1 /* $OpenBSD: process.c,v 1.33 2017/12/13 16:06:34 millert Exp $ */ 2 3 /*- 4 * Copyright (c) 1992 Diomidis Spinellis. 5 * Copyright (c) 1992, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * This code is derived from software contributed to Berkeley by 9 * Diomidis Spinellis of Imperial College, University of London. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/types.h> 37 #include <sys/stat.h> 38 #include <sys/uio.h> 39 40 #include <ctype.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <limits.h> 44 #include <regex.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <unistd.h> 49 50 #include "defs.h" 51 #include "extern.h" 52 53 static SPACE HS, PS, SS; 54 #define pd PS.deleted 55 #define ps PS.space 56 #define psl PS.len 57 #define psanl PS.append_newline 58 #define hs HS.space 59 #define hsl HS.len 60 61 static inline int applies(struct s_command *); 62 static void flush_appends(void); 63 static void lputs(char *); 64 static inline int regexec_e(regex_t *, const char *, int, int, size_t, 65 size_t); 66 static void regsub(SPACE *, char *, char *); 67 static int substitute(struct s_command *); 68 69 struct s_appends *appends; /* Array of pointers to strings to append. */ 70 static size_t appendx; /* Index into appends array. */ 71 size_t appendnum; /* Size of appends array. */ 72 73 static int lastaddr; /* Set by applies if last address of a range. */ 74 static int sdone; /* If any substitutes since last line input. */ 75 /* Iov structure for 'w' commands. */ 76 static regex_t *defpreg; 77 size_t maxnsub; 78 regmatch_t *match; 79 80 #define OUT() do {\ 81 fwrite(ps, 1, psl, outfile);\ 82 if (psanl) fputc('\n', outfile);\ 83 } while (0) 84 85 void 86 process(void) 87 { 88 struct s_command *cp; 89 SPACE tspace; 90 size_t len, oldpsl; 91 char *p; 92 93 for (linenum = 0; mf_fgets(&PS, REPLACE);) { 94 pd = 0; 95 top: 96 cp = prog; 97 redirect: 98 while (cp != NULL) { 99 if (!applies(cp)) { 100 cp = cp->next; 101 continue; 102 } 103 switch (cp->code) { 104 case '{': 105 cp = cp->u.c; 106 goto redirect; 107 case 'a': 108 if (appendx >= appendnum) { 109 appends = xreallocarray(appends, 110 appendnum, 111 2 * sizeof(struct s_appends)); 112 appendnum *= 2; 113 } 114 appends[appendx].type = AP_STRING; 115 appends[appendx].s = cp->t; 116 appends[appendx].len = strlen(cp->t); 117 appendx++; 118 break; 119 case 'b': 120 cp = cp->u.c; 121 goto redirect; 122 case 'c': 123 pd = 1; 124 psl = 0; 125 if (cp->a2 == NULL || lastaddr || lastline()) 126 (void)fprintf(outfile, "%s", cp->t); 127 break; 128 case 'd': 129 pd = 1; 130 goto new; 131 case 'D': 132 if (pd) 133 goto new; 134 if (psl == 0 || 135 (p = memchr(ps, '\n', psl)) == NULL) { 136 pd = 1; 137 goto new; 138 } else { 139 psl -= (p + 1) - ps; 140 memmove(ps, p + 1, psl); 141 goto top; 142 } 143 case 'g': 144 cspace(&PS, hs, hsl, REPLACE); 145 break; 146 case 'G': 147 cspace(&PS, "\n", 1, 0); 148 cspace(&PS, hs, hsl, 0); 149 break; 150 case 'h': 151 cspace(&HS, ps, psl, REPLACE); 152 break; 153 case 'H': 154 cspace(&HS, "\n", 1, 0); 155 cspace(&HS, ps, psl, 0); 156 break; 157 case 'i': 158 (void)fprintf(outfile, "%s", cp->t); 159 break; 160 case 'l': 161 lputs(ps); 162 break; 163 case 'n': 164 if (!nflag && !pd) 165 OUT(); 166 flush_appends(); 167 if (!mf_fgets(&PS, REPLACE)) 168 exit(0); 169 pd = 0; 170 break; 171 case 'N': 172 flush_appends(); 173 cspace(&PS, "\n", 1, 0); 174 if (!mf_fgets(&PS, 0)) 175 exit(0); 176 break; 177 case 'p': 178 if (pd) 179 break; 180 OUT(); 181 break; 182 case 'P': 183 if (pd) 184 break; 185 if ((p = memchr(ps, '\n', psl)) != NULL) { 186 