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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)parser.c 8.7 (Berkeley) 5/16/95 37 * $FreeBSD: src/bin/sh/parser.c,v 1.58 2006/11/05 18:36:05 stefanf Exp $ 38 * $DragonFly: src/bin/sh/parser.c,v 1.12 2007/01/18 17:03:18 corecode Exp $ 39 */ 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 /* 92 * 1 == check for kwds 93 * 2 == also eat newlines 94 * 3 == check for TNOT 95 */ 96 MKINIT int checkkwd; 97 STATIC struct nodelist *backquotelist; 98 STATIC union node *redirnode; 99 STATIC struct heredoc *heredoc; 100 STATIC int quoteflag; /* set if (part of) last token was quoted */ 101 STATIC int startlinno; /* line # where last token started */ 102 103 /* XXX When 'noaliases' is set to one, no alias expansion takes place. */ 104 static int noaliases = 0; 105 106 107 STATIC union node *list(int); 108 STATIC union node *andor(void); 109 STATIC union node *pipeline(void); 110 STATIC union node *command(void); 111 STATIC union node *simplecmd(union node **, union node *); 112 STATIC union node *makename(void); 113 STATIC void parsefname(void); 114 STATIC void parseheredoc(void); 115 STATIC int peektoken(void); 116 STATIC int readtoken(void); 117 STATIC int xxreadtoken(void); 118 STATIC int readtoken1(int, char const *, char *, int); 119 STATIC int noexpand(char *); 120 STATIC void synexpect(int); 121 STATIC void synerror(const char *); 122 STATIC void setprompt(int); 123 124 125 /* 126 * Read and parse a command. Returns NEOF on end of file. (NULL is a 127 * valid parse tree indicating a blank line.) 128 */ 129 130 union node * 131 parsecmd(int interact) 132 { 133 int t; 134 135 tokpushback = 0; 136 doprompt = interact; 137 if (doprompt) 138 setprompt(1); 139 else 140 setprompt(0); 141 needprompt = 0; 142 t = readtoken(); 143 if (t == TEOF) 144 return NEOF; 145 if (t == TNL) 146 return NULL; 147 tokpushback++; 148 return list(1); 149 } 150 151 152 STATIC union node * 153 list(int nlflag) 154 { 155 union node *n1, *n2, *n3; 156 int tok; 157 158 checkkwd = 2; 159 if (nlflag == 0 && tokendlist[peektoken()]) 160 return NULL; 161 n1 = NULL; 162 for (;;) { 163 n2 = andor(); 164 tok = readtoken(); 165 if (tok == TBACKGND) { 166 if (n2->type == NCMD || n2->type == NPIPE) { 167 n2->ncmd.backgnd = 1; 168 } else if (n2->type == NREDIR) { 169 n2->type = NBACKGND; 170 } else { 171 n3 = (union node *)stalloc(sizeof (struct nredir)); 172 n3->type = NBACKGND; 173 n3->nredir.n = n2; 174 n3->nredir.redirect = NULL; 175 n2 = n3; 176 } 177 } 178 if (n1 == NULL) { 179 n1 = n2; 180 } 181 else { 182 n3 = (union node *)stalloc(sizeof (struct nbinary)); 183 n3->type = NSEMI; 184 n3->nbinary.ch1 = n1; 185 n3->nbinary.ch2 = n2; 186 n1 = n3; 187 } 188 switch (tok) { 189 case TBACKGND: 190 case TSEMI: 191 tok = readtoken(); 192 /* FALLTHROUGH */ 193 case TNL: 194 if (tok == TNL) { 195 parseheredoc(); 196 if (nlflag) 197 return n1; 198 } else { 199 tokpushback++; 200 } 201 checkkwd = 2; 202 if (tokendlist[peektoken()]) 203 return n1; 204 break; 205 case TEOF: 206 if (heredoclist) 207 parseheredoc(); 208 else 209 pungetc(); /* push back EOF on input */ 210 return n1; 211 default: 212 if (nlflag) 213 synexpect(-1); 214 tokpushback++; 215 return n1; 216 } 217 } 218 } 219 220 221 222 STATIC union node * 223 andor(void) 224 { 225 union node *n1, *n2, *n3; 226 int t; 227 228 n1 = pipeline(); 229 for (;;) { 230 if ((t = readtoken()) == TAND) { 231 t = NAND; 232 } else if (t == TOR) { 233 t = NOR; 234 } else { 235 tokpushback++; 236 return n1; 237 } 238 n2 = pipeline(); 239 n3 = (union node *)stalloc(sizeof (struct nbinary)); 240 n3->type = t; 241 n3->nbinary.ch1 = n1; 242 n3->nbinary.ch2 = n2; 243 n1 = n3; 244 } 245 } 246 247 248 249 STATIC union node * 250 pipeline(void) 251 { 252 union node *n1, *n2, *pipenode; 253 struct nodelist *lp, *prev; 254 int negate; 255 256 negate = 0; 257 TRACE(("pipeline: entered\n")); 258 259 checkkwd = 3; 260 while (readtoken() == TNOT) 261 negate = !negate; 262 tokpushback++; 263 264 n1 = command(); 265 if (readtoken() == TPIPE) { 266 pipenode = (union node *)stalloc(sizeof (struct npipe)); 267 pipenode->type = NPIPE; 268 pipenode->npipe.backgnd = 0; 269 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 270 pipenode->npipe.cmdlist = lp; 271 lp->n = n1; 272 do { 273 int innernegate = 0; 274 275 checkkwd = 3; 276 while (readtoken() == TNOT) 277 innernegate = !innernegate; 278 tokpushback++; 279 280 prev = lp; 281 lp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 