9a7cef930

Denis Vlasenko

2006-12-20

FAILED Duration: 3s

Subject

less: somewhat buggy applet, but nice. Muchly reduced xstrdup'ing and memory consumption. Made linewrap saner. regex matching code was awful - still buggy, but not as leaky as before. Made buffer size configurable. Killed several static and on-stack buffers. Hopefully eliminated staircase effect on

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 →

libbb/get_line_from_file.c +2 -2 miscutils/Config.in +5 -0 miscutils/less.c +201 -212

libbb/get_line_from_file.c+2 -2

@@ -13,7 +13,7 @@

	/* This function reads an entire line from a text file, up to a newline
	* or NUL byte, inclusive. It returns a malloc'ed char * which must be
-	* stored and free'ed by the caller. If end is null '\n' isn't considered
+	* stored and free'ed by the caller. If end is null '\n' isn't considered
	* end of line. If end isn't null, length of the chunk read is stored in it. */

	char bb_get_chunk_from_file(FILE file, int *end)
@@ -62,7 +62,7 @@ char xmalloc_getline(FILE file)
	char *c = bb_get_chunk_from_file(file, &i);

	if (i && c[--i] == '\n')
-	c[i] = 0;
+	c[i] = '\0';

	return c;
	}

miscutils/Config.in+5 -0

@@ -133,6 +133,11 @@ config LESS
	'less' is a pager, meaning that it displays text files. It possesses
	a wide array of features, and is an improvement over 'more'.

+	config FEATURE_LESS_MAXLINES
+	int "Max number of input lines less will try to eat"
+	default 9999999
+	depends on LESS
+
	config FEATURE_LESS_BRACKETS
	bool "Enable bracket searching"
	default y

miscutils/less.c+201 -212

@@ -32,7 +32,7 @@

	#include "busybox.h"

-	#ifdef CONFIG_FEATURE_LESS_REGEXP
+	#if ENABLE_FEATURE_LESS_REGEXP
	#include "xregex.h"
	#endif

@@ -64,13 +64,12 @@
	/* The escape code to clear the screen */
	#define CLEAR "\033[H\033[J"

-	/* Maximum number of lines in a file */
-	#define MAXLINES 10000
+	#define MAXLINES CONFIG_FEATURE_LESS_MAXLINES

	static int height;
	static int width;
	static char **files;
-	static char filename[256];
+	static char *filename;
	static char **buffer;
	static char **flines;
	static int current_file = 1;
@@ -79,24 +78,21 @@ static int num_flines;
	static int num_files = 1;

	/* Command line options */
-	static unsigned flags;
	#define FLAG_E 1
	#define FLAG_M (1<<1)
	#define FLAG_m (1<<2)
	#define FLAG_N (1<<3)
	#define FLAG_TILDE (1<<4)
	/* hijack command line options variable for internal state vars */
-	#define LESS_STATE_INP_STDIN (1<<5)
-	#define LESS_STATE_PAST_EOF (1<<6)
-	#define LESS_STATE_MATCH_BACKWARDS (1<<7)
-	/* INP_STDIN is used to change behaviour when input comes from stdin */
+	#define LESS_STATE_PAST_EOF (1<<5)
+	#define LESS_STATE_MATCH_BACKWARDS (1<<6)

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

-	#ifdef CONFIG_FEATURE_LESS_REGEXP
+	#if ENABLE_FEATURE_LESS_REGEXP
	static int match_found;
	static int *match_lines;
	static int match_pos;
@@ -143,7 +139,7 @@ static int tless_getch(void)
	them accordingly */

	if (input == '\033' && getc(inp) == '[') {
-	unsigned int i;
+	unsigned i;
	input = getc(inp);
	set_tty_cooked();

@@ -152,13 +148,12 @@ static int tless_getch(void)
	return 20 + i;
	else if ((i = input - REAL_PAGE_UP) < 4)
	return 24 + i;
+	else
+	return 0; /* ?? */
	}
	/* The input is a normal ASCII value */
-	else {
-	set_tty_cooked();
-	return input;
-	}
-	return 0;
+	set_tty_cooked();
+	return input;
	}

	/* Move the cursor to a position (x,y), where (0,0) is the
@@ -174,51 +169,62 @@ static void clear_line(void)
	printf("\033[K");
	}

