/* _vv_flush.c

    *********** Copyright 1987-1995 by Vermont Creative Software ***********

_vv_flush()
Flushes the Vermont Views output buffer

Call

#include <vv_sys.h>

void _vv_flush()

Returns

None

Description

Flushes as many characters as are in the Vermont Views output buffer to the
operating system.  Uses write() for UNIX and POSIX, sys$qiow for VMS.

Cautions

This function only flushes the Vermont Views output buffer.  It will not
work on output streams.

*/

#include <vv_sys.h>

#if VMS
#include <iodef.h>
#endif

#if POSIX
#include <unistd.h>
#endif

#if UNIX
#ifdef LINT_ARGS
PROTOTYPE int write(int, char *, int);
#else
extern int write();
#endif
#endif

#if OLD_STYLE
void _vv_flush()
#else
void _vv_flush(void)
#endif
{
#if VMS
    IOSB_WR iosb;
#else
    int retval;
    int tty_out = 1;
#endif
    int written = 0;

    if (_outbufcnt > 0)			/*if characters to write	      */
    {
	/*--------------------------------------------------------------------*/
	/*  Write what is in the output buffer.  If the whole buffer is not   */
	/*  flushed, try again if the write was interrupted.  Keep trying     */
	/*  until the whole buffer is flushed or the write fails completely.  */
	/*--------------------------------------------------------------------*/
#if VMS
	do
	{
	    sys$qiow(0, _outchan, 
		IO$_WRITELBLK | IO$M_BREAKTHRU | IO$M_NOFORMAT, &iosb, NULLFP,
		0, _outbuf + written, _outbufcnt - written, 0, 0, 0, 0);
	    written += iosb.byte_count;
	}
	while (written < _outbufcnt && iosb.byte_count > 0);
#else
	do
        {
            retval = write(tty_out,(char *)(_outbuf + written), 
			    _outbufcnt - written);
            if (retval < 0)
		written = _outbufcnt;	/* I/O error! break out of loop now!  */
	    else
                written += retval;
        }
        while (written < _outbufcnt);
	/*--------------------------------------------------------------------*/
	/*  This really should only loop if errno is set to EINTR, but this   */
	/*  doesn't seem to work as well, for reasons as yet unknown.	      */
	/*--------------------------------------------------------------------*/
#endif
    }
    _outbufcnt = 0;
    return;
}