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 10.11 1996/09/15 15:59:45 bostic Exp $ (Berkeley) $Date: 1996/09/15 15:59:45 $";
  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(sp, cmdp)
  38         SCR *sp;
  39         EXCMD *cmdp;
  40 {
  41         return (shift(sp, cmdp, LEFT));
  42 }
  43
  44 /*
  45  * ex_shiftr -- :>[>...]
  46  *
  47  * PUBLIC: int ex_shiftr __P((SCR *, EXCMD *));
  48  */
  49 int
  50 ex_shiftr(sp, cmdp)
  51         SCR *sp;
  52         EXCMD *cmdp;
  53 {
  54         return (shift(sp, cmdp, RIGHT));
  55 }
  56
  57 /*
  58  * shift --
  59  *      Ex shift support.
  60  */
  61 static int
  62 shift(sp, cmdp, rl)
  63         SCR *sp;
  64         EXCMD *cmdp;
  65         enum which rl;
  66 {
  67         recno_t from, to;
  68         size_t blen, len, newcol, newidx, oldcol, oldidx, sw;
  69         int curset;
  70         char *p, *bp, *tbp;
  71
  72         NEEDFILE(sp, cmdp);
  73
  74         if (O_VAL(sp, O_SHIFTWIDTH) == 0) {
  75                 msgq(sp, M_INFO, "152|shiftwidth option set to 0");
  76                 return (0);
  77         }
  78
  79         /* Copy the lines being shifted into the unnamed buffer. */
  80         if (cut(sp, NULL, &cmdp->addr1, &cmdp->addr2, CUT_LINEMODE))
  81                 return (1);
  82
  83         /*
  84          * The historic version of vi permitted the user to string any number
  85          * of '>' or '<' characters together, resulting in an indent of the
  86          * appropriate levels.  There's a special hack in ex_cmd() so that
  87          * cmdp->argv[0] points to the string of '>' or '<' characters.
  88          *
  89          * Q: What's the difference between the people adding features
  90          *    to vi and the Girl Scouts?
  91          * A: The Girl Scouts have mint cookies and adult supervision.
  92          */
  93         for (p = cmdp->argv[0]->bp, sw = 0; *p == '>' || *p == '<'; ++p)
  94                 sw += O_VAL(sp, O_SHIFTWIDTH);
  95
  96         GET_SPACE_RET(sp, bp, blen, 256);
  97
  98         curset = 0;
  99         for (from = cmdp->addr1.lno, to = cmdp->addr2.lno; from <= to; ++from) {
 100                 if (db_get(sp, from, DBG_FATAL, &p, &len))
 101                         goto err;
 102                 if (!len) {
 103                         if (sp->lno == from)
 104                                 curset = 1;
 105                         continue;
 106                 }
 107
 108                 /*
 109                  * Calculate the old indent amount and the number of
 110                  * characters it used.
 111                  */
 112                 for (oldidx = 0, oldcol = 0; oldidx < len; ++oldidx)
 113                         if (p[oldidx] == ' ')
 114                                 ++oldcol;
 115                         else if (p[oldidx] == '\t')
 116                                 oldcol += O_VAL(sp, O_TABSTOP) -
 117                                     oldcol % O_VAL(sp, O_TABSTOP);
 118                         else
 119                                 break;
 120
 121                 /* Calculate the new indent amount. */
 122                 if (rl == RIGHT)
 123                         newcol = oldcol + sw;
 124                 else {
 125                         newcol = oldcol < sw ? 0 : oldcol - sw;
 126                         if (newcol == oldcol) {
 127                                 if (sp->lno == from)
 128                                         curset = 1;
 129                                 continue;
 130                         }
 131                 }
 132
 133                 /* Get a buffer that will hold the new line. */
 134                 ADD_SPACE_RET(sp, bp, blen, newcol + len);
 135
 136                 /*
 137                  * Build a new indent string and count the number of
 138                  * characters it uses.
 139                  */
 140                 for (tbp = bp, newidx = 0;
 141                     newcol >= O_VAL(sp, O_TABSTOP); ++newidx) {
 142                         *tbp++ = '\t';
 143                         newcol -= O_VAL(sp, O_TABSTOP);
 144                 }
 145                 for (; newcol > 0; --newcol, ++newidx)
 146                         *tbp++ = ' ';
 147
 148                 /* Add the original line. */
 149                 memcpy(tbp, p + oldidx, len - oldidx);
 150
 151                 /* Set the replacement line. */
 152                 if (db_set(sp, from, bp, (tbp + (len - oldidx)) - bp)) {
 153 err:                    FREE_SPACE(sp, bp, blen);
 154                         return (1);
 155                 }
 156
 157                 /*
 158                  * !!!
 159                  * The shift command in historic vi had the usual bizarre
 160                  * collection of cursor semantics.  If called from vi, the
 161                  * cursor was repositioned to the first non-blank character
 162                  * of the lowest numbered line shifted.  If called from ex,
 163                  * the cursor was repositioned to the first non-blank of the
 164                  * highest numbered line shifted.  Here, if the cursor isn't
 165                  * part of the set of lines that are moved, move it to the
 166                  * first non-blank of the last line shifted.  (This makes
 167                  * ":3>>" in vi work reasonably.)  If the cursor is part of
 168                  * the shifted lines, it doesn't get moved at all.  This
 169                  * permits shifting of marked areas, i.e. ">'a." shifts the
 170                  * marked area twice, something that couldn't be done with
 171                  * historic vi.
 172                  */
 173                 if (sp->lno == from) {
 174                         curset = 1;
 175                         if (newidx > oldidx)
 176                                 sp->cno += newidx - oldidx;
 177                         else if (sp->cno >= oldidx - newidx)
 178                                 sp->cno -= oldidx - newidx;
 179                 }
 180         }
 181         if (!curset) {
 182                 sp->lno = to;
 183                 sp->cno = 0;
 184                 (void)nonblank(sp, to, &sp->cno);
 185         }
 186
 187         FREE_SPACE(sp, bp, blen);
 188
 189         sp->rptlines[L_SHIFT] += cmdp->addr2.lno - cmdp->addr1.lno + 1;
 190         return (0);
 191 }