-	/* This adds line numbers to every line, as the -N flag necessitates */
-	static void add_linenumbers(void)
-	{
-	int i;
-
-	for (i = 0; i <= num_flines; i++) {
-	char *new = xasprintf("%5d %s", i + 1, flines[i]);
-	free(flines[i]);
-	flines[i] = new;
-	}
-	}
-
	static void data_readlines(void)
	{
-	int i;
-	char current_line[256];
+	unsigned i;
+	unsigned n = 1;
+	int w = width;
+	char last_nl = (char)1; /* "not NULL" */
+	char *current_line;
	FILE *fp;

-	fp = (flags & LESS_STATE_INP_STDIN) ? stdin : xfopen(filename, "r");
+	fp = filename ? xfopen(filename, "r") : stdin;
	flines = NULL;
-	for (i = 0; (feof(fp)==0) && (i <= MAXLINES); i++) {
-	strcpy(current_line, "");
-	fgets(current_line, 256, fp);
+	if (option_mask32 & FLAG_N) {
+	w -= 6;
+	if (w < 1) w = 1; /* paranoia */
+	}
+	for (i = 0; !feof(fp) && i <= MAXLINES; i++) {
+	flines = xrealloc(flines, (i+1) * sizeof(char *));
+
+	current_line = xmalloc(w);
+	again:
+	current_line[0] = '\0';
+	fgets(current_line, w, fp);
	if (fp != stdin)
	die_if_ferror(fp, filename);
-	flines = xrealloc(flines, (i+1) * sizeof(char *));
-	flines[i] = xstrdup(current_line);
+
+	/* Corner case: linewrap with only '\n' wrapping */
+	/* Looks ugly on screen, so we handle it specially */
+	if (!last_nl && current_line[0] == '\n') {
+	last_nl = (char)1; / "not NULL" */
+	n++;
+	goto again;
+	}
+	last_nl = last_char_is(current_line, '\n');
+	if (last_nl)
+	*last_nl = '\0';
+	if (option_mask32 & FLAG_N) {
+	flines[i] = xasprintf((n <= 99999) ? "%5u %s" : "%05u %s",
+	n % 100000, current_line);
+	free(current_line);
+	if (last_nl)
+	n++;
+	} else {
+	flines[i] = xrealloc(current_line, strlen(current_line)+1);
+	}
	}
	num_flines = i - 2;

	/* Reset variables for a new file */

	line_pos = 0;
-	flags &= ~LESS_STATE_PAST_EOF;
+	option_mask32 &= ~LESS_STATE_PAST_EOF;

	fclose(fp);
-
-	if (inp == NULL)
-	inp = (flags & LESS_STATE_INP_STDIN) ? xfopen(CURRENT_TTY, "r") : stdin;
-
-	if (flags & FLAG_N)
-	add_linenumbers();
	}

-	#ifdef CONFIG_FEATURE_LESS_FLAGS
+	#if ENABLE_FEATURE_LESS_FLAGS

	/* Interestingly, writing calc_percent as a function and not a prototype saves around 32 bytes
	* on my build. */
@@ -232,19 +238,18 @@ static void m_status_print(void)
	{
	int percentage;

