usr.bin/sed/process.c

   1 /*-
   2  * Copyright (c) 1992 Diomidis Spinellis.
   3  * Copyright (c) 1992, 1993, 1994
   4  *      The Regents of the University of California.  All rights reserved.
   5  *
   6  * This code is derived from software contributed to Berkeley by
   7  * Diomidis Spinellis of Imperial College, University of London.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #ifndef lint
  38 static const char sccsid[] = "@(#)process.c     8.6 (Berkeley) 4/20/94";
  39 #endif
  40
  41 #include <sys/types.h>
  42 #include <sys/stat.h>
  43 #include <sys/ioctl.h>
  44 #include <sys/uio.h>
  45
  46 #include <ctype.h>
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <fcntl.h>
  50 #include <limits.h>
  51 #include <regex.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <string.h>
  55 #include <unistd.h>
  56 #include <wchar.h>
  57 #include <wctype.h>
  58
  59 #include "defs.h"
  60 #include "extern.h"
  61
  62 static SPACE HS, PS, SS, YS;
  63 #define pd              PS.deleted
  64 #define ps              PS.space
  65 #define psl             PS.len
  66 #define hs              HS.space
  67 #define hsl             HS.len
  68
  69 static __inline int      applies(struct s_command *);
  70 static void              do_tr(struct s_tr *);
  71 static void              flush_appends(void);
  72 static void              lputs(char *, size_t);
  73 static __inline int      regexec_e(regex_t *, const char *, int, int, size_t);
  74 static void              regsub(SPACE *, char *, char *);
  75 static int               substitute(struct s_command *);
  76
  77 struct s_appends *appends;      /* Array of pointers to strings to append. */
  78 static int appendx;             /* Index into appends array. */
  79 int appendnum;                  /* Size of appends array. */
  80
  81 static int lastaddr;            /* Set by applies if last address of a range. */
  82 static int sdone;               /* If any substitutes since last line input. */
  83                                 /* Iov structure for 'w' commands. */
  84 static regex_t *defpreg;
  85 size_t maxnsub;
  86 regmatch_t *match;
  87
  88 #define OUT(s) { fwrite(s, sizeof(u_char), psl, outfile); fputc('\n', outfile); }
  89
  90 void
  91 process(void)
  92 {
  93         struct s_command *cp;
  94         SPACE tspace;
  95         size_t oldpsl = 0;
  96         char *p;
  97
  98         p = NULL;
  99
 100         for (linenum = 0; mf_fgets(&PS, REPLACE);) {
 101                 pd = 0;
 102 top:
 103                 cp = prog;
 104 redirect:
 105                 while (cp != NULL) {
 106                         if (!applies(cp)) {
 107                                 cp = cp->next;
 108                                 continue;
 109                         }
 110                         switch (cp->code) {
 111                         case '{':
 112                                 cp = cp->u.c;
 113                                 goto redirect;
 114                         case 'a':
 115                                 if (appendx >= appendnum)
 116                                         if ((appends = realloc(appends,
 117                                             sizeof(struct s_appends) *
 118                                             (appendnum *= 2))) == NULL)
 119                                                 err(1, "realloc");
 120                                 appends[appendx].type = AP_STRING;
 121                                 appends[appendx].s = cp->t;
 122                                 appends[appendx].len = strlen(cp->t);
 123                                 appendx++;
 124                                 break;
 125                         case 'b':
 126                                 cp = cp->u.c;
 127                                 goto redirect;
 128                         case 'c':
 129                                 pd = 1;
 130                                 psl = 0;
 131                                 if (cp->a2 == NULL || lastaddr || lastline())
 132                                         (void)fprintf(outfile, "%s", cp->t);
 133                                 break;
 134                         case 'd':
 135                                 pd = 1;
 136                                 goto new;
 137                         case 'D':
 138                                 if (pd)
 139                                         goto new;
 140                                 if (psl == 0 ||
 141                                     (p = memchr(ps, '\n', psl)) == NULL) {
 142                                         pd = 1;
 143                                         goto new;
 144                                 } else {
 145                                         psl -= (p + 1) - ps;
 146                                         memmove(ps, p + 1, psl);
 147                                         goto top;
 148                                 }
 149                         case 'g':
 150                                 cspace(&PS, hs, hsl, REPLACE);
 151                                 break;
 152                         case 'G':
 153                                 cspace(&PS, "\n", 1, 0);
 154                                 cspace(&PS, hs, hsl, 0);
 155                                 break;
 156                         case 'h':
 157                                 cspace(&HS, ps, psl, REPLACE);
