busybox/libbb/get_terminal_width_height.c
Eric Andersen 97310d0253 Brian Pomerantz writes:
I've noticed a bug in the "autowidth" feature more, and is probably in
others.  The call to the function get_terminal_width_height() passes
in a file descriptor but that file descriptor is never used, instead
the ioctl() is called with 0.  In more_main() the call to
get_terminal_width_height() passes 0 as the file descriptor instead of
fileno(cin).  This isn't a problem when you more a file (e.g. "more
/etc/passwd") but when you pipe a file to it (e.g. "cat /etc/passwd |
more") the size of the terminal cannot be determined because file
descriptor 0 is not a terminal.  The fix is simple, I've attached a
patch for more.c and get_terminal_width_height.c.


BAPper
2004-03-23 23:15:36 +00:00

67 lines
1.7 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Determine the width and height of the terminal.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <unistd.h>
#include <unistd.h>
#include <termios.h>
#include <sys/ioctl.h>
#include "busybox.h"
/* It is perfectly ok to pass in a NULL for either width or for
* height, in which case that value will not be set. It is also
* perfectly ok to have CONFIG_FEATURE_AUTOWIDTH disabled, in
* which case you will always get 80x24 */
void get_terminal_width_height(int fd, int *width, int *height)
{
struct winsize win = { 0, 0, 0, 0 };
#ifdef CONFIG_FEATURE_AUTOWIDTH
if (ioctl(fd, TIOCGWINSZ, &win) != 0) {
win.ws_row = 24;
win.ws_col = 80;
}
#endif
if (win.ws_row <= 1) {
win.ws_row = 24;
}
if (win.ws_col <= 1) {
win.ws_col = 80;
}
if (height) {
*height = (int) win.ws_row;
}
if (width) {
*width = (int) win.ws_col;
}
}
/* END CODE */
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/