first try at POSIX tty

[unix-history] / usr / src / usr.bin / window / ttoutput.c

/*
* Copyright (c) 1983 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
static char sccsid[] = "@(#)ttoutput.c  3.7 (Berkeley) %G%";
#endif /* not lint */

#include "ww.h"
#include "tt.h"
#include <sys/errno.h>

/*
* Buffered output package.
* We need this because stdio fails on non-blocking writes.
*/

ttflush()
{
       register char *p;
       register n;
       extern errno;

       wwnflush++;
       for (p = tt_ob; p < tt_obp;) {
               wwnwr++;
               n = write(1, p, tt_obp - p);
               if (n < 0) {
                       wwnwre++;
                       if (errno != EWOULDBLOCK) {
                               /* can't deal with this */
                               p = tt_obp;
                       }
               } else if (n == 0) {
                       /* what to do? */
                       wwnwrz++;
               } else {
                       wwnwrc += n;
                       p += n;
               }
       }
       tt_obp = tt_ob;
}

ttputs(s)
register char *s;
{
       while (*s)
               ttputc(*s++);
}

ttwrite(s, n)
       register char *s;
       register n;
{
       switch (n) {
       case 0:
               break;
       case 1:
               ttputc(*s);
               break;
       case 2:
               if (tt_obe - tt_obp < 2)
                       (*tt.tt_flush)();
               *tt_obp++ = *s++;
               *tt_obp++ = *s;
               break;
       case 3:
               if (tt_obe - tt_obp < 3)
                       (*tt.tt_flush)();
               *tt_obp++ = *s++;
               *tt_obp++ = *s++;
               *tt_obp++ = *s;
               break;
       case 4:
               if (tt_obe - tt_obp < 4)
                       (*tt.tt_flush)();
               *tt_obp++ = *s++;
               *tt_obp++ = *s++;
               *tt_obp++ = *s++;
               *tt_obp++ = *s;
               break;
       case 5:
               if (tt_obe - tt_obp < 5)
                       (*tt.tt_flush)();
               *tt_obp++ = *s++;
               *tt_obp++ = *s++;
               *tt_obp++ = *s++;
               *tt_obp++ = *s++;
               *tt_obp++ = *s;
               break;
       default:
               while (n > 0) {
                       register m;

                       while ((m = tt_obe - tt_obp) == 0)
                               (*tt.tt_flush)();
                       if ((m = tt_obe - tt_obp) > n)
                               m = n;
                       bcopy(s, tt_obp, m);
                       tt_obp += m;
                       s += m;
                       n -= m;
               }
       }
}