprintf(
-	(lineno <= 9999999) ? "%7u %s" : "%07u %s",
-	lineno % 10000000, current_line);
+	flines[max_fline] = xasprintf(
+	(max_lineno <= 9999999) ? "%7u %s" : "%07u %s",
+	max_lineno % 10000000, current_line);
	free(current_line);
	if (terminated)
-	lineno++;
+	max_lineno++;
	} else {
-	flines[i] = xrealloc(current_line, strlen(current_line)+1);
+	flines[max_fline] = xrealloc(current_line, strlen(current_line)+1);
	}
+	if (max_fline >= MAXLINES)
+	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;
	}
-	num_flines = i - 1; /* buggie: 'num_flines' must be 'max_fline' */
-
-	/* Reset variables for a new file */
-
-	line_pos = 0;
-
-	fclose(fp);
+	#undef readbuf
	}

	#if ENABLE_FEATURE_LESS_FLAGS

-	/* Interestingly, writing calc_percent as a function and not a prototype saves around 32 bytes
+	/* Interestingly, writing calc_percent as a function saves around 32 bytes
	* on my build. */
	static int calc_percent(void)
	{
-	return ((100 * (line_pos + height - 2) / num_flines) + 1);
+	unsigned p = 100 * (cur_fline + max_displayed_line) / (max_fline + 1);
+	return p <= 100 ? p : 100;
	}

	/* Print a status line if -M was specified */
@@ -289,16 +277,16 @@ static void m_status_print(void)
	if (num_files > 1)
	printf(" (file %i of %i)", current_file, num_files);
	printf(" lines %i-%i/%i ",
-	line_pos + 1, line_pos + height - 1,
-	num_flines + 1);
-	if (line_pos >= num_flines - height + 2) {
+	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]);
+	printf(HIGHLIGHT" - next: %s"NORMAL, files[current_file]);
	return;
	}
	percentage = calc_percent();
-	printf("%i%% "NORMAL, percentage);
+	printf("%i%%"NORMAL, percentage);
	}

	#endif
@@ -318,15 +306,15 @@ static void status_print(void)
	#endif

	clear_line();
-	if (line_pos && line_pos < num_flines - height + 2) {
+	if (cur_fline && cur_fline < max_fline - max_displayed_line) {
	putchar(':');
	return;
	}
	p = "(END)";
-	if (!line_pos)
+	if (!cur_fline)
	p = filename;
	if (num_files > 1) {
-	printf(HIGHLIGHT"%s (file %i of %i) "NORMAL,
+	printf(HIGHLIGHT"%s (file %i of %i)"NORMAL,
	p, current_file, num_files);
	return;
	}
@@ -423,7 +411,7 @@ static void print_ascii(const char *str)
	do {
	if (*str == 0x7f)
	*p++ = '?';
-	else if (*str == 0x9b)
+	else if (*str == (char)0x9b)
	/* VT100's CSI, aka Meta-ESC. Who's inventor? */
	/* I want to know who committed this sin */
	*p++ = '{';
@@ -443,7 +431,7 @@ static void buffer_print(void)
	int i;

	move_cursor(0, 0);
-	for (i = 0; i < height - 1; i++)
+	for (i = 0; i <= max_displayed_line; i++)
	if (pattern_valid)
	print_found(buffer[i]);
	else
@@ -451,111 +439,194 @@ static void buffer_print(void)
	status_print();
	}

-	/* Initialise the buffer */
-	static void buffer_init(void)
+	static void buffer_fill_and_print(void)
	{
	int i;
-
-	/* Fill the buffer until the end of the file or the
-	end of the buffer is reached */
-	for (i = 0; i < height - 1 && i <= num_flines; i++) {
-	buffer[i] = flines[i];
+	for (i = 0; i <= max_displayed_line && cur_fline + i <= max_fline; i++) {
+	buffer[i] = flines[cur_fline + i];
	}
-
-	/* If the buffer still isn't full, fill it with blank lines */
-	for (; i < height - 1; 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)
	{
-	int i;
+	int diff;
+	cur_fline += nlines;
+	read_lines();

