1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)parser.c 8.7 (Berkeley) 5/16/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <stdlib.h> 42 #include <unistd.h> 43 44 #include "shell.h" 45 #include "parser.h" 46 #include "nodes.h" 47 #include "expand.h" /* defines rmescapes() */ 48 #include "syntax.h" 49 #include "options.h" 50 #include "input.h" 51 #include "output.h" 52 #include "var.h" 53 #include "error.h" 54 #include "memalloc.h" 55 #include "mystring.h" 56 #include "alias.h" 57 #include "show.h" 58 #include "eval.h" 59 #ifndef NO_HISTORY 60 #include "myhistedit.h" 61 #endif 62 63 /* 64 * Shell command parser. 65 */ 66 67 #define EOFMARKLEN 79 68 #define PROMPTLEN 128 69 70 /* values returned by readtoken */ 71 #include "token.h" 72 73 74 75 struct heredoc { 76 struct heredoc *next; /* next here document in list */ 77 union node *here; /* redirection node */ 78 char *eofmark; /* string indicating end of input */ 79 int striptabs; /* if set, strip leading tabs */ 80 }; 81 82 83 84 STATIC struct heredoc *heredoclist; /* list of here documents to read */ 85 STATIC int parsebackquote; /* nonzero if we are inside backquotes */ 86 STATIC int doprompt; /* if set, prompt the user */ 87 STATIC int needprompt; /* true if interactive and at start of line */ 88 STATIC int lasttoken; /* last token read */ 89 MKINIT int tokpushback; /* last token pushed back */ 90 STATIC char *wordtext; /* text of last word returned by readtoken */ 91 MKINIT int checkkwd; /* 1 == check for kwds, 2 == also eat newlines */ 92 STATIC struct nodelist *backquotelist; 93 STATIC union node *redirnode; 94 STATIC struct heredoc *heredoc; 95 STATIC int quoteflag; /* set if (part of) last token was quoted */ 96 STATIC int startlinno; /* line # where last token started */ 97 STATIC int funclinno; /* line # where the current function started */ 98 99 /* XXX When 'noaliases' is set to one, no alias expansion takes place. */ 100 static int noaliases = 0; 101 102 103 STATIC union node *list(int); 104 STATIC union node *andor(void); 105 STATIC union node *pipeline(void); 106 STATIC union node *command(void); 107 STATIC union node *simplecmd(union node **, union node *); 108 STATIC union node *makename(void); 109 STATIC void parsefname(void); 110 STATIC void parseheredoc(void); 111 STATIC int peektoken(void); 112 STATIC int readtoken(void); 113 STATIC int xxreadtoken(void); 114 STATIC int readtoken1(int, char const *, char *, int); 115 STATIC int noexpand(char *); 116 STATIC void synexpect(int); 117 STATIC void synerror(char *); 118 STATIC void setprompt(int); 119 120 121 /* 122 * Read and parse a command. Returns NEOF on end of file. (NULL is a 123 * valid parse tree indicating a blank line.) 124 */ 125 126 union node * 127 parsecmd(int interact) 128 { 129 int t; 130 131 tokpushback = 0; 132 doprompt = interact; 133 if (doprompt) 134 setprompt(1); 135 else 136 setprompt(0); 137 needprompt = 0; 138 t = readtoken(); 139 if (t == TEOF) 140 return NEOF; 141 if (t == TNL) 142 return NULL; 143 tokpushback++; 144 return list(1); 145 } 146 147 148 STATIC union node * 149 list(int nlflag) 150 { 151 union node *n1, *n2, *n3; 152 int tok; 153 154 checkkwd = 2; 155 if (nlflag == 0 && tokendlist[peektoken()]) 156 return NULL; 157 n1 = NULL; 158 for (;;) { 159 n2 = andor(); 160 tok = readtoken(); 161 if (tok == TBACKGND) { 162 if (n2->type == NCMD || n2->type == NPIPE) { 163 n2->ncmd.backgnd = 1; 164 } else if (n2->type == NREDIR) { 165 n2->type = NBACKGND; 166 } else { 167 n3 = (union node *)stalloc(sizeof (struct nredir)); 168 n3->type = NBACKGND; 169 n3->nredir.n = n2; 170 n3->nredir.redirect = NULL; 171 n2 = n3; 172 } 173 } 174 if (n1 == NULL) { 175 n1 = n2; 176 } 177 else { 178 n3 = (union node *)stalloc(sizeof (struct nbinary)); 179 n3->type = NSEMI; 180 n3->nbinary.ch1 = n1; 181 n3->nbinary.ch2 = n2; 182 n1 = n3; 183 } 184 switch (tok) { 185 case TBACKGND: 186 case TSEMI: 187 tok = readtoken(); 188 /* FALLTHROUGH */ 189 case TNL: 190 if (tok == TNL) { 191 parseheredoc(); 192 if (nlflag) 193 return n1; 194 } else { 195 tokpushback++; 196 } 197 checkkwd = 2; 198 if (tokendlist[peektoken()]) 199 return n1; 200 break; 201 case TEOF: 202 if (heredoclist) 203 parseheredoc(); 204 else 205 pungetc(); /* push back EOF on input */ 206 return n1; 207 default: 208 if (nlflag) 209 synexpect(-1); 210 tokpushback++; 211 return n1; 212 } 213 } 214 } 215 216 217 218 STATIC union node * 219 andor(void) 220 { 221 union node *n1, *n2, *n3; 222 int t; 223 224 n1 = pipeline(); 225 for (;;) { 226 if ((t = readtoken()) == TAND) { 227 t = NAND; 228 } else if (t == TOR) { 229 t = NOR; 230 } else { 231 tokpushback++; 232 return n1; 233 } 234 n2 = pipeline(); 235 n3 = (union node *)stalloc(sizeof (struct nbinary)); 236 n3->type = t; 237 n3->nbinary.ch1 = n1; 238 n3->nbinary.ch2 = n2; 239 n1 = n3; 240 } 241 } 242 243 244 245 STATIC union node * 246 pipeline(void) 247 { 248 union node *n1, *n2, *pipenode; 249 struct nodelist *lp, *prev; 250 int negate; 251 252 negate = 0; 253 TRACE(("pipeline: entered\n")); 254 while (readtoken() == TNOT) 255 negate = !negate; 256 tokpushback++; 257 n1 = command(); 258 if (readtoken() == TPIPE) { 259 pipenode = (union node *)stalloc(sizeof (struct npipe)); 260 pipenode->type = NPIPE; 261 pipenode->npipe.backgnd = 0; 262 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 263 pipenode->npipe.cmdlist = lp; 264 lp->n = n1; 265 do { 266 prev = lp; 267 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 268 lp->n = command(); 269 prev->next = lp; 270 } while (readtoken() == TPIPE); 271 lp->next = NULL; 272 n1 = pipenode; 273 } 274 tokpushback++; 275 if (negate) { 276 n2 = (union node *)stalloc(sizeof (struct nnot)); 277 n2->type = NNOT; 278 n2->nnot.com = n1; 279 return n2; 280 } else 281 return n1; 282 } 283 284 285 286 STATIC union node * 287 command(void) 288 { 289 union node *n1, *n2; 290 union node *ap, **app; 291 union node *cp, **cpp; 292 union node *redir, **rpp; 293 int t, negate = 0; 294 295 checkkwd = 2; 296 redir = NULL; 297 n1 = NULL; 298 rpp = &redir; 299 300 /* Check for redirection which may precede command */ 301 while (readtoken() == TREDIR) { 302 *rpp = n2 = redirnode; 303 rpp = &n2->nfile.next; 304 parsefname(); 305 } 306 tokpushback++; 307 308 while (readtoken() == TNOT) { 309 TRACE(("command: TNOT recognized\n")); 310 negate = !negate; 311 } 312 tokpushback++; 313 314 switch (readtoken()) { 315 case TIF: 316 n1 = (union node *)stalloc(sizeof (struct nif)); 317 n1->type = NIF; 318 if ((n1->nif.test = list(0)) == NULL) 319 synexpect(-1); 320 if (readtoken() != TTHEN) 321 synexpect(TTHEN); 322 n1->nif.ifpart = list(0); 323 n2 = n1; 324 while (readtoken() == TELIF) { 325 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 326 n2 = n2->nif.elsepart; 327 n2->type = NIF; 328 if ((n2->nif.test = list(0)) == NULL) 329 synexpect(-1); 330 if (readtoken() != TTHEN) 331 synexpect(TTHEN); 332 n2->nif.ifpart = list(0); 333 } 334 if (lasttoken == TELSE) 335 n2->nif.elsepart = list(0); 336 else { 337 n2->nif.elsepart = NULL; 338 tokpushback++; 339 } 340 if (readtoken() != TFI) 341 synexpect(TFI); 342 checkkwd = 1; 343 break; 344 case TWHILE: 345 case TUNTIL: { 346 int got; 347 n1 = (union node *)stalloc(sizeof (struct nbinary)); 348 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 349 if ((n1->nbinary.ch1 = list(0)) == NULL) 350 synexpect(-1); 351 if ((got=readtoken()) != TDO) { 352 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 353 synexpect(TDO); 354 } 355 n1->nbinary.ch2 = list(0); 356 if (readtoken() != TDONE) 357 synexpect(TDONE); 358 checkkwd = 1; 359 break; 360 } 361 case TFOR: 362 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 363 synerror("Bad for loop variable"); 364 n1 = (union node *)stalloc(sizeof (struct nfor)); 365 n1->type = NFOR; 366 n1->nfor.var = wordtext; 367 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 368 app = ≈ 369 while (readtoken() == TWORD) { 370 n2 = (union node *)stalloc(sizeof (struct narg)); 371 n2->type = NARG; 372 n2->narg.text = wordtext; 373 n2->narg.backquote = backquotelist; 374 *app = n2; 375 app = &n2->narg.next; 376 } 377 *app = NULL; 378 n1->nfor.args = ap; 379 if (lasttoken != TNL && lasttoken != TSEMI) 380 synexpect(-1); 381 } else { 382 static char argvars[5] = { 383 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' 384 }; 385 n2 = (union node *)stalloc(sizeof (struct narg)); 386 n2->type = NARG; 387 n2->narg.text = argvars; 388 n2->narg.backquote = NULL; 389 n2->narg.next = NULL; 390 n1->nfor.args = n2; 391 /* 392 * Newline or semicolon here is optional (but note 393 * that the original Bourne shell only allowed NL). 394 */ 395 if (lasttoken != TNL && lasttoken != TSEMI) 396 tokpushback++; 397 } 398 checkkwd = 2; 399 if ((t = readtoken()) == TDO) 400 t = TDONE; 401 else if (t == TBEGIN) 402 t = TEND; 403 else 404 synexpect(-1); 405 n1->nfor.body = list(0); 406 if (readtoken() != t) 407 synexpect(t); 408 checkkwd = 1; 409 break; 410 case TCASE: 411 n1 = (union node *)stalloc(sizeof (struct ncase)); 412 n1->type = NCASE; 413 if (readtoken() != TWORD) 414 synexpect(TWORD); 415 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 416 n2->type = NARG; 417 n2->narg.text = wordtext; 418 n2->narg.backquote = backquotelist; 419 n2->narg.next = NULL; 420 while (readtoken() == TNL); 421 if (lasttoken != TWORD || ! equal(wordtext, "in")) 422 synerror("expecting \"in\""); 423 cpp = &n1->ncase.cases; 424 noaliases = 