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