text_cmds/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
  29 #include <sys/cdefs.h>
  30 __FBSDID("$FreeBSD: src/bin/ed/sub.c,v 1.15 2002/06/30 05:13:53 obrien Exp $");
  31
  32 #include "ed.h"
  33
  34
  35 char *rhbuf;                    /* rhs substitution buffer */
  36 int rhbufsz;                    /* rhs substitution buffer size */
  37 int rhbufi;                     /* rhs substitution buffer index */
  38
  39 /* extract_subst_tail: extract substitution tail from the command buffer */
  40 int
  41 extract_subst_tail(int *flagp, long *np)
  42 {
  43         char delimiter;
  44
  45         *flagp = *np = 0;
  46         if ((delimiter = *ibufp) == '\n') {
  47                 rhbufi = 0;
  48                 *flagp = GPR;
  49                 return 0;
  50         } else if (extract_subst_template() == NULL)
  51                 return  ERR;
  52         else if (*ibufp == '\n') {
  53                 *flagp = GPR;
  54                 return 0;
  55         } else if (*ibufp == delimiter)
  56                 ibufp++;
  57         if ('1' <= *ibufp && *ibufp <= '9') {
  58                 STRTOL(*np, ibufp);
  59                 return 0;
  60         } else if (*ibufp == 'g') {
  61                 ibufp++;
  62                 *flagp = GSG;
  63                 return 0;
  64         }
  65         return 0;
  66 }
  67
  68
  69 /* extract_subst_template: return pointer to copy of substitution template
  70    in the command buffer */
  71 char *
  72 extract_subst_template(void)
  73 {
  74         int n = 0;
  75         int i = 0;
  76         char c;
  77         char delimiter = *ibufp++;
  78
  79         if (*ibufp == '%' && *(ibufp + 1) == delimiter) {
  80                 ibufp++;
  81                 if (!rhbuf)
  82                         errmsg = "no previous substitution";
  83                 return rhbuf;
  84         }
  85         while (*ibufp != delimiter) {
  86                 REALLOC(rhbuf, rhbufsz, i + 2, NULL);
  87                 if ((c = rhbuf[i++] = *ibufp++) == '\n' && *ibufp == '\0') {
  88                         i--, ibufp--;
  89                         break;
  90                 } else if (c != '\\')
  91                         ;
  92                 else if ((rhbuf[i++] = *ibufp++) != '\n')
  93                         ;
  94                 else if (!isglobal) {
  95                         while ((n = get_tty_line()) == 0 ||
  96                             (n > 0 && ibuf[n - 1] != '\n'))
  97                                 clearerr(stdin);
  98                         if (n < 0)
  99                                 return NULL;
 100                 }
 101         }
 102         REALLOC(rhbuf, rhbufsz, i + 1, NULL);
 103         rhbuf[rhbufi = i] = '\0';
 104         return  rhbuf;
 105 }
 106
 107
 108 char *rbuf;                     /* substitute_matching_text buffer */
 109 int rbufsz;                     /* substitute_matching_text buffer size */
 110
 111 /* search_and_replace: for each line in a range, change text matching a pattern
 112    according to a substitution template; return status  */
 113 int
 114 search_and_replace(pattern_t *pat, int gflag, int kth)
 115 {
 116         undo_t *up;
 117         const char *txt;
 118         const char *eot;
 119         long lc;
 120         long xa = current_addr;
 121         int nsubs = 0;
 122         line_t *lp;
 123         int len;
 124
 125         current_addr = first_addr - 1;
 126         for (lc = 0; lc <= second_addr - first_addr; lc++) {
 127                 lp = get_addressed_line_node(++current_addr);
 128                 if ((len = substitute_matching_text(pat, lp, gflag, kth)) < 0)
 129                         return ERR;
 130                 else if (len) {
 131                         up = NULL;
 132                         if (delete_lines(current_addr, current_addr) < 0)
 133                                 return ERR;
 134                         txt = rbuf;
 135                         eot = rbuf + len;
 136                         SPL1();
 137                         do {
 138                                 if ((txt = put_sbuf_line(txt)) == NULL) {
 139                                         SPL0();
 140                                         return ERR;
 141                                 } else if (up)
 142                                         up->t = get_addressed_line_node(current_addr);
 143                                 else if ((up = push_undo_stack(UADD,
 144                                     current_addr, current_addr)) == NULL) {
 145                                         SPL0();
 146                                         return ERR;
 147                                 }