282 lp->n = command(); 283 prev->next = lp; 284 285 if (innernegate) { 286 n2 = (union node *)stalloc(sizeof (struct nnot)); 287 n2->type = NNOT; 288 n2->nnot.com = lp->n; 289 lp->n = n2; 290 } 291 } while (readtoken() == TPIPE); 292 lp->next = NULL; 293 n1 = pipenode; 294 } 295 tokpushback++; 296 if (negate) { 297 n2 = (union node *)stalloc(sizeof (struct nnot)); 298 n2->type = NNOT; 299 n2->nnot.com = n1; 300 return n2; 301 } else 302 return n1; 303 } 304 305 306 307 STATIC union node * 308 command(void) 309 { 310 union node *n1, *n2; 311 union node *ap, **app; 312 union node *cp, **cpp; 313 union node *redir, **rpp; 314 int t; 315 316 checkkwd = 2; 317 redir = NULL; 318 n1 = NULL; 319 rpp = &redir; 320 321 /* Check for redirection which may precede command */ 322 while (readtoken() == TREDIR) { 323 *rpp = n2 = redirnode; 324 rpp = &n2->nfile.next; 325 parsefname(); 326 } 327 tokpushback++; 328 329 switch (readtoken()) { 330 case TIF: 331 n1 = (union node *)stalloc(sizeof (struct nif)); 332 n1->type = NIF; 333 if ((n1->nif.test = list(0)) == NULL) 334 synexpect(-1); 335 if (readtoken() != TTHEN) 336 synexpect(TTHEN); 337 n1->nif.ifpart = list(0); 338 n2 = n1; 339 while (readtoken() == TELIF) { 340 n2->nif.elsepart = (union node *)stalloc(sizeof (struct nif)); 341 n2 = n2->nif.elsepart; 342 n2->type = NIF; 343 if ((n2->nif.test = list(0)) == NULL) 344 synexpect(-1); 345 if (readtoken() != TTHEN) 346 synexpect(TTHEN); 347 n2->nif.ifpart = list(0); 348 } 349 if (lasttoken == TELSE) 350 n2->nif.elsepart = list(0); 351 else { 352 n2->nif.elsepart = NULL; 353 tokpushback++; 354 } 355 if (readtoken() != TFI) 356 synexpect(TFI); 357 checkkwd = 1; 358 break; 359 case TWHILE: 360 case TUNTIL: { 361 int got; 362 n1 = (union node *)stalloc(sizeof (struct nbinary)); 363 n1->type = (lasttoken == TWHILE)? NWHILE : NUNTIL; 364 if ((n1->nbinary.ch1 = list(0)) == NULL) 365 synexpect(-1); 366 if ((got=readtoken()) != TDO) { 367 TRACE(("expecting DO got %s %s\n", tokname[got], got == TWORD ? wordtext : "")); 368 synexpect(TDO); 369 } 370 n1->nbinary.ch2 = list(0); 371 if (readtoken() != TDONE) 372 synexpect(TDONE); 373 checkkwd = 1; 374 break; 375 } 376 case TFOR: 377 if (readtoken() != TWORD || quoteflag || ! goodname(wordtext)) 378 synerror("Bad for loop variable"); 379 n1 = (union node *)stalloc(sizeof (struct nfor)); 380 n1->type = NFOR; 381 n1->nfor.var = wordtext; 382 if (readtoken() == TWORD && ! quoteflag && equal(wordtext, "in")) { 383 app = ≈ 384 while (readtoken() == TWORD) { 385 n2 = (union node *)stalloc(sizeof (struct narg)); 386 n2->type = NARG; 387 n2->narg.text = wordtext; 388 n2->narg.backquote = backquotelist; 389 *app = n2; 390 app = &n2->narg.next; 391 } 392 *app = NULL; 393 n1->nfor.args = ap; 394 if (lasttoken != TNL && lasttoken != TSEMI) 395 synexpect(-1); 396 } else { 397 static char argvars[5] = { 398 CTLVAR, VSNORMAL|VSQUOTE, '@', '=', '\0' 399 }; 400 n2 = (union node *)stalloc(sizeof (struct narg)); 401 n2->type = NARG; 402 n2->narg.text = argvars; 403 n2->narg.backquote = NULL; 404 n2->narg.next = NULL; 405 n1->nfor.args = n2; 406 /* 407 * Newline or semicolon here is optional (but note 408 * that the original Bourne shell only allowed NL). 409 */ 410 if (lasttoken != TNL && lasttoken != TSEMI) 411 tokpushback++; 412 } 413 checkkwd = 2; 414 if ((t = readtoken()) == TDO) 415 t = TDONE; 416 else if (t == TBEGIN) 417 t = TEND; 418 else 419 synexpect(-1); 420 n1->nfor.body = list(0); 421 if (readtoken() != t) 422 synexpect(t); 423 checkkwd = 1; 424 break; 425 case TCASE: 426 n1 = (union node *)stalloc(sizeof (struct ncase)); 427 n1->type = NCASE; 428 if (readtoken() != TWORD) 429 synexpect(TWORD); 430 n1->ncase.expr = n2 = (union node *)stalloc(sizeof (struct narg)); 431 n2->type = NARG; 432 n2->narg.text = wordtext; 433 n2->narg.backquote = backquotelist; 434 n2->narg.next = NULL; 435 while (readtoken() == TNL); 436 if (lasttoken != TWORD || ! equal(wordtext, "in")) 437 synerror("expecting \"in\""); 438 cpp = &n1->ncase.cases; 439 noaliases = 1; /* turn off alias expansion */ 440 checkkwd = 2, readtoken(); 441 while (lasttoken != TESAC) { 442 *cpp = cp = (union node *)stalloc(sizeof (struct nclist)); 443 cp->type = NCLIST; 444 app = &cp->nclist.pattern; 445 if (lasttoken == TLP) 446 readtoken(); 447 for (;;) { 448 *app = ap = (union node *)stalloc(sizeof (struct narg)); 449 ap->type = NARG; 450 ap->narg.text = wordtext; 451 ap->narg.backquote = backquotelist; 452 if (checkkwd = 2, readtoken() != TPIPE) 453 break; 454 app = &ap->narg.next; 455 readtoken(); 456 } 457 ap->narg.next = NULL; 458 if (lasttoken != TRP) 459 noaliases = 0, synexpect(TRP); 460 cp->nclist.body = list(0); 461 462 checkkwd = 2; 463 if ((t = readtoken()) != TESAC) { 464 if (t != TENDCASE) 465 noaliases = 0, synexpect(TENDCASE); 466 else 467 checkkwd = 2, readtoken(); 468 } 469 cpp = &cp->nclist.next; 470 } 471 noaliases = 0; /* reset alias expansion */ 472 *cpp = NULL; 473 checkkwd = 1; 474 break; 475 case TLP: 476 n1 = (union node *)stalloc(sizeof (struct nredir)); 477 n1->type = NSUBSHELL; 478 n1->nredir.n = list(0); 479 n1->nredir.redirect = NULL; 480 if (readtoken() != TRP) 481 synexpect(TRP); 482 checkkwd = 1; 483 break; 484 case TBEGIN: 485 n1 = list(0); 486 if (readtoken() != TEND) 487 synexpect(TEND); 488 checkkwd = 1; 489 break; 490 /* Handle an empty command like other simple commands. */ 491 case TSEMI: 492 case TAND: 493 case TOR: 494 /* 495 * An empty command before a ; doesn't make much sense, and 496 * should certainly be disallowed in the case of `if ;'. 497 */ 498 if (!redir) 499 synexpect(-1); 500 case TNL: 501 case TEOF: 502 case TWORD: 503 case TRP: 504 tokpushback++; 505 return simplecmd(rpp, redir); 506 default: 507 synexpect(-1); 508 } 509 510 /* Now check for redirection which may follow command */ 511 while (readtoken() == TREDIR) { 512 *rpp = n2 = redirnode; 513 rpp = &n2->nfile.next; 514 parsefname(); 515 } 516 tokpushback++; 517 *rpp = NULL; 518 if (redir) { 519 if (n1->type != NSUBSHELL) { 520 n2 = (union node *)stalloc(sizeof (struct nredir)); 521 n2->type = NREDIR; 522 n2->nredir.n = n1; 523 n1 = n2; 524 } 525 n1->nredir.redirect = redir; 526 } 527 return n1; 528 } 529 530 531 STATIC union node * 532 simplecmd(union node **rpp, union node *redir) 533 { 534 union node *args, **app; 535 union node **orig_rpp = rpp; 536 union node *n = NULL; 537 538 /* If we don't have any redirections already, then we must reset */ 539 /* rpp to be the address of the local redir variable. */ 540 if (redir == 0) 541 rpp = &redir; 542 543 args = NULL; 544 app = &args; 545 /* 546 * We save the incoming value, because we need this for shell 547 * functions. There can not be a redirect or an argument between 548 * the function name and the open parenthesis. 549 */ 550 orig_rpp = rpp; 551 552 for (;;) { 553 if (readtoken() == TWORD) { 554 n = (union node *)stalloc(sizeof (struct narg)); 555 n->type = NARG; 556 n->narg.text = wordtext; 557 n->narg.backquote = backquotelist; 558 *app = n; 559 app = &n->narg.next; 560 } else if (lasttoken == TREDIR) { 561 *rpp = n = redirnode; 562 rpp = &n->nfile.next; 563 parsefname(); /* read name of redirection file */ 564 } else if (lasttoken == TLP && app == &args->narg.next 565 && rpp == orig_rpp) { 566 /* We have a function */ 567 if (readtoken() != TRP) 568 synexpect(TRP); 569 #ifdef notdef 570 if (! goodname(n->narg.text)) 571 synerror("Bad function name"); 572 #endif 573 n->type = NDEFUN; 574 n->narg.next = command(); 575 return n; 576 } else { 577 tokpushback++; 578 break; 579 } 580 } 581 *app = NULL; 582 *rpp = NULL; 583 n = (union node *)stalloc(sizeof (struct ncmd)); 584 n->type = NCMD; 585 n->ncmd.backgnd = 0; 586 n->ncmd.args = args; 587 n->ncmd.redirect = redir; 588 return n; 589 } 590 591 STATIC union node * 592 makename(void) 593 { 594 union node *n; 595 596 n = (union node *)stalloc(sizeof (struct narg)); 597 n->type = NARG; 598 n->narg.next = NULL; 599 n->narg.text = wordtext; 600 n->narg.backquote = backquotelist; 601 return n; 602 } 603 604 void 605 fixredir(union node *n, const char *text, int err) 606 { 607 TRACE(("Fix redir %s %d\n", text, err)); 608 if (!err) 609 n->ndup.vname = NULL; 610 611 if (is_digit(text[0]) && text[1] == '\0') 612 n->ndup.dupfd = digit_val(text[0]); 613 else if (text[0] == '-' && text[1] == '\0') 614 n->ndup.dupfd = -1; 615 else { 616 617 if (err) 618 synerror("Bad fd number"); 619 else 620 n->ndup.vname = makename(); 621 } 622 } 623 624 625 STATIC void 626 parsefname(void) 627 { 628 union node *n = redirnode; 629 630 if (readtoken() != TWORD) 631 synexpect(-1); 632 if (n->type == NHERE) { 633 struct heredoc *here = heredoc; 634 struct heredoc *p; 635 int i; 636 637 if (quoteflag == 0) 638 n->type = NXHERE; 639 TRACE(("Here document %d\n", n->type)); 640 if (here->striptabs) { 641 while (*wordtext == '\t') 642 wordtext++; 643 } 644 if (! noexpand(wordtext) || (i = strlen(wordtext)) == 0 || i > EOFMARKLEN) 645 synerror("Illegal eof marker for << redirection"); 646 rmescapes(wordtext); 647 here->eofmark = wordtext; 648 here->next = NULL; 649 if (heredoclist == NULL) 650 heredoclist = here; 651 else { 652 for (p = heredoclist ; p->next ; p = p->next); 653 p->next = here; 654 } 655 } else if (n->type == NTOFD || n->type == NFROMFD) { 656 fixredir(n, wordtext, 0); 657 } else { 658 n->nfile.fname = makename(); 659 } 660 } 661 662 663 /* 664 * Input any here documents. 