-	if (!(flags & LESS_STATE_PAST_EOF)) {
+	if (!(option_mask32 & LESS_STATE_PAST_EOF)) {
	if (!line_pos) {
-	if (num_files > 1)
+	if (num_files > 1) {
	printf("%s%s %s%i%s%i%s%i-%i/%i ", HIGHLIGHT,
	filename, "(file ", current_file, " of ", num_files, ") lines ",
	line_pos + 1, line_pos + height - 1, num_flines + 1);
-	else {
+	} else {
	printf("%s%s lines %i-%i/%i ", HIGHLIGHT,
	filename, line_pos + 1, line_pos + height - 1,
	num_flines + 1);
	}
-	}
-	else {
+	} else {
	printf("%s %s lines %i-%i/%i ", HIGHLIGHT, filename,
	line_pos + 1, line_pos + height - 1, num_flines + 1);
	}
@@ -253,13 +258,11 @@ static void m_status_print(void)
	printf("(END) %s", NORMAL);
	if ((num_files > 1) && (current_file != num_files))
	printf("%s- Next: %s%s", HIGHLIGHT, files[current_file], NORMAL);
-	}
-	else {
+	} else {
	percentage = calc_percent();
	printf("%i%% %s", percentage, NORMAL);
	}
-	}
-	else {
+	} else {
	printf("%s%s lines %i-%i/%i (END) ", HIGHLIGHT, filename,
	line_pos + 1, num_flines + 1, num_flines + 1);
	if ((num_files > 1) && (current_file != num_files))
@@ -287,10 +290,10 @@ static void medium_status_print(void)
	static void status_print(void)
	{
	/* Change the status if flags have been set */
-	#ifdef CONFIG_FEATURE_LESS_FLAGS
-	if (flags & FLAG_M)
+	#if ENABLE_FEATURE_LESS_FLAGS
+	if (option_mask32 & FLAG_M)
	m_status_print();
-	else if (flags & FLAG_m)
+	else if (option_mask32 & FLAG_m)
	medium_status_print();
	/* No flags set */
	else {
@@ -300,16 +303,14 @@ static void status_print(void)
	if (num_files > 1)
	printf("%s%s%i%s%i%s%s", HIGHLIGHT, "(file ",
	current_file, " of ", num_files, ")", NORMAL);
-	}
-	else if (line_pos == num_flines - height + 2) {
+	} else if (line_pos == num_flines - height + 2) {
	printf("%s%s %s", HIGHLIGHT, "(END)", NORMAL);
	if ((num_files > 1) && (current_file != num_files))
	printf("%s%s%s%s", HIGHLIGHT, "- Next: ", files[current_file], NORMAL);
-	}
-	else {
+	} else {
	putchar(':');
	}
-	#ifdef CONFIG_FEATURE_LESS_FLAGS
+	#if ENABLE_FEATURE_LESS_FLAGS
	}
	#endif
	}
@@ -322,13 +323,12 @@ static void buffer_print(void)
	printf("%s", CLEAR);
	if (num_flines >= height - 2) {
	for (i = 0; i < height - 1; i++)
-	printf("%s", buffer[i]);
-	}
-	else {
+	printf("%.*s\n", width, buffer[i]);
+	} else {
	for (i = 1; i < (height - 1 - num_flines); i++)
	putchar('\n');
	for (i = 0; i < height - 1; i++)
-	printf("%s", buffer[i]);
+	printf("%.*s\n", width, buffer[i]);
	}

	status_print();
@@ -341,21 +341,18 @@ static void buffer_init(void)

	if (buffer == NULL) {
	/* malloc the number of lines needed for the buffer */
-	buffer = xrealloc(buffer, height * sizeof(char *));
-	} else {
-	for (i = 0; i < (height - 1); i++)
-	free(buffer[i]);
+	buffer = xmalloc(height * sizeof(char *));
	}

	/* 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] = xstrdup(flines[i]);
+	buffer[i] = flines[i];
	}

	/* If the buffer still isn't full, fill it with blank lines */
	for (; i < (height - 1); i++) {
-	buffer[i] = xstrdup("");
+	buffer[i] = "";
	}
	}

@@ -364,28 +361,25 @@ static void buffer_down(int nlines)
	{
	int i;

-	if (!(flags & LESS_STATE_PAST_EOF)) {
+	if (!(option_mask32 & LESS_STATE_PAST_EOF)) {
	if (line_pos + (height - 3) + nlines < num_flines) {
	line_pos += nlines;
	for (i = 0; i < (height - 1); i++) {
-	free(buffer[i]);
-	buffer[i] = xstrdup(flines[line_pos + i]);
+	buffer[i] = flines[line_pos + i];
	}
-	}
-	else {
+	} else {
	/* 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++) {
-	free(buffer[i]);
-	buffer[i] = xstrdup(flines[line_pos + i]);
+	buffer[i] = flines[line_pos + i];
	}
	}
	}

	/* We exit if the -E flag has been set */
-	if ((flags & FLAG_E) && (line_pos + (height - 2) == num_flines))
+	if ((option_mask32 & FLAG_E) && (line_pos + (height - 2) == num_flines))
	tless_exit(0);
	}
	}
@@ -395,22 +389,19 @@ static void buffer_up(int nlines)
	int i;
	int tilde_line;

