external/bsd/nvi/dist/ex/ex_z.c

   1 /*      $NetBSD: ex_z.c,v 1.2 2013/11/22 15:52:05 christos Exp $ */
   2 /*-
   3  * Copyright (c) 1993, 1994
   4  *      The Regents of the University of California.  All rights reserved.
   5  * Copyright (c) 1993, 1994, 1995, 1996
   6  *      Keith Bostic.  All rights reserved.
   7  *
   8  * See the LICENSE file for redistribution information.
   9  */
  10
  11 #include "config.h"
  12
  13 #ifndef lint
  14 static const char sccsid[] = "Id: ex_z.c,v 10.12 2001/06/25 15:19:22 skimo Exp  (Berkeley) Date: 2001/06/25 15:19:22 ";
  15 #endif /* not lint */
  16
  17 #include <sys/types.h>
  18 #include <sys/queue.h>
  19
  20 #include <bitstring.h>
  21 #include <limits.h>
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 #include "../common/common.h"
  27
  28 /*
  29  * ex_z -- :[line] z [^-.+=] [count] [flags]
  30  *      Adjust window.
  31  *
  32  * PUBLIC: int ex_z __P((SCR *, EXCMD *));
  33  */
  34 int
  35 ex_z(SCR *sp, EXCMD *cmdp)
  36 {
  37         MARK abm;
  38         db_recno_t cnt, equals, lno;
  39         int eofcheck;
  40
  41         NEEDFILE(sp, cmdp);
  42
  43         /*
  44          * !!!
  45          * If no count specified, use either two times the size of the
  46          * scrolling region, or the size of the window option.  POSIX
  47          * 1003.2 claims that the latter is correct, but historic ex/vi
  48          * documentation and practice appear to use the scrolling region.
  49          * I'm using the window size as it means that the entire screen
  50          * is used instead of losing a line to roundoff.  Note, we drop
  51          * a line from the cnt if using the window size to leave room for
  52          * the next ex prompt.
  53          */
  54         if (FL_ISSET(cmdp->iflags, E_C_COUNT))
  55                 cnt = cmdp->count;
  56         else
  57 #ifdef HISTORIC_PRACTICE
  58                 cnt = O_VAL(sp, O_SCROLL) * 2;
  59 #else
  60                 cnt = O_VAL(sp, O_WINDOW) - 1;
  61 #endif
  62
  63         equals = 0;
  64         eofcheck = 0;
  65         lno = cmdp->addr1.lno;
  66
  67         switch (FL_ISSET(cmdp->iflags,
  68             E_C_CARAT | E_C_DASH | E_C_DOT | E_C_EQUAL | E_C_PLUS)) {
  69         case E_C_CARAT:         /* Display cnt * 2 before the line. */
  70                 eofcheck = 1;
  71                 if (lno > cnt * 2)
  72                         cmdp->addr1.lno = (lno - cnt * 2) + 1;
  73                 else
  74                         cmdp->addr1.lno = 1;
  75                 cmdp->addr2.lno = (cmdp->addr1.lno + cnt) - 1;
  76                 break;
  77         case E_C_DASH:          /* Line goes at the bottom of the screen. */
  78                 cmdp->addr1.lno = lno > cnt ? (lno - cnt) + 1 : 1;
  79                 cmdp->addr2.lno = lno;
  80                 break;
  81         case E_C_DOT:           /* Line goes in the middle of the screen. */
  82                 /*
  83                  * !!!
  84                  * Historically, the "middleness" of the line overrode the
  85                  * count, so that "3z.19" or "3z.20" would display the first
  86                  * 12 lines of the file, i.e. (N - 1) / 2 lines before and
  87                  * after the specified line.
  88                  */
  89                 eofcheck = 1;
  90                 cnt = (cnt - 1) / 2;
  91                 cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
  92                 cmdp->addr2.lno = lno + cnt;
  93
  94                 /*
  95                  * !!!
  96                  * Historically, z. set the absolute cursor mark.
  97                  */
  98                 abm.lno = sp->lno;
  99                 abm.cno = sp->cno;
 100                 (void)mark_set(sp, ABSMARK1, &abm, 1);
 101                 break;
 102         case E_C_EQUAL:         /* Center with hyphens. */
 103                 /*
 104                  * !!!
 105                  * Strangeness.  The '=' flag is like the '.' flag (see the
 106                  * above comment, it applies here as well) but with a special
 107                  * little hack.  Print out lines of hyphens before and after
 108                  * the specified line.  Additionally, the cursor remains set
 109                  * on that line.
 110                  */
 111                 eofcheck = 1;
 112                 cnt = (cnt - 1) / 2;
 113                 cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
 114                 cmdp->addr2.lno = lno - 1;
 115                 if (ex_pr(sp, cmdp))
 116                         return (1);
 117                 (void)ex_puts(sp, "----------------------------------------\n");
 118                 cmdp->addr2.lno = cmdp->addr1.lno = equals = lno;
 119                 if (ex_pr(sp, cmdp))
 120                         return (1);
 121                 (void)ex_puts(sp, "----------------------------------------\n");
 122                 cmdp->addr1.lno = lno + 1;
 123                 cmdp->addr2.lno = (lno + cnt) - 1;
 124                 break;
 125         default:
 126                 /* If no line specified, move to the next one. */
 127                 if (F_ISSET(cmdp, E_ADDR_DEF))
 128                         ++lno;
 129                 /* FALLTHROUGH */
 130         case E_C_PLUS:          /* Line goes at the top of the screen. */
 131                 eofcheck = 1;
 132                 cmdp->addr1.lno = lno;
 133                 cmdp->addr2.lno = (lno + cnt) - 1;
 134                 break;
 135         }
 136
 137         if (eofcheck) {
 138                 if (db_last(sp, &lno))
 139                         return (1);
 140                 if (cmdp->addr2.lno > lno)
 141                         cmdp->addr2.lno = lno;
 142         }
 143
 144         if (ex_pr(sp, cmdp))
 145                 return (1);
 146         if (equals)
 147                 sp->lno = equals;
 148         return (0);
 149 }