 158                                 break;
 159                         case 'H':
 160                                 cspace(&HS, "\n", 1, 0);
 161                                 cspace(&HS, ps, psl, 0);
 162                                 break;
 163                         case 'i':
 164                                 (void)fprintf(outfile, "%s", cp->t);
 165                                 break;
 166                         case 'l':
 167                                 lputs(ps, psl);
 168                                 break;
 169                         case 'n':
 170                                 if (!nflag && !pd)
 171                                         OUT(ps)
 172                                 flush_appends();
 173                                 if (!mf_fgets(&PS, REPLACE))
 174                                         exit(0);
 175                                 pd = 0;
 176                                 break;
 177                         case 'N':
 178                                 flush_appends();
 179                                 cspace(&PS, "\n", 1, 0);
 180                                 if (!mf_fgets(&PS, 0))
 181                                         exit(0);
 182                                 break;
 183                         case 'p':
 184                                 if (pd)
 185                                         break;
 186                                 OUT(ps)
 187                                 break;
 188                         case 'P':
 189                                 if (pd)
 190                                         break;
 191                                 if ((p = memchr(ps, '\n', psl)) != NULL) {
 192                                         oldpsl = psl;
 193                                         psl = p - ps;
 194                                 }
 195                                 OUT(ps)
 196                                 if (p != NULL)
 197                                         psl = oldpsl;
 198                                 break;
 199                         case 'q':
 200                                 if (!nflag && !pd)
 201                                         OUT(ps)
 202                                 flush_appends();
 203                                 exit(0);
 204                         case 'r':
 205                                 if (appendx >= appendnum)
 206                                         if ((appends = realloc(appends,
 207                                             sizeof(struct s_appends) *
 208                                             (appendnum *= 2))) == NULL)
 209                                                 err(1, "realloc");
 210                                 appends[appendx].type = AP_FILE;
 211                                 appends[appendx].s = cp->t;
 212                                 appends[appendx].len = strlen(cp->t);
 213                                 appendx++;
 214                                 break;
 215                         case 's':
 216                                 sdone |= substitute(cp);
 217                                 break;
 218                         case 't':
 219                                 if (sdone) {
 220                                         sdone = 0;
 221                                         cp = cp->u.c;
 222                                         goto redirect;
 223                                 }
 224                                 break;
 225                         case 'w':
 226                                 if (pd)
 227                                         break;
 228                                 if (cp->u.fd == -1 && (cp->u.fd = open(cp->t,
 229                                     O_WRONLY|O_APPEND|O_CREAT|O_TRUNC,
 230                                     DEFFILEMODE)) == -1)
 231                                         err(1, "%s", cp->t);
 232                                 if (write(cp->u.fd, ps, psl) != psl ||
 233                                     write(cp->u.fd, "\n", 1) != 1)
 234                                         err(1, "%s", cp->t);
 235                                 break;
 236                         case 'x':
 237                                 if (hs == NULL)
 238                                         cspace(&HS, "", 0, REPLACE);
 239                                 tspace = PS;
 240                                 PS = HS;
 241                                 HS = tspace;
 242                                 break;
 243                         case 'y':
 244                                 if (pd || psl == 0)
 245                                         break;
 246                                 do_tr(cp->u.y);
 247                                 break;
 248                         case ':':
 249                         case '}':
 250                                 break;
 251                         case '=':
 252                                 (void)fprintf(outfile, "%lu\n", linenum);
 253                         }
 254                         cp = cp->next;
 255                 } /* for all cp */
 256
 257 new:            if (!nflag && !pd)
 258                         OUT(ps)
 259                 flush_appends();
 260         } /* for all lines */
 261 }
 262
 263 /*
 264  * TRUE if the address passed matches the current program state
 265  * (lastline, linenumber, ps).
