1 /* $OpenBSD: process.c,v 1.39 2024/12/10 23:49:55 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 <err.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 *, size_t); 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_getline(&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 goto new; 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, psl); 162 break; 163 case 'n': 164 if (!nflag && !pd) 165 OUT(); 166 flush_appends(); 167 if (!mf_getline(&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_getline(&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 finish_file(); 200 exit(0); 201 case 'r': 202 if (appendx >= appendnum) { 203 appends = xreallocarray(appends, 204 appendnum, 205 2 * sizeof(struct s_appends)); 206 appendnum *= 2; 207 } 208 appends[appendx].type = AP_FILE; 209 appends[appendx].s = cp->t; 210 appends[appendx].len = strlen(cp->t); 211 appendx++; 212 break; 213 case 's': 214 sdone |= substitute(cp); 215 break; 216 case 't': 217 if (sdone) { 218 sdone = 0; 219 cp = cp->u.c; 220 goto redirect; 221 } 222 break; 223 case 'w': 224 if (pd) 225 break; 226 if (cp->u.fd == -1 && (cp->u.fd = open(cp->t, 227 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 228 DEFFILEMODE)) == -1) 229 err(1, "%s", cp->t); 230 if ((size_t)write(cp->u.fd, ps, psl) != psl || 231 write(cp->u.fd, "\n", 1) != 1) 232 err(1, "%s", cp->t); 233 break; 234 case 'x': 235 if (hs == NULL) 236 cspace(&HS, "", 0, REPLACE); 237 tspace = PS; 238 PS = HS; 239 psanl = tspace.append_newline; 240 HS = tspace; 241 break; 242 case 'y': 243 if (pd || psl == 0) 244 break; 245 for (p = ps, len = psl; len--; ++p) 246 *p = cp->u.y[(unsigned char)*p]; 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(); 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, 0, 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 } 289 r = 1; 290 } else if (MATCH(cp->a1)) { 291 /* 292 * If the second address is a number less than or 293 * equal to the line number first selected, only 294 * one line shall be selected. 295 * -- POSIX 1003.2 296 */ 297 if (cp->a2->type == AT_LINE && 298 linenum >= cp->a2->u.l) 299 lastaddr = 1; 300 else 301 cp->inrange = 1; 302 r = 1; 303 } else 304 r = 0; 305 else 306 r = MATCH(cp->a1); 307 return (cp->nonsel ? !r : r); 308 } 309 310 /* 311 * Reset all inrange markers. 312 */ 313 void 314 resetstate(void) 315 { 316 struct s_command *cp; 317 318 free(HS.back); 319 memset(&HS, 0, sizeof(HS)); 320 321 for (cp = prog; cp; cp = cp->code == '{' ? cp->u.c : cp->next) 322 if (cp->a2) 323 cp->inrange = 0; 324 } 325 326 /* 327 * substitute -- 328 * Do substitutions in the pattern space. Currently, we build a 329 * copy of the new pattern space in the substitute space structure 330 * and then swap them. 331 */ 332 static int 333 substitute(struct s_command *cp) 334 { 335 SPACE tspace; 336 regex_t *re; 337 regoff_t slen; 338 int n, lastempty; 339 regoff_t le = 0; 340 char *s; 341 342 s = ps; 343 re = cp->u.s->re; 344 if (re == NULL) { 345 if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) { 346 linenum = cp->u.s->linenum; 347 error("\\%d not defined in the RE", cp->u.s->maxbref); 348 } 349 } 350 if (!regexec_e(re, ps, 0, 0, 0, psl)) 351 return (0); 352 353 SS.len = 0; /* Clean substitute space. */ 354 slen = psl; 355 n = cp->u.s->n; 356 lastempty = 1; 357 358 do { 359 /* Copy the leading retained string. */ 360 if (n <= 1 && (match[0].rm_so > le)) 361 cspace(&SS, s, match[0].rm_so - le, APPEND); 362 363 /* Skip zero-length matches right after other matches. */ 364 if (lastempty || (match[0].rm_so - le) || 365 match[0].rm_so != match[0].rm_eo) { 366 if (n <= 1) { 367 /* Want this match: append replacement. */ 368 regsub(&SS, ps, cp->u.s->new); 369 if (n == 1) 370 n = -1; 371 } else { 372 /* Want a later match: append original. */ 373 if (match[0].rm_eo - le) 374 cspace(&SS, s, match[0].rm_eo - le, 375 APPEND); 376 n--; 377 } 378 } 379 380 /* Move past this match. */ 381 s = ps + match[0].rm_eo; 382 slen = psl - match[0].rm_eo; 383 le = match[0].rm_eo; 384 385 /* 386 * After a zero-length match, advance one byte, 387 * and at the end of the line, terminate. 388 */ 389 if (match[0].rm_so == match[0].rm_eo) { 390 if (slen > 0) { 391 cspace(&SS, s++, 1, APPEND); 392 slen--; 393 le++; 394 } else 395 slen = -1; 396 lastempty = 1; 397 } else 398 lastempty = 0; 399 400 } while (n >= 0 && slen >= 0 && 401 regexec_e(re, ps, REG_NOTBOL, 0, le, psl)); 402 403 /* Did not find the requested number of matches. */ 404 if (n > 0) 405 return (0); 406 407 /* Copy the trailing retained string. */ 408 if (slen > 0) 409 cspace(&SS, s, slen, APPEND); 410 411 /* 412 * Swap the substitute space and the pattern space, and make sure 413 * that any leftover pointers into stdio memory get lost. 414 */ 415 tspace = PS; 416 PS = SS; 417 psanl = tspace.append_newline; 418 SS = tspace; 419 SS.space = SS.back; 420 421 /* Handle the 'p' flag. */ 422 if (cp->u.s->p) 423 OUT(); 424 425 /* Handle the 'w' flag. */ 426 if (cp->u.s->wfile && !pd) { 427 if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile, 428 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1) 429 err(1, "%s", cp->u.s->wfile); 430 if ((size_t)write(cp->u.s->wfd, ps, psl) != psl || 431 write(cp->u.s->wfd, "\n", 1) != 1) 432 err(1, "%s", cp->u.s->wfile); 433 } 434 return (1); 435 } 436 437 /* 438 * Flush append requests. Always called before reading a line, 439 * therefore it also resets the substitution done (sdone) flag. 440 */ 441 static void 442 flush_appends(void) 443 { 444 FILE *f; 445 size_t count, idx; 446 char buf[8 * 1024]; 447 448 for (idx = 0; idx < appendx; idx++) 449 switch (appends[idx].type) { 450 case AP_STRING: 451 fwrite(appends[idx].s, sizeof(char), appends[idx].len, 452 outfile); 453 break; 454 case AP_FILE: 455 /* 456 * Read files probably shouldn't be cached. Since 457 * it's not an error to read a non-existent file, 458 * it's possible that another program is interacting 459 * with the sed script through the file system. It 460 * would be truly bizarre, but possible. It's probably 461 * not that big a performance win, anyhow. 462 */ 463 if ((f = fopen(appends[idx].s, "r")) == NULL) 464 break; 465 while ((count = fread(buf, sizeof(char), sizeof(buf), f))) 466 (void)fwrite(buf, sizeof(char), count, outfile); 467 (void)fclose(f); 468 break; 469 } 470 if (ferror(outfile)) 471 err(1, "%s", outfname); 472 appendx = sdone = 0; 473 } 474 475 static void 476 lputs(char *s, size_t len) 477 { 478 int count; 479 extern int termwidth; 480 const char *escapes; 481 char *p; 482 483 for (count = 0; len > 0; len--, s++) { 484 if (count >= termwidth) { 485 (void)fprintf(outfile, "\\\n"); 486 count = 0; 487 } 488 if (isascii((unsigned char)*s) && isprint((unsigned char)*s) 489 && *s != '\\') { 490 (void)fputc(*s, outfile); 