contrib/nvi2/ex/ex_z.c

   1 /*-
   2  * Copyright (c) 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1993, 1994, 1995, 1996
   5  *      Keith Bostic.  All rights reserved.
   6  *
   7  * See the LICENSE file for redistribution information.
   8  */
   9
  10 #include "config.h"
  11
  12 #ifndef lint
  13 static const char sccsid[] = "$Id: ex_z.c,v 10.12 2001/06/25 15:19:22 skimo Exp $";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18 #include <sys/time.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(SCR *, EXCMD *);
  33  */
  34 int
  35 ex_z(SCR *sp, EXCMD *cmdp)
  36 {
  37         MARK abs;
  38         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                 cnt = O_VAL(sp, O_WINDOW) - 1;
  58
  59         equals = 0;
  60         eofcheck = 0;
  61         lno = cmdp->addr1.lno;
  62
  63         switch (FL_ISSET(cmdp->iflags,
  64             E_C_CARAT | E_C_DASH | E_C_DOT | E_C_EQUAL | E_C_PLUS)) {
  65         case E_C_CARAT:         /* Display cnt * 2 before the line. */
  66                 eofcheck = 1;
  67                 if (lno > cnt * 2)
  68                         cmdp->addr1.lno = (lno - cnt * 2) + 1;
  69                 else
  70                         cmdp->addr1.lno = 1;
  71                 cmdp->addr2.lno = (cmdp->addr1.lno + cnt) - 1;
  72                 break;
  73         case E_C_DASH:          /* Line goes at the bottom of the screen. */
  74                 cmdp->addr1.lno = lno > cnt ? (lno - cnt) + 1 : 1;
  75                 cmdp->addr2.lno = lno;
  76                 break;
  77         case E_C_DOT:           /* Line goes in the middle of the screen. */
  78                 /*
  79                  * !!!
  80                  * Historically, the "middleness" of the line overrode the
  81                  * count, so that "3z.19" or "3z.20" would display the first
  82                  * 12 lines of the file, i.e. (N - 1) / 2 lines before and
  83                  * after the specified line.
  84                  */
  85                 eofcheck = 1;
  86                 cnt = (cnt - 1) / 2;
  87                 cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
  88                 cmdp->addr2.lno = lno + cnt;
  89
  90                 /*
  91                  * !!!
  92                  * Historically, z. set the absolute cursor mark.
  93                  */
  94                 abs.lno = sp->lno;
  95                 abs.cno = sp->cno;
  96                 (void)mark_set(sp, ABSMARK1, &abs, 1);
  97                 break;
  98         case E_C_EQUAL:         /* Center with hyphens. */
  99                 /*
 100                  * !!!
 101                  * Strangeness.  The '=' flag is like the '.' flag (see the
 102                  * above comment, it applies here as well) but with a special
 103                  * little hack.  Print out lines of hyphens before and after
 104                  * the specified line.  Additionally, the cursor remains set
 105                  * on that line.
 106                  */
 107                 eofcheck = 1;
 108                 cnt = (cnt - 1) / 2;
 109                 cmdp->addr1.lno = lno > cnt ? lno - cnt : 1;
 110                 cmdp->addr2.lno = lno - 1;
 111                 if (ex_pr(sp, cmdp))
 112                         return (1);
 113                 (void)ex_puts(sp, "----------------------------------------\n");
 114                 cmdp->addr2.lno = cmdp->addr1.lno = equals = lno;
 115                 if (ex_pr(sp, cmdp))
 116                         return (1);
 117                 (void)ex_puts(sp, "----------------------------------------\n");
 118                 cmdp->addr1.lno = lno + 1;
 119                 cmdp->addr2.lno = (lno + cnt) - 1;
 120                 break;
 121         default:
 122                 /* If no line specified, move to the next one. */
 123                 if (F_ISSET(cmdp, E_ADDR_DEF))
 124                         ++lno;
 125                 /* FALLTHROUGH */
 126         case E_C_PLUS:          /* Line goes at the top of the screen. */
 127                 eofcheck = 1;
 128                 cmdp->addr1.lno = lno;
 129                 cmdp->addr2.lno = (lno + cnt) - 1;
 130                 break;
 131         }
 132
 133         if (eofcheck) {
 134                 if (db_last(sp, &lno))
 135                         return (1);
 136                 if (cmdp->addr2.lno > lno)
 137                         cmdp->addr2.lno = lno;
 138         }
 139
 140         if (ex_pr(sp, cmdp))
 141                 return (1);
 142         if (equals)
 143                 sp->lno = equals;
 144         return (0);
 145 }