1 /* $NetBSD: eval.c,v 1.27 2024/10/03 20:14:01 rillig Exp $ */ 2 3 /* 4 * Expansion - quoting, separation, substitution, globbing 5 */ 6 #include <sys/cdefs.h> 7 8 #ifndef lint 9 __RCSID("$NetBSD: eval.c,v 1.27 2024/10/03 20:14:01 rillig Exp $"); 10 #endif 11 12 #include <sys/stat.h> 13 #include <stdint.h> 14 #include <pwd.h> 15 16 #include "sh.h" 17 #include "ksh_dir.h" 18 19 /* 20 * string expansion 21 * 22 * first pass: quoting, IFS separation, ~, ${}, $() and $(()) substitution. 23 * second pass: alternation ({,}), filename expansion (*?[]). 24 */ 25 26 /* expansion generator state */ 27 typedef struct Expand { 28 /* int type; */ /* see expand() */ 29 const char *str; /* string */ 30 union { 31 const char **strv;/* string[] */ 32 struct shf *shf;/* file */ 33 } u; /* source */ 34 struct tbl *var; /* variable in ${var..} */ 35 short split; /* split "$@" / call waitlast $() */ 36 } Expand; 37 38 #define XBASE 0 /* scanning original */ 39 #define XSUB 1 /* expanding ${} string */ 40 #define XARGSEP 2 /* ifs0 between "$*" */ 41 #define XARG 3 /* expanding $*, $@ */ 42 #define XCOM 4 /* expanding $() */ 43 #define XNULLSUB 5 /* "$@" when $# is 0 (don't generate word) */ 44 45 /* States used for field splitting */ 46 #define IFS_WORD 0 /* word has chars (or quotes) */ 47 #define IFS_WS 1 /* have seen IFS white-space */ 48 #define IFS_NWS 2 /* have seen IFS non-white-space */ 49 50 static int varsub ARGS((Expand *xp, char *sp, char *word, int *stypep, int *slenp)); 51 static int comsub ARGS((Expand *xp, char *cp)); 52 static char *trimsub ARGS((char *str, char *pat, int how)); 53 static void ksh_glob ARGS((char *cp, XPtrV *wp, int markdirs)); 54 static void globit ARGS((XString *xs, char **xpp, char *sp, XPtrV *wp, 55 int check)); 56 static char *maybe_expand_tilde ARGS((char *p, XString *dsp, char **dpp, 57 int isassign)); 58 static char *tilde ARGS((char *acp)); 59 static char *homedir ARGS((char *name)); 60 #ifdef BRACE_EXPAND 61 static void alt_expand ARGS((XPtrV *wp, char *start, char *exp_start, 62 char *end, int fdo)); 63 #endif 64 65 /* compile and expand word */ 66 char * 67 substitute(cp, f) 68 const char *cp; 69 int f; 70 { 71 struct source *s, *sold; 72 73 sold = source; 74 s = pushs(SWSTR, ATEMP); 75 s->start = s->str = cp; 76 source = s; 77 if (yylex(ONEWORD) != LWORD) 78 internal_errorf(1, "substitute"); 79 source = sold; 80 afree(s, ATEMP); 81 return evalstr(yylval.cp, f); 82 } 83 84 /* 85 * expand arg-list 86 */ 87 char ** 88 eval(ap, f) 89 char **ap; 90 int f; 91 { 92 XPtrV w; 93 94 if (*ap == NULL) 95 return ap; 96 XPinit(w, 32); 97 XPput(w, NULL); /* space for shell name */ 98 while (*ap != NULL) 99 expand(*ap++, &w, f); 100 XPput(w, NULL); 101 return (char **) XPclose(w) + 1; 102 } 103 104 /* 105 * expand string 106 */ 107 char * 108 evalstr(cp, f) 109 char *cp; 110 int f; 111 { 112 XPtrV w; 113 114 XPinit(w, 1); 115 expand(cp, &w, f); 116 cp = (XPsize(w) == 0) ? null : (char*) *XPptrv(w); 117 XPfree(w); 118 return cp; 119 } 120 121 /* 122 * expand