-	if (!(flags & LESS_STATE_PAST_EOF)) {
+	if (!(option_mask32 & LESS_STATE_PAST_EOF)) {
	if (line_pos - nlines >= 0) {
	line_pos -= nlines;
	for (i = 0; i < (height - 1); i++) {
-	free(buffer[i]);
-	buffer[i] = xstrdup(flines[line_pos + i]);
+	buffer[i] = flines[line_pos + i];
	}
-	}
-	else {
+	} else {
	/* As the requested number of lines to move was too large, we
	move one line up at a time until we can't. */
	while (line_pos != 0) {
	line_pos -= 1;
	for (i = 0; i < (height - 1); i++) {
-	free(buffer[i]);
-	buffer[i] = xstrdup(flines[line_pos + i]);
+	buffer[i] = flines[line_pos + i];
	}
	}
	}
@@ -423,19 +414,17 @@ static void buffer_up(int nlines)
	/* Going backwards nlines lines has taken us to a point where
	nothing is past the EOF, so we revert to normal. */
	if (line_pos < num_flines - height + 3) {
-	flags &= ~LESS_STATE_PAST_EOF;
+	option_mask32 &= ~LESS_STATE_PAST_EOF;
	buffer_up(nlines);
-	}
-	else {
+	} else {
	/* We only move part of the buffer, as the rest
	is past the EOF */
	for (i = 0; i < (height - 1); i++) {
-	free(buffer[i]);
-	if (i < tilde_line - nlines + 1)
-	buffer[i] = xstrdup(flines[line_pos + i]);
-	else {
+	if (i < tilde_line - nlines + 1) {
+	buffer[i] = flines[line_pos + i];
+	} else {
	if (line_pos >= num_flines - height + 2)
-	buffer[i] = xstrdup("~\n");
+	buffer[i] = "~";
	}
	}
	}
@@ -445,7 +434,7 @@ static void buffer_up(int nlines)
	static void buffer_line(int linenum)
	{
	int i;
-	flags &= ~LESS_STATE_PAST_EOF;
+	option_mask32 &= ~LESS_STATE_PAST_EOF;

	if (linenum < 0 \|\| linenum > num_flines) {
	clear_line();
@@ -453,23 +442,20 @@ static void buffer_line(int linenum)
	}
	else if (linenum < (num_flines - height - 2)) {
	for (i = 0; i < (height - 1); i++) {
-	free(buffer[i]);
-	buffer[i] = xstrdup(flines[linenum + i]);
+	buffer[i] = flines[linenum + i];
	}
	line_pos = linenum;
	buffer_print();
-	}
-	else {
+	} else {
	for (i = 0; i < (height - 1); i++) {
-	free(buffer[i]);
	if (linenum + i < num_flines + 2)
-	buffer[i] = xstrdup(flines[linenum + i]);
+	buffer[i] = flines[linenum + i];
	else
-	buffer[i] = xstrdup((flags & FLAG_TILDE) ? "\n" : "~\n");
+	buffer[i] = (option_mask32 & FLAG_TILDE) ? "" : "~";
	}
	line_pos = linenum;
	/* Set past_eof so buffer_down and buffer_up act differently */
-	flags \|= LESS_STATE_PAST_EOF;
+	option_mask32 \|= LESS_STATE_PAST_EOF;
	buffer_print();
	}
	}
@@ -490,22 +476,13 @@ static void reinitialise(void)

	static void examine_file(void)
	{
-	int newline_offset;
-
	clear_line();
	printf("Examine: ");
-	fgets(filename, 256, inp);
-
-	/* As fgets adds a newline to the end of an input string, we
-	need to remove it */
-	newline_offset = strlen(filename) - 1;
-	filename[newline_offset] = '\0';
-
-	files[num_files] = xstrdup(filename);
+	free(filename);
+	filename = xmalloc_getline(inp);
+	files[num_files] = filename;
	current_file = num_files + 1;
	num_files++;
-
-	flags &= ~LESS_STATE_INP_STDIN;
	reinitialise();
	}

