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/* 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 source tree.
*/
//config:config RESIZE
//config: bool "resize (903 bytes)"
//config: default y
//config: help
//config: This program is used to (re)set the width and height of your current
//config: terminal.
//config:
//config:config FEATURE_RESIZE_PRINT
//config: bool "Print environment variables"
//config: default y
//config: depends on RESIZE
//config: help
//config: Prints the newly set size (number of columns and rows) of
//config: the terminal.
//config: E.g.:
//config: COLUMNS=80;LINES=44;export COLUMNS LINES;
//applet:IF_RESIZE(APPLET_NOEXEC(resize, resize, BB_DIR_USR_BIN, BB_SUID_DROP, resize))
/* bb_common_bufsiz1 usage here is safe wrt NOEXEC: not expecting it to be zeroed. */
//kbuild:lib-$(CONFIG_RESIZE) += resize.o
//usage:#define resize_trivial_usage
//usage: ""
//usage:#define resize_full_usage "\n\n"
//usage: "Resize the screen"
#include "libbb.h"
#include "common_bufsiz.h"
#define ESC "\033"
#define old_termios_p ((struct termios*)bb_common_bufsiz1)
#define INIT_G() do { setup_common_bufsiz(); } while (0)
static void
onintr(int sig UNUSED_PARAM)
{
tcsetattr(STDERR_FILENO, TCSANOW, old_termios_p);
_exit(EXIT_FAILURE);
}
int resize_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int resize_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
{
struct termios new;
struct winsize w = { 0, 0, 0, 0 };
int ret;
INIT_G();
/* We use _stderr_ in order to make resize usable
* in shell backticks (those redirect stdout away from tty).
* NB: other versions of resize open "/dev/tty"
* and operate on it - should we do the same?
*/
tcgetattr(STDERR_FILENO, old_termios_p); /* fiddle echo */
//TODO: die if the above fails?
memcpy(&new, old_termios_p, sizeof(new));
new.c_cflag |= (CLOCAL | CREAD);
new.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG);
bb_signals(0
+ (1 << SIGINT)
+ (1 << SIGQUIT)
+ (1 << SIGTERM)
+ (1 << SIGALRM)
, onintr);
tcsetattr(STDERR_FILENO, TCSANOW, &new);
/* save_cursor_pos 7
* scroll_whole_screen [r
* put_cursor_waaaay_off [$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 */
//BUG: death by signal won't restore termios
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;
}
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