 266  */
 267 #define MATCH(a)                                                        \
 268         ((a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) :      \
 269             (a)->type == AT_LINE ? linenum == (a)->u.l : lastline())
 270
 271 /*
 272  * Return TRUE if the command applies to the current line.  Sets the inrange
 273  * flag to process ranges.  Interprets the non-select (``!'') flag.
 274  */
 275 static __inline int
 276 applies(struct s_command *cp)
 277 {
 278         int r;
 279
 280         lastaddr = 0;
 281         if (cp->a1 == NULL && cp->a2 == NULL)
 282                 r = 1;
 283         else if (cp->a2)
 284                 if (cp->inrange) {
 285                         if (MATCH(cp->a2)) {
 286                                 cp->inrange = 0;
 287                                 lastaddr = 1;
 288                                 r = 1;
 289                         } else if (cp->a2->type == AT_LINE &&
 290                                    linenum > cp->a2->u.l) {
 291                                 /*
 292                                  * We missed the 2nd address due to a branch,
 293                                  * so just close the range and return false.
 294                                  */
 295                                 cp->inrange = 0;
 296                                 r = 0;
 297                         } else
 298                                 r = 1;
 299                 } else if (MATCH(cp->a1)) {
 300                         /*
 301                          * If the second address is a number less than or
 302                          * equal to the line number first selected, only
 303                          * one line shall be selected.
 304                          *      -- POSIX 1003.2
 305                          */
 306                         if (cp->a2->type == AT_LINE &&
 307                             linenum >= cp->a2->u.l)
 308                                 lastaddr = 1;
 309                         else
 310                                 cp->inrange = 1;
 311                         r = 1;
 312                 } else
 313                         r = 0;
 314         else
 315                 r = MATCH(cp->a1);
 316         return (cp->nonsel ? ! r : r);
 317 }
 318
 319 /*
 320  * Reset all inrange markers.
 321  */
 322 void
 323 resetranges(void)
 324 {
 325         struct s_command *cp;
 326
 327         for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next)
 328                 if (cp->a2)
 329                         cp->inrange = 0;
 330 }
 331
 332 /*
 333  * substitute --
 334  *      Do substitutions in the pattern space.  Currently, we build a
 335  *      copy of the new pattern space in the substitute space structure
 336  *      and then swap them.
 337  */
 338 static int
 339 substitute(struct s_command *cp)
 340 {
 341         SPACE tspace;
 342         regex_t *re;
 343         regoff_t re_off, slen;
 344         int lastempty, n;
 345         char *s;
 346
 347         s = ps;
 348         re = cp->u.s->re;
 349         if (re == NULL) {
 350                 if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) {
 351                         linenum = cp->u.s->linenum;
 352                         errx(1, "%lu: %s: \\%d not defined in the RE",
 353                                         linenum, fname, cp->u.s->maxbref);
 354                 }
 355         }
 356         if (!regexec_e(re, s, 0, 0, psl))
 357                 return (0);
 358
 359         SS.len = 0;                             /* Clean substitute space. */
 360         slen = psl;
 361         n = cp->u.s->n;
 362         lastempty = 1;
 363
 364         switch (n) {
 365         case 0:                                 /* Global */
 366                 do {
 367                         if (lastempty || match[0].rm_so != match[0].rm_eo) {
 368                                 /* Locate start of replaced string. */
 369                                 re_off = match[0].rm_so;
 370                                 /* Copy leading retained string. */
 371                                 cspace(&SS, s, re_off, APPEND);
 372                                 /* Add in regular expression. */
 373                                 regsub(&SS, s, cp->u.s->new);
 374                         }
 375
 376                         /* Move past this match. */
 377                         if (match[0].rm_so != match[0].rm_eo) {
 378                                 s += match[0].rm_eo;
 379                                 slen -= match[0].rm_eo;
 380                                 lastempty = 0;
 381                         } else {
 382                                 if (match[0].rm_so < slen)
 383                                         cspace(&SS, s + match[0].rm_so, 1,
 384                                             APPEND);
 385                                 s += match[0].rm_so + 1;
 386                                 slen -= match[0].rm_so + 1;