@@ -518,10 +495,10 @@ static void change_file(int direction)
	{
	if (current_file != ((direction > 0) ? num_files : 1)) {
	current_file = direction ? current_file + direction : 1;
-	strcpy(filename, files[current_file - 1]);
+	free(filename);
+	filename = xstrdup(files[current_file - 1]);
	reinitialise();
-	}
-	else {
+	} else {
	clear_line();
	printf("%s%s%s", HIGHLIGHT, (direction > 0) ? "No next file" : "No previous file", NORMAL);
	}
@@ -537,8 +514,7 @@ static void remove_current_file(void)
	files[i - 2] = files[i - 1];
	num_files--;
	buffer_print();
-	}
-	else {
+	} else {
	change_file(1);
	for (i = 2; i <= num_files; i++)
	files[i - 2] = files[i - 1];
@@ -564,7 +540,7 @@ static void colon_process(void)
	case 'e':
	examine_file();
	break;
-	#ifdef CONFIG_FEATURE_LESS_FLAGS
+	#if ENABLE_FEATURE_LESS_FLAGS
	case 'f':
	clear_line();
	m_status_print();
@@ -587,7 +563,7 @@ static void colon_process(void)
	}
	}

-	#ifdef CONFIG_FEATURE_LESS_REGEXP
+	#if ENABLE_FEATURE_LESS_REGEXP
	/* The below two regular expression handler functions NEED development. */

	/* Get a regular expression from the user, and then go through the current
@@ -595,48 +571,50 @@ static void colon_process(void)

	static char process_regex_on_line(char line, regex_t *pattern, int action)
	{
+	/* UNTESTED. LOOKED BUGGY AND LEAKY AS HELL. */
+	/* FIXED. NEED TESTING. */
+	/* 'line' should be either returned or free()ed */
+
	/* This function takes the regex and applies it to the line.
	Each part of the line that matches has the HIGHLIGHT
	and NORMAL escape sequences placed around it by
	insert_highlights if action = 1, or has the escape sequences
	removed if action = 0, and then the line is returned. */
	int match_status;
-	char line2 = xmalloc((sizeof(char) (strlen(line) + 1)) + 64);
-	char *growline = "";
+	char *line2 = line;
+	char *growline = xstrdup("");
+	char *ng;
	regmatch_t match_structs;

-	line2 = xstrdup(line);
-
	match_found = 0;
	match_status = regexec(pattern, line2, 1, &match_structs, 0);

	while (match_status == 0) {
-	if (match_found == 0)
-	match_found = 1;
-
+	match_found = 1;
	if (action) {
-	growline = xasprintf("%s%.s%s%.s%s", growline,
+	ng = xasprintf("%s%.s%s%.s%s", growline,
	match_structs.rm_so, line2, HIGHLIGHT,
	match_structs.rm_eo - match_structs.rm_so,
	line2 + match_structs.rm_so, NORMAL);
-	}
-	else {
-	growline = xasprintf("%s%.s%.s", growline,
+	} else {
+	ng = xasprintf("%s%.s%.s", growline,
	match_structs.rm_so - 4, line2,
	match_structs.rm_eo - match_structs.rm_so,
	line2 + match_structs.rm_so);
	}
-
+	free(growline); growline = ng;
	line2 += match_structs.rm_eo;
	match_status = regexec(pattern, line2, 1, &match_structs, REG_NOTBOL);
	}

-	growline = xasprintf("%s%s", growline, line2);
-
-	return (match_found ? growline : line);
-
+	if (match_found) {
+	ng = xasprintf("%s%s", growline, line2);
+	free(line);
+	} else {
+	ng = line;
+	}
	free(growline);
-	free(line2);
+	return ng;
	}

	static void goto_match(int match)
@@ -651,35 +629,33 @@ static void goto_match(int match)

	static void regex_process(void)
	{
-	char uncomp_regex[100];
-	char *current_line;
+	char *uncomp_regex;
	int i;
	int j = 0;
	regex_t pattern;
+
	/* Get the uncompiled regular expression from the user */
	clear_line();
-	putchar((flags & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
-	uncomp_regex[0] = 0;
-	fgets(uncomp_regex, sizeof(uncomp_regex), inp);
-
-	if (strlen(uncomp_regex) == 1) {
+	putchar((option_mask32 & LESS_STATE_MATCH_BACKWARDS) ? '?' : '/');
+	uncomp_regex = xmalloc_getline(inp);
+	if (!uncomp_regex \|\| !uncomp_regex[0]) {
+	free(uncomp_regex);
	if (num_matches)
-	goto_match((flags & LESS_STATE_MATCH_BACKWARDS)
+	goto_match((option_mask32 & LESS_STATE_MATCH_BACKWARDS)
	? match_pos - 1 : match_pos + 1);
	else
	buffer_print();
	return;
	}
-	uncomp_regex[strlen(uncomp_regex) - 1] = '\0';

