2 * Copyright (c) 1992, 1993, 1994
3 * The Regents of the University of California. All rights reserved.
4 * Copyright (c) 1992, 1993, 1994, 1995, 1996
5 * Keith Bostic. All rights reserved.
7 * See the LICENSE file for redistribution information.
13 static const char sccsid
[] = "$Id: getc.c,v 10.11 2000/06/27 17:19:07 skimo Exp $ (Berkeley) $Date: 2000/06/27 17:19:07 $";
16 #include <sys/types.h>
17 #include <sys/queue.h>
20 #include <bitstring.h>
26 #include "../common/common.h"
30 * Character stream routines --
31 * These routines return the file a character at a time. There are two
32 * special cases. First, the end of a line, end of a file, start of a
33 * file and empty lines are returned as special cases, and no character
34 * is returned. Second, empty lines include lines that have only white
35 * space in them, because the vi search functions don't care about white
36 * space, and this makes it easier for them to be consistent.
41 * Initialize character stream routines.
43 * PUBLIC: int cs_init __P((SCR *, VCS *));
52 if (db_eget(sp
, csp
->cs_lno
, &csp
->cs_bp
, &csp
->cs_len
, &isempty
)) {
54 msgq(sp
, M_BERR
, "177|Empty file");
57 if (csp
->cs_len
== 0 || v_isempty(csp
->cs_bp
, csp
->cs_len
)) {
59 csp
->cs_flags
= CS_EMP
;
62 csp
->cs_ch
= csp
->cs_bp
[csp
->cs_cno
];
69 * Retrieve the next character.
71 * PUBLIC: int cs_next __P((SCR *, VCS *));
80 switch (csp
->cs_flags
) {
81 case CS_EMP
: /* EMP; get next line. */
82 case CS_EOL
: /* EOL; get next line. */
83 if (db_get(sp
, ++csp
->cs_lno
, 0, &p
, &csp
->cs_len
)) {
85 csp
->cs_flags
= CS_EOF
;
88 if (csp
->cs_len
== 0 ||
89 v_isempty(csp
->cs_bp
, csp
->cs_len
)) {
91 csp
->cs_flags
= CS_EMP
;
94 csp
->cs_ch
= csp
->cs_bp
[csp
->cs_cno
= 0];
99 if (csp
->cs_cno
== csp
->cs_len
- 1)
100 csp
->cs_flags
= CS_EOL
;
102 csp
->cs_ch
= csp
->cs_bp
[++csp
->cs_cno
];
104 case CS_EOF
: /* EOF. */
115 * If on a space, eat forward until something other than a
116 * whitespace character.
119 * Semantics of checking the current character were coded for the fword()
120 * function -- once the other word routines are converted, they may have
123 * PUBLIC: int cs_fspace __P((SCR *, VCS *));
130 if (csp
->cs_flags
!= 0 || !isblank(csp
->cs_ch
))
133 if (cs_next(sp
, csp
))
135 if (csp
->cs_flags
!= 0 || !isblank(csp
->cs_ch
))
143 * Eat forward to the next non-whitespace character.
145 * PUBLIC: int cs_fblank __P((SCR *, VCS *));
153 if (cs_next(sp
, csp
))
155 if (csp
->cs_flags
== CS_EOL
|| csp
->cs_flags
== CS_EMP
||
156 csp
->cs_flags
== 0 && isblank(csp
->cs_ch
))
165 * Retrieve the previous character.
167 * PUBLIC: int cs_prev __P((SCR *, VCS *));
174 switch (csp
->cs_flags
) {
175 case CS_EMP
: /* EMP; get previous line. */
176 case CS_EOL
: /* EOL; get previous line. */
177 if (csp
->cs_lno
== 1) { /* SOF. */
178 csp
->cs_flags
= CS_SOF
;
181 if (db_get(sp
, /* The line should exist. */
182 --csp
->cs_lno
, DBG_FATAL
, &csp
->cs_bp
, &csp
->cs_len
)) {
186 if (csp
->cs_len
== 0 || v_isempty(csp
->cs_bp
, csp
->cs_len
)) {
188 csp
->cs_flags
= CS_EMP
;
191 csp
->cs_cno
= csp
->cs_len
- 1;
192 csp
->cs_ch
= csp
->cs_bp
[csp
->cs_cno
];
195 case CS_EOF
: /* EOF: get previous char. */
197 if (csp
->cs_cno
== 0)
198 if (csp
->cs_lno
== 1)
199 csp
->cs_flags
= CS_SOF
;
201 csp
->cs_flags
= CS_EOL
;
203 csp
->cs_ch
= csp
->cs_bp
[--csp
->cs_cno
];
205 case CS_SOF
: /* SOF. */
216 * Eat backward to the next non-whitespace character.
218 * PUBLIC: int cs_bblank __P((SCR *, VCS *));
226 if (cs_prev(sp
, csp
))
228 if (csp
->cs_flags
== CS_EOL
|| csp
->cs_flags
== CS_EMP
||
229 csp
->cs_flags
== 0 && isblank(csp
->cs_ch
))