 387                                 lastempty = 1;
 388                         }
 389                 } while (slen >= 0 && regexec_e(re, s, REG_NOTBOL, 0, slen));
 390                 /* Copy trailing retained string. */
 391                 if (slen > 0)
 392                         cspace(&SS, s, slen, APPEND);
 393                 break;
 394         default:                                /* Nth occurrence */
 395                 while (--n) {
 396                         if (match[0].rm_eo == match[0].rm_so)
 397                                 match[0].rm_eo = match[0].rm_so + 1;
 398                         s += match[0].rm_eo;
 399                         slen -= match[0].rm_eo;
 400                         if (slen < 0)
 401                                 return (0);
 402                         if (!regexec_e(re, s, REG_NOTBOL, 0, slen))
 403                                 return (0);
 404                 }
 405                 /* FALLTHROUGH */
 406         case 1:                                 /* 1st occurrence */
 407                 /* Locate start of replaced string. */
 408                 re_off = match[0].rm_so + (s - ps);
 409                 /* Copy leading retained string. */
 410                 cspace(&SS, ps, re_off, APPEND);
 411                 /* Add in regular expression. */
 412                 regsub(&SS, s, cp->u.s->new);
 413                 /* Copy trailing retained string. */
 414                 s += match[0].rm_eo;
 415                 slen -= match[0].rm_eo;
 416                 cspace(&SS, s, slen, APPEND);
 417                 break;
 418         }
 419
 420         /*
 421          * Swap the substitute space and the pattern space, and make sure
 422          * that any leftover pointers into stdio memory get lost.
 423          */
 424         tspace = PS;
 425         PS = SS;
 426         SS = tspace;
 427         SS.space = SS.back;
 428
 429         /* Handle the 'p' flag. */
 430         if (cp->u.s->p)
 431                 OUT(ps)
 432
 433         /* Handle the 'w' flag. */
 434         if (cp->u.s->wfile && !pd) {
 435                 if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile,
 436                     O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1)
 437                         err(1, "%s", cp->u.s->wfile);
 438                 if (write(cp->u.s->wfd, ps, psl) != psl ||
 439                     write(cp->u.s->wfd, "\n", 1) != 1)
 440                         err(1, "%s", cp->u.s->wfile);
 441         }
 442         return (1);
 443 }
 444
 445 /*
 446  * do_tr --
 447  *      Perform translation ('y' command) in the pattern space.
 448  */
 449 static void
 450 do_tr(struct s_tr *y)
 451 {
 452         SPACE tmp;
 453         char c, *p;
 454         size_t clen, left;
 455         int i;
 456
 457         if (MB_CUR_MAX == 1) {
 458                 /*
 459                  * Single-byte encoding: perform in-place translation
 460                  * of the pattern space.
 461                  */
 462                 for (p = ps; p < &ps[psl]; p++)
 463                         *p = y->bytetab[(u_char)*p];
 464         } else {
 465                 /*
 466                  * Multi-byte encoding: perform translation into the
 467                  * translation space, then swap the translation and
 468                  * pattern spaces.
 469                  */
 470                 /* Clean translation space. */
 471                 YS.len = 0;
 472                 for (p = ps, left = psl; left > 0; p += clen, left -= clen) {
 473                         if ((c = y->bytetab[(u_char)*p]) != '\0') {
 474                                 cspace(&YS, &c, 1, APPEND);
 475                                 clen = 1;
 476                                 continue;
 477                         }
 478                         for (i = 0; i < y->nmultis; i++)
 479                                 if (left >= y->multis[i].fromlen &&
 480                                     memcmp(p, y->multis[i].from,
 481                                     y->multis[i].fromlen) == 0)
 482                                         break;
 483                         if (i < y->nmultis) {
 484                                 cspace(&YS, y->multis[i].to,
 485                                     y->multis[i].tolen, APPEND);
 486                                 clen = y->multis[i].fromlen;
 487                         } else {
 488                                 cspace(&YS, p, 1, APPEND);
 489                                 clen = 1;
 490                         }
 491                 }
 492                 /* Swap the translation space and the pattern space. */
 493                 tmp = PS;
 494                 PS = YS;
 495                 YS = tmp;
 496                 YS.space = YS.back;
 497         }
 498 }
 499
 500 /*
 501  * Flush append requests.  Always called before reading a line,
 502  * therefore it also resets the substitution done (sdone) flag.