	/* Compile the regex and check for errors */
	xregcomp(&pattern, uncomp_regex, 0);
+	free(uncomp_regex);

	if (num_matches) {
	/* Get rid of all the highlights we added previously */
	for (i = 0; i <= num_flines; i++) {
-	current_line = process_regex_on_line(flines[i], &old_pattern, 0);
-	flines[i] = xstrdup(current_line);
+	flines[i] = process_regex_on_line(flines[i], &old_pattern, 0);
	}
	}
	old_pattern = pattern;
@@ -692,8 +668,7 @@ static void regex_process(void)
	match_found = 0;
	/* Run the regex on each line of the current file here */
	for (i = 0; i <= num_flines; i++) {
-	current_line = process_regex_on_line(flines[i], &pattern, 1);
-	flines[i] = xstrdup(current_line);
+	flines[i] = process_regex_on_line(flines[i], &pattern, 1);
	if (match_found) {
	match_lines = xrealloc(match_lines, (j + 1) * sizeof(int));
	match_lines[j] = i;
@@ -703,7 +678,7 @@ static void regex_process(void)

	num_matches = j;
	if ((match_lines[0] != -1) && (num_flines > height - 2)) {
-	if (flags & LESS_STATE_MATCH_BACKWARDS) {
+	if (option_mask32 & LESS_STATE_MATCH_BACKWARDS) {
	for (i = 0; i < num_matches; i++) {
	if (match_lines[i] > line_pos) {
	match_pos = i - 1;
@@ -711,11 +686,9 @@ static void regex_process(void)
	break;
	}
	}
-	}
-	else
+	} else
	buffer_line(match_lines[0]);
-	}
-	else
+	} else
	buffer_init();
	}
	#endif
@@ -724,9 +697,8 @@ static void number_process(int first_digit)
	{
	int i = 1;
	int num;
-	char num_input[80];
+	char num_input[sizeof(int)4]; / more than enough */
	char keypress;
-	char *endptr;

	num_input[0] = first_digit;

@@ -734,8 +706,11 @@ static void number_process(int first_digit)
	clear_line();
	printf(":%c", first_digit);

-	/* Receive input until a letter is given (max 80 chars)*/
-	while((i < 80) && (num_input[i] = tless_getch()) && isdigit(num_input[i])) {
+	/* Receive input until a letter is given */
+	while (i < sizeof(num_input)-1) {
+	num_input[i] = tless_getch();
+	if (!num_input[i] \|\| !isdigit(num_input[i]))
+	break;
	putchar(num_input[i]);
	i++;
	}
@@ -743,8 +718,9 @@ static void number_process(int first_digit)
	/* Take the final letter out of the digits string */
	keypress = num_input[i];
	num_input[i] = '\0';
-	num = strtol(num_input, &endptr, 10);
-	if (endptr==num_input \|\| *endptr!='\0' \|\| num < 1 \|\| num > MAXLINES) {
+	num = bb_strtou(num_input, NULL, 10);
+	/* on format error, num == -1 */
+	if (num < 1 \|\| num > MAXLINES) {
	buffer_print();
	return;
	}
@@ -764,16 +740,16 @@ static void number_process(int first_digit)
	case 'p': case '%':
	buffer_line(((num / 100) * num_flines) - 1);
	break;
-	#ifdef CONFIG_FEATURE_LESS_REGEXP
+	#if ENABLE_FEATURE_LESS_REGEXP
	case 'n':
	goto_match(match_pos + num);
	break;
	case '/':
-	flags &= ~LESS_STATE_MATCH_BACKWARDS;
+	option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
	regex_process();
	break;
	case '?':
-	flags \|= LESS_STATE_MATCH_BACKWARDS;
+	option_mask32 \|= LESS_STATE_MATCH_BACKWARDS;
	regex_process();
	break;
	#endif
@@ -782,7 +758,7 @@ static void number_process(int first_digit)
	}
	}