-	if (line_pos + (height - 3) + nlines < num_flines) {
-	line_pos += nlines;
-	for (i = 0; i < (height - 1); i++) {
-	buffer[i] = flines[line_pos + i];
-	}
-	} else {
+	if (cur_fline + max_displayed_line > max_fline + TILDES) {
+	cur_fline -= nlines;
+	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 */
-	while (line_pos + (height - 3) + 1 < num_flines) {
-	line_pos += 1;
-	for (i = 0; i < (height - 1); i++) {
-	buffer[i] = flines[line_pos + i];
-	}
-	}
+	if (diff > 0)
+	cur_fline += diff;
	}
-
-	/* We exit if the -E flag has been set */
-	if ((option_mask32 & FLAG_E) && (line_pos + (height - 2) == num_flines))
-	tless_exit(0);
+	buffer_fill_and_print();
	}

	static void buffer_up(int nlines)
	{
-	int i;
+	cur_fline -= nlines;
+	if (cur_fline < 0) cur_fline = 0;
+	read_lines();
+	buffer_fill_and_print();
+	}

-	line_pos -= nlines;
-	if (line_pos < 0) line_pos = 0;
-	for (i = 0; i < height - 1; i++) {
-	if (line_pos + i <= num_flines) {
-	buffer[i] = flines[line_pos + i];
-	} else {
-	buffer[i] = empty_line_marker;
-	}
+	static void buffer_line(int linenum)
+	{
+	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();
	}

-	static void buffer_line(int linenum)
+	/* Reinitialize everything for a new file - free the memory and start over */
+	static void reinitialize(void)
	{
	int i;

-	if (linenum < 0 \|\| linenum > num_flines) {
-	clear_line();
-	printf(HIGHLIGHT"%s%u"NORMAL, "Cannot seek to line ", linenum + 1);
-	return;
+	if (flines) {
+	for (i = 0; i <= max_fline; i++)
+	free((void*)(flines[i]));
+	free(flines);
+	flines = NULL;
	}

-	for (i = 0; i < height - 1; i++) {
-	if (linenum + i <= num_flines)
-	buffer[i] = flines[linenum + i];
-	else {
-	buffer[i] = empty_line_marker;
-	}
+	max_fline = -1;
+	cur_fline = 0;
+	max_lineno = 0;
+	open_file_and_read_lines();
+	buffer_fill_and_print();
+	}
+
+	static char* getch_nowait(void)
+	{
+	static char input[16];
+	ssize_t sz;
+	fd_set readfds;
+	again:
+	fflush(stdout);
+	FD_ZERO(&readfds);
+	if (max_fline <= cur_fline + max_displayed_line && eof_error > 0) {
+	/* We are interested in stdin */
+	FD_SET(0, &readfds);
	}
-	line_pos = linenum;
-	buffer_print();
+	FD_SET(kbd_fd, &readfds);
+	tcsetattr(kbd_fd, TCSANOW, &term_vi);
+	select(kbd_fd + 1, &readfds, NULL, NULL, NULL);
+
+	input[0] = '\0';
+	ndelay_on(kbd_fd);
+	sz = read(kbd_fd, input, sizeof(input));
+	ndelay_off(kbd_fd);
+	if (sz < 0) {
+	/* No keyboard input, but we have input on stdin! */
+	if (errno != EAGAIN) /* Huh?? */
+	return input;
+	read_lines();
+	buffer_fill_and_print();
+	goto again;
+	}
+	return input;
	}

-	/* Reinitialise everything for a new file - free the memory and start over */
-	static void reinitialise(void)
+	/* 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)
	{
-	int i;
+	char *input;
+	unsigned i;
+	again:
+	input = getch_nowait();
+	/* Detect escape sequences (i.e. arrow keys) and handle
+	* them accordingly */

-	for (i = 0; i <= num_flines; i++)
-	free(flines[i]);
-	free(flines);
+	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;
+	return 0;
+	}
+	/* Reject almost all control chars */
+	i = input[0];
+	if (i < ' ' && i != 0x0d && i != 8) goto again;
+	set_tty_cooked();
+	return i;
+	}

-	data_readlines();
-	buffer_init();
-	buffer_print();
+	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_vi);
+
+	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 = tless_gets(sizeof("Examine: ")-1);
+	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;
-	reinitialise();
+	reinitialize();
	}

	/* This function changes the file currently being paged. direction can be one of the following:
@@ -569,7 +640,7 @@ static void change_file(int direction)
	current_file = direction ? current_file + direction : 1;
	free(filename);
	filename = xstrdup(files[current_file - 1]);
-	reinitialise();
+	reinitialize();
	} else {
	print_statusline(direction > 0 ? "No next file" : "No previous file");
	}
@@ -579,19 +650,20 @@ 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--;
-	buffer_print();
	} else {
	change_file(1);
	for (i = 2; i <= num_files; i++)
	files[i - 2] = files[i - 1];
	num_files--;
	current_file--;
-	buffer_print();
	}
	}

@@ -602,33 +674,31 @@ static void colon_process(void)
	/* Clear the current line and print a prompt */
	print_statusline(" :");