 503  */
 504 static void
 505 flush_appends(void)
 506 {
 507         FILE *f;
 508         int count, i;
 509         char buf[8 * 1024];
 510
 511         for (i = 0; i < appendx; i++)
 512                 switch (appends[i].type) {
 513                 case AP_STRING:
 514                         fwrite(appends[i].s, sizeof(char), appends[i].len,
 515                             outfile);
 516                         break;
 517                 case AP_FILE:
 518                         /*
 519                          * Read files probably shouldn't be cached.  Since
 520                          * it's not an error to read a non-existent file,
 521                          * it's possible that another program is interacting
 522                          * with the sed script through the filesystem.  It
 523                          * would be truly bizarre, but possible.  It's probably
 524                          * not that big a performance win, anyhow.
 525                          */
 526                         if ((f = fopen(appends[i].s, "r")) == NULL)
 527                                 break;
 528                         while ((count = fread(buf, sizeof(char), sizeof(buf), f)))
 529                                 (void)fwrite(buf, sizeof(char), count, outfile);
 530                         (void)fclose(f);
 531                         break;
 532                 }
 533         if (ferror(outfile))
 534                 errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
 535         appendx = sdone = 0;
 536 }
 537
 538 static void
 539 lputs(char *s, size_t len)
 540 {
 541         static const char escapes[] = "\\\a\b\f\r\t\v";
 542         int c, col, width;
 543         char *p;
 544         struct winsize win;
 545         static int termwidth = -1;
 546         size_t clen, i;
 547         wchar_t wc;
 548         mbstate_t mbs;
 549
 550         if (outfile != stdout)
 551                 termwidth = 60;
 552         if (termwidth == -1) {
 553                 if ((p = getenv("COLUMNS")) && *p != '\0')
 554                         termwidth = atoi(p);
 555                 else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 &&
 556                     win.ws_col > 0)
 557                         termwidth = win.ws_col;
 558                 else
 559                         termwidth = 60;
 560         }
 561
 562         memset(&mbs, 0, sizeof(mbs));
 563         col = 0;
 564         while (len != 0) {
 565                 clen = mbrtowc(&wc, s, len, &mbs);
 566                 if (clen == 0)
 567                         clen = 1;
 568                 if (clen == (size_t)-1 || clen == (size_t)-2) {
 569                         wc = (unsigned char)*s;
 570                         clen = 1;
 571                         memset(&mbs, 0, sizeof(mbs));
 572                 }
 573                 if (wc == '\n') {
 574                         if (col + 1 >= termwidth)
 575                                 fprintf(outfile, "\\\n");
 576                         fputc('$', outfile);
 577                         fputc('\n', outfile);
 578                         col = 0;
 579                 } else if (iswprint(wc)) {
 580                         width = wcwidth(wc);
 581                         if (col + width >= termwidth) {
 582                                 fprintf(outfile, "\\\n");
 583                                 col = 0;
 584                         }
 585                         fwrite(s, 1, clen, outfile);
 586                         col += width;
 587                 } else if (wc != L'\0' && (c = wctob(wc)) != EOF &&
 588                     (p = strchr(escapes, c)) != NULL) {
 589                         if (col + 2 >= termwidth) {
 590                                 fprintf(outfile, "\\\n");
 591                                 col = 0;
 592                         }
 593                         fprintf(outfile, "\\%c", "\\abfrtv"[p - escapes]);
 594                         col += 2;
 595                 } else {
 596                         if (col + 4 * clen >= termwidth) {
 597                                 fprintf(outfile, "\\\n");
 598                                 col = 0;
 599                         }
 600                         for (i = 0; i < clen; i++)
 601                                 fprintf(outfile, "\\%03o",
 602                                     (int)(unsigned char)s[i]);
 603                         col += 4 * clen;
 604                 }
 605                 s += clen;
 606                 len -= clen;
 607         }
 608         if (col + 1 >= termwidth)
 609                 fprintf(outfile, "\\\n");
 610         (void)fputc('$', outfile);
 611         (void)fputc('\n', outfile);
