1 /* $OpenBSD: process.c,v 1.11 2003/06/10 22:20:51 deraadt 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 #ifndef lint 37 /* from: static char sccsid[] = "@(#)process.c 8.1 (Berkeley) 6/6/93"; */ 38 static char *rcsid = "$OpenBSD: process.c,v 1.11 2003/06/10 22:20:51 deraadt Exp $"; 39 #endif /* not lint */ 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 <errno.h> 48 #include <fcntl.h> 49 #include <limits.h> 50 #include <regex.h> 51 #include <stdio.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <unistd.h> 55 56 #include "defs.h" 57 #include "extern.h" 58 59 static SPACE HS, PS, SS; 60 #define pd PS.deleted 61 #define ps PS.space 62 #define psl PS.len 63 #define hs HS.space 64 #define hsl HS.len 65 66 static inline int applies(struct s_command *); 67 static void flush_appends(void); 68 static void lputs(char *); 69 static inline int regexec_e(regex_t *, const char *, int, int, size_t); 70 static void regsub(SPACE *, char *, char *); 71 static int substitute(struct s_command *); 72 73 struct s_appends *appends; /* Array of pointers to strings to append. */ 74 static int appendx; /* Index into appends array. */ 75 int appendnum; /* Size of appends array. */ 76 77 static int lastaddr; /* Set by applies if last address of a range. */ 78 static int sdone; /* If any substitutes since last line input. */ 79 /* Iov structure for 'w' commands. */ 80 static regex_t *defpreg; 81 size_t maxnsub; 82 regmatch_t *match; 83 84 #define OUT(s) { fwrite(s, sizeof(u_char), psl, stdout); } 85 86 void 87 process(void) 88 { 89 struct s_command *cp; 90 SPACE tspace; 91 size_t len, oldpsl; 92 char *p; 93 94 for (linenum = 0; mf_fgets(&PS, REPLACE);) { 95 pd = 0; 96 top: 97 cp = prog; 98 redirect: 99 while (cp != NULL) { 100 if (!applies(cp)) { 101 cp = cp->next; 102 continue; 103 } 104 switch (cp->code) { 105 case '{': 106 cp = cp->u.c; 107 goto redirect; 108 case 'a': 109 if (appendx >= appendnum) 110 appends = xrealloc(appends, 111 sizeof(struct s_appends) * 112 (appendnum *= 2)); 113 appends[appendx].type = AP_STRING; 114 appends[appendx].s = cp->t; 115 appends[appendx].len = strlen(cp->t); 116 appendx++; 117 break; 118 case 'b': 119 cp = cp->u.c; 120 goto redirect; 121 case 'c': 122 pd = 1; 123 psl = 0; 124 if (cp->a2 == NULL || lastaddr) 125 (void)printf("%s", cp->t); 126 break; 127 case 'd': 128 pd = 1; 129 goto new; 130 case 'D': 131 if (pd) 132 goto new; 133 if (psl == 0 || 134 (p = memchr(ps, '\n', psl - 1)) == NULL) { 135 pd = 1; 136 goto new; 137 } else { 138 psl -= (p + 1) - ps; 139 memmove(ps, p + 1, psl); 140 goto top; 141 } 142 case 'g': 143 cspace(&PS, hs, hsl, REPLACE); 144 break; 145 case 'G': 146 if (hs == NULL) 147 cspace(&HS, "\n", 1, REPLACE); 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, ps, psl, 0); 155 break; 156 case 'i': 157 (void)printf("%s", cp->t); 158 break; 159 case 'l': 160 lputs(ps); 161 break; 162 case 'n': 163 if (!nflag && !pd) 164 OUT(ps) 165 flush_appends(); 166 if (!mf_fgets(&PS, REPLACE)) 167 exit(0); 168 pd = 0; 169 break; 170 case 'N': 171 flush_appends(); 172 if (!mf_fgets(&PS, 0)) { 173 if (!nflag && !pd) 174 OUT(ps) 175 exit(0); 176 } 177 break; 178 case 'p': 179 if (pd) 180 break; 181 OUT(ps) 182 break; 183 case 'P': 184 if (pd) 185 break; 186 if (psl != 0 && 187 (p = memchr(ps, '\n', psl - 1)) != NULL) { 188 oldpsl = psl; 189 psl = (p + 1) - ps; 190 } 191 OUT(ps) 192 if (p != NULL) 193 psl = oldpsl; 194 break; 195 case 'q': 196 if (!nflag && !pd) 197 OUT(ps) 198 flush_appends(); 199 exit(0); 200 case 'r': 201 if (appendx >= appendnum) 202 appends = xrealloc(appends, 203 sizeof(struct s_appends) * 204 (appendnum *= 2)); 205 appends[appendx].type = AP_FILE; 206 appends[appendx].s = cp->t; 207 appends[appendx].len = strlen(cp->t); 208 appendx++; 209 break; 210 case 's': 211 sdone |= substitute(cp); 212 break; 213 case 't': 214 if (sdone) { 215 sdone = 0; 216 cp = cp->u.c; 217 goto redirect; 218 } 219 break; 220 case 'w': 221 if (pd) 222 break; 223 if (cp->u.fd == -1 && (cp->u.fd = open(cp->t, 224 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, 225 DEFFILEMODE)) == -1) 226 err(FATAL, "%s: %s", 227 cp->t, strerror(errno)); 228 if (write(cp->u.fd, ps, psl) != psl) 229 err(FATAL, "%s: %s", 230 cp->t, strerror(errno)); 231 break; 232 case 'x': 233 if (hs == NULL) 234 cspace(&HS, "\n", 1, REPLACE); 235 tspace = PS; 236 PS = HS; 237 HS = tspace; 238 break; 239 case 'y': 240 if (pd || psl == 0) 241 break; 242 for (p = ps, len = psl; --len; ++p) 243 *p = cp->u.y[(unsigned char)*p]; 244 break; 245 case ':': 246 case '}': 247 break; 248 case '=': 249 (void)printf("%lu\n", linenum); 250 } 251 cp = cp->next; 252 } /* for all cp */ 253 254 new: if (!nflag && !pd) 255 OUT(ps) 256 flush_appends(); 257 } /* for all lines */ 258 } 259 260 /* 261 * TRUE if the address passed matches the current program state 262 * (lastline, linenumber, ps). 263 */ 264 #define MATCH(a) \ 265 (a)->type == AT_RE ? regexec_e((a)->u.r, ps, 0, 1, psl) : \ 266 (a)->type == AT_LINE ? linenum == (a)->u.l : lastline 267 268 /* 269 * Return TRUE if the command applies to the current line. Sets the inrange 270 * flag to process ranges. Interprets the non-select (``!'') flag. 271 */ 272 static inline int 273 applies(struct s_command *cp) 274 { 275 int r; 276 277 lastaddr = 0; 278 if (cp->a1 == NULL && cp->a2 == NULL) 279 r = 1; 280 else if (cp->a2) 281 if (cp->inrange) { 282 if (MATCH(cp->a2)) { 283 cp->inrange = 0; 284 lastaddr = 1; 285 } 286 r = 1; 287 } else if (MATCH(cp->a1)) { 288 /* 289 * If the second address is a number less than or 290 * equal to the line number first selected, only 291 * one line shall be selected. 292 * -- POSIX 1003.2 293 */ 294 if (cp->a2->type == AT_LINE && 295 linenum >= cp->a2->u.l) 296 lastaddr = 1; 297 else 298 cp->inrange = 1; 299 r = 1; 300 } else 301 r = 0; 302 else 303 r = MATCH(cp->a1); 304 return (cp->nonsel ? ! r : r); 305 } 306 307 /* 308 * substitute -- 309 * Do substitutions in the pattern space. Currently, we build a 310 * copy of the new pattern space in the substitute space structure 311 * and then swap them. 312 */ 313 static int 314 substitute(struct s_command *cp) 315 { 316 SPACE tspace; 317 regex_t *re; 318 size_t re_off, slen; 319 int n, lastempty; 320 char *s; 321 322 s = ps; 323 re = cp->u.s->re; 324 if (re == NULL) { 325 if (defpreg != NULL && cp->u.s->maxbref > defpreg->re_nsub) { 326 linenum = cp->u.s->linenum; 327 err(COMPILE, "\\%d not defined in the RE", 328 cp->u.s->maxbref); 329 } 330 } 331 if (!regexec_e(re, s, 0, 0, psl)) 332 return (0); 333 334 SS.len = 0; /* Clean substitute space. */ 335 slen = psl; 336 n = cp->u.s->n; 337 lastempty = 1; 338 339 switch (n) { 340 case 0: /* Global */ 341 do { 342 if (lastempty || match[0].rm_so != match[0].rm_eo) { 343 /* Locate start of replaced string. */ 344 re_off = match[0].rm_so; 345 /* Copy leading retained string. */ 346 cspace(&SS, s, re_off, APPEND); 347 /* Add in