-	keypress = tless_getch();
+	keypress = less_getch();
	switch (keypress) {
-	case 'd':
-	remove_current_file();
-	break;
-	case 'e':
-	examine_file();
-	break;
+	case 'd':
+	remove_current_file();
+	break;
+	case 'e':
+	examine_file();
+	break;
	#if ENABLE_FEATURE_LESS_FLAGS
-	case 'f':
-	m_status_print();
-	break;
+	case 'f':
+	m_status_print();
+	break;
	#endif
-	case 'n':
-	change_file(1);
-	break;
-	case 'p':
-	change_file(-1);
-	break;
-	case 'q':
-	tless_exit(0);
-	break;
-	case 'x':
-	change_file(0);
-	break;
-	default:
-	break;
+	case 'n':
+	change_file(1);
+	break;
+	case 'p':
+	change_file(-1);
+	break;
+	case 'q':
+	less_exit(0);
+	break;
+	case 'x':
+	change_file(0);
+	break;
	}
	}

@@ -638,7 +708,7 @@ static int normalize_match_pos(int match)
	if (match >= num_matches)
	match_pos = num_matches - 1;
	if (match < 0)
-	return (match_pos = 0);
+	match_pos = 0;
	return match_pos;
	}

@@ -654,8 +724,8 @@ static void regex_process(void)
	char uncomp_regex, err;

	/* Reset variables */
-	match_lines = xrealloc(match_lines, sizeof(int));
-	match_lines[0] = -1;
+	free(match_lines);
+	match_lines = NULL;
	match_pos = 0;
	num_matches = 0;
	if (pattern_valid) {
@@ -666,8 +736,8 @@ static void regex_process(void)
	/* Get the uncompiled regular expression from the user */
	clear_line();
	putchar((option_mask32 & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
-	uncomp_regex = tless_gets(1);
-	if (/!uncomp_regex \|\|/ !uncomp_regex[0]) {
+	uncomp_regex = less_gets(1);
+	if (!uncomp_regex[0]) {
	free(uncomp_regex);
	buffer_print();
	return;
@@ -684,19 +754,19 @@ static void regex_process(void)
	pattern_valid = 1;

	/* Run the regex on each line of the current file */
-	for (match_pos = 0; match_pos <= num_flines; match_pos++) {
+	for (match_pos = 0; match_pos <= max_fline; match_pos++) {
	if (regexec(&pattern, flines[match_pos], 0, NULL, 0) == 0) {
	match_lines = xrealloc(match_lines, (num_matches+1) * sizeof(int));
	match_lines[num_matches++] = match_pos;
	}
	}

-	if (num_matches == 0 \|\| num_flines <= height - 2) {
+	if (num_matches == 0 \|\| max_fline <= max_displayed_line) {
	buffer_print();
	return;
	}
	for (match_pos = 0; match_pos < num_matches; match_pos++) {
-	if (match_lines[match_pos] > line_pos)
+	if (match_lines[match_pos] > cur_fline)
	break;
	}
	if (option_mask32 & LESS_STATE_MATCH_BACKWARDS) match_pos--;
@@ -719,7 +789,7 @@ static void number_process(int first_digit)

	/* Receive input until a letter is given */
	while (i < sizeof(num_input)-1) {
-	num_input[i] = tless_getch();
+	num_input[i] = less_getch();
	if (!num_input[i] \|\| !isdigit(num_input[i]))
	break;
	putchar(num_input[i]);
@@ -738,34 +808,38 @@ static void number_process(int first_digit)

	/* 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 '>':
-	if (num_flines >= height - 2)
-	buffer_line(num - 1);
-	break;
-	case 'p': case '%':
-	buffer_line(((num / 100) * num_flines) - 1);
-	break;
+	case KEY_DOWN: case 'z': case 'd': case 'e': case ' ': case '\015':
+	buffer_down(num);
+	buffer_print();
+	break;
+	case KEY_UP: case 'b': case 'w': case 'y': case 'u':
+	buffer_up(num);
+	buffer_print();
+	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;
+	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
-	default:
-	break;
	}
	}

@@ -776,23 +850,21 @@ static void flag_change(void)

	clear_line();
	putchar('-');
-	keypress = tless_getch();
+	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;
-	default:
-	break;
+	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;
	}
	}

@@ -803,27 +875,27 @@ static void show_flag_status(void)

	clear_line();
	putchar('_');
-	keypress = tless_getch();
+	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;
+	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();
@@ -831,15 +903,6 @@ static void show_flag_status(void)
	}
	#endif