 612         if (ferror(outfile))
 613                 errx(1, "%s: %s", outfname, strerror(errno ? errno : EIO));
 614 }
 615
 616 static __inline int
 617 regexec_e(regex_t *preg, const char *string, int eflags, int nomatch,
 618         size_t slen)
 619 {
 620         int eval;
 621
 622         if (preg == NULL) {
 623                 if (defpreg == NULL)
 624                         errx(1, "first RE may not be empty");
 625         } else
 626                 defpreg = preg;
 627
 628         /* Set anchors */
 629         match[0].rm_so = 0;
 630         match[0].rm_eo = slen;
 631
 632         eval = regexec(defpreg, string,
 633             nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND);
 634         switch(eval) {
 635         case 0:
 636                 return (1);
 637         case REG_NOMATCH:
 638                 return (0);
 639         }
 640         errx(1, "RE error: %s", strregerror(eval, defpreg));
 641         /* NOTREACHED */
 642 }
 643
 644 /*
 645  * regsub - perform substitutions after a regexp match
 646  * Based on a routine by Henry Spencer
 647  */
 648 static void
 649 regsub(SPACE *sp, char *string, char *src)
 650 {
 651         int len, no;
 652         char c, *dst;
 653
 654 #define NEEDSP(reqlen)                                                  \
 655         /* XXX What is the +1 for? */                                   \
 656         if (sp->len + (reqlen) + 1 >= sp->blen) {                       \
 657                 sp->blen += (reqlen) + 1024;                            \
 658                 if ((sp->space = sp->back = realloc(sp->back, sp->blen)) \
 659                     == NULL)                                            \
 660                         err(1, "realloc");                              \
 661                 dst = sp->space + sp->len;                              \
 662         }
 663
 664         dst = sp->space + sp->len;
 665         while ((c = *src++) != '\0') {
 666                 if (c == '&')
 667                         no = 0;
 668                 else if (c == '\\' && isdigit((unsigned char)*src))
 669                         no = *src++ - '0';
 670                 else
 671                         no = -1;
 672                 if (no < 0) {           /* Ordinary character. */
 673                         if (c == '\\' && (*src == '\\' || *src == '&'))
 674                                 c = *src++;
 675                         NEEDSP(1);
 676                         *dst++ = c;
 677                         ++sp->len;
 678                 } else if (match[no].rm_so != -1 && match[no].rm_eo != -1) {
 679                         len = match[no].rm_eo - match[no].rm_so;
 680                         NEEDSP(len);
 681                         memmove(dst, string + match[no].rm_so, len);
 682                         dst += len;
 683                         sp->len += len;
 684                 }
 685         }
 686         NEEDSP(1);
 687         *dst = '\0';
 688 }
 689
 690 /*
 691  * cspace --
 692  *      Concatenate space: append the source space to the destination space,
 693  *      allocating new space as necessary.
 694  */
 695 void
 696 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag)
 697 {
 698         size_t tlen;
 699
 700         /* Make sure SPACE has enough memory and ramp up quickly. */
 701         tlen = sp->len + len + 1;
 702         if (tlen > sp->blen) {
 703                 sp->blen = tlen + 1024;
 704                 if ((sp->space = sp->back = realloc(sp->back, sp->blen)) ==
 705                     NULL)
 706                         err(1, "realloc");
 707         }
 708
 709         if (spflag == REPLACE)
 710                 sp->len = 0;
 711
 712         memmove(sp->space + sp->len, p, len);
 713
 714         sp->space[sp->len += len] = '\0';
 715 }
 716
 717 /*
 718  * Close all cached opened files and report any errors
 719  */
 720 void
 721 cfclose(struct s_command *cp, struct s_command *end)
 722 {
 723
 724         for (; cp != end; cp = cp->next)
 725                 switch(cp->code) {
 726                 case 's':
 727                         if (cp->u.s->wfd != -1 && close(cp->u.s->wfd))
 728                                 err(1, "%s", cp->u.s->wfile);
 729                         cp->u.s->wfd = -1;
 730                         break;
 731                 case 'w':
 732                         if (cp->u.fd != -1 && close(cp->u.fd))
 733                                 err(1, "%s", cp->t);
 734                         cp->u.fd = -1;
 735                         break;
 736                 case '{':
 737                         cfclose(cp->u.c, cp->next);
 738                         break;
 739                 }
 740 }