-	#ifdef CONFIG_FEATURE_LESS_FLAGCS
+	#if ENABLE_FEATURE_LESS_FLAGCS
	static void flag_change(void)
	{
	int keypress;
@@ -793,16 +769,16 @@ static void flag_change(void)

	switch (keypress) {
	case 'M':
-	flags ^= FLAG_M;
+	option_mask32 ^= FLAG_M;
	break;
	case 'm':
-	flags ^= FLAG_m;
+	option_mask32 ^= FLAG_m;
	break;
	case 'E':
-	flags ^= FLAG_E;
+	option_mask32 ^= FLAG_E;
	break;
	case '~':
-	flags ^= FLAG_TILDE;
+	option_mask32 ^= FLAG_TILDE;
	break;
	default:
	break;
@@ -820,19 +796,19 @@ static void show_flag_status(void)

	switch (keypress) {
	case 'M':
-	flag_val = flags & FLAG_M;
+	flag_val = option_mask32 & FLAG_M;
	break;
	case 'm':
-	flag_val = flags & FLAG_m;
+	flag_val = option_mask32 & FLAG_m;
	break;
	case '~':
-	flag_val = flags & FLAG_TILDE;
+	flag_val = option_mask32 & FLAG_TILDE;
	break;
	case 'N':
-	flag_val = flags & FLAG_N;
+	flag_val = option_mask32 & FLAG_N;
	break;
	case 'E':
-	flag_val = flags & FLAG_E;
+	flag_val = option_mask32 & FLAG_E;
	break;
	default:
	flag_val = 0;
@@ -855,26 +831,31 @@ static void full_repaint(void)

	static void save_input_to_file(void)
	{
-	char current_line[256];
+	char *current_line;
	int i;
	FILE *fp;

	clear_line();
	printf("Log file: ");
-	fgets(current_line, 256, inp);
-	current_line[strlen(current_line) - 1] = '\0';
-	if (strlen(current_line) > 1) {
-	fp = xfopen(current_line, "w");
+	current_line = xmalloc_getline(inp);
+	if (strlen(current_line) > 0) {
+	fp = fopen(current_line, "w");
+	free(current_line);
+	if (!fp) {
+	printf("%s%s%s", HIGHLIGHT, "Error opening log file", NORMAL);
+	return;
+	}
	for (i = 0; i < num_flines; i++)
-	fprintf(fp, "%s", flines[i]);
+	fprintf(fp, "%s\n", flines[i]);
	fclose(fp);
	buffer_print();
+	return;
	}
-	else
-	printf("%s%s%s", HIGHLIGHT, "No log file", NORMAL);
+	free(current_line);
+	printf("%s%s%s", HIGHLIGHT, "No log file", NORMAL);
	}

-	#ifdef CONFIG_FEATURE_LESS_MARKS
+	#if ENABLE_FEATURE_LESS_MARKS
	static void add_mark(void)
	{
	int letter;
@@ -892,8 +873,7 @@ static void add_mark(void)
	mark_lines[num_marks][0] = letter;
	mark_lines[num_marks][1] = line_pos;
	num_marks++;
-	}
-	else {
+	} else {
	clear_line();
	printf("%s%s%s", HIGHLIGHT, "Invalid mark letter", NORMAL);
	}
@@ -917,14 +897,13 @@ static void goto_mark(void)
	}
	if ((num_marks == 14) && (letter != mark_lines[14][0]))
	printf("%s%s%s", HIGHLIGHT, "Mark not set", NORMAL);
-	}
-	else
+	} else
	printf("%s%s%s", HIGHLIGHT, "Invalid mark letter", NORMAL);
	}
	#endif


-	#ifdef CONFIG_FEATURE_LESS_BRACKETS
+	#if ENABLE_FEATURE_LESS_BRACKETS

	static char opp_bracket(char bracket)
	{
@@ -977,8 +956,7 @@ static void match_left_bracket(char bracket)
	printf("%s%s%s", HIGHLIGHT, "No bracket in bottom line", NORMAL);
	printf("%s", flines[line_pos + height]);
	sleep(4);
-	}
-	else {
+	} else {
	for (i = line_pos + height - 2; i >= 0; i--) {
	if (strchr(flines[i], opp_bracket(bracket)) != NULL) {
	bracket_line = i;
@@ -993,7 +971,7 @@ static void match_left_bracket(char bracket)
	}
	}