string - return only one component 123 * used from iosetup to expand redirection files 124 */ 125 char * 126 evalonestr(cp, f) 127 char *cp; 128 int f; 129 { 130 XPtrV w; 131 132 XPinit(w, 1); 133 expand(cp, &w, f); 134 switch (XPsize(w)) { 135 case 0: 136 cp = null; 137 break; 138 case 1: 139 cp = (char*) *XPptrv(w); 140 break; 141 default: 142 cp = evalstr(cp, f&~DOGLOB); 143 break; 144 } 145 XPfree(w); 146 return cp; 147 } 148 149 /* for nested substitution: ${var:=$var2} */ 150 typedef struct SubType { 151 short stype; /* [=+-?%#] action after expanded word */ 152 short base; /* begin position of expanded word */ 153 short f; /* saved value of f (DOPAT, etc) */ 154 struct tbl *var; /* variable for ${var..} */ 155 short quote; /* saved value of quote (for ${..[%#]..}) */ 156 struct SubType *prev; /* old type */ 157 struct SubType *next; /* poped type (to avoid re-allocating) */ 158 } SubType; 159 160 void 161 expand(cp, wp, f) 162 char *cp; /* input word */ 163 XPtrV *wp; /* output words */ 164 int f; /* DO* flags */ 165 { 166 int UNINITIALIZED(c); 167 int type; /* expansion type */ 168 int quote = 0; /* quoted */ 169 XString ds; /* destination string */ 170 char *dp, *sp; /* dest., source */ 171 int fdo, word; /* second pass flags; have word */ 172 int doblank; /* field splitting of parameter/command subst */ 173 Expand x; /* expansion variables */ 174 SubType st_head, *st; 175 int UNINITIALIZED(newlines); /* For trailing newlines in COMSUB */ 176 int saw_eq; 177 unsigned int tilde_ok; 178 int make_magic; 179 size_t len; 180 181 x.split = 0; /* XXX gcc */ 182 x.str = NULL; /* XXX gcc */ 183 x.u.strv = NULL;/* XXX gcc */ 184 if (cp == NULL) 185 internal_errorf(1, "expand(NULL)"); 186 /* for alias, readonly, set, typeset commands */ 187 if ((f & DOVACHECK) && is_wdvarassign(cp)) { 188 f &= ~(DOVACHECK|DOBLANK|DOGLOB|DOTILDE); 189 f |= DOASNTILDE; 190 } 191 if (Flag(FNOGLOB)) 192 f &= ~DOGLOB; 193 if (Flag(FMARKDIRS)) 194 f |= DOMARKDIRS; 195 #ifdef BRACE_EXPAND 196 if (Flag(FBRACEEXPAND) && (f & DOGLOB)) 197 f |= DOBRACE_; 198 #endif /* BRACE_EXPAND */ 199 200 Xinit(ds, dp, 128, ATEMP); /* init dest. string */ 201 type = XBASE; 202 sp = cp; 203 fdo = 0; 204 saw_eq = 0; 205 tilde_ok = (f & (DOTILDE|DOASNTILDE)) ? 1 : 0; /* must be 1/0 */ 206 doblank = 0; 207 make_magic = 0; 208 word = (f&DOBLANK) ? IFS_WS : IFS_WORD; 209 st_head.next = (SubType *) 0; 210 st = &st_head; 211 212 while (1) { 213 Xcheck(ds, dp); 214 215 switch (type) { 216 case XBASE: /* original prefixed string */ 217 c = *sp++; 218 switch (c) { 219 case EOS: 220 c = 0; 221 break; 222 case CHAR: 223 c = *sp++; 224 break; 225 case QCHAR: 226 quote |= 2; /* temporary quote */ 227 c = *sp++; 228 break; 229 case OQUOTE: 230 word = IFS_WORD; 231 tilde_ok = 0; 232 quote = 1; 233 continue; 234 case CQUOTE: 235 quote = 0; 236 continue; 237 case COMSUB: 238 tilde_ok = 0; 239 if (f & DONTRUNCOMMAND) { 240 word = IFS_WORD; 241 *dp++ = '$'; *dp++ = '('; 242 while (*sp != '\0') { 243 Xcheck(ds, dp); 244 *dp++ = *sp++; 