1; /* turn off alias expansion */ 425 checkkwd = 2, readtoken(); 426 while (lasttoken != TESAC) { 427 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 428 cp->type = NCLIST; 429 app = &cp->nclist.pattern; 430 if (lasttoken == TLP) 431 readtoken(); 432 for (;;) { 433 *app = ap = (union node *)stalloc(sizeof (struct narg)); 434 ap->type = NARG; 435 ap->narg.text = wordtext; 436 ap->narg.backquote = backquotelist; 437 if (checkkwd = 2, readtoken() != TPIPE) 438 break; 439 app = &ap->narg.next; 440 readtoken(); 441 } 442 ap->narg.next = NULL; 443 if (lasttoken != TRP) 444 noaliases = 0, synexpect(TRP); 445 cp->nclist.body = list(0); 446 447 checkkwd = 2; 448 if ((t = readtoken()) != TESAC) { 449 if (t != TENDCASE) 450 noaliases = 0, synexpect(TENDCASE); 451 else 452 checkkwd = 2, readtoken(); 453 } 454 cpp = &cp->nclist.next; 455 } 456 noaliases = 0; /* reset alias expansion */ 457 *cpp = NULL; 458 checkkwd = 1; 459 break; 460 case TLP: 461 n1 = (union node *)stalloc(sizeof (struct nredir)); 462 n1->type = NSUBSHELL; 463 n1->nredir.n = list(0); 464 n1->nredir.redirect = NULL; 465 if (readtoken() != TRP) 466 synexpect(TRP); 467 checkkwd = 1; 468 break; 469 case TBEGIN: 470 n1 = list(0); 471 if (readtoken() != TEND) 472 synexpect(TEND); 473 checkkwd = 1; 474 break; 475 /* Handle an empty command like other simple commands. */ 476 case TSEMI: 477 case TAND: 478 case TOR: 479 /* 480 * An empty command before a ; doesn't make much sense, and 481 * should certainly be disallowed in the case of `if ;'. 482 */ 483 if (!redir) 484 synexpect(-1); 485 case TNL: 486 case TEOF: 487 case TWORD: 488 case TRP: 489 tokpushback++; 490 n1 = simplecmd(rpp, redir); 491 goto checkneg; 492 default: 493 synexpect(-1); 494 } 495 496 /* Now check for redirection which may follow command */ 497 while (readtoken() == TREDIR) { 498 *rpp = n2 = redirnode; 499 rpp = &n2->nfile.next; 500 parsefname(); 501 } 502 tokpushback++; 503 *rpp = NULL; 504 if (redir) { 505 if (n1->type != NSUBSHELL) { 506 n2 = (union node *)stalloc(sizeof (struct nredir)); 507 n2->type = NREDIR; 508 n2->nredir.n = n1; 509 n1 = n2; 510 } 511 n1->nredir.redirect = redir; 512 } 513 514 checkneg: 515 if (negate) { 516 n2 = (union node *)stalloc(sizeof (struct nnot)); 517 n2->type = NNOT; 518 n2->nnot.com = n1; 519 return n2; 520 } 521 else 522 return n1; 523 } 524 525 526 STATIC union node * 527 simplecmd(union node **rpp, union node *redir) 528 { 529 union node *args, **app; 530 union node **orig_rpp = rpp; 531 union node *n = NULL, *n2; 532 int negate = 0; 533 534 /* If we don't have any redirections already, then we must reset */ 535 /* rpp to be the address of the local redir variable. */ 536 if (redir == 0) 537 rpp = &redir; 538 539 args = NULL; 540 app = &args; 541 /* 542 * We save the incoming value, because we need this for shell 543 * functions. There can not be a redirect or an argument between 544 * the function name and the open parenthesis. 545 */ 546 orig_rpp = rpp; 547 548 while (readtoken() == TNOT) { 549 TRACE(("command: TNOT recognized\n")); 550 negate = !negate; 551 } 552 tokpushback++; 553 554 for (;;) { 555 if (readtoken() == TWORD) { 556 n = (union node *)stalloc(sizeof (struct narg)); 557 n->type = NARG; 558 n->narg.text = wordtext; 559 n->narg.backquote = backquotelist; 560 *app = n; 561 app = &n->narg.next; 562 } else if (lasttoken == TREDIR) { 563 *rpp = n = redirnode; 564 rpp = &n->nfile.next; 565 parsefname(); /* read name of redirection file */ 566 } else if (lasttoken == TLP && app == &args->narg.next 567 && rpp == orig_rpp) { 568 /* We have a function */ 569 if (readtoken() != TRP) 570 synexpect(TRP); 571 funclinno = plinno; 572 #ifdef notdef 573 if (! goodname(n->narg.text)) 574 synerror("Bad function name"); 575 #endif 576 n->type = NDEFUN; 577 n->narg.next = command(); 578 funclinno = 0; 579 goto checkneg; 580 } else { 581 tokpushback++; 582 break; 583 } 584 } 585 *app = NULL; 586 *rpp = NULL; 587 n = (union node *)stalloc(sizeof (struct ncmd)); 588 n->type = NCMD; 589 n->ncmd.backgnd = 0; 590 n->ncmd.args = args; 591 n->ncmd.redirect = redir; 592 593 checkneg: 594 if (negate) { 595 n2 = (union node *)stalloc(sizeof (struct nnot)); 596 n2->type = NNOT; 597 n2->nnot.com = n; 598 return n2; 599 } 600 else 601 return n; 602 } 603 604 STATIC union node * 605 makename(void) 606 { 607 union node *n; 608 609 n = (union node *)stalloc(sizeof (struct narg)); 610 n->type = NARG; 611 n->narg.next = NULL; 612 n->narg.text = wordtext; 613 n->narg.backquote = backquotelist; 614 return n; 615 } 616 617 void fixredir(union node *n, const char *text, int err) 618 { 619 TRACE(("Fix redir %s %d\n", text, err)); 620 if (!err) 621 n->ndup.vname = NULL; 622 623 if (is_digit(text[0]) && text[1] == '\0') 624 n->ndup.dupfd = digit_val(text[0]); 625 else if (text[0] == '-' && text[1] == '\0') 626 n->ndup.dupfd = -1; 627 else { 628 629 if (err) 630 synerror("Bad fd number"); 631 else 632 n->ndup.vname = makename(); 633 } 634 } 635 636 637 STATIC void 638 parsefname(void) 639 { 640 union node *n = redirnode; 641 642 if (readtoken() != TWORD) 643 synexpect(-1); 644 if (n->type == NHERE) { 645 struct heredoc *here = heredoc; 646 struct heredoc *p; 647 int i; 648 649 if (quoteflag == 0) 650 n->type = NXHERE; 651 TRACE(("Here document %d\n", n->type)); 652 if (here->striptabs) { 653 while (*wordtext == '\t') 654 wordtext++; 655 } 656 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 657 synerror("Illegal eof marker for << redirection"); 658 rmescapes(wordtext); 659 here->eofmark = wordtext; 660 here->next = NULL; 661 if (heredoclist == NULL) 662 heredoclist = here; 663 else { 664 for (p = heredoclist ; p->next ; p = p->next); 665 p->next = here; 666 } 667 } else if (n->type == NTOFD || n->type == NFROMFD) { 668 fixredir(n, wordtext, 0); 669 } else { 670 n->nfile.fname = makename(); 671 } 672 } 673 674 675 /* 676 * Input any here documents. 677 */ 678 679 STATIC void 680 parseheredoc(void) 681 { 682 struct heredoc *here; 683 union node *n; 684 685 while (heredoclist) { 686 here = heredoclist; 687 heredoclist = here->next; 688 if (needprompt) { 689 setprompt(2); 690 needprompt = 0; 691 } 692 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 693 here->eofmark, here->striptabs); 694 n = (union node *)stalloc(sizeof (struct narg)); 695 n->narg.type = NARG; 696 n->narg.next = NULL; 697 n->narg.text = wordtext; 698 n->narg.backquote = backquotelist; 699 here->here->nhere.doc = n; 700 } 701 } 702 703 STATIC int 704 peektoken(void) 705 { 706 int t; 707 708 t = readtoken(); 709 tokpushback++; 710 return (t); 711 } 712 713 STATIC int 714 readtoken(void) 715 { 716 int t; 717 int savecheckkwd = checkkwd; 718 struct alias *ap; 719 #ifdef DEBUG 720 int alreadyseen = tokpushback; 721 #endif 722 723 top: 724 t = xxreadtoken(); 725 726 if (checkkwd) { 727 /* 728 * eat newlines 729 */ 730 if (checkkwd == 2) { 731 checkkwd = 0; 732 while (t == TNL) { 733 parseheredoc(); 734 t = xxreadtoken(); 735 } 736 } else 737 checkkwd = 0; 738 /* 739 * check for keywords and aliases 740 */ 741 if (t == TWORD && !quoteflag) 742 { 743 const char * const *pp; 744 745 for (pp = parsekwd; *pp; pp++) { 746 if (**pp == *wordtext && equal(*pp, wordtext)) 747 { 748 lasttoken = t = pp - parsekwd + KWDOFFSET; 749 TRACE(("keyword %s recognized\n", tokname[t])); 750 goto out; 751 } 752 } 753 if (noaliases == 0 && 754 (ap = lookupalias(wordtext, 1)) != NULL) { 755 pushstring(ap->val, strlen(ap->val), ap); 756 checkkwd = savecheckkwd; 757 goto top; 758 } 759 } 760 out: 761 checkkwd = (t == TNOT) ? savecheckkwd : 0; 762 } 763 #ifdef DEBUG 764 if (!alreadyseen) 765 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 766 else 767 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 768 #endif 769 return (t); 770 } 771 772 773 /* 774 * Read the next input token. 775 * If the token is a word, we set backquotelist to the list of cmds in 776 * backquotes. We set quoteflag to true if any part of the word was 777 * quoted. 778 * If the token is TREDIR, then we set redirnode to a structure containing 779 * the redirection. 780 * In all cases, the variable startlinno is set to the number of the line 781 * on which the token starts. 782 * 783 * [Change comment: here documents and internal procedures] 784 * [Readtoken shouldn't have any arguments. Perhaps we should make the 785 * word parsing code into a separate routine. In this case, readtoken 786 * doesn't need to have any internal procedures, but parseword does. 787 * We could also make parseoperator in essence the main routine, and 788 * have parseword (readtoken1?) handle both words and redirection.] 789 */ 790 791 #define RETURN(token) return lasttoken = token 792 793 STATIC int 794 xxreadtoken(void) 795 { 796 int c; 797 798 if (tokpushback) { 799 tokpushback = 0; 800 return lasttoken; 801 } 802 if (needprompt) { 803 setprompt(2); 804 needprompt = 0; 805 } 806 startlinno = plinno; 807 for (;;) { /* until token or start of word found */ 808 c = pgetc_macro(); 809 if (c == ' ' || c == '\t') 810 continue; /* quick check for white space first */ 811 switch (c) { 812 case ' ': case '\t': 813 continue; 814 case '#': 815 while ((c = pgetc()) != '\n' && c != PEOF); 816 pungetc(); 817 continue; 818 case '\\': 819 if (pgetc() == '\n') { 820 startlinno = ++plinno; 821 if (doprompt) 822 setprompt(2); 823 else 824 setprompt(0); 825 continue; 826 } 827 pungetc(); 828 goto breakloop; 829 case '\n': 830 plinno++; 831 needprompt = doprompt; 832 RETURN(TNL); 833 case PEOF: 834 RETURN(TEOF); 835 case '&': 836 if (pgetc() == '&') 837 RETURN(TAND); 838 pungetc(); 839 RETURN(TBACKGND); 840 case '|': 841 if (pgetc() == '|') 842 RETURN(TOR); 843 pungetc(); 844 RETURN(TPIPE); 845 case ';': 846 if (pgetc() == ';') 847 RETURN(TENDCASE); 848 pungetc(); 849 RETURN(TSEMI); 850 case '(': 851 RETURN(TLP); 852 case ')': 853 RETURN(TRP); 854 default: 855 goto breakloop; 856 } 857 } 858 breakloop: 859 return readtoken1(c, BASESYNTAX, (char *)NULL, 0); 860 #undef RETURN 861 } 862 863 864 865 /* 866 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 867 * is not NULL, read a here document. In the latter case, eofmark is the 868 * word which marks the end of the document and striptabs is true if 869 * leading tabs should be stripped from the document. The argument firstc 870 * is the first character of the input token or document. 871 * 872 * Because C does not have internal subroutines, I have simulated them 873 * using goto's to implement the subroutine linkage. The following macros 874 * will run code that appears at the end of readtoken1. 875 */ 876 877 #define CHECKEND() {goto checkend; checkend_return:;} 878 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 879 #define PARSESUB() {goto parsesub; parsesub_return:;} 880 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 881 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 882 #define PARSEARITH() {goto parsearith; parsearith_return:;} 883 884 STATIC int 885 readtoken1(int firstc, char const *syntax, char *eofmark, int striptabs) 886 { 887 int c = firstc; 888 char *out; 889 int len; 890 char line[EOFMARKLEN + 1]; 891 struct nodelist *bqlist; 892 int quotef; 893 int dblquote; 894 int varnest; /* levels of variables expansion */ 895 int arinest; /* levels of arithmetic expansion */ 896 int parenlevel; /* levels of parens in arithmetic */ 897 int oldstyle; 898 char const *prevsyntax; /* syntax before arithmetic */ 899 int synentry; 900 #if __GNUC__ 901 /* Avoid longjmp clobbering */ 902 (void) &out; 903 (void) "ef; 904 (void) &dblquote; 905 (void) &varnest; 906 (void) &arinest; 907 (void) &parenlevel; 908 (void) &oldstyle; 909 (void) &prevsyntax; 910 (void) &syntax; 911 (void) &synentry; 912 #endif 913 914 startlinno = plinno; 915 dblquote = 0; 916 if (syntax == DQSYNTAX) 917 dblquote = 1; 918 quotef = 0; 919 bqlist = NULL; 920 varnest = 0; 921 arinest = 0; 922 parenlevel = 0; 923 924 STARTSTACKSTR(out); 925 loop: { /* for each line, until end of word */ 926 CHECKEND(); /* set c to PEOF if at end of here document */ 927 for (;;) { /* until end of line or end of word */ 928 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 929 930 synentry = syntax[c]; 931 932 switch(synentry) { 933 case CNL: /* '\n' */ 934 if (syntax == BASESYNTAX) 935 goto endword; /* exit outer loop */ 936 USTPUTC(c, out); 937 plinno++; 938 if (doprompt) 939 setprompt(2); 940 else 941 setprompt(0); 942 c = pgetc(); 943 goto loop; /* continue outer loop */ 944 case CWORD: 945 USTPUTC(c, out); 946 break; 947 case CCTL: 948 if (eofmark == NULL || dblquote) 949 USTPUTC(CTLESC, out); 950 USTPUTC(c, out); 951 break; 952 case CBACK: /* backslash */ 953 c = pgetc(); 954 if (c == PEOF) { 955 USTPUTC('\\', out); 956 pungetc(); 957 } else if (c == '\n') { 958 plinno++; 959 if (doprompt) 960 setprompt(2); 961 else 962 setprompt(0); 963 } else { 964 if (dblquote && c != '\\' && 965 c != '`' && c != '$' && 966 (c != '"' || eofmark != NULL)) 967 USTPUTC('\\', out); 968 if (SQSYNTAX[c] == CCTL) 969 USTPUTC(CTLESC, out); 970 else if (eofmark == NULL) 971 USTPUTC(CTLQUOTEMARK, out); 972 USTPUTC(c, out); 973 quotef++; 974 } 975 break; 976 case CSQUOTE: 977 if (eofmark == NULL) 978 USTPUTC(CTLQUOTEMARK, out); 979 syntax = SQSYNTAX; 980 break; 981 case CDQUOTE: 982 if (eofmark == NULL) 983 USTPUTC(CTLQUOTEMARK, out); 984 syntax = DQSYNTAX; 985 dblquote = 1; 986 break; 987 case CENDQUOTE: 988 if (eofmark != NULL && arinest == 0 && 989 varnest == 0) { 990 USTPUTC(c, out); 991 } else { 992 if (arinest) { 993 syntax = ARISYNTAX; 994 dblquote = 0; 995 } else if (eofmark == NULL) { 996 syntax = BASESYNTAX; 997 dblquote = 0; 998 } 999 quotef++; 1000 } 1001 break; 1002 case CVAR: /* '$' */ 1003 PARSESUB(); /* parse substitution */ 1004 break; 1005 case CENDVAR: /* '}' */ 1006 if (varnest > 0) { 1007 varnest--; 1008 USTPUTC(CTLENDVAR, out); 1009 } else { 1010 USTPUTC(c, out); 1011 } 1012 break; 1013 case CLP: /* '(' in arithmetic */ 1014 parenlevel++; 1015 USTPUTC(c, out); 1016 break; 1017 case CRP: /* ')' in arithmetic */ 1018 if (parenlevel > 0) { 1019 USTPUTC(c, out); 1020 --parenlevel; 1021 } else { 1022 if (pgetc() == ')') { 1023 if (--arinest == 0) { 1024 