* Copyright (c) 1989, 1990, 1991, 1992 William F. Jolitz, TeleMuse
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This software is a component of "386BSD" developed by
William F. Jolitz, TeleMuse.
* 4. Neither the name of the developer nor the name "386BSD"
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
* THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ
* AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS
* SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT.
* THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT
* NOT MAKE USE THIS WORK.
* FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
* BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN
* REFERENCES SUCH AS THE "PORTING UNIX TO THE 386" SERIES
* (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING
* JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND
* LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE
* ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS
* OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE DEVELOPER BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
static char rcsid
[] = "$Header: /usr/bill/working/sys/kern/RCS/tty_ring.c,v 1.2 92/01/21 21:29:55 william Exp $";
putc(c
, rbp
) struct ringb
*rbp
;
if ( (nxtp
= RB_SUCC(rbp
, rbp
->rb_tl
)) == rbp
->rb_hd
) return (-1);
getc(rbp
) struct ringb
*rbp
;
if (rbp
->rb_hd
== rbp
->rb_tl
) return(-1);
/* fetch character, locate next character */
c
= *(u_char
*) rbp
->rb_hd
;
rbp
->rb_hd
= RB_SUCC(rbp
, rbp
->rb_hd
);
nextc(cpp
, rbp
) struct ringb
*rbp
; char **cpp
; {
if (*cpp
== rbp
->rb_tl
) return (0);
ungetc(c
, rbp
) struct ringb
*rbp
;
if ( (backp
= RB_PRED(rbp
, rbp
->rb_hd
)) == rbp
->rb_tl
) return (-1);
unputc(rbp
) struct ringb
*rbp
;
if (rbp
->rb_hd
== rbp
->rb_tl
) return(-1);
/* backup buffer and dig out previous character */
backp
= RB_PRED(rbp
, rbp
->rb_tl
);
#define peekc(rbp) (*(rbp)->rb_hd)
initrb(rbp
) struct ringb
*rbp
; {
rbp
->rb_hd
= rbp
->rb_tl
= rbp
->rb_buf
;
* Example code for contiguous operations:
bcopy("ABCDEFGHI", rb.rb_tl, nc);
rb.rb_tl = RB_ROLLOVER(&rb, rb.rb_tl);
bcopy(rb.rb_hd, stringbuf, nc);
rb.rb_hd = RB_ROLLOVER(&rb, rb.rb_hd);
printf("%s|", stringbuf);
* Concatinate ring buffers.
while ((c
= getc(from
)) >= 0)