From c9c893d4f59418c50c8eb42bd80390026e123dd8 Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Mon, 12 Mar 2007 23:41:07 +0000 Subject: [PATCH] resize: make it usable in in backticks; have a timeout (if display doesn't respond to 'get cursor pos' ESC sequence...) --- console-tools/resize.c | 45 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 37 insertions(+), 8 deletions(-) diff --git a/console-tools/resize.c b/console-tools/resize.c index 40a1b4ee0..64f318c76 100644 --- a/console-tools/resize.c +++ b/console-tools/resize.c @@ -11,31 +11,60 @@ #define ESC "\033" +struct termios old; + +static void +onintr(int sig ATTRIBUTE_UNUSED) +{ + tcsetattr(STDERR_FILENO, TCSANOW, &old); + exit(1); +} + + int resize_main(int argc, char **argv); int resize_main(int argc, char **argv) { - struct termios old, new; - struct winsize w = {0,0,0,0}; + struct termios new; + struct winsize w = { 0,0,0,0 }; int ret; - tcgetattr(STDOUT_FILENO, &old); /* fiddle echo */ + /* 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); /* fiddle echo */ new = old; new.c_cflag |= (CLOCAL | CREAD); new.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); - tcsetattr(STDOUT_FILENO, TCSANOW, &new); + signal(SIGINT, onintr); + signal(SIGQUIT, onintr); + signal(SIGTERM, onintr); + signal(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 */ - printf(ESC"7" ESC"[r" ESC"[999;999H" ESC"[6n"); + 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); - ret = ioctl(STDOUT_FILENO, TIOCSWINSZ, &w); - printf(ESC"8"); - tcsetattr(STDOUT_FILENO, TCSANOW, &old); + 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); + if (ENABLE_FEATURE_RESIZE_PRINT) printf("COLUMNS=%d;LINES=%d;export COLUMNS LINES;\n", w.ws_col, w.ws_row); + return ret; }