USTPUTC(CTLENDARI, out); 1025 syntax = prevsyntax; 1026 if (syntax == DQSYNTAX) 1027 dblquote = 1; 1028 else 1029 dblquote = 0; 1030 } else 1031 USTPUTC(')', out); 1032 } else { 1033 /* 1034 * unbalanced parens 1035 * (don't 2nd guess - no error) 1036 */ 1037 pungetc(); 1038 USTPUTC(')', out); 1039 } 1040 } 1041 break; 1042 case CBQUOTE: /* '`' */ 1043 PARSEBACKQOLD(); 1044 break; 1045 case CEOF: 1046 goto endword; /* exit outer loop */ 1047 default: 1048 if (varnest == 0) 1049 goto endword; /* exit outer loop */ 1050 USTPUTC(c, out); 1051 } 1052 c = pgetc_macro(); 1053 } 1054 } 1055 endword: 1056 if (syntax == ARISYNTAX) 1057 synerror("Missing '))'"); 1058 if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL) 1059 synerror("Unterminated quoted string"); 1060 if (varnest != 0) { 1061 startlinno = plinno; 1062 synerror("Missing '}'"); 1063 } 1064 USTPUTC('\0', out); 1065 len = out - stackblock(); 1066 out = stackblock(); 1067 if (eofmark == NULL) { 1068 if ((c == '>' || c == '<') 1069 && quotef == 0 1070 && len <= 2 1071 && (*out == '\0' || is_digit(*out))) { 1072 PARSEREDIR(); 1073 return lasttoken = TREDIR; 1074 } else { 1075 pungetc(); 1076 } 1077 } 1078 quoteflag = quotef; 1079 backquotelist = bqlist; 1080 grabstackblock(len); 1081 wordtext = out; 1082 return lasttoken = TWORD; 1083 /* end of readtoken routine */ 1084 1085 1086 1087 /* 1088 * Check to see whether we are at the end of the here document. When this 1089 * is called, c is set to the first character of the next input line. If 1090 * we are at the end of the here document, this routine sets the c to PEOF. 1091 */ 1092 1093 checkend: { 1094 if (eofmark) { 1095 if (striptabs) { 1096 while (c == '\t') 1097 c = pgetc(); 1098 } 1099 if (c == *eofmark) { 1100 if (pfgets(line, sizeof line) != NULL) { 1101 char *p, *q; 1102 1103 p = line; 1104 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1105 if (*p == '\n' && *q == '\0') { 1106 c = PEOF; 1107 plinno++; 1108 needprompt = doprompt; 1109 } else { 1110 pushstring(line, strlen(line), NULL); 1111 } 1112 } 1113 } 1114 } 1115 goto checkend_return; 1116 } 1117 1118 1119 /* 1120 * Parse a redirection operator. The variable "out" points to a string 1121 * specifying the fd to be redirected. The variable "c" contains the 1122 * first character of the redirection operator. 1123 */ 1124 1125 parseredir: { 1126 char fd = *out; 1127 union node *np; 1128 1129 np = (union node *)stalloc(sizeof (struct nfile)); 1130 if (c == '>') { 1131 np->nfile.fd = 1; 1132 c = pgetc(); 1133 if (c == '>') 1134 np->type = NAPPEND; 1135 else if (c == '&') 1136 np->type = NTOFD; 1137 else if (c == '|') 1138 np->type = NCLOBBER; 1139 else { 1140 np->type = NTO; 1141 pungetc(); 1142 } 1143 } else { /* c == '<' */ 1144 np->nfile.fd = 0; 1145 c = pgetc(); 1146 if (c == '<') { 1147 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1148 np = (union node *)stalloc(sizeof (struct nhere)); 1149 np->nfile.fd = 0; 1150 } 1151 np->type = NHERE; 1152 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1153 heredoc->here = np; 1154 if ((c = pgetc()) == '-') { 1155 heredoc->striptabs = 1; 1156 } else { 1157 heredoc->striptabs = 0; 1158 pungetc(); 1159 } 1160 } else if (c == '&') 1161 np->type = NFROMFD; 1162 else if (c == '>') 1163 np->type = NFROMTO; 1164 else { 1165 np->type = NFROM; 1166 pungetc(); 1167 } 1168 } 1169 if (fd != '\0') 1170 np->nfile.fd = digit_val(fd); 1171 redirnode = np; 1172 goto parseredir_return; 1173 } 1174 1175 1176 /* 1177 * Parse a substitution. At this point, we have read the dollar sign 1178 * and nothing else. 1179 */ 1180 1181 parsesub: { 1182 char buf[10]; 1183 int subtype; 1184 int typeloc; 1185 int flags; 1186 char *p; 1187 static const char types[] = "}-+?="; 1188 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1189 int i; 1190 int linno; 1191 1192 c = pgetc(); 1193 if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) && 1194 !is_special(c)) { 1195 USTPUTC('$', out); 1196 pungetc(); 1197 } else if (c == '(') { /* $(command) or $((arith)) */ 1198 if (pgetc() == '(') { 1199 PARSEARITH(); 1200 } else { 1201 pungetc(); 1202 PARSEBACKQNEW(); 1203 } 1204 } else { 1205 USTPUTC(CTLVAR, out); 1206 typeloc = out - stackblock(); 1207 USTPUTC(VSNORMAL, out); 1208 subtype = VSNORMAL; 1209 flags = 0; 1210 if (c == '{') { 1211 bracketed_name = 1; 1212 c = pgetc(); 1213 if (c == '#') { 1214 if ((c = pgetc()) == '}') 1215 c = '#'; 1216 else 1217 subtype = VSLENGTH; 1218 } 1219 else 1220 subtype = 0; 1221 } 1222 if (!is_eof(c) && is_name(c)) { 1223 p = out; 1224 do { 1225 STPUTC(c, out); 1226 c = pgetc(); 1227 } while (!is_eof(c) && is_in_name(c)); 1228 if (out - p == 6 && strncmp(p, "LINENO", 6) == 0) { 1229 /* Replace the variable