665 */ 666 667 STATIC void 668 parseheredoc(void) 669 { 670 struct heredoc *here; 671 union node *n; 672 673 while (heredoclist) { 674 here = heredoclist; 675 heredoclist = here->next; 676 if (needprompt) { 677 setprompt(2); 678 needprompt = 0; 679 } 680 readtoken1(pgetc(), here->here->type == NHERE? SQSYNTAX : DQSYNTAX, 681 here->eofmark, here->striptabs); 682 n = (union node *)stalloc(sizeof (struct narg)); 683 n->narg.type = NARG; 684 n->narg.next = NULL; 685 n->narg.text = wordtext; 686 n->narg.backquote = backquotelist; 687 here->here->nhere.doc = n; 688 } 689 } 690 691 STATIC int 692 peektoken(void) 693 { 694 int t; 695 696 t = readtoken(); 697 tokpushback++; 698 return (t); 699 } 700 701 STATIC int 702 readtoken(void) 703 { 704 int t; 705 int savecheckkwd = checkkwd; 706 struct alias *ap; 707 #ifdef DEBUG 708 int alreadyseen = tokpushback; 709 #endif 710 711 top: 712 t = xxreadtoken(); 713 714 if (checkkwd) { 715 /* 716 * eat newlines 717 */ 718 if (checkkwd > 1) { 719 checkkwd = 0; 720 while (t == TNL) { 721 parseheredoc(); 722 t = xxreadtoken(); 723 } 724 } else 725 checkkwd = 0; 726 /* 727 * check for keywords and aliases 728 */ 729 if (t == TWORD && !quoteflag) 730 { 731 const char * const *pp; 732 733 for (pp = parsekwd; *pp; pp++) { 734 if (**pp == *wordtext && equal(*pp, wordtext)) 735 { 736 lasttoken = t = pp - parsekwd + KWDOFFSET; 737 TRACE(("keyword %s recognized\n", tokname[t])); 738 goto out; 739 } 740 } 741 if (noaliases == 0 && 742 (ap = lookupalias(wordtext, 1)) != NULL) { 743 pushstring(ap->val, strlen(ap->val), ap); 744 checkkwd = savecheckkwd; 745 goto top; 746 } 747 } 748 out: 749 checkkwd = 0; 750 } 751 #ifdef DEBUG 752 if (!alreadyseen) 753 TRACE(("token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 754 else 755 TRACE(("reread token %s %s\n", tokname[t], t == TWORD ? wordtext : "")); 756 #endif 757 return (t); 758 } 759 760 761 /* 762 * Read the next input token. 763 * If the token is a word, we set backquotelist to the list of cmds in 764 * backquotes. We set quoteflag to true if any part of the word was 765 * quoted. 766 * If the token is TREDIR, then we set redirnode to a structure containing 767 * the redirection. 768 * In all cases, the variable startlinno is set to the number of the line 769 * on which the token starts. 770 * 771 * [Change comment: here documents and internal procedures] 772 * [Readtoken shouldn't have any arguments. Perhaps we should make the 773 * word parsing code into a separate routine. In this case, readtoken 774 * doesn't need to have any internal procedures, but parseword does. 775 * We could also make parseoperator in essence the main routine, and 776 * have parseword (readtoken1?) handle both words and redirection.] 777 */ 778 779 #define RETURN(token) return lasttoken = token 780 781 STATIC int 782 xxreadtoken(void) 783 { 784 int c; 785 786 if (tokpushback) { 787 tokpushback = 0; 788 return lasttoken; 789 } 790 if (needprompt) { 791 setprompt(2); 792 needprompt = 0; 793 } 794 startlinno = plinno; 795 for (;;) { /* until token or start of word found */ 796 c = pgetc_macro(); 797 if (c == ' ' || c == '\t') 798 continue; /* quick check for white space first */ 799 switch (c) { 800 case ' ': case '\t': 801 continue; 802 case '#': 803 while ((c = pgetc()) != '\n' && c != PEOF); 804 pungetc(); 805 continue; 806 case '\\': 807 if (pgetc() == '\n') { 808 startlinno = ++plinno; 809 if (doprompt) 810 setprompt(2); 811 else 812 setprompt(0); 813 continue; 814 } 815 pungetc(); 816 goto breakloop; 817 case '\n': 818 plinno++; 819 needprompt = doprompt; 820 RETURN(TNL); 821 case PEOF: 822 RETURN(TEOF); 823 case '&': 824 if (pgetc() == '&') 825 RETURN(TAND); 826 pungetc(); 827 RETURN(TBACKGND); 828 case '|': 829 if (pgetc() == '|') 830 RETURN(TOR); 831 pungetc(); 832 RETURN(TPIPE); 833 case ';': 834 if (pgetc() == ';') 835 RETURN(TENDCASE); 836 pungetc(); 837 RETURN(TSEMI); 838 case '(': 839 RETURN(TLP); 840 case ')': 841 RETURN(TRP); 842 case '!': 843 if (checkkwd == 3) 844 RETURN(TNOT); 845 /* else FALLTHROUGH */ 846 default: 847 goto breakloop; 848 } 849 } 850 breakloop: 851 return readtoken1(c, BASESYNTAX, NULL, 0); 852 #undef RETURN 853 } 854 855 856 857 /* 858 * If eofmark is NULL, read a word or a redirection symbol. If eofmark 859 * is not NULL, read a here document. In the latter case, eofmark is the 860 * word which marks the end of the document and striptabs is true if 861 * leading tabs should be stripped from the document. The argument firstc 862 * is the first character of the input token or document. 