oldpsl = psl; 187 psl = p - ps; 188 psanl = 1; 189 OUT(); 190 psl = oldpsl; 191 } else { 192 OUT(); 193 } 194 break; 195 case 'q': 196 if (!nflag && !pd) 197 OUT(); 198 flush_appends(); 199 exit(0); 200 case 'r': 201 if (appendx >= appendnum) { 202 appends = xreallocarray(appends, 203 appendnum, 204 2 * sizeof(struct s_appends)); 205 appendnum *= 2; 206 } 207 appends[appendx].type = AP_FILE; 208 appends[appendx].s = cp->t; 209 appends[appendx].len = strlen(cp->t); 210 appendx++; 211 break; 212 case 's': 213 sdone |= substitute(cp); 214 break; 215 case 't': 216 if (sdone) { 217 sdone = 0; 218 cp = cp->u.c; 219 goto redirect; 220 } 221 break; 222 case 'w': 223 if (pd) 224 break; 225 if (cp->u.fd == -1 && (cp->u.fd = open(cp->t, 226 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 227 DEFFILEMODE)) == -1) 228 error(FATAL, "%s: %s", 229 cp->t, strerror(errno)); 230 if ((size_t)write(cp->u.fd, ps, psl) != psl || 231 write(cp->u.fd, "\n", 1) != 1) 232 error(FATAL, "%s: %s", 233 cp->t, strerror(errno)); 234 break; 235 case 'x': 236 if (hs == NULL) 237 cspace(&HS, "", 0, REPLACE); 238 tspace = PS; 239 PS = HS; 240 psanl = tspace.append_newline; 241 HS = tspace; 242 break; 243 case 'y': 244 if (pd || psl == 0) 245 break; 246 for (p = ps, len = psl; len--; ++p) 247 *p = cp->u.y[(unsigned char)*p]; 248 break; 249 case ':': 250 case '}': 251 break; 252 case '=': 253 (void)fprintf(outfile, "%lu\n", linenum); 254 } 255 cp = cp->next; 256 } /* for all cp */ 257 258 new: if (!nflag && !pd) 259 OUT(); 260 flush_appends(); 261 } /* for all lines */ 262 } 263 264 /* 265 * TRUE if the address passed matches the current program state 266 * (lastline, linenumber, ps). 267 */ 268 #define MATCH(a) \ 269 (a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, 0, psl) : \ 270 (a)->type == AT_LINE ? linenum == (a)->u.l : lastline() 271 272 /* 273 * Return TRUE if the command applies to the current line. Sets the inrange 274 * flag to process ranges. Interprets the non-select (``!'') flag. 275 */ 276 static inline int 277 applies(struct s_command *cp) 278 { 279 int r; 280 281 lastaddr = 0; 282 if (cp->a1 == NULL && cp->a2 == NULL) 283 r = 1; 284 else if (cp->a2) 285 if (cp->inrange) { 286 if (MATCH(cp->a2)) { 287 cp->inrange = 0; 288 lastaddr = 1; 289 } 290 r = 1; 291 } else if (MATCH(cp->a1)) { 292 /* 293 * If the second address is a number less than or 294 * equal to the line number first selected, only 295 * one line shall be selected. 296 * -- POSIX 1003.2 297 */ 298 if (cp->a2->type == AT_LINE && 299 linenum >= cp->a2->u.l) 300 lastaddr = 1; 301 else 302 cp->inrange = 1; 303 r = 1; 304 } else 305 r = 0; 306 else 307 r = MATCH(cp->a1); 308 return (cp->nonsel ? !r : r); 309 } 310 311 /* 312 * Reset all inrange markers. 313 */ 314 void 315 resetranges(void) 316 { 317 struct s_command *cp; 318 319 for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next) 320 if (cp->a2) 321 cp->inrange = 0; 322 } 323 324 /* 325 * substitute -- 326 * Do substitutions in the pattern space. Currently, we build a 327 * copy of the new pattern space in the substitute space structure 328 * and then swap them. 329 */ 330 static int 331 substitute(struct s_command *cp) 332 { 333 SPACE tspace; 334 regex_t *re; 335 regoff_t slen; 336 int n, lastempty; 337 regoff_t le = 0; 338 char *s; 339 340 s = ps; 341 re = cp->u.s->re; 342 if (re == NULL) { 343 if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) { 344 linenum = cp->u.s->linenum; 345 error(COMPILE, "\\%d not defined in the RE", 346 cp->u.s->maxbref); 347 } 348 } 349 if (!regexec_e(re, ps, 0, 0, 0, psl)) 350 