name with the 1230 * current line number. */ 1231 linno = plinno; 1232 if (funclinno != 0) 1233 linno -= funclinno - 1; 1234 snprintf(buf, sizeof(buf), "%d", linno); 1235 STADJUST(-6, out); 1236 for (i = 0; buf[i] != '\0'; i++) 1237 STPUTC(buf[i], out); 1238 flags |= VSLINENO; 1239 } 1240 } else if (is_digit(c)) { 1241 if (bracketed_name) { 1242 do { 1243 STPUTC(c, out); 1244 c = pgetc(); 1245 } while (is_digit(c)); 1246 } else { 1247 STPUTC(c, out); 1248 c = pgetc(); 1249 } 1250 } else { 1251 if (! is_special(c)) { 1252 subtype = VSERROR; 1253 if (c == '}') 1254 pungetc(); 1255 else 1256 USTPUTC(c, out); 1257 } else { 1258 USTPUTC(c, out); 1259 c = pgetc(); 1260 } 1261 } 1262 if (subtype == 0) { 1263 switch (c) { 1264 case ':': 1265 flags |= VSNUL; 1266 c = pgetc(); 1267 /*FALLTHROUGH*/ 1268 default: 1269 p = strchr(types, c); 1270 if (p == NULL) { 1271 if (flags == VSNUL) 1272 STPUTC(':', out); 1273 STPUTC(c, out); 1274 subtype = VSERROR; 1275 } else 1276 subtype = p - types + VSNORMAL; 1277 break; 1278 case '%': 1279 case '#': 1280 { 1281 int cc = c; 1282 subtype = c == '#' ? VSTRIMLEFT : 1283 VSTRIMRIGHT; 1284 c = pgetc(); 1285 if (c == cc) 1286 subtype++; 1287 else 1288 pungetc(); 1289 break; 1290 } 1291 } 1292 } else if (subtype != VSERROR) { 1293 pungetc(); 1294 } 1295 STPUTC('=', out); 1296 if (subtype != VSLENGTH && (dblquote || arinest)) 1297 flags |= VSQUOTE; 1298 *(stackblock() + typeloc) = subtype | flags; 1299 if (subtype != VSNORMAL) 1300 varnest++; 1301 } 1302 goto parsesub_return; 1303 } 1304 1305 1306 /* 1307 * Called to parse command substitutions. Newstyle is set if the command 1308 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1309 * list of commands (passed by reference), and savelen is the number of 1310 * characters on the top of the stack which must be preserved. 1311 */ 1312 1313 parsebackq: { 1314 struct nodelist **nlpp; 1315 int savepbq; 1316 union node *n; 1317 char *volatile str; 1318 struct jmploc jmploc; 1319 struct jmploc *volatile savehandler; 1320 int savelen; 1321 int saveprompt; 1322 #if __GNUC__ 1323 /* Avoid longjmp clobbering */ 1324 (void) &saveprompt; 1325 #endif 1326 1327 savepbq = parsebackquote; 1328 if (setjmp(jmploc.loc)) { 1329 if (str) 1330 ckfree(str); 1331 parsebackquote = 0; 1332 handler = savehandler; 1333 longjmp(handler->loc, 1); 1334 } 1335 INTOFF; 1336 str = NULL; 1337 savelen = out - stackblock(); 1338 if (savelen > 0) { 1339 str = ckmalloc(savelen); 1340 memcpy(str, stackblock(), savelen); 1341 } 1342 savehandler = handler; 1343 handler = &jmploc; 1344 INTON; 1345 if (oldstyle) { 1346 /* We must read until the closing backquote, giving special 1347 treatment to some slashes, and then push the string and 1348 reread it as input, interpreting it normally. */ 1349 char *out; 1350 int c; 1351 int savelen; 1352 char *str; 1353 1354 1355 STARTSTACKSTR(out); 1356 for (;;) { 1357 if (needprompt) { 1358 setprompt(2); 1359 needprompt = 0; 1360 } 1361 switch (c = pgetc()) { 1362 case '`': 1363 goto done; 1364 1365 case '\\': 1366 if ((c = pgetc()) == '\n') { 1367 plinno++; 1368 if (doprompt) 1369 setprompt(2); 1370 else 1371 setprompt(0); 1372 /* 1373 * If eating a newline, avoid putting 1374 * the newline into the new character 1375 * stream (via the STPUTC after the 1376 * switch). 1377 */ 1378 continue; 1379 } 1380 if (c != '\\' && c != '`' && c != '$' 1381 && (!dblquote || c != '"')) 1382 STPUTC('\\', out); 1383 break; 1384 1385 case '\n': 1386 plinno++; 1387 needprompt = doprompt; 1388 break; 1389 1390 case PEOF: 1391 startlinno = plinno; 1392 synerror("EOF in backquote substitution"); 1393 break; 1394 1395 default: 1396 break; 1397 } 1398 STPUTC(c, out); 1399 } 1400 done: 1401 STPUTC('\0', out); 1402 savelen = out - stackblock(); 1403 if (savelen > 0) { 1404 str = ckmalloc(savelen); 1405 memcpy(str, stackblock(), savelen); 1406 setinputstring(str, 1); 1407 } 1408 } 1409 nlpp = &bqlist; 1410 while (*nlpp) 1411 nlpp = &(*nlpp)->next; 1412 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1413 (*nlpp)->next = NULL; 1414 parsebackquote = oldstyle; 1415 1416 if (oldstyle) { 1417 saveprompt = doprompt; 1418 doprompt = 0; 1419 } 1420 1421 n = list(0); 1422 1423 if (oldstyle) 1424 doprompt = saveprompt; 1425 else { 1426 if (readtoken() != TRP) 1427 synexpect(TRP); 1428 } 1429 1430 (*nlpp)->n = n; 1431 if (oldstyle) { 1432 /* 1433 * Start reading from old file again, ignoring any pushed back 1434 * tokens left from the backquote parsing 1435 */ 1436 popfile(); 1437 tokpushback = 0; 1438 } 1439 while (stackblocksize() <= savelen) 1440 growstackblock(); 1441 STARTSTACKSTR(out); 1442 if (str) { 1443 memcpy(out, str, savelen); 1444 STADJUST(savelen, out); 1445 INTOFF; 1446 ckfree(str); 