X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;ds=sidebyside;f=miscutils%2Fless.c;h=0b0a9aed4be26e7290d9813cf946e5b25e2d44ca;hb=179e88bec91cfe58096900dc5509a080ff37b083;hp=d7076dbbc78b66d284abc2fdffdc3d1306318d23;hpb=9de2e5a22213842da5b116723392de88de9ed419;p=oweals%2Fbusybox.git

diff --git a/miscutils/less.c b/miscutils/less.c
index d7076dbbc..0b0a9aed4 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -87,7 +87,6 @@
 //config:	  this option makes less perform a last-ditch effort to find it:
 //config:	  position cursor to 999,999 and ask terminal to report real
 //config:	  cursor position using "ESC [ 6 n" escape sequence, then read stdin.
-//config:
 //config:	  This is not clean but helps a lot on serial lines and such.
 //config:
 //config:config FEATURE_LESS_DASHCMD
@@ -99,11 +98,13 @@
 //config:	  less itself ('-' keyboard command).
 //config:
 //config:config FEATURE_LESS_LINENUMS
-//config:	bool "Enable dynamic switching of line numbers"
+//config:	bool "Enable -N (dynamic switching of line numbers)"
 //config:	default y
 //config:	depends on FEATURE_LESS_DASHCMD
-//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_REGEXP("I")IF_FEATURE_LESS_FLAGS("Mm")
@@ -169,6 +170,7 @@ 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;
@@ -304,6 +306,8 @@ 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 */
@@ -1589,16 +1593,23 @@ 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;
 		}
 	}
@@ -1607,16 +1618,22 @@ 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;
 		}
@@ -1784,9 +1801,10 @@ 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) {
@@ -1798,10 +1816,12 @@ 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);