245 } 246 *dp++ = ')'; 247 } else { 248 type = comsub(&x, sp); 249 if (type == XCOM && (f&DOBLANK)) 250 doblank++; 251 sp = strchr(sp, 0) + 1; 252 newlines = 0; 253 } 254 continue; 255 case EXPRSUB: 256 word = IFS_WORD; 257 tilde_ok = 0; 258 if (f & DONTRUNCOMMAND) { 259 *dp++ = '$'; *dp++ = '('; *dp++ = '('; 260 while (*sp != '\0') { 261 Xcheck(ds, dp); 262 *dp++ = *sp++; 263 } 264 *dp++ = ')'; *dp++ = ')'; 265 } else { 266 struct tbl v; 267 char *p; 268 269 v.flag = DEFINED|ISSET|INTEGER; 270 v.type = 10; /* not default */ 271 v.name[0] = '\0'; 272 v_evaluate(&v, substitute(sp, 0), 273 KSH_UNWIND_ERROR); 274 sp = strchr(sp, 0) + 1; 275 for (p = str_val(&v); *p; ) { 276 Xcheck(ds, dp); 277 *dp++ = *p++; 278 } 279 } 280 continue; 281 case OSUBST: /* ${{#}var{:}[=+-?#%]word} */ 282 /* format is: 283 * OSUBST [{x] plain-variable-part \0 284 * compiled-word-part CSUBST [}x] 285 * This is were all syntax checking gets done... 286 */ 287 { 288 char *varname = ++sp; /* skip the { or x (}) */ 289 int stype; 290 int slen; 291 292 slen = -1; /* XXX gcc */ 293 sp = strchr(sp, '\0') + 1; /* skip variable */ 294 type = varsub(&x, varname, sp, &stype, &slen); 295 if (type < 0) { 296 char endc; 297 char *str, *end; 298 299 end = (char *) wdscan(sp, CSUBST); 300 /* ({) the } or x is already skipped */ 301 endc = *end; 302 *end = EOS; 303 str = snptreef((char *) 0, 64, "%S", 304 varname - 1); 305 *end = endc; 306 errorf("%s: bad substitution", str); 307 } 308 if (f&DOBLANK) 309 doblank++; 310 tilde_ok = 0; 311 if (type == XBASE) { /* expand? */ 312 if (!st->next) { 313 SubType *newst; 314 315 newst = (SubType *) alloc( 316 sizeof(SubType), ATEMP); 317 newst->next = (SubType *) 0; 318 newst->prev = st; 319 st->next = newst; 320 } 321 st = st->next; 322 st->stype = stype; 323 st->base = Xsavepos(ds, dp); 324 st->f = f; 325 st->var = x.var; 326 st->quote = quote; 327 /* skip qualifier(s) */ 328 if (stype) 329 sp += slen; 330 switch (stype & 0x7f) { 331 case '#': 332 case '%': 333 /* ! DOBLANK,DOBRACE_,DOTILDE */ 334 f = DOPAT | (f&DONTRUNCOMMAND) 335 | DOTEMP_; 336 quote = 0; 337 /* Prepend open pattern (so | 338 * in a trim will work as 339 * expected) 340 */ 341 *dp++ = MAGIC; 342 *dp++ = (char)('@' + 0x80); 343 break; 344 case '=': 345 /* Enabling tilde expansion 346 * after :'s here is 347 * non-standard ksh, but is 348 * consistent with rules for 349 * other assignments. Not 350 * sure what POSIX thinks of 351 * this. 352 * Not doing tilde expansion 353 * for integer variables is a 354 * non-POSIX thing - makes 355 * sense though, since ~ is 356 * a arithmetic operator. 357 */ 358 if (!(x.var->flag & INTEGER)) 359 f |= DOASNTILDE|DOTILDE; 360 f |= DOTEMP_; 361 /* These will be done after the 362 * value has been assigned. 