common/port/astwinsize.c

	astwinsize.c revision da2e3ebdc1edfbc5028edf1354e7dd2fa69a7968
/***********************************************************************
*                                                                      *
*               This software is part of the ast package               *
*           Copyright (c) 1985-2007 AT&T Knowledge Ventures            *
*                      and is licensed under the                       *
*                  Common Public License, Version 1.0                  *
*                      by AT&T Knowledge Ventures                      *
*                                                                      *
*                A copy of the License is available at                 *
*            http://www.opensource.org/licenses/cpl1.0.txt             *
*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
*                                                                      *
*              Information and Software Systems Research               *
*                            AT&T Research                             *
*                           Florham Park NJ                            *
*                                                                      *
*                 Glenn Fowler <gsf@research.att.com>                  *
*                  David Korn <dgk@research.att.com>                   *
*                   Phong Vo <kpv@research.att.com>                    *
*                                                                      *
***********************************************************************/
#pragma prototyped

/*
 * AT&T Research
 * return terminal rows and cols
 */

#include <ast.h>
#include <ast_tty.h>

#if defined(__STDPP__directive) && defined(__STDPP__hide)
__STDPP__directive pragma pp:hide ioctl sleep
#else
#define ioctl       ______ioctl
#define sleep       ______sleep
#endif

#if _sys_ioctl
#include <sys/ioctl.h>
#endif

#if defined(TIOCGWINSZ)
#if _sys_stream && _sys_ptem
#include <sys/stream.h>
#include <sys/ptem.h>
#endif
#else
#if !defined(TIOCGSIZE) && !defined(TIOCGWINSZ)
#if _hdr_jioctl
#define jwinsize    winsize
#include <jioctl.h>
#else
#if _sys_jioctl
#define jwinsize    winsize
#include <sys/jioctl.h>
#endif
#endif
#endif
#endif

#if defined(__STDPP__directive) && defined(__STDPP__hide)
__STDPP__directive pragma pp:nohide ioctl sleep
#else
#undef  ioctl
#undef  sleep
#endif

static int      ttctl(int, int, void*);

void
astwinsize(int fd, register int* rows, register int* cols)
{
#ifdef  TIOCGWINSZ
#define NEED_ttctl
    struct winsize  ws;

    if (!ttctl(fd, TIOCGWINSZ, &ws) && ws.ws_col > 0 && ws.ws_row > 0)
    {
        if (rows) *rows = ws.ws_row;
        if (cols) *cols = ws.ws_col;
    }
    else
#else
#ifdef  TIOCGSIZE
#define NEED_ttctl
    struct ttysize  ts;

    if (!ttctl(fd, TIOCGSIZE, &ts) && ts.ts_lines > 0 && ts.ts_cols > 0)
    {
        if (rows) *rows = ts.ts_lines;
        if (cols) *cols = ts.ts_cols;
    }
    else
#else
#ifdef  JWINSIZE
#define NEED_ttctl
    struct winsize  ws;

    if (!ttctl(fd, JWINSIZE, &ws) && ws.bytesx > 0 && ws.bytesy > 0)
    {
        if (rows) *rows = ws.bytesy;
        if (cols) *cols = ws.bytesx;
    }
    else
#endif
#endif
#endif
    {
        char*       s;

        if (rows) *rows = (s = getenv("LINES")) ? strtol(s, NiL, 0) : 0;
        if (cols) *cols = (s = getenv("COLUMNS")) ? strtol(s, NiL, 0) : 0;
    }
}

#ifdef  NEED_ttctl

/*
 * tty ioctl() -- no cache
 */

static int
ttctl(register int fd, int op, void* tt)
{
    register int    v;

    if (fd < 0)
    {
        for (fd = 0; fd <= 2; fd++)
            if (!ioctl(fd, op, tt)) return(0);
        if ((fd = open("/dev/tty", O_RDONLY)) >= 0)
        {
            v = ioctl(fd, op, tt);
            close(fd);
            return(v);
        }
    }
    else if (!ioctl(fd, op, tt)) return(0);
    return(-1);
}

#endif