863 * 864 * Because C does not have internal subroutines, I have simulated them 865 * using goto's to implement the subroutine linkage. The following macros 866 * will run code that appears at the end of readtoken1. 867 */ 868 869 #define CHECKEND() {goto checkend; checkend_return:;} 870 #define PARSEREDIR() {goto parseredir; parseredir_return:;} 871 #define PARSESUB() {goto parsesub; parsesub_return:;} 872 #define PARSEBACKQOLD() {oldstyle = 1; goto parsebackq; parsebackq_oldreturn:;} 873 #define PARSEBACKQNEW() {oldstyle = 0; goto parsebackq; parsebackq_newreturn:;} 874 #define PARSEARITH() {goto parsearith; parsearith_return:;} 875 876 STATIC int 877 readtoken1(int firstc, char const *syn, char *eofmark, int striptabs) 878 { 879 int c = firstc; 880 char const * volatile syntax = syn; 881 char * volatile out; 882 int len; 883 char line[EOFMARKLEN + 1]; 884 struct nodelist *bqlist; 885 volatile int quotef; 886 volatile int dblquote; 887 volatile int varnest; /* levels of variables expansion */ 888 volatile int arinest; /* levels of arithmetic expansion */ 889 volatile int parenlevel; /* levels of parens in arithmetic */ 890 volatile int oldstyle; 891 char const * volatile prevsyntax = NULL; /* syntax before arithmetic */ 892 int synentry; 893 894 startlinno = plinno; 895 dblquote = 0; 896 if (syntax == DQSYNTAX) 897 dblquote = 1; 898 quotef = 0; 899 bqlist = NULL; 900 varnest = 0; 901 arinest = 0; 902 parenlevel = 0; 903 904 STARTSTACKSTR(out); 905 loop: { /* for each line, until end of word */ 906 CHECKEND(); /* set c to PEOF if at end of here document */ 907 for (;;) { /* until end of line or end of word */ 908 CHECKSTRSPACE(3, out); /* permit 3 calls to USTPUTC */ 909 910 synentry = syntax[c]; 911 912 switch(synentry) { 913 case CNL: /* '\n' */ 914 if (syntax == BASESYNTAX) 915 goto endword; /* exit outer loop */ 916 USTPUTC(c, out); 917 plinno++; 918 if (doprompt) 919 setprompt(2); 920 else 921 setprompt(0); 922 c = pgetc(); 923 goto loop; /* continue outer loop */ 924 case CWORD: 925 USTPUTC(c, out); 926 break; 927 case CCTL: 928 if (eofmark == NULL || dblquote) 929 USTPUTC(CTLESC, out); 930 USTPUTC(c, out); 931 break; 932 case CBACK: /* backslash */ 933 c = pgetc(); 934 if (c == PEOF) { 935 USTPUTC('\\', out); 936 pungetc(); 937 } else if (c == '\n') { 938 plinno++; 939 if (doprompt) 940 setprompt(2); 941 else 942 setprompt(0); 943 } else { 944 if (dblquote && c != '\\' && 945 c != '`' && c != '$' && 946 (c != '"' || eofmark != NULL)) 947 USTPUTC('\\', out); 948 if (SQSYNTAX[c] == CCTL) 949 USTPUTC(CTLESC, out); 950 else if (eofmark == NULL) 951 USTPUTC(CTLQUOTEMARK, out); 952 USTPUTC(c, out); 953 quotef++; 954 } 955 break; 956 case CSQUOTE: 957 if (eofmark == NULL) 958 USTPUTC(CTLQUOTEMARK, out); 959 syntax = SQSYNTAX; 960 break; 961 case CDQUOTE: 962 if (eofmark == NULL) 963 USTPUTC(CTLQUOTEMARK, out); 964 syntax = DQSYNTAX; 965 dblquote = 1; 966 break; 967 case CENDQUOTE: 968 if (eofmark != NULL && arinest == 0 && 969 varnest == 0) { 970 USTPUTC(c, out); 971 } else { 972 if (arinest) { 973 syntax = ARISYNTAX; 974 dblquote = 0; 975 } else if (eofmark == NULL) { 976 syntax = BASESYNTAX; 977 dblquote = 0; 978 } 979 quotef++; 980 } 981 break; 982 case CVAR: /* '$' */ 983 PARSESUB(); /* parse substitution */ 984 break; 985 case CENDVAR: /* '}' */ 986 if (varnest > 0) { 987 varnest--; 988 USTPUTC(CTLENDVAR, out); 989 } else { 990 USTPUTC(c, out); 991 } 992 break; 993 case CLP: /* '(' in arithmetic */ 994 parenlevel++; 995 USTPUTC(c, out); 996 break; 997 case CRP: /* ')' in arithmetic */ 998 if (parenlevel > 0) { 999 USTPUTC(c, out); 1000 --parenlevel; 1001 } else { 1002 if (pgetc() == ')') { 1003 if (--arinest == 0) { 1004 USTPUTC(CTLENDARI, out); 1005 syntax = prevsyntax; 1006 if (syntax == DQSYNTAX) 1007 dblquote = 1; 1008 else 1009 dblquote = 0; 1010 } else 1011 USTPUTC(')', out); 1012 } else { 1013 /* 1014 * unbalanced parens 1015 * (don't 2nd guess - no error) 1016 */ 1017 pungetc(); 1018 USTPUTC(')', out); 1019 } 1020 } 1021 break; 1022 case CBQUOTE: /* '`' */ 1023 PARSEBACKQOLD(); 1024 break; 1025 case CEOF: 1026 goto endword; /* exit outer loop */ 1027 default: 1028 if (varnest == 0) 1029 goto endword; /* exit outer loop */ 1030 USTPUTC(c, out); 1031 } 1032 c = pgetc_macro(); 1033 } 1034 } 1035 endword: 1036 if (syntax == ARISYNTAX) 1037 synerror("Missing '))'"); 1038 if (syntax != BASESYNTAX && ! parsebackquote && eofmark == NULL) 1039 synerror("Unterminated quoted string"); 1040 if (varnest != 0) { 1041 startlinno = plinno; 1042 synerror("Missing '}'"); 1043 } 1044 USTPUTC('\0', out); 1045 len = out - stackblock(); 1046 out = stackblock(); 1047 if (eofmark == NULL) { 1048 if ((c == '>' || c == '<') 1049 && quotef == 0 1050 && len <= 2 1051 && (*out == '\0' || is_digit(*out))) { 1052 PARSEREDIR(); 1053 return lasttoken = TREDIR; 1054 } else { 1055 pungetc(); 1056 } 1057 } 1058 quoteflag = quotef; 1059 backquotelist = bqlist; 1060 grabstackblock(len); 1061 wordtext = out; 1062 return lasttoken = TWORD; 1063 /* end of readtoken routine */ 1064 1065 1066 1067 /* 1068 * Check to see whether we are at the end of the here document. When this 1069 * is called, c is set to the first character of the next input line. If 1070 * we are at the end of the here document, this routine sets the c to PEOF. 1071 */ 1072 1073 checkend: { 1074 if (eofmark) { 1075 if (striptabs) { 1076 while (c == '\t') 1077 c = pgetc(); 1078 } 1079 if (c == *eofmark) { 1080 if (pfgets(line, sizeof line) != NULL) { 1081 char *p, *q; 1082 1083 p = line; 1084 for (q = eofmark + 1 ; *q && *p == *q ; p++, q++); 1085 if (*p == '\n' && *q == '\0') { 1086 c = PEOF; 1087 plinno++; 1088 needprompt = doprompt; 1089 } else { 1090 pushstring(line, strlen(line), NULL); 1091 } 1092 } 1093 } 1094 } 1095 goto checkend_return; 1096 } 1097 1098 1099 /* 1100 * Parse a redirection operator. The variable "out" points to a string 1101 * specifying the fd to be redirected. The variable "c" contains the 1102 * first character of the redirection operator. 1103 */ 1104 1105 parseredir: { 1106 char fd = *out; 1107 union node *np; 1108 1109 np = (union node *)stalloc(sizeof (struct nfile)); 1110 if (c == '>') { 1111 np->nfile.fd = 1; 1112 c = pgetc(); 1113 if (c == '>') 1114 np->type = NAPPEND; 1115 else if (c == '&') 1116 np->type = NTOFD; 1117 else if (c == '|') 1118 np->type = NCLOBBER; 1119 else { 1120 np->type = NTO; 1121 pungetc(); 1122 } 1123 } else { /* c == '<' */ 1124 np->nfile.fd = 0; 1125 c = pgetc(); 1126 if (c == '<') { 1127 if (sizeof (struct nfile) != sizeof (struct nhere)) { 1128 np = (union node *)stalloc(sizeof (struct nhere)); 1129 np->nfile.fd = 0; 1130 } 1131 np->type = NHERE; 1132 heredoc = (struct heredoc *)stalloc(sizeof (struct heredoc)); 1133 heredoc->here = np; 1134 if ((c = pgetc()) == '-') { 1135 heredoc->striptabs = 1; 1136 } else { 1137 heredoc->striptabs = 0; 1138 pungetc(); 1139 } 1140 } else if (c == '&') 1141 np->type = NFROMFD; 1142 else if (c == '>') 1143 np->type = NFROMTO; 1144 else { 1145 np->type = NFROM; 1146 pungetc(); 1147 } 1148 } 1149 if (fd != '\0') 1150 np->nfile.fd = digit_val(fd); 1151 redirnode = np; 1152 goto parseredir_return; 1153 } 1154 1155 1156 /* 1157 * Parse a substitution. At this point, we have read the dollar sign 1158 * and nothing else. 1159 */ 1160 1161 parsesub: { 1162 int subtype; 1163 int typeloc; 1164 int flags; 1165 char *p; 1166 static const char types[] = "}-+?="; 1167 int bracketed_name = 0; /* used to handle ${[0-9]*} variables */ 1168 1169 c = pgetc(); 1170 if (c != '(' && c != '{' && (is_eof(c) || !is_name(c)) && 1171 !is_special(c)) { 1172 USTPUTC('$', out); 1173 pungetc(); 1174 } else if (c == '(') { /* $(command) or $((arith)) */ 1175 if (pgetc() == '(') { 1176 PARSEARITH(); 1177 } else { 1178 pungetc(); 1179 PARSEBACKQNEW(); 1180 } 1181 } else { 1182 USTPUTC(CTLVAR, out); 1183 typeloc = out - stackblock(); 1184 USTPUTC(VSNORMAL, out); 1185 subtype = VSNORMAL; 1186 if (c == '{') { 1187 bracketed_name = 1; 1188 c = pgetc(); 1189 if (c == '#') { 1190 if ((c = pgetc()) == '}') 1191 c = '#'; 1192 else 1193 subtype = VSLENGTH; 1194 } 1195 else 1196 subtype = 0; 1197 } 1198 if (!is_eof(c) && is_name(c)) { 1199 do { 1200 STPUTC(c, out); 1201 c = pgetc(); 1202 } while (!is_eof(c) && is_in_name(c)); 1203 } else if (is_digit(c)) { 1204 if (bracketed_name) { 1205 do { 1206 STPUTC(c, out); 1207 c = pgetc(); 1208 } while (is_digit(c)); 1209 } else { 1210 