-	static void full_repaint(void)
-	{
-	int temp_line_pos = line_pos;
-	data_readlines();
-	buffer_init();
-	buffer_line(temp_line_pos);
-	}
-
-
	static void save_input_to_file(void)
	{
	char *current_line;
@@ -847,7 +910,7 @@ static void save_input_to_file(void)
	FILE *fp;

	print_statusline("Log file: ");
-	current_line = tless_gets(sizeof("Log file: ")-1);
+	current_line = less_gets(sizeof("Log file: ")-1);
	if (strlen(current_line) > 0) {
	fp = fopen(current_line, "w");
	free(current_line);
@@ -855,7 +918,7 @@ static void save_input_to_file(void)
	print_statusline("Error opening log file");
	return;
	}
-	for (i = 0; i < num_flines; i++)
+	for (i = 0; i < max_fline; i++)
	fprintf(fp, "%s\n", flines[i]);
	fclose(fp);
	buffer_print();
@@ -871,16 +934,15 @@ static void add_mark(void)
	int letter;

	print_statusline("Mark: ");
-	letter = tless_getch();
+	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] = line_pos;
+	mark_lines[num_marks][1] = cur_fline;
	num_marks++;
	} else {
	print_statusline("Invalid mark letter");
@@ -893,7 +955,7 @@ static void goto_mark(void)
	int i;

	print_statusline("Go to mark: ");
-	letter = tless_getch();
+	letter = less_getch();
	clear_line();

	if (isalpha(letter)) {
@@ -915,17 +977,16 @@ static void goto_mark(void)
	static char opp_bracket(char bracket)
	{
	switch (bracket) {
-	case '{': case '[':
-	return bracket + 2;
-	case '(':
-	return ')';
-	case '}': case ']':
-	return bracket - 2;
-	case ')':
-	return '(';
-	default:
-	return 0;
+	case '{': case '[':
+	return bracket + 2;
+	case '(':
+	return ')';
+	case '}': case ']':
+	return bracket - 2;
+	case ')':
+	return '(';
	}
+	return 0;
	}

	static void match_right_bracket(char bracket)
@@ -933,11 +994,11 @@ static void match_right_bracket(char bracket)
	int bracket_line = -1;
	int i;

-	if (strchr(flines[line_pos], bracket) == NULL) {
+	if (strchr(flines[cur_fline], bracket) == NULL) {
	print_statusline("No bracket in top line");
	return;
	}
-	for (i = line_pos + 1; i < num_flines; i++) {
+	for (i = cur_fline + 1; i < max_fline; i++) {
	if (strchr(flines[i], opp_bracket(bracket)) != NULL) {
	bracket_line = i;
	break;
@@ -945,7 +1006,7 @@ static void match_right_bracket(char bracket)
	}
	if (bracket_line == -1)
	print_statusline("No matching bracket found");
-	buffer_line(bracket_line - height + 2);
+	buffer_line(bracket_line - max_displayed_line);
	}

	static void match_left_bracket(char bracket)
@@ -953,12 +1014,12 @@ static void match_left_bracket(char bracket)
	int bracket_line = -1;
	int i;

-	if (strchr(flines[line_pos + height - 2], bracket) == NULL) {
+	if (strchr(flines[cur_fline + max_displayed_line], bracket) == NULL) {
	print_statusline("No bracket in bottom line");
	return;
	}