363 */ 364 f &= ~(DOBLANK|DOGLOB|DOBRACE_); 365 tilde_ok = 1; 366 break; 367 case '?': 368 f &= ~DOBLANK; 369 f |= DOTEMP_; 370 /* fall through */ 371 default: 372 /* Enable tilde expansion */ 373 tilde_ok = 1; 374 f |= DOTILDE; 375 } 376 } else 377 /* skip word */ 378 sp = (char *) wdscan(sp, CSUBST); 379 continue; 380 } 381 case CSUBST: /* only get here if expanding word */ 382 sp++; /* ({) skip the } or x */ 383 tilde_ok = 0; /* in case of ${unset:-} */ 384 *dp = '\0'; 385 quote = st->quote; 386 f = st->f; 387 if (f&DOBLANK) 388 doblank--; 389 switch (st->stype&0x7f) { 390 case '#': 391 case '%': 392 /* Append end-pattern */ 393 *dp++ = MAGIC; *dp++ = ')'; *dp = '\0'; 394 dp = Xrestpos(ds, dp, st->base); 395 /* Must use st->var since calling 396 * global would break things 397 * like x[i+=1]. 398 */ 399 x.str = trimsub(str_val(st->var), 400 dp, st->stype); 401 type = XSUB; 402 if (f&DOBLANK) 403 doblank++; 404 st = st->prev; 405 continue; 406 case '=': 407 /* Restore our position and substitute 408 * the value of st->var (may not be 409 * the assigned value in the presence 410 * of integer/right-adj/etc attributes). 411 */ 412 dp = Xrestpos(ds, dp, st->base); 413 /* Must use st->var since calling 414 * global would cause with things 415 * like x[i+=1] to be evaluated twice. 416 */ 417 /* Note: not exported by FEXPORT 418 * in at&t ksh. 419 */ 420 /* XXX POSIX says readonly is only 421 * fatal for special builtins (setstr 422 * does readonly check). 423 */ 424 len = strlen(dp) + 1; 425 setstr(st->var, 426 debunk((char *) alloc(len, ATEMP), 427 dp, len), 428 KSH_UNWIND_ERROR); 429 x.str = str_val(st->var); 430 type = XSUB; 431 if (f&DOBLANK) 432 doblank++; 433 st = st->prev; 434 continue; 435 case '?': 436 { 437 char *s = Xrestpos(ds, dp, st->base); 438 439 errorf("%s: %s", st->var->name, 440 dp == s ? 441 "parameter null or not set" 442 : (debunk(s, s, strlen(s) + 1), s)); 443 } 444 } 445 st = st->prev; 446 type = XBASE; 447 continue; 448 449 case OPAT: /* open pattern: *(foo|bar) */ 450 /* Next char is the type of pattern */ 451 make_magic = 1; 452 c = *sp++ + 0x80; 453 break; 454 455 case SPAT: /* pattern separator (|) */ 456 make_magic = 1; 457 c = '|'; 458 break; 459 460 case CPAT: /* close pattern */ 461 make_magic = 1; 462 c = /*(*/ ')'; 463 break; 464 } 465 break; 466 467 case XNULLSUB: 468 /* Special case for "$@" (and "${foo[@]}") - no 469 * word is generated if $# is 0 (unless there is 470 * other stuff inside the quotes). 471 */ 472 type = XBASE; 473 if (f&DOBLANK) { 474 doblank--; 475 /* not really correct: x=; "$x$@" should 476 * generate a null argument and 477 * set A; "${@:+}" shouldn't. 478 */ 479 if (dp == Xstring(ds, dp)) 480 word = IFS_WS; 481 } 482 continue; 483 484 case XSUB: 485 if ((c = *x.str++) == 0) { 486 type = XBASE; 487 if (f&DOBLANK) 488 doblank--; 489 continue; 490 } 491 break; 492 493 case XARGSEP: 494 type = XARG; 495 quote = 1; 496 /* FALLTHROUGH */ 497 case XARG: 498 if ((c = *x.str++) == '\0') { 499 /* force null words to be created so 500 * set -- '' 2 ''; foo "$@" will do 501 * the right thing 502 */ 503 if (quote && x.split) 504 word = IFS_WORD; 505 if ((x.str = *x.u.strv++) == NULL) { 506 type = XBASE; 507 if (f&DOBLANK) 508 doblank--; 509 continue; 510 } 511 c = ifs0; 512 if (c == 0) { 