STPUTC(c, out); 1211 c = pgetc(); 1212 } 1213 } else { 1214 if (! is_special(c)) { 1215 subtype = VSERROR; 1216 if (c == '}') 1217 pungetc(); 1218 else 1219 USTPUTC(c, out); 1220 } else { 1221 USTPUTC(c, out); 1222 c = pgetc(); 1223 } 1224 } 1225 flags = 0; 1226 if (subtype == 0) { 1227 switch (c) { 1228 case ':': 1229 flags = VSNUL; 1230 c = pgetc(); 1231 /*FALLTHROUGH*/ 1232 default: 1233 p = strchr(types, c); 1234 if (p == NULL) { 1235 if (flags == VSNUL) 1236 STPUTC(':', out); 1237 STPUTC(c, out); 1238 subtype = VSERROR; 1239 } else 1240 subtype = p - types + VSNORMAL; 1241 break; 1242 case '%': 1243 case '#': 1244 { 1245 int cc = c; 1246 subtype = c == '#' ? VSTRIMLEFT : 1247 VSTRIMRIGHT; 1248 c = pgetc(); 1249 if (c == cc) 1250 subtype++; 1251 else 1252 pungetc(); 1253 break; 1254 } 1255 } 1256 } else if (subtype != VSERROR) { 1257 pungetc(); 1258 } 1259 STPUTC('=', out); 1260 if (subtype != VSLENGTH && (dblquote || arinest)) 1261 flags |= VSQUOTE; 1262 *(stackblock() + typeloc) = subtype | flags; 1263 if (subtype != VSNORMAL) 1264 varnest++; 1265 } 1266 goto parsesub_return; 1267 } 1268 1269 1270 /* 1271 * Called to parse command substitutions. Newstyle is set if the command 1272 * is enclosed inside $(...); nlpp is a pointer to the head of the linked 1273 * list of commands (passed by reference), and savelen is the number of 1274 * characters on the top of the stack which must be preserved. 1275 */ 1276 1277 parsebackq: { 1278 struct nodelist **nlpp; 1279 int savepbq; 1280 union node *n; 1281 char *volatile str; 1282 struct jmploc jmploc; 1283 struct jmploc *volatile savehandler; 1284 int savelen; 1285 volatile int saveprompt; 1286 1287 savepbq = parsebackquote; 1288 if (setjmp(jmploc.loc)) { 1289 if (str) 1290 ckfree(str); 1291 parsebackquote = 0; 1292 handler = savehandler; 1293 longjmp(handler->loc, 1); 1294 } 1295 INTOFF; 1296 str = NULL; 1297 savelen = out - stackblock(); 1298 if (savelen > 0) { 1299 str = ckmalloc(savelen); 1300 memcpy(str, stackblock(), savelen); 1301 } 1302 savehandler = handler; 1303 handler = &jmploc; 1304 INTON; 1305 if (oldstyle) { 1306 /* We must read until the closing backquote, giving special 1307 treatment to some slashes, and then push the string and 1308 reread it as input, interpreting it normally. */ 1309 char *pout; 1310 int pc; 1311 int psavelen; 1312 char *pstr; 1313 1314 1315 STARTSTACKSTR(pout); 1316 for (;;) { 1317 if (needprompt) { 1318 setprompt(2); 1319 needprompt = 0; 1320 } 1321 switch (pc = pgetc()) { 1322 case '`': 1323 goto done; 1324 1325 case '\\': 1326 if ((pc = pgetc()) == '\n') { 1327 plinno++; 1328 if (doprompt) 1329 setprompt(2); 1330 else 1331 setprompt(0); 1332 /* 1333 * If eating a newline, avoid putting 1334 * the newline into the new character 1335 * stream (via the STPUTC after the 1336 * switch). 1337 */ 1338 continue; 1339 } 1340 if (pc != '\\' && pc != '`' && pc != '$' 1341 && (!dblquote || pc != '"')) 1342 STPUTC('\\', pout); 1343 break; 1344 1345 case '\n': 1346 plinno++; 1347 needprompt = doprompt; 1348 break; 1349 1350 case PEOF: 1351 startlinno = plinno; 1352 synerror("EOF in backquote substitution"); 1353 break; 1354 1355 default: 1356 break; 1357 } 1358 STPUTC(pc, pout); 1359 } 1360 done: 1361 STPUTC('\0', pout); 1362 psavelen = pout - stackblock(); 1363 if (psavelen > 0) { 1364 pstr = ckmalloc(psavelen); 1365 memcpy(pstr, stackblock(), psavelen); 1366 setinputstring(pstr, 1); 1367 } 1368 } 1369 nlpp = &bqlist; 1370 while (*nlpp) 1371 nlpp = &(*nlpp)->next; 1372 *nlpp = (struct nodelist *)stalloc(sizeof (struct nodelist)); 1373 (*nlpp)->next = NULL; 1374 parsebackquote = oldstyle; 1375 1376 if (oldstyle) { 1377 saveprompt = doprompt; 1378 doprompt = 0; 1379 } 1380 1381 n = list(0); 1382 1383 if (oldstyle) 1384 doprompt = saveprompt; 1385 else { 1386 if (readtoken() != TRP) 1387 synexpect(TRP); 1388 } 1389 1390 (*nlpp)->n = n; 1391 if (oldstyle) { 1392 /* 1393 * Start reading from old file again, ignoring any pushed back 1394 * tokens left from the backquote parsing 1395 */ 1396 popfile(); 1397 tokpushback = 0; 1398 } 1399 while (stackblocksize() <= savelen) 1400 growstackblock(); 1401 STARTSTACKSTR(out); 1402 if (str) { 1403 memcpy(out, str, savelen); 1404 STADJUST(savelen, out); 1405 INTOFF; 1406 ckfree(str); 1407 str = NULL; 1408 INTON; 1409 } 1410 parsebackquote = savepbq; 1411 handler = savehandler; 1412 if (arinest || dblquote) 1413 USTPUTC(CTLBACKQ | CTLQUOTE, out); 1414 else 1415 USTPUTC(CTLBACKQ, out); 1416 