bin/ed/sub.c

   1 /* sub.c: This file contains the substitution routines for the ed
   2    line editor */
   3 /*-
   4  * Copyright (c) 1993 Andrew Moore, Talke Studio.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  *
  28  * @(#)sub.c,v 1.1 1994/02/01 00:34:44 alm Exp
  29  * $FreeBSD: src/bin/ed/sub.c,v 1.15 2002/06/30 05:13:53 obrien Exp $
  30  * $DragonFly: src/bin/ed/sub.c,v 1.4 2007/04/06 23:36:54 pavalos Exp $
  31  */
  32
  33 #include "ed.h"
  34
  35
  36 char *rhbuf;                    /* rhs substitution buffer */
  37 int rhbufsz;                    /* rhs substitution buffer size */
  38 int rhbufi;                     /* rhs substitution buffer index */
  39
  40 /* extract_subst_tail: extract substitution tail from the command buffer */
  41 int
  42 extract_subst_tail(int *flagp, long *np)
  43 {
  44         char delimiter;
  45
  46         *flagp = *np = 0;
  47         if ((delimiter = *ibufp) == '\n') {
  48                 rhbufi = 0;
  49                 *flagp = GPR;
  50                 return 0;
  51         } else if (extract_subst_template() == NULL)
  52                 return  ERR;
  53         else if (*ibufp == '\n') {
  54                 *flagp = GPR;
  55                 return 0;
  56         } else if (*ibufp == delimiter)
  57                 ibufp++;
  58         if ('1' <= *ibufp && *ibufp <= '9') {
  59                 STRTOL(*np, ibufp);
  60                 return 0;
  61         } else if (*ibufp == 'g') {
  62                 ibufp++;
  63                 *flagp = GSG;
  64                 return 0;
  65         }
  66         return 0;
  67 }
  68
  69
  70 /* extract_subst_template: return pointer to copy of substitution template
  71    in the command buffer */
  72 char *
  73 extract_subst_template(void)
  74 {
  75         int n = 0;
  76         int i = 0;
  77         char c;
  78         char delimiter = *ibufp++;
  79
  80         if (*ibufp == '%' && *(ibufp + 1) == delimiter) {
  81                 ibufp++;
  82                 if (!rhbuf)
  83                         errmsg = "no previous substitution";
  84                 return rhbuf;
  85         }
  86         while (*ibufp != delimiter) {
  87                 REALLOC(rhbuf, rhbufsz, i + 2, NULL);
  88                 if ((c = rhbuf[i++] = *ibufp++) == '\n' && *ibufp == '\0') {
  89                         i--, ibufp--;
  90                         break;
  91                 } else if (c != '\\')
  92                         ;
  93                 else if ((rhbuf[i++] = *ibufp++) != '\n')
  94                         ;
  95                 else if (!isglobal) {
  96                         while ((n = get_tty_line()) == 0 ||
  97                             (n > 0 && ibuf[n - 1] != '\n'))
  98                                 clearerr(stdin);
  99                         if (n < 0)
 100                                 return NULL;
 101                 }
 102         }
 103         REALLOC(rhbuf, rhbufsz, i + 1, NULL);
 104         rhbuf[rhbufi = i] = '\0';
 105         return  rhbuf;
 106 }
 107
 108
 109 char *rbuf;                     /* substitute_matching_text buffer */
 110 int rbufsz;                     /* substitute_matching_text buffer size */
 111
 112 /* search_and_replace: for each line in a range, change text matching a pattern
 113    according to a substitution template; return status  */
 114 int
 115 search_and_replace(pattern_t *pat, int gflag, int kth)
 116 {
 117         undo_t *up;
 118         const char *txt;
 119         const char *eot;
 120         long lc;
 121         long xa = current_addr;
 122         int nsubs = 0;
 123         line_t *lp;
 124         int len;
 125
 126         current_addr = first_addr - 1;
 127         for (lc = 0; lc <= second_addr - first_addr; lc++) {
 128                 lp = get_addressed_line_node(++current_addr);
 129                 if ((len = substitute_matching_text(pat, lp, gflag, kth)) < 0)
 130                         return ERR;
 131                 else if (len) {
 132                         up = NULL;
 133                         if (delete_lines(current_addr, current_addr) < 0)
 134                                 return ERR;
 135                         txt = rbuf;
 136                         eot = rbuf + len;
 137                         SPL1();
 138                         do {
 139                                 if ((txt = put_sbuf_line(txt)) == NULL) {
 140                                         SPL0();
 141                                         return ERR;
 142                                 } else if (up)
 143                                         up->t = get_addressed_line_node(current_addr);
 144                                 else if ((up = push_undo_stack(UADD,