513 if (quote && !x.split) 514 continue; 515 c = ' '; 516 } 517 if (quote && x.split) { 518 /* terminate word for "$@" */ 519 type = XARGSEP; 520 quote = 0; 521 } 522 } 523 break; 524 525 case XCOM: 526 if (newlines) { /* Spit out saved nl's */ 527 c = '\n'; 528 --newlines; 529 } else { 530 while ((c = shf_getc(x.u.shf)) == 0 || c == '\n') 531 if (c == '\n') 532 newlines++; /* Save newlines */ 533 if (newlines && c != EOF) { 534 shf_ungetc(c, x.u.shf); 535 c = '\n'; 536 --newlines; 537 } 538 } 539 if (c == EOF) { 540 newlines = 0; 541 shf_close(x.u.shf); 542 if (x.split) 543 subst_exstat = waitlast(); 544 type = XBASE; 545 if (f&DOBLANK) 546 doblank--; 547 continue; 548 } 549 break; 550 } 551 552 /* check for end of word or IFS separation */ 553 if (c == 0 || (!quote && (f & DOBLANK) && doblank && !make_magic 554 && ctype(c, C_IFS))) 555 { 556 /* How words are broken up: 557 * | value of c 558 * word | ws nws 0 559 * ----------------------------------- 560 * IFS_WORD w/WS w/NWS w 561 * IFS_WS -/WS w/NWS - 562 * IFS_NWS -/NWS w/NWS w 563 * (w means generate a word) 564 * Note that IFS_NWS/0 generates a word (at&t ksh 565 * doesn't do this, but POSIX does). 566 */ 567 if (word == IFS_WORD 568 || (!ctype(c, C_IFSWS) && (c || word == IFS_NWS))) 569 { 570 char *p; 571 572 *dp++ = '\0'; 573 p = Xclose(ds, dp); 574 #ifdef BRACE_EXPAND 575 if (fdo & DOBRACE_) 576 /* also does globbing */ 577 alt_expand(wp, p, p, 578 p + Xlength(ds, (dp - 1)), 579 fdo | (f & DOMARKDIRS)); 580 else 581 #endif /* BRACE_EXPAND */ 582 if (fdo & DOGLOB) 583 ksh_glob(p, wp, f & DOMARKDIRS); 584 else if ((f & DOPAT) || !(fdo & DOMAGIC_)) 585 XPput(*wp, p); 586 else 587 XPput(*wp, debunk(p, p, strlen(p) + 1)); 588 fdo = 0; 589 saw_eq = 0; 590 tilde_ok = (f & (DOTILDE|DOASNTILDE)) ? 1 : 0; 591 if (c != 0) 592 Xinit(ds, dp, 128, ATEMP); 593 } 594 if (c == 0) 595 return; 596 if (word != IFS_NWS) 597 word = ctype(c, C_IFSWS) ? IFS_WS : IFS_NWS; 598 } else { 599 /* age tilde_ok info - ~ code tests second bit */ 600 tilde_ok <<= 1; 601 /* mark any special second pass chars */ 602 if (!quote) 603 switch (c) { 604 case '[': 605 case NOT: 606 case '-': 607 case ']': 608 /* For character classes - doesn't hurt 609 * to have magic !,-,]'s outside of 610 * [...] expressions. 611 */ 612 if (f & (DOPAT | DOGLOB)) { 613 fdo |= DOMAGIC_; 614 if (c == '[') 615 fdo |= f & DOGLOB; 616 *dp++ = MAGIC; 617 } 618 break; 619 case '*': 620 case '?': 621 if (f & (DOPAT | DOGLOB)) { 622 fdo |= DOMAGIC_ | (f & DOGLOB); 623 *dp++ = MAGIC; 624 } 625 break; 626 #ifdef BRACE_EXPAND 627 case OBRACE: 628 case ',': 629 case CBRACE: 630 if ((f & DOBRACE_) && (c == OBRACE 631 || (fdo & DOBRACE_))) 632 { 633 fdo |= DOBRACE_|DOMAGIC_; 634 *dp++ = MAGIC; 635 } 636 break; 637 #endif /* BRACE_EXPAND */ 638 case '=': 639 /* Note first unquoted = for ~ */ 640 if (!(f & DOTEMP_) && !saw_eq) { 641 saw_eq = 1; 642 tilde_ok = 1; 643 } 644 break; 645 case PATHSEP: /* : */ 646 /* Note unquoted : for ~ */ 647 if (!