/* This version of resize.c has been modified from the original, which
 * came with X11/xterm.  It no longer tries to emit shell commands for
 * setting LINES, COLUMNS, or TERMCAP.  It assumes an ANSI terminal,
 * and the availability of the TIOCGWINSZ ioctl.  The portability
 * ifdefs were also removed -- posix termios access is assumed.
 *      Paul Fox, June 2006
 *
 * original copyright messages preserved below...
 */

/*
 *      $Xorg: resize.c,v 1.3 2000/08/17 19:55:09 cpqbld Exp $
 */

/* $XFree86: xc/programs/xterm/resize.c,v 3.51 2001/10/09 21:52:40 alanh Exp $ */

/*
 * Copyright 1987 by Digital Equipment Corporation, Maynard, Massachusetts.
 *
 *                         All Rights Reserved
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted,
 * provided that the above copyright notice appear in all copies and that
 * both that copyright notice and this permission notice appear in
 * supporting documentation, and that the name of Digital Equipment
 * Corporation not be used in advertising or publicity pertaining to
 * distribution of the software without specific, written prior permission.
 *
 *
 * DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING
 * ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL
 * DIGITAL BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR
 * ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */


/* resize.c */

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <string.h>
#include <termio.h>
#include <termios.h>


#include <signal.h>
#include <pwd.h>

#define ESC "\033"


#define TIMEOUT         10


char *myname;

char getsize[] = ESC "7"  ESC "[r" ESC "[999;999H" ESC "[6n";
char restore[] = ESC "8";

struct termios tioorig;

char size[] = ESC "[%d;%dR";

int tty;
FILE *ttyfp;

static void onintr (int sig);
static void resize_timeout (int sig);
static void Usage (void);
static void readstring (FILE *fp, char *buf, char *str);

char *
x_basename(char *name)
{
	char *cp;

	cp = strrchr(name, '/');
	return (cp ? cp + 1 : name);
}


/*
 *   tells tty driver to reflect current screen size
 */

int
main (int argc, char **argv)
{
	int rows, cols;
	struct termios tio;
	char buf[BUFSIZ];
	struct winsize ws;
	char *name_of_tty;

	myname = x_basename(argv[0]);

	if (argc > 1) Usage();

	name_of_tty = "/dev/tty";

	if ((ttyfp = fopen (name_of_tty, "r+")) == NULL) {
		fprintf (stderr, "%s:  can't open terminal %s\n",
			 myname, name_of_tty);
		exit (1);
	}
	tty = fileno(ttyfp);

	tcgetattr(tty, &tioorig);
	tio = tioorig;
	tio.c_iflag &= ~ICRNL;
	tio.c_lflag &= ~(ICANON | ECHO);
	tio.c_cflag |= CS8;
	tio.c_cc[VMIN] = 6;
	tio.c_cc[VTIME] = 1;
	signal(SIGINT, onintr);
	signal(SIGQUIT, onintr);
	signal(SIGTERM, onintr);
	tcsetattr(tty, TCSADRAIN, &tio);

	write(tty, getsize, strlen(getsize));
	readstring(ttyfp, buf, size);
	if(sscanf (buf, size, &rows, &cols) != 2) {
		fprintf(stderr, "%s: Can't get rows and columns\r\n", myname);
		onintr(0);
	}
	write(tty, restore, strlen(restore));

	if (ioctl (tty, TIOCGWINSZ, &ws) != -1) {
		/* we don't have any way of directly finding out
		   the current height & width of the window in pixels.  We try
		   our best by computing the font height and width from the "old"
		   struct winsize values, and multiplying by these ratios...*/
		if (ws.ws_col != 0)
			ws.ws_xpixel = cols * (ws.ws_xpixel / ws.ws_col);
		if (ws.ws_row != 0)
			ws.ws_ypixel = rows * (ws.ws_ypixel / ws.ws_row);
		ws.ws_row = rows;
		ws.ws_col = cols;
		ioctl (tty, TIOCSWINSZ, &ws);
	}

	tcsetattr(tty, TCSADRAIN, &tioorig);
	signal(SIGINT, SIG_DFL);
	signal(SIGQUIT, SIG_DFL);
	signal(SIGTERM, SIG_DFL);

	exit(0);
}


static void
readstring(register FILE *fp, register char *buf, char *str)
{
	register int last, c;

	signal(SIGALRM, resize_timeout);
	alarm (TIMEOUT);
	if ((c = getc(fp)) == 0233) {   /* meta-escape, CSI */
		*buf++ = c = ESC[0];
		*buf++ = '[';
	} else {
		*buf++ = c;
	}
	if (c != *str) {
		fprintf(stderr, "%s: unknown character, exiting.\r\n", myname);
		onintr(0);
	}
	last = str[strlen(str) - 1];
	while((*buf++ = getc(fp)) != last)
		;
	alarm (0);
	*buf = 0;
}

static void
Usage(void)
{
	fprintf(stderr,
	"Usage: %s\n"
	"   sets size via ioctl\n", myname);
	exit(1);
}

static void
resize_timeout(int sig)
{
	fprintf(stderr, "\n%s: timeout occurred\r\n", myname);
	onintr(sig);
}

/* ARGSUSED */
static void
onintr(int sig)
{
	tcsetattr (tty, TCSADRAIN, &tioorig);
	exit(1);
}