regular expression. */ 348 regsub(&SS, s, cp->u.s->new); 349 } 350 351 /* Move past this match. */ 352 if (match[0].rm_so != match[0].rm_eo) { 353 s += match[0].rm_eo; 354 slen -= match[0].rm_eo; 355 lastempty = 0; 356 } else { 357 if (match[0].rm_so == 0) 358 cspace(&SS, s, match[0].rm_so + 1, 359 APPEND); 360 else 361 cspace(&SS, s + match[0].rm_so, 1, 362 APPEND); 363 s += match[0].rm_so + 1; 364 slen -= match[0].rm_so + 1; 365 lastempty = 1; 366 } 367 } while (slen > 0 && regexec_e(re, s, REG_NOTBOL, 0, slen)); 368 /* Copy trailing retained string. */ 369 if (slen > 0) 370 cspace(&SS, s, slen, APPEND); 371 break; 372 default: /* Nth occurrence */ 373 while (--n) { 374 s += match[0].rm_eo; 375 slen -= match[0].rm_eo; 376 if (!regexec_e(re, s, REG_NOTBOL, 0, slen)) 377 return (0); 378 } 379 /* FALLTHROUGH */ 380 case 1: /* 1st occurrence */ 381 /* Locate start of replaced string. */ 382 re_off = match[0].rm_so + (s - ps); 383 /* Copy leading retained string. */ 384 cspace(&SS, ps, re_off, APPEND); 385 /* Add in regular expression. */ 386 regsub(&SS, s, cp->u.s->new); 387 /* Copy trailing retained string. */ 388 s += match[0].rm_eo; 389 slen -= match[0].rm_eo; 390 cspace(&SS, s, slen, APPEND); 391 break; 392 } 393 394 /* 395 * Swap the substitute space and the pattern space, and make sure 396 * that any leftover pointers into stdio memory get lost. 397 */ 398 tspace = PS; 399 PS = SS; 400 SS = tspace; 401 SS.space = SS.back; 402 403 /* Handle the 'p' flag. */ 404 if (cp->u.s->p) 405 OUT(ps) 406 407 /* Handle the 'w' flag. */ 408 if (cp->u.s->wfile && !pd) { 409 if (cp->u.s->wfd == -1 && (cp->u.s->wfd = open(cp->u.s->wfile, 410 O_WRONLY|O_APPEND|O_CREAT|O_TRUNC, DEFFILEMODE)) == -1) 411 err(FATAL, "%s: %s", cp->u.s->wfile, strerror(errno)); 412 if (write(cp->u.s->wfd, ps, psl) != psl) 413 err(FATAL, "%s: %s", cp->u.s->wfile, strerror(errno)); 414 } 415 return (1); 416 } 417 418 /* 419 * Flush append requests. Always called before reading a line, 420 * therefore it also resets the substitution done (sdone) flag. 421 */ 422 static void 423 flush_appends(void) 424 { 425 FILE *f; 426 int count, i; 427 char buf[8 * 1024]; 428 429 for (i = 0; i < appendx; i++) 430 switch (appends[i].type) { 431 case AP_STRING: 432 fwrite(appends[i].s, sizeof(char), appends[i].len, 433 stdout); 434 break; 435 case AP_FILE: 436 /* 437 * Read files probably shouldn't be cached. Since 438 * it's not an error to read a non-existent file, 439 * it's possible that another program is interacting 440 * with the sed script through the file system. It 441 * would be truly bizarre, but possible. It's probably 442 * not that big a performance win, anyhow. 443 */ 444 if ((f = fopen(appends[i].s, "r")) == NULL) 445 break; 446 while ((count = fread(buf, sizeof(char), sizeof(buf), f))) 447 (void)fwrite(buf, sizeof(char), count, stdout); 448 (void)fclose(f); 449 break; 450 } 451 if (ferror(stdout)) 452 err(FATAL, "stdout: %s", strerror(errno ? errno : EIO)); 453 appendx = sdone = 0; 454 } 455 456 static void 457 lputs(char *s) 458 { 459 int count; 460 char *escapes, *p; 461 struct winsize win; 462 static int termwidth = -1; 463 464 if (termwidth == -1) 465 if ((p = getenv("COLUMNS"))) 466 termwidth = atoi(p); 467 else if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &win) == 0 && 468 win.ws_col > 0) 469 termwidth = win.ws_col; 470 else 471 termwidth = 60; 472 473 for (count = 0; *s; ++s) { 474 if (count >= termwidth) { 475 (void)printf("\\\n"); 476 count = 0; 477 } 478 if (isascii(*s) && isprint(*s) && *s != '\\') { 479 (void)putchar(*s); 480 count++; 481 } else { 482 escapes = "\\\a\b\f\n\r\t\v"; 483 (void)putchar('\\'); 484 if ((p = strchr(escapes, *s))) { 485 (void)putchar("\\abfnrtv"[p - escapes]); 486 count += 2; 487 } else { 488 (void)printf("%03o", *(u_char *)s); 489 count += 4; 490 } 491 } 492 } 493 (void)putchar('$'); 494 (void)putchar('\n'); 495 if (ferror(stdout)) 496 err(FATAL, "stdout: %s", strerror(errno ? errno : EIO)); 497 } 498 499 static inline int 500 regexec_e(regex_t *preg, const char *string, int eflags, 501 int nomatch, size_t slen) 502 { 503 int eval; 504 505 if (preg == NULL) { 506 if (defpreg == NULL) 507 err(FATAL, "first RE may not be empty"); 508 } else 509 defpreg = preg; 510 511 /* Set anchors, discounting trailing newline (if any). */ 512 if (slen > 0 && string[slen - 1] == '\n') 513 slen--; 514 match[0].rm_so = 0; 515 match[0].rm_eo = slen; 516 517 eval = regexec(defpreg, string, 518 nomatch ? 0 : maxnsub + 1, match, eflags | REG_STARTEND); 519 switch(eval) { 520 case 0: 521 return (1); 522 case REG_NOMATCH: 523 return (0); 524 } 525 err(FATAL, "RE error: %s", strregerror(eval, defpreg)); 526 /* NOTREACHED */ 527 } 528 529 /* 530 * regsub - perform substitutions after a regexp match 531 * Based on a routine by Henry Spencer 532 */ 533 static void 534 regsub(SPACE *sp, char *string, char *src) 535 { 536 int len, no; 537 char c, *dst; 538 539 #define NEEDSP(reqlen) \ 540 if (sp->len >= sp->blen - (reqlen) - 1) { \ 541 sp->blen += (reqlen) + 1024; \ 542 sp->space = sp->back = xrealloc(sp->back, sp->blen); \ 543 dst = sp->space + sp->len; \ 544 } 545 546 dst = sp->space + sp->len; 547 while ((c = *src++) != '\0') { 548 if (c == '&') 549 no = 0; 550 else if (c == '\\' && isdigit(*src)) 551 no = *src++ - '0'; 552 else 553 no = -1; 554 if (no < 0) { /* Ordinary character. */ 555 if (c == '\\' && (*src == '\\' || *src == '&')) 556 c = *src++; 557 NEEDSP(1); 558 *dst++ = c; 559 ++sp->len; 560 } else if (match[no].rm_so != -1 && match[no].rm_eo != -1) { 561 len = match[no].rm_eo - match[no].rm_so; 562 NEEDSP(len); 563 memmove(dst, string + match[no].rm_so, len); 564 dst += len; 565 sp->len += len; 566 } 567 } 568 NEEDSP(1); 569 *dst = '\0'; 570 } 571 572 /* 573 * aspace -- 574 * Append the source space to the destination space, allocating new 575 * space as necessary. 576 */ 577 void 578 cspace(SPACE *sp, char *p, size_t len, enum e_spflag spflag) 579 { 580 size_t tlen; 581 582 /* Make sure SPACE has enough memory and ramp up quickly. */ 583 tlen = sp->len + len + 1; 584 if (tlen > sp->blen) { 585 sp->blen = tlen + 1024; 586 sp->space = sp->back = xrealloc(sp->back, sp->blen); 587 } 588 589 if (spflag == REPLACE) 590 sp->len = 0; 591 592 memmove(sp->space + sp->len, p, len); 593 594 sp->space[sp->len += len] = '\0'; 595 } 596 597 /* 598 * Close all cached opened files and report any errors 599 */ 600 void 601 cfclose(struct s_command *cp, struct s_command *end) 602 { 603 604 for (; cp != end; cp = cp->next) 605 switch(cp->code) { 606 case 's': 607 if (cp->u.s->wfd != -1 && close(cp->u.s->wfd)) 608 err(FATAL, 609 "%s: %s", cp->u.s->wfile, strerror(errno)); 610 cp->u.s->wfd = -1; 611 break; 612 case 'w': 613 if (cp->u.fd != -1 && close(cp->u.fd)) 614 err(FATAL, "%s: %s", cp->t, strerror(errno)); 615 cp->u.fd = -1; 616 break; 617 case '{': 618 cfclose(cp->u.c, cp->next); 619 break; 620 } 621 } 622