(f & DOTEMP_) && (f & DOASNTILDE)) 648 tilde_ok = 1; 649 break; 650 case '~': 651 /* tilde_ok is reset whenever 652 * any of ' " $( $(( ${ } are seen. 653 * Note that tilde_ok must be preserved 654 * through the sequence ${A=a=}~ 655 */ 656 if (type == XBASE 657 && (f & (DOTILDE|DOASNTILDE)) 658 && (tilde_ok & 2)) 659 { 660 char *p, *dp_x; 661 662 dp_x = dp; 663 p = maybe_expand_tilde(sp, 664 &ds, &dp_x, 665 f & DOASNTILDE); 666 if (p) { 667 if (dp != dp_x) 668 word = IFS_WORD; 669 dp = dp_x; 670 sp = p; 671 continue; 672 } 673 } 674 break; 675 } 676 else 677 quote &= ~2; /* undo temporary */ 678 679 if (make_magic) { 680 make_magic = 0; 681 fdo |= DOMAGIC_ | (f & DOGLOB); 682 *dp++ = MAGIC; 683 } else if (ISMAGIC(c)) { 684 fdo |= DOMAGIC_; 685 *dp++ = MAGIC; 686 } 687 *dp++ = c; /* save output char */ 688 word = IFS_WORD; 689 } 690 } 691 } 692 693 /* 694 * Prepare to generate the string returned by ${} substitution. 695 */ 696 static int 697 varsub(xp, sp, word, stypep, slenp) 698 Expand *xp; 699 char *sp; 700 char *word; 701 int *stypep; /* becomes qualifier type */ 702 int *slenp; /* " " len (=, :=, etc.) valid iff *stypep != 0 */ 703 { 704 int c; 705 int state; /* next state: XBASE, XARG, XSUB, XNULLSUB */ 706 int stype; /* substitution type */ 707 int slen; 708 char *p; 709 struct tbl *vp; 710 711 if (sp[0] == '\0') /* Bad variable name */ 712 return -1; 713 714 xp->var = NULL; 715 716 /* ${#var}, string length or array size */ 717 if (sp[0] == '#' && (c = sp[1]) != '\0') { 718 int zero_ok = 0; 719 720 /* Can't have any modifiers for ${#...} */ 721 if (*word != CSUBST) 722 return -1; 723 sp++; 724 /* Check for size of array */ 725 if ((p=strchr(sp,'[')) && (p[1]=='*'||p[1]=='@') && p[2]==']') { 726 int n = 0; 727 vp = global(arrayname(sp)); 728 if (vp->flag & (ISSET|ARRAY)) 729 zero_ok = 1; 730 for (; vp; vp = vp->u.array) 731 if (vp->flag & ISSET) { 732 n++; 733 } 734 c = n; /* ksh88/ksh93 go for number, not max index */ 735 } else if (c == '*' || c == '@') 736 c = e->loc->argc; 737 else { 738 p = str_val(global(sp)); 739 zero_ok = p != null; 740 c = strlen(p); 741 } 742 if (Flag(FNOUNSET) && c == 0 && !zero_ok) 743 errorf("%s: parameter not set", sp); 744 *stypep = 0; /* unqualified variable/string substitution */ 745 xp->str = str_save(ulton((unsigned long)c, 10), ATEMP); 746 return XSUB; 747 } 748 749 /* Check for qualifiers in word part */ 750 stype = 0; 751 c = word[slen = 0] == CHAR ? word[1] : 0; 752 if (c == ':') { 753 slen += 2; 754 stype = 0x80; 755 c = word[slen + 0] == CHAR ? word[slen + 1] : 0; 756 } 757 if (ctype(c, C_SUBOP1)) { 758 slen += 2; 759 stype |= c; 760 } else if (ctype(c, C_SUBOP2)) { /* Note: ksh88 allows :%, :%%, etc */ 761 slen += 2; 762 stype = c; 763 if (word[slen + 0] == CHAR && c == word[slen + 1]) { 764 stype |= 0x80; 765 slen += 2; 766 } 767 } else if (stype) /* : is not ok */ 768 return -1; 769 if (!stype && *word != CSUBST) 770 return -1; 771 *stypep = stype; 772 *slenp = slen; 773 774 c = sp[0]; 775 if (c == '*' || c == '@') { 776 switch (stype & 0x7f) { 777 case '