hush/console-tools/resize.c
Denys Vlasenko 98a4c7cf3d *: suppress ~60% of "aliased warnings" on gcc-4.4.1
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2010-02-04 15:00:15 +01:00

72 lines
1.9 KiB
C

/* vi: set sw=4 ts=4: */
/*
* resize - set terminal width and height.
*
* Copyright 2006 Bernhard Reutner-Fischer
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/* no options, no getopt */
#include "libbb.h"
#define ESC "\033"
#define old_termios_p ((struct termios*)&bb_common_bufsiz1)
static void
onintr(int sig UNUSED_PARAM)
{
tcsetattr(STDERR_FILENO, TCSANOW, old_termios_p);
exit(EXIT_FAILURE);
}
int resize_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int resize_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
{
struct termios new;
struct winsize w = { 0, 0, 0, 0 };
int ret;
/* We use _stderr_ in order to make resize usable
* in shell backticks (those redirect stdout away from tty).
* NB: other versions of resize open "/dev/tty"
* and operate on it - should we do the same?
*/
tcgetattr(STDERR_FILENO, old_termios_p); /* fiddle echo */
memcpy(&new, old_termios_p, sizeof(new));
new.c_cflag |= (CLOCAL | CREAD);
new.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
bb_signals(0
+ (1 << SIGINT)
+ (1 << SIGQUIT)
+ (1 << SIGTERM)
+ (1 << SIGALRM)
, onintr);
tcsetattr(STDERR_FILENO, TCSANOW, &new);
/* save_cursor_pos 7
* scroll_whole_screen [r
* put_cursor_waaaay_off [$x;$yH
* get_cursor_pos [6n
* restore_cursor_pos 8
*/
fprintf(stderr, ESC"7" ESC"[r" ESC"[999;999H" ESC"[6n");
alarm(3); /* Just in case terminal won't answer */
scanf(ESC"[%hu;%huR", &w.ws_row, &w.ws_col);
fprintf(stderr, ESC"8");
/* BTW, other versions of resize recalculate w.ws_xpixel, ws.ws_ypixel
* by calculating character cell HxW from old values
* (gotten via TIOCGWINSZ) and recomputing *pixel values */
ret = ioctl(STDERR_FILENO, TIOCSWINSZ, &w);
tcsetattr(STDERR_FILENO, TCSANOW, old_termios_p);
if (ENABLE_FEATURE_RESIZE_PRINT)
printf("COLUMNS=%d;LINES=%d;export COLUMNS LINES;\n",
w.ws_col, w.ws_row);
return ret;
}