 145                                     current_addr, current_addr)) == NULL) {
 146                                         SPL0();
 147                                         return ERR;
 148                                 }
 149                         } while (txt != eot);
 150                         SPL0();
 151                         nsubs++;
 152                         xa = current_addr;
 153                 }
 154         }
 155         current_addr = xa;
 156         if  (nsubs == 0 && !(gflag & GLB)) {
 157                 errmsg = "no match";
 158                 return ERR;
 159         } else if ((gflag & (GPR | GLS | GNP)) &&
 160             display_lines(current_addr, current_addr, gflag) < 0)
 161                 return ERR;
 162         return 0;
 163 }
 164
 165
 166 /* substitute_matching_text: replace text matched by a pattern according to
 167    a substitution template; return pointer to the modified text */
 168 int
 169 substitute_matching_text(pattern_t *pat, line_t *lp, int gflag, int kth)
 170 {
 171         int off = 0;
 172         int changed = 0;
 173         int matchno = 0;
 174         int i = 0;
 175         regmatch_t rm[SE_MAX];
 176         char *txt;
 177         char *eot;
 178
 179         if ((txt = get_sbuf_line(lp)) == NULL)
 180                 return ERR;
 181         if (isbinary)
 182                 NUL_TO_NEWLINE(txt, lp->len);
 183         eot = txt + lp->len;
 184         if (!regexec(pat, txt, SE_MAX, rm, 0)) {
 185                 do {
 186                         if (!kth || kth == ++matchno) {
 187                                 changed++;
 188                                 i = rm[0].rm_so;
 189                                 REALLOC(rbuf, rbufsz, off + i, ERR);
 190                                 if (isbinary)
 191                                         NEWLINE_TO_NUL(txt, rm[0].rm_eo);
 192                                 memcpy(rbuf + off, txt, i);
 193                                 off += i;
 194                                 if ((off = apply_subst_template(txt, rm, off,
 195                                     pat->re_nsub)) < 0)
 196                                         return ERR;
 197                         } else {
 198                                 i = rm[0].rm_eo;
 199                                 REALLOC(rbuf, rbufsz, off + i, ERR);
 200                                 if (isbinary)
 201                                         NEWLINE_TO_NUL(txt, i);
 202                                 memcpy(rbuf + off, txt, i);
 203                                 off += i;
 204                         }
 205                         txt += rm[0].rm_eo;
 206                 } while (*txt &&
 207                         (!changed || ((gflag & GSG) && rm[0].rm_eo)) &&
 208                         !regexec(pat, txt, SE_MAX, rm, REG_NOTBOL));
 209                 i = eot - txt;
 210                 REALLOC(rbuf, rbufsz, off + i + 2, ERR);
 211                 if (i > 0 && !rm[0].rm_eo && (gflag & GSG)) {
 212                         errmsg = "infinite substitution loop";
 213                         return  ERR;
 214                 }
 215                 if (isbinary)
 216                         NEWLINE_TO_NUL(txt, i);
 217                 memcpy(rbuf + off, txt, i);
 218                 memcpy(rbuf + off + i, "\n", 2);
 219         }
 220         return changed ? off + i + 1 : 0;
 221 }
 222
 223
 224 /* apply_subst_template: modify text according to a substitution template;
 225    return offset to end of modified text */
 226 int
 227 apply_subst_template(const char *boln, regmatch_t *rm, int off, int re_nsub)
 228 {
 229         int j = 0;
 230         int k = 0;
 231         int n;
 232         char *sub = rhbuf;
 233
 234         for (; sub - rhbuf < rhbufi; sub++)
 235                 if (*sub == '&') {
 236                         j = rm[0].rm_so;
 237                         k = rm[0].rm_eo;
 238                         REALLOC(rbuf, rbufsz, off + k - j, ERR);
 239                         while (j < k)
 240                                 rbuf[off++] = boln[j++];
 241                 } else if (*sub == '\\' && '1' <= *++sub && *sub <= '9' &&
 242                     (n = *sub - '0') <= re_nsub) {
 243                         j = rm[n].rm_so;
 244                         k = rm[n].rm_eo;
 245                         REALLOC(rbuf, rbufsz, off + k - j, ERR);
 246                         while (j < k)
 247                                 rbuf[off++] = boln[j++];
 248                 } else {
 249                         REALLOC(rbuf, rbufsz, off + 1, ERR);
 250                         rbuf[off++] = *sub;
 251                 }
 252         REALLOC(rbuf, rbufsz, off + 1, ERR);
 253         rbuf[off] = '\0';
 254         return off;
 255 }