return (0); 351 352 SS.len = 0; /* Clean substitute space. */ 353 slen = psl; 354 n = cp->u.s->n; 355 lastempty = 1; 356 357 do { 358 /* Copy the leading retained string. */ 359 if (n <= 1 && (match[0].rm_so > le)) 360 cspace(&SS, s, match[0].rm_so - le, APPEND); 361 362 /* Skip zero-length matches right after other matches. */ 363 if (lastempty || (match[0].rm_so - le) || 364 match[0].rm_so != match[0].rm_eo) { 365 if (n <= 1) { 366 /* Want this match: append replacement. */ 367 regsub(&SS, ps, cp->u.s->new); 368 if (n == 1) 369 n = -1; 370 } else { 371 /* Want a later match: append original. */ 372 if (match[0].rm_eo - le) 373 cspace(&SS, s, match[0].rm_eo - le, 374 APPEND); 375 n--; 376 } 377 } 378 379 /* Move past this match. */ 380 s = ps + match[0].rm_eo; 381 slen = psl - match[0].rm_eo; 382 le = match[0].rm_eo; 383 384 /* 385 * After a zero-length match, advance one byte, 386 * and at the end of the line, terminate. 387 */ 388 if (match[0].rm_so == match[0].rm_eo) { 389 if (*s == '\0' || *s == '\n') 390 slen = -1; 391 else 392 slen--; 393 if (*s != '\0') { 394 cspace(&SS, s++, 1, APPEND); 395 le++; 396 } 397 lastempty = 1; 398 } else 399 lastempty = 0; 400 401 } while (n >= 0 && slen >= 0 && 402 regexec_e(re, ps, REG_NOTBOL, 0, le, psl)); 403 404 /* Did not find the requested number of matches. */ 405 if (n > 0) 406 return (0); 407 408 /* Copy the trailing retained string. */ 409 if (slen > 0) 410 cspace(&SS, s, slen, APPEND); 411 412 /* 413 * Swap the substitute space and the pattern space, and make sure 414 * that any leftover pointers into stdio memory get lost. 415 */ 416 tspace = PS; 417 PS = SS; 418 psanl = tspace.append_newline; 419 SS = tspace; 420 SS.space = SS.back; 421 422 /* Handle the 'p' flag. */ 423 if (cp->u.s->p) 424 OUT(); 425 426 /* Handle the 'w' flag. */ 427 if (cp->u.s->wfile && !pd) { 428 if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile, 429 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1) 430 error(FATAL, "%s: %s", cp->u.s->wfile, strerror(errno)); 431 if ((size_t)write(cp->u.s->wfd, ps, psl) != psl || 432 write(cp->u.s->wfd, "\n", 1) != 1) 433 error(FATAL, "%s: %s", cp->u.s->wfile, strerror(errno)); 434 } 435 return (1); 436 } 437 438 /* 439 * Flush append requests. Always called before reading a line, 440 * therefore it also resets the substitution done (sdone) flag. 441 */ 442 static void 443 flush_appends(void) 444 { 445 FILE *f; 446 size_t count, idx; 447 char buf[8 * 1024]; 448 449 for (idx = 0; idx < appendx; idx++) 450 switch (appends[idx].type) { 451 case AP_STRING: 452 fwrite(appends[idx].s, sizeof(char), appends[idx].len, 453 outfile); 454 break; 455 case AP_FILE: 456 /* 457 * Read files probably shouldn't be cached. Since 458 * it's not an error to read a non-existent file, 459 * it's possible that another program is interacting 460 * with the sed script through the file system. It 461 * would be truly bizarre, but possible. It's probably 462 * not that big a performance win, anyhow. 463 */ 464 if ((f = fopen(appends[idx].s, "r")) == NULL) 465 break; 466 while ((count = fread(buf, sizeof(char), sizeof(buf), f))) 467 (void)fwrite(buf, sizeof(char), count, outfile); 468 (void)fclose(f); 469 break; 470 } 471 if (ferror(outfile)) 472 error(FATAL, "%s: %s", outfname, strerror(errno ? errno : EIO)); 473 appendx = sdone = 0; 474 } 475 476 static void 477 lputs(char *s) 478 { 479 int count; 480 extern int termwidth; 481 const char *escapes; 482 char *p; 483 484 for (count = 0; *s; ++s) { 485 if (count >= termwidth) { 486 (void)fprintf(outfile, "\\\n"); 487 count = 0; 488 } 489 