ex/ex_shift.c

   1 /*-
   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.
   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_shift.c,v 10.17 2001/06/25 15:19:20 skimo Exp $ (Berkeley) $Date: 2001/06/25 15:19:20 $";
  14 #endif /* not lint */
  15
  16 #include <sys/types.h>
  17 #include <sys/queue.h>
  18
  19 #include <bitstring.h>
  20 #include <limits.h>
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 #include "../common/common.h"
  26
  27 enum which {LEFT, RIGHT};
  28 static int shift __P((SCR *, EXCMD *, enum which));
  29
  30 /*
  31  * ex_shiftl -- :<[<...]
  32  *
  33  *
  34  * PUBLIC: int ex_shiftl __P((SCR *, EXCMD *));
  35  */
  36 int
  37 ex_shiftl(SCR *sp, EXCMD *cmdp)
  38 {
  39         return (shift(sp, cmdp, LEFT));
  40 }
  41
  42 /*
  43  * ex_shiftr -- :>[>...]
  44  *
  45  * PUBLIC: int ex_shiftr __P((SCR *, EXCMD *));
  46  */
  47 int
  48 ex_shiftr(SCR *sp, EXCMD *cmdp)
  49 {
  50         return (shift(sp, cmdp, RIGHT));
  51 }
  52
  53 /*
  54  * shift --
  55  *      Ex shift support.
  56  */
  57 static int
  58 shift(SCR *sp, EXCMD *cmdp, enum which rl)
  59 {
  60         db_recno_t from, to;
  61         size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
  62         int curset;
  63         CHAR_T *p;
  64         CHAR_T *bp, *tbp;
  65
  66         NEEDFILE(sp, cmdp);
  67
  68         if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
  69                 msgq(sp, M_INFO, "152|shiftwidth option set to 0");
  70                 return (0);
  71         }
  72
  73         /* Copy the lines being shifted into the unnamed buffer. */
  74         if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
  75                 return (1);
  76
  77         /*
  78          * The historic version of vi permitted the user to string any number
  79          * of '>' or '<' characters together, resulting in an indent of the
  80          * appropriate levels.  There's a special hack in ex_cmd() so that
  81          * cmdp->argv[0] points to the string of '>' or '<' characters.
  82          *
  83          * Q: What's the difference between the people adding features
  84          *    to vi and the Girl Scouts?
  85          * A: The Girl Scouts have mint cookies and adult supervision.
  86          */
  87         for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
  88                 sw += O_VAL(sp, O_SHIFTWIDTH);
  89
  90         GET_SPACE_RETW(sp, bp, blen, 256);
  91
  92         curset = 0;
  93         for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
  94                 if (db_get(sp, from, DBG_FATAL, &p, &len))
  95                         goto err;
  96                 if (!len) {
  97                         if (sp->lno == from)
  98                                 curset = 1;
  99                         continue;
 100                 }
 101
 102                 /*
 103                  * Calculate the old indent amount and the number of
 104                  * characters it used.
 105                  */
 106                 for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
 107                         if (p[oldidx] == ' ')
 108                                 ++oldcol;
 109                         else if (p[oldidx] == '\t')
 110                                 oldcol += O_VAL(sp, O_TABSTOP) -
 111                                     oldcol % O_VAL(sp, O_TABSTOP);
 112                         else
 113                                 break;
 114
 115                 /* Calculate the new indent amount. */
 116                 if (rl == RIGHT)
 117                         newcol = oldcol + sw;
 118                 else {
 119                         newcol = oldcol < sw ? 0 : oldcol - sw;
 120                         if (newcol == oldcol) {
 121                                 if (sp->lno == from)
 122                                         curset = 1;
 123                                 continue;
 124                         }
 125                 }
 126
 127                 /* Get a buffer that will hold the new line. */
 128                 ADD_SPACE_RETW(sp, bp, blen, newcol + len);
 129
 130                 /*
 131                  * Build a new indent string and count the number of
 132                  * characters it uses.
 133                  */
 134                 for (tbp = bp, newidx = 0;
 135                     newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
 136                         *tbp++ = '\t';
 137                         newcol -= O_VAL(sp, O_TABSTOP);
 138                 }
 139                 for (; newcol > 0; --newcol, ++newidx)
 140                         *tbp++ = ' ';
 141
 142                 /* Add the original line. */
 143                 MEMCPYW(tbp, p + oldidx, len - oldidx);
 144
 145                 /* Set the replacement line. */
 146                 if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
 147 err:                    FREE_SPACEW(sp, bp, blen);
 148                         return (1);
 149                 }
 150
 151                 /*
 152                  * !!!
 153                  * The shift command in historic vi had the usual bizarre
 154                  * collection of cursor semantics.  If called from vi, the
 155                  * cursor was repositioned to the first non-blank character
 156                  * of the lowest numbered line shifted.  If called from ex,
 157                  * the cursor was repositioned to the first non-blank of the
 158                  * highest numbered line shifted.  Here, if the cursor isn't
 159                  * part of the set of lines that are moved, move it to the
 160                  * first non-blank of the last line shifted.  (This makes
 161                  * ":3>>" in vi work reasonably.)  If the cursor is part of
 162                  * the shifted lines, it doesn't get moved at all.  This
 163                  * permits shifting of marked areas, i.e. ">'a." shifts the
 164                  * marked area twice, something that couldn't be done with
 165                  * historic vi.
 166                  */
 167                 if (sp->lno == from) {
 168                         curset = 1;
 169                         if (newidx > oldidx)
 170                                 sp->cno += newidx - oldidx;
 171                         else if (sp->cno >= oldidx - newidx)
 172                                 sp->cno -= oldidx - newidx;
 173                 }
 174         }
 175         if (!curset) {
 176                 sp->lno = to;
 177                 sp->cno = 0;
 178                 (void)nonblank(sp, to, &sp->cno);
 179         }
 180
 181         FREE_SPACEW(sp, bp, blen);
 182
 183         sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
 184         return (0);
 185 }