1447 str = NULL; 1448 INTON; 1449 } 1450 parsebackquote = savepbq; 1451 handler = savehandler; 1452 if (arinest || dblquote) 1453 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1454 else 1455 USTPUTC(CTLBACKQ, out); 1456 if (oldstyle) 1457 goto parsebackq_oldreturn; 1458 else 1459 goto parsebackq_newreturn; 1460 } 1461 1462 /* 1463 * Parse an arithmetic expansion (indicate start of one and set state) 1464 */ 1465 parsearith: { 1466 1467 if (++arinest == 1) { 1468 prevsyntax = syntax; 1469 syntax = ARISYNTAX; 1470 USTPUTC(CTLARI, out); 1471 if (dblquote) 1472 USTPUTC('"',out); 1473 else 1474 USTPUTC(' ',out); 1475 } else { 1476 /* 1477 * we collapse embedded arithmetic expansion to 1478 * parenthesis, which should be equivalent 1479 */ 1480 USTPUTC('(', out); 1481 } 1482 goto parsearith_return; 1483 } 1484 1485 } /* end of readtoken */ 1486 1487 1488 1489 #ifdef mkinit 1490 RESET { 1491 tokpushback = 0; 1492 checkkwd = 0; 1493 } 1494 #endif 1495 1496 /* 1497 * Returns true if the text contains nothing to expand (no dollar signs 1498 * or backquotes). 1499 */ 1500 1501 STATIC int 1502 noexpand(char *text) 1503 { 1504 char *p; 1505 char c; 1506 1507 p = text; 1508 while ((c = *p++) != '\0') { 1509 if ( c == CTLQUOTEMARK) 1510 continue; 1511 if (c == CTLESC) 1512 p++; 1513 else if (BASESYNTAX[(int)c] == CCTL) 1514 return 0; 1515 } 1516 return 1; 1517 } 1518 1519 1520 /* 1521 * Return true if the argument is a legal variable name (a letter or 1522 * underscore followed by zero or more letters, underscores, and digits). 1523 */ 1524 1525 int 1526 goodname(char *name) 1527 { 1528 char *p; 1529 1530 p = name; 1531 if (! is_name(*p)) 1532 return 0; 1533 while (*++p) { 1534 if (! is_in_name(*p)) 1535 return 0; 1536 } 1537 return 1; 1538 } 1539 1540 1541 /* 1542 * Called when an unexpected token is read during the parse. The argument 1543 * is the token that is expected, or -1 if more than one type of token can 1544 * occur at this point. 1545 */ 1546 1547 STATIC void 1548 synexpect(int token) 1549 { 1550 char msg[64]; 1551 1552 if (token >= 0) { 1553 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1554 tokname[lasttoken], tokname[token]); 1555 } else { 1556 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1557 } 1558 synerror(msg); 1559 } 1560 1561 1562 STATIC void 1563 synerror(char *msg) 1564 { 1565 if (commandname) 1566 outfmt(&errout, "%s: %d: ", commandname, startlinno); 1567 outfmt(&errout, "Syntax error: %s\n", msg); 1568 error((char *)NULL); 1569 } 1570 1571 STATIC void 1572 setprompt(int which) 1573 { 1574 whichprompt = which; 1575 1576 #ifndef NO_HISTORY 1577 if (!el) 1578 #endif 1579 out2str(getprompt(NULL)); 1580 } 1581 1582 /* 1583 * called by editline -- any expansions to the prompt 1584 * should be added here. 1585 */ 1586 char * 1587 getprompt(void *unused __unused) 1588 { 1589 static char ps[PROMPTLEN]; 1590 char *fmt; 1591 int i, j, trim; 1592 1593 /* 1594 * Select prompt format. 1595 */ 1596 switch (whichprompt) { 1597 case 0: 1598 fmt = ""; 1599 break; 1600 case 1: 1601 fmt = ps1val(); 1602 break; 1603 case 2: 1604 fmt = ps2val(); 1605 break; 1606 default: 1607 return "<internal prompt error>"; 1608 } 1609 1610 /* 1611 * Format prompt string. 1612 */ 1613 for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++) 1614 if (*fmt == '\\') 1615 switch (*++fmt) { 1616 1617 /* 1618 * Hostname. 1619 * 1620 * \h specifies just the local hostname, 1621 * \H specifies fully-qualified hostname. 1622 */ 1623 case 'h': 1624 case 'H': 1625 ps[i] = '\0'; 1626 gethostname(&ps[i], PROMPTLEN - i); 1627 /* Skip to end of hostname. */ 1628 trim = (*fmt == 'h') ? '.' : '\0'; 1629 while ((ps[i+1] != '\0') && (ps[i+1] != trim)) 1630 i++; 1631 break; 1632 1633 /* 1634 * Working directory. 1635 * 1636 * \W specifies just the final component, 1637 * \w specifies the entire path. 1638 */ 1639 case 'W': 1640 case 'w': 1641 ps[i] = '\0'; 1642 getcwd(&ps[i], PROMPTLEN - i); 1643 if (*fmt == 'W') { 1644 /* Final path component only. */ 1645 trim = 1; 1646 for (j = i; ps[j] != '\0'; j++) 1647 if (ps[j] == '/') 1648 trim = j + 1; 1649 memmove(&ps[i], &ps[trim], 1650 j - trim + 1); 1651 } 1652 /* Skip to end of path. */ 1653 while (ps[i + 1] != '\0') 1654 i++; 1655 break; 1656 1657 /* 1658 * Superuser status. 1659 * 1660 * '$' for normal users, '#' for root. 1661 */ 1662 case '$': 1663 ps[i] = (geteuid() != 0) ? '$' : '#'; 1664 break; 1665 1666 /* 1667 * A literal \. 1668 */ 1669 case '\\': 1670 ps[i] = '\\'; 1671 break; 1672 1673 /* 1674 * Emit unrecognized formats verbatim. 1675 */ 1676 default: 1677 ps[i++] = '\\'; 1678 ps[i] = *fmt; 1679 break; 1680 } 1681 else 1682 ps[i] = *fmt; 1683 ps[i] = '\0'; 1684 return (ps); 1685 } 1686