-	for (i = line_pos + height - 2; i >= 0; i--) {
+	for (i = cur_fline + max_displayed_line; i >= 0; i--) {
	if (strchr(flines[i], opp_bracket(bracket)) != NULL) {
	bracket_line = i;
	break;
@@ -974,105 +1035,104 @@ static void match_left_bracket(char bracket)
	static void keypress_process(int keypress)
	{
	switch (keypress) {
-	case KEY_DOWN: case 'e': case 'j': case 0x0d:
-	buffer_down(1);
-	buffer_print();
-	break;
-	case KEY_UP: case 'y': case 'k':
-	buffer_up(1);
-	buffer_print();
-	break;
-	case PAGE_DOWN: case ' ': case 'z':
-	buffer_down(height - 1);
-	buffer_print();
-	break;
-	case PAGE_UP: case 'w': case 'b':
-	buffer_up(height - 1);
-	buffer_print();
-	break;
-	case 'd':
-	buffer_down((height - 1) / 2);
-	buffer_print();
-	break;
-	case 'u':
-	buffer_up((height - 1) / 2);
-	buffer_print();
-	break;
-	case KEY_HOME: case 'g': case 'p': case '<': case '%':
-	buffer_line(0);
-	break;
-	case KEY_END: case 'G': case '>':
-	buffer_line(num_flines - height + 2);
-	break;
-	case 'q': case 'Q':
-	tless_exit(0);
-	break;
+	case KEY_DOWN: case 'e': case 'j': case 0x0d:
+	buffer_down(1);
+	buffer_print();
+	break;
+	case KEY_UP: case 'y': case 'k':
+	buffer_up(1);
+	buffer_print();
+	break;
+	case PAGE_DOWN: case ' ': case 'z':
+	buffer_down(max_displayed_line + 1);
+	buffer_print();
+	break;
+	case PAGE_UP: case 'w': case 'b':
+	buffer_up(max_displayed_line + 1);
+	buffer_print();
+	break;
+	case 'd':
+	buffer_down((max_displayed_line + 1) / 2);
+	buffer_print();
+	break;
+	case 'u':
+	buffer_up((max_displayed_line + 1) / 2);
+	buffer_print();
+	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;
+	case 'm':
+	add_mark();
+	buffer_print();
+	break;
+	case '\'':
+	goto_mark();
+	buffer_print();
+	break;
	#endif
-	case 'r':
-	buffer_print();
-	break;
-	case 'R':
-	full_repaint();
-	break;
-	case 's':
-	save_input_to_file();
-	break;
-	case 'E':
-	examine_file();
-	break;
+	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;
+	case '=':
+	m_status_print();
+	break;
	#endif
	#if ENABLE_FEATURE_LESS_REGEXP
-	case '/':
-	option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
-	regex_process();
-	break;
-	case 'n':
-	//printf("HERE 3\n");sleep(1);
-	goto_match(match_pos + 1);
-	break;
-	case 'N':
-	goto_match(match_pos - 1);
-	break;
-	case '?':
-	option_mask32 \|= LESS_STATE_MATCH_BACKWARDS;
-	regex_process();
-	break;
+	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;
+	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;
+	case '{': case '(': case '[':
+	match_right_bracket(keypress);
+	break;
+	case '}': case ')': case ']':
+	match_left_bracket(keypress);
+	break;
	#endif
-	case ':':
-	colon_process();
-	break;
-	default:
-	break;
+	case ':':
+	colon_process();
+	break;
	}

	if (isdigit(keypress))
@@ -1092,8 +1152,8 @@ int less_main(int argc, char **argv)
	getopt32(argc, argv, "EMmN~");
	argc -= optind;
	argv += optind;
-	files = argv;
	num_files = argc;
+	files = argv;

	/* Another popular pager, most, detects when stdout
	* is not a tty and turns into cat. This makes sense. */
@@ -1109,33 +1169,35 @@ int less_main(int argc, char **argv)
	} else
	filename = xstrdup(files[0]);

-	inp = xfopen(CURRENT_TTY, "r");
+	kbd_fd = xopen(CURRENT_TTY, O_RDONLY);

-	get_terminal_width_height(fileno(inp), &width, &height);
-	if (width < 10 \|\| height < 3)
+	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(height * sizeof(char *));
+	buffer = xmalloc((max_displayed_line+1) * sizeof(char *));
	if (option_mask32 & FLAG_TILDE)
	empty_line_marker = "";

-	data_readlines();
-
-	tcgetattr(fileno(inp), &term_orig);
+	tcgetattr(kbd_fd, &term_orig);
	signal(SIGTERM, sig_catcher);
	signal(SIGINT, sig_catcher);
	term_vi = term_orig;
-	term_vi.c_lflag &= (~ICANON & ~ECHO);
-	term_vi.c_iflag &= (~IXON & ~ICRNL);
-	term_vi.c_oflag &= (~ONLCR);
+	term_vi.c_lflag &= ~(ICANON \| ECHO);
+	term_vi.c_iflag &= ~(IXON \| ICRNL);
+	/term_vi.c_oflag &= ~ONLCR;/
	term_vi.c_cc[VMIN] = 1;
	term_vi.c_cc[VTIME] = 0;

-	buffer_init();
-	buffer_print();
+	/* 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_vi);/

+	reinitialize();
	while (1) {
-	keypress = tless_getch();
+	keypress = less_getch();
	keypress_process(keypress);
	}
	}

shell/ash.c+1 -1

@@ -12693,7 +12693,7 @@ readcmd(int argc, char **argv)
	FD_ZERO (&set);
	FD_SET (0, &set);

-	i = select (FD_SETSIZE, &set, NULL, NULL, &ts);
+	i = select(FD_SETSIZE, &set, NULL, NULL, &ts);
	if (!i) {
	#if defined(CONFIG_ASH_READ_NCHARS)
	if (nch_flag)