491 count++; 492 } else if (*s == '\n') { 493 (void)fputc('$', outfile); 494 (void)fputc('\n', outfile); 495 count = 0; 496 } else { 497 escapes = "\\\a\b\f\r\t\v"; 498 (void)fputc('\\', outfile); 499 if ((p = strchr(escapes, *s)) && *s != '\0') { 500 (void)fputc("\\abfrtv"[p - escapes], outfile); 501 count += 2; 502 } else { 503 (void)fprintf(outfile, "%03o", *(u_char *)s); 504 count += 4; 505 } 506 } 507 } 508 (void)fputc('$', outfile); 509 (void)fputc('\n', outfile); 510 if (ferror(outfile)) 511 err(1, "%s", outfname); 512 } 513 514 static inline int 515 regexec_e(regex_t *preg, const char *string, int eflags, 516 int nomatch, size_t start, size_t stop) 517 { 518 int eval; 519 520 if (preg == NULL) { 521 if (defpreg == NULL) 522 errx(1, "first RE may not be empty"); 523 } else 524 defpreg = preg; 525 526 /* Set anchors */ 527 match[0].rm_so = start; 528 match[0].rm_eo = stop; 529 530 eval = regexec(defpreg, string, 531 nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND); 532 switch (eval) { 533 case 0: 534 return (1); 535 case REG_NOMATCH: 536 return (0); 537 } 538 errx(1, "RE error: %s", strregerror(eval, defpreg)); 539 } 540 541 /* 542 * regsub - perform substitutions after a regexp match 543 * Based on a routine by Henry Spencer 544 */ 545 static void 546 regsub(SPACE *sp, char *string, char *src) 547 { 548 int len, no; 549 char c, *dst; 550 551 #define NEEDSP(reqlen) \ 552 if (sp->len + (reqlen) + 1 >= sp->blen) { \ 553 size_t newlen = sp->blen + (reqlen) + 1024; \ 554 sp->space = sp->back = xrealloc(sp->back, newlen); \ 555 sp->blen = newlen; \ 556 dst = sp->space + sp->len; \ 557 } 558 559 dst = sp->space + sp->len; 560 while ((c = *src++) != '\0') { 561 if (c == '&') 562 no = 0; 563 else if (c == '\\' && isdigit((unsigned char)*src)) 564 no = *src++ - '0'; 565 else 566 no = -1; 567 if (no < 0) { /* Ordinary character. */ 568 if (c == '\\' && (*src == '\\' || *src == '&')) 569 c = *src++; 570 NEEDSP(1); 571 *dst++ = c; 572 ++sp->len; 573 } else if (match[no].rm_so != -1 && match[no].rm_eo != -1) { 574 len = match[no].rm_eo - match[no].rm_so; 575 NEEDSP(len); 576 memmove(dst, string + match[no].rm_so, len); 577 dst += len; 578 sp->len += len; 579 } 580 } 581 NEEDSP(1); 582 *dst = '\0'; 583 } 584 585 /* 586 * aspace -- 587 * Append the source space to the destination space, allocating new 588 * space as necessary. 589 */ 590 void 591 cspace(SPACE *sp, const char *p, size_t len, enum e_spflag spflag) 592 { 593 size_t tlen; 594 595 /* Make sure SPACE has enough memory and ramp up quickly. */ 596 tlen = sp->len + len + 1; 597 if (tlen > sp->blen) { 598 size_t newlen = tlen + 1024; 599 sp->space = sp->back = xrealloc(sp->back, newlen); 600 sp->blen = newlen; 601 } 602 603 if (spflag == REPLACE) 604 sp->len = 0; 605 606 memmove(sp->space + sp->len, p, len); 607 608 sp->space[sp->len += len] = '\0'; 609 } 610 611 /* 612 * Close all cached opened files and report any errors 613 */ 614 void 615 cfclose(struct s_command *cp, struct s_command *end) 616 { 617 618 for (; cp != end; cp = cp->next) 619 switch (cp->code) { 620 case 's': 621 if (cp->u.s->wfd != -1 && close(cp->u.s->wfd)) 622 err(1, "%s", cp->u.s->wfile); 623 cp->u.s->wfd = -1; 624 break; 625 case 'w': 626 if (cp->u.fd != -1 && close(cp->u.fd)) 627 err(1, "%s", cp->t); 628 cp->u.fd = -1; 629 break; 630 case '{': 631 cfclose(cp->u.c, cp->next); 632 break; 633 } 634 } 635