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/*-
* Copyright (c) 1993, 1994
* The Regents of the University of California. All rights reserved.
* Copyright (c) 1993, 1994, 1995, 1996
* Keith Bostic. All rights reserved.
*
* See the LICENSE file for redistribution information.
*/
#include "config.h"
#ifndef lint
static const char sccsid[] = "@(#)ex_z.c 10.10 (Berkeley) 3/6/96";
#endif /* not lint */
#include <sys/types.h>
#include <sys/queue.h>
#include <bitstring.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "../common/common.h"
/*
* ex_z -- :[line] z [^-.+=] [count] [flags]
* Adjust window.
*
* PUBLIC: int ex_z __P((SCR *, EXCMD *));
*/
int
ex_z(sp, cmdp)
SCR *sp;
EXCMD *cmdp;
{
MARK abs;
recno_t cnt, equals, lno;
int eofcheck;
NEEDFILE(sp, cmdp);
/*
* !!!
* If no count specified, use either two times the size of the
* scrolling region, or the size of the window option. POSIX
* 1003.2 claims that the latter is correct, but historic ex/vi
* documentation and practice appear to use the scrolling region.
* I'm using the window size as it means that the entire screen
* is used instead of losing a line to roundoff. Note, we drop
* a line from the cnt if using the window size to leave room for
* the next ex prompt.
*/
if (FL_ISSET(cmdp->iflags, E_C_COUNT))
cnt = cmdp->count;
else
#ifdef HISTORIC_PRACTICE
cnt = O_VAL(sp, O_SCROLL) * 2;
#else
cnt = O_VAL(sp, O_WINDOW) - 1;
#endif
equals = 0;
eofcheck = 0;
lno = cmdp->addr1.lno;
switch (FL_ISSET(cmdp->iflags,
E_C_CARAT | E_C_DASH | E_C_DOT | E_C_EQUAL | E_C_PLUS)) {
case E_C_CARAT: /* Display cnt * 2 before the line. */
eofcheck = 1;
if (lno > cnt * 2)
cmdp->addr1.lno = (lno - cnt * 2) + 1;
else
cmdp->addr1.lno = 1;
cmdp->addr2.lno = (cmdp->addr1.lno + cnt) - 1;
break;
case E_C_DASH: /* Line goes at the bottom of the screen. */
cmdp->addr1.lno = lno > cnt ? (lno - cnt) + 1 : 1;
cmdp->addr2.lno = lno;
break;
case E_C_DOT: /* Line goes in the middle of the screen. */
/*
* !!!
* Historically, the "middleness" of the line overrode the
* count, so that "3z.19" or "3z.20" would display the first
* 12 lines of the file, i.e. (N - 1) / 2 lines before and
* after the specified line.
*/
eofcheck = 1;
cnt = (cnt - 1) / 2;
cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
cmdp->addr2.lno = lno + cnt;
/*
* !!!
* Historically, z. set the absolute cursor mark.
*/
abs.lno = sp->lno;
abs.cno = sp->cno;
(void)mark_set(sp, ABSMARK1, &abs, 1);
break;
case E_C_EQUAL: /* Center with hyphens. */
/*
* !!!
* Strangeness. The '=' flag is like the '.' flag (see the
* above comment, it applies here as well) but with a special
* little hack. Print out lines of hyphens before and after
* the specified line. Additionally, the cursor remains set
* on that line.
*/
eofcheck = 1;
cnt = (cnt - 1) / 2;
cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
cmdp->addr2.lno = lno - 1;
if (ex_pr(sp, cmdp))
return (1);
(void)ex_puts(sp, "----------------------------------------\n");
cmdp->addr2.lno = cmdp->addr1.lno = equals = lno;
if (ex_pr(sp, cmdp))
return (1);
(void)ex_puts(sp, "----------------------------------------\n");
cmdp->addr1.lno = lno + 1;
cmdp->addr2.lno = (lno + cnt) - 1;
break;
default:
/* If no line specified, move to the next one. */
if (F_ISSET(cmdp, E_ADDR_DEF))
++lno;
/* FALLTHROUGH */
case E_C_PLUS: /* Line goes at the top of the screen. */
eofcheck = 1;
cmdp->addr1.lno = lno;
cmdp->addr2.lno = (lno + cnt) - 1;
break;
}
if (eofcheck) {
if (db_last(sp, &lno))
return (1);
if (cmdp->addr2.lno > lno)
cmdp->addr2.lno = lno;
}
if (ex_pr(sp, cmdp))
return (1);
if (equals)
sp->lno = equals;
return (0);
}
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