 148                         } while (txt != eot);
 149                         SPL0();
 150                         nsubs++;
 151                         /* 3751351 */
 152                         replace_marks(lp, get_addressed_line_node(current_addr));
 153                         xa = current_addr;
 154                 }
 155         }
 156         current_addr = xa;
 157         if  (nsubs == 0 && !(gflag & GLB)) {
 158                 errmsg = "no match";
 159                 return ERR;
 160         } else if ((gflag & (GPR | GLS | GNP)) &&
 161             display_lines(current_addr, current_addr, gflag) < 0)
 162                 return ERR;
 163         return 0;
 164 }
 165
 166
 167 /* substitute_matching_text: replace text matched by a pattern according to
 168    a substitution template; return pointer to the modified text */
 169 int
 170 substitute_matching_text(pattern_t *pat, line_t *lp, int gflag, int kth)
 171 {
 172         int off = 0;
 173         int changed = 0;
 174         int matchno = 0;
 175         int i = 0;
 176         regmatch_t rm[SE_MAX];
 177         char *txt;
 178         char *eot;
 179
 180         if ((txt = get_sbuf_line(lp)) == NULL)
 181                 return ERR;
 182         if (isbinary)
 183                 NUL_TO_NEWLINE(txt, lp->len);
 184         eot = txt + lp->len;
 185         if (!regexec(pat, txt, SE_MAX, rm, 0)) {
 186                 do {
 187                         if (!kth || kth == ++matchno) {
 188                                 changed++;
 189                                 i = rm[0].rm_so;
 190                                 REALLOC(rbuf, rbufsz, off + i, ERR);
 191                                 if (isbinary)
 192                                         NEWLINE_TO_NUL(txt, rm[0].rm_eo);
 193                                 memcpy(rbuf + off, txt, i);
 194                                 off += i;
 195                                 if ((off = apply_subst_template(txt, rm, off,
 196                                     pat->re_nsub)) < 0)
 197                                         return ERR;
 198                         } else {
 199                                 i = rm[0].rm_eo;
 200                                 REALLOC(rbuf, rbufsz, off + i, ERR);
 201                                 if (isbinary)
 202                                         NEWLINE_TO_NUL(txt, i);
 203                                 memcpy(rbuf + off, txt, i);
 204                                 off += i;
 205                         }
 206                         txt += rm[0].rm_eo;
 207                 } while (*txt &&
 208                         (!changed || ((gflag & GSG) && rm[0].rm_eo)) &&
 209                         !regexec(pat, txt, SE_MAX, rm, REG_NOTBOL));
 210                 i = eot - txt;
 211                 REALLOC(rbuf, rbufsz, off + i + 2, ERR);
 212                 if (i > 0 && !rm[0].rm_eo && (gflag & GSG)) {
 213                         errmsg = "infinite substitution loop";
 214                         return  ERR;
 215                 }
 216                 if (isbinary)
 217                         NEWLINE_TO_NUL(txt, i);
 218                 memcpy(rbuf + off, txt, i);
 219                 memcpy(rbuf + off + i, "\n", 2);
 220         }
 221         return changed ? off + i + 1 : 0;
 222 }
 223
 224
 225 /* apply_subst_template: modify text according to a substitution template;
 226    return offset to end of modified text */
 227 int
 228 apply_subst_template(const char *boln, regmatch_t *rm, int off, int re_nsub)
 229 {
 230         int j = 0;
 231         int k = 0;
 232         int n;
 233         char *sub = rhbuf;
 234
 235         for (; sub - rhbuf < rhbufi; sub++)
 236                 if (*sub == '&') {
 237                         j = rm[0].rm_so;
 238                         k = rm[0].rm_eo;
 239                         REALLOC(rbuf, rbufsz, off + k - j, ERR);
 240                         while (j < k)
 241                                 rbuf[off++] = boln[j++];
 242                 } else if (*sub == '\\' && '1' <= *++sub && *sub <= '9' &&
 243                     (n = *sub - '0') <= re_nsub) {
 244                         j = rm[n].rm_so;
 245                         k = rm[n].rm_eo;
 246                         REALLOC(rbuf, rbufsz, off + k - j, ERR);
 247                         while (j < k)
 248                                 rbuf[off++] = boln[j++];
 249                 } else {
 250                         REALLOC(rbuf, rbufsz, off + 1, ERR);
 251                         rbuf[off++] = *sub;
 252                 }
 253         REALLOC(rbuf, rbufsz, off + 1, ERR);
 254         rbuf[off] = '\0';
 255         return off;
 256 }