if (isascii((unsigned char)*s) && isprint((unsigned char)*s) 490 && *s != '\\') { 491 (void)fputc(*s, outfile); 492 count++; 493 } else if (*s == '\n') { 494 (void)fputc('$', outfile); 495 (void)fputc('\n', outfile); 496 count = 0; 497 } else { 498 escapes = "\\\a\b\f\r\t\v"; 499 (void)fputc('\\', outfile); 500 if ((p = strchr(escapes, *s))) { 501 (void)fputc("\\abfrtv"[p - escapes], outfile); 502 count += 2; 503 } else { 504 (void)fprintf(outfile, "%03o", *(u_char *)s); 505 count += 4; 506 } 507 } 508 } 509 (void)fputc('$', outfile); 510 (void)fputc('\n', outfile); 511 if (ferror(outfile)) 512 error(FATAL, "%s: %s", outfname, strerror(errno ? errno : EIO)); 513 } 514 515 static inline int 516 regexec_e(regex_t *preg, const char *string, int eflags, 517 int nomatch, size_t start, size_t stop) 518 { 519 int eval; 520 521 if (preg == NULL) { 522 if (defpreg == NULL) 523 error(FATAL, "first RE may not be empty"); 524 } else 525 defpreg = preg; 526 527 /* Set anchors */ 528 match[0].rm_so = start; 529 match[0].rm_eo = stop; 530 531 eval = regexec(defpreg, string, 532 nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND); 533 switch (eval) { 534 case 0: 535 return (1); 536 case REG_NOMATCH: 537 return (0); 538 } 539 error(FATAL, "RE error: %s", strregerror(eval, defpreg)); 540 } 541 542 /* 543 * regsub - perform substitutions after a regexp match 544 * Based on a routine by Henry Spencer 545 */ 546 static void 547 regsub(SPACE *sp, char *string, char *src) 548 { 549 int len, no; 550 char c, *dst; 551 552 #define NEEDSP(reqlen) \ 553 if (sp->len + (reqlen) + 1 >= sp->blen) { \ 554 size_t newlen = sp->blen + (reqlen) + 1024; \ 555 sp->space = sp->back = xrealloc(sp->back, newlen); \ 556 sp->blen = newlen; \ 557 dst = sp->space + sp->len; \ 558 } 559 560 dst = sp->space + sp->len; 561 while ((c = *src++) != '\0') { 562 if (c == '&') 563 no = 0; 564 else if (c == '\\' && isdigit((unsigned char)*src)) 565 no = *src++ - '0'; 566 else 567 no = -1; 568 if (no < 0) { /* Ordinary character. */ 569 if (c == '\\' && (*src == '\\' || *src == '&')) 570 c = *src++; 571 NEEDSP(1); 572 *dst++ = c; 573 ++sp->len; 574 } else if (match[no].rm_so != -1 && match[no].rm_eo != -1) { 575 len = match[no].rm_eo - match[no].rm_so; 576 NEEDSP(len); 577 memmove(dst, string + match[no].rm_so, len); 578 dst += len; 579 sp->len += len; 580 } 581 } 582 NEEDSP(1); 583 *dst = '\0'; 584 } 585 586 /* 587 * aspace -- 588 * Append the source space to the destination space, allocating new 589 * space as necessary. 590 */ 591 void 592 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag) 593 { 594 size_t tlen; 595 596 /* Make sure SPACE has enough memory and ramp up quickly. */ 597 tlen = sp->len + len + 1; 598 if (tlen > sp->blen) { 599 size_t newlen = tlen + 1024; 600 sp->space = sp->back = xrealloc(sp->back, newlen); 601 sp->blen = newlen; 602 } 603 604 if (spflag == REPLACE) 605 sp->len = 0; 606 607 memmove(sp->space + sp->len, p, len); 608 609 sp->space[sp->len += len] = '\0'; 610 } 611 612 /* 613 * Close all cached opened files and report any errors 614 */ 615 void 616 cfclose(struct s_command *cp, struct s_command *end) 617 { 618 619 for (; cp != end; cp = cp->next) 620 switch (cp->code) { 621 case 's': 622 if (cp->u.s->wfd != -1 && close(cp->u.s->wfd)) 623 error(FATAL, 624 "%s: %s", cp->u.s->wfile, strerror(errno)); 625 cp->u.s->wfd = -1; 626 break; 627 case 'w': 628 if (cp->u.fd != -1 && close(cp->u.fd)) 629 error(FATAL, "%s: %s", cp->t, strerror(errno)); 630 cp->u.fd = -1; 631 break; 632 case '{': 633 cfclose(cp->u.c, cp->next); 634 break; 635 } 636 } 637