-	#endif /* CONFIG_FEATURE_LESS_BRACKETS */
+	#endif /* FEATURE_LESS_BRACKETS */

	static void keypress_process(int keypress)
	{
@@ -1031,7 +1009,7 @@ static void keypress_process(int keypress)
	case 'q': case 'Q':
	tless_exit(0);
	break;
-	#ifdef CONFIG_FEATURE_LESS_MARKS
+	#if ENABLE_FEATURE_LESS_MARKS
	case 'm':
	add_mark();
	buffer_print();
@@ -1048,21 +1026,20 @@ static void keypress_process(int keypress)
	full_repaint();
	break;
	case 's':
-	if (flags & LESS_STATE_INP_STDIN)
-	save_input_to_file();
+	save_input_to_file();
	break;
	case 'E':
	examine_file();
	break;
-	#ifdef CONFIG_FEATURE_LESS_FLAGS
+	#if ENABLE_FEATURE_LESS_FLAGS
	case '=':
	clear_line();
	m_status_print();
	break;
	#endif
-	#ifdef CONFIG_FEATURE_LESS_REGEXP
+	#if ENABLE_FEATURE_LESS_REGEXP
	case '/':
-	flags &= ~LESS_STATE_MATCH_BACKWARDS;
+	option_mask32 &= ~LESS_STATE_MATCH_BACKWARDS;
	regex_process();
	break;
	case 'n':
@@ -1072,11 +1049,11 @@ static void keypress_process(int keypress)
	goto_match(match_pos - 1);
	break;
	case '?':
-	flags \|= LESS_STATE_MATCH_BACKWARDS;
+	option_mask32 \|= LESS_STATE_MATCH_BACKWARDS;
	regex_process();
	break;
	#endif
-	#ifdef CONFIG_FEATURE_LESS_FLAGCS
+	#if ENABLE_FEATURE_LESS_FLAGCS
	case '-':
	flag_change();
	buffer_print();
@@ -1085,7 +1062,7 @@ static void keypress_process(int keypress)
	show_flag_status();
	break;
	#endif
-	#ifdef CONFIG_FEATURE_LESS_BRACKETS
+	#if ENABLE_FEATURE_LESS_BRACKETS
	case '{': case '(': case '[':
	match_right_bracket(keypress);
	break;
@@ -1104,30 +1081,42 @@ static void keypress_process(int keypress)
	number_process(keypress);
	}

-	int less_main(int argc, char **argv) {
+	static void sig_catcher(int sig ATTRIBUTE_UNUSED)
+	{
+	set_tty_cooked();
+	exit(1);
+	}

+	int less_main(int argc, char **argv)
+	{
	int keypress;

-	flags = getopt32(argc, argv, "EMmN~");
-
+	getopt32(argc, argv, "EMmN~");
	argc -= optind;
	argv += optind;
	files = argv;
	num_files = argc;

	if (!num_files) {
-	if (ttyname(STDIN_FILENO) == NULL)
-	flags \|= LESS_STATE_INP_STDIN;
-	else {
+	if (isatty(STDIN_FILENO)) {
+	/* Just "less"? No file and no redirection? */
	bb_error_msg("missing filename");
	bb_show_usage();
	}
-	}
+	} else
+	filename = xstrdup(files[0]);
+
+	/* FIXME: another popular pager, most, detects when stdout
+	* is not a tty and turns into cat */
+	inp = xfopen(CURRENT_TTY, "r");

-	strcpy(filename, (flags & LESS_STATE_INP_STDIN) ? bb_msg_standard_input : files[0]);
-	get_terminal_width_height(0, &width, &height);
+	get_terminal_width_height(fileno(inp), &width, &height);
	data_readlines();
+
+	signal(SIGTERM, sig_catcher);
+	signal(SIGINT, sig_catcher);
	tcgetattr(fileno(inp), &term_orig);
+
	term_vi = term_orig;
	term_vi.c_lflag &= (~ICANON & ~ECHO);
	term_vi.c_iflag &= (~IXON & ~ICRNL);