if (oldstyle) 1417 goto parsebackq_oldreturn; 1418 else 1419 goto parsebackq_newreturn; 1420 } 1421 1422 /* 1423 * Parse an arithmetic expansion (indicate start of one and set state) 1424 */ 1425 parsearith: { 1426 1427 if (++arinest == 1) { 1428 prevsyntax = syntax; 1429 syntax = ARISYNTAX; 1430 USTPUTC(CTLARI, out); 1431 if (dblquote) 1432 USTPUTC('"',out); 1433 else 1434 USTPUTC(' ',out); 1435 } else { 1436 /* 1437 * we collapse embedded arithmetic expansion to 1438 * parenthesis, which should be equivalent 1439 */ 1440 USTPUTC('(', out); 1441 } 1442 goto parsearith_return; 1443 } 1444 1445 } /* end of readtoken */ 1446 1447 1448 1449 #ifdef mkinit 1450 RESET { 1451 tokpushback = 0; 1452 checkkwd = 0; 1453 } 1454 #endif 1455 1456 /* 1457 * Returns true if the text contains nothing to expand (no dollar signs 1458 * or backquotes). 1459 */ 1460 1461 STATIC int 1462 noexpand(char *text) 1463 { 1464 char *p; 1465 char c; 1466 1467 p = text; 1468 while ((c = *p++) != '\0') { 1469 if ( c == CTLQUOTEMARK) 1470 continue; 1471 if (c == CTLESC) 1472 p++; 1473 else if (BASESYNTAX[(int)c] == CCTL) 1474 return 0; 1475 } 1476 return 1; 1477 } 1478 1479 1480 /* 1481 * Return true if the argument is a legal variable name (a letter or 1482 * underscore followed by zero or more letters, underscores, and digits). 1483 */ 1484 1485 int 1486 goodname(char *name) 1487 { 1488 char *p; 1489 1490 p = name; 1491 if (! is_name(*p)) 1492 return 0; 1493 while (*++p) { 1494 if (! is_in_name(*p)) 1495 return 0; 1496 } 1497 return 1; 1498 } 1499 1500 1501 /* 1502 * Called when an unexpected token is read during the parse. The argument 1503 * is the token that is expected, or -1 if more than one type of token can 1504 * occur at this point. 1505 */ 1506 1507 STATIC void 1508 synexpect(int token) 1509 { 1510 char msg[64]; 1511 1512 if (token >= 0) { 1513 fmtstr(msg, 64, "%s unexpected (expecting %s)", 1514 tokname[lasttoken], tokname[token]); 1515 } else { 1516 fmtstr(msg, 64, "%s unexpected", tokname[lasttoken]); 1517 } 1518 synerror(msg); 1519 } 1520 1521 1522 STATIC void 1523 synerror(const char *msg) 1524 { 1525 if (commandname) 1526 outfmt(&errout, "%s: %d: ", commandname, startlinno); 1527 outfmt(&errout, "Syntax error: %s\n", msg); 1528 error(NULL); 1529 } 1530 1531 STATIC void 1532 setprompt(int which) 1533 { 1534 whichprompt = which; 1535 1536 #ifndef NO_HISTORY 1537 if (!el) 1538 #endif 1539 out2str(getprompt(NULL)); 1540 } 1541 1542 /* 1543 * called by editline -- any expansions to the prompt 1544 * should be added here. 1545 */ 1546 const char * 1547 getprompt(void *unused __unused) 1548 { 1549 static char ps[PROMPTLEN]; 1550 const char *fmt; 1551 int i, j, trim; 1552 1553 /* 1554 * Select prompt format. 1555 */ 1556 switch (whichprompt) { 1557 case 0: 1558 fmt = ""; 1559 break; 1560 case 1: 1561 fmt = ps1val(); 1562 break; 1563 case 2: 1564 fmt = ps2val(); 1565 break; 1566 default: 1567 return "<internal prompt error>"; 1568 } 1569 1570 /* 1571 * Format prompt string. 1572 */ 1573 for (i = 0; (i < 127) && (*fmt != '\0'); i++, fmt++) 1574 if (*fmt == '\\') 1575 switch (*++fmt) { 1576 1577 /* 1578 * Hostname. 1579 * 1580 * \h specifies just the local hostname, 1581 * \H specifies fully-qualified hostname. 1582 */ 1583 case 'h': 1584 case 'H': 1585 ps[i] = '\0'; 1586 gethostname(&ps[i], PROMPTLEN - i); 1587 /* Skip to end of hostname. */ 1588 trim = (*fmt == 'h') ? '.' : '\0'; 1589 while ((ps[i+1] != '\0') && (ps[i+1] != trim)) 1590 i++; 1591 break; 1592 1593 /* 1594 * Working directory. 1595 * 1596 * \W specifies just the final component, 1597 * \w specifies the entire path. 1598 */ 1599 case 'W': 1600 case 'w': 1601 ps[i] = '\0'; 1602 getcwd(&ps[i], PROMPTLEN - i); 1603 if (*fmt == 'W') { 1604 /* Final path component only. */ 1605 trim = 1; 1606 for (j = i; ps[j] != '\0'; j++) 1607 if (ps[j] == '/') 1608 trim = j + 1; 1609 memmove(&ps[i], &ps[trim], 1610 j - trim + 1); 1611 } 1612 /* Skip to end of path. */ 1613 while (ps[i + 1] != '\0') 1614 i++; 1615 break; 1616 1617 /* 1618 * Superuser status. 1619 * 1620 * '$' for normal users, '#' for root. 1621 */ 1622 case '$': 1623 ps[i] = (geteuid() != 0) ? '$' : '#'; 1624 break; 1625 1626 /* 1627 * A literal \. 1628 */ 1629 case '\\': 1630 ps[i] = '\\'; 1631 break; 1632 1633 /* 1634 * Emit unrecognized formats verbatim. 1635 */ 1636 default: 1637 ps[i++] = '\\'; 1638 ps[i] = *fmt; 1639 break; 1640 } 1641 else 1642 ps[i] = *fmt; 1643 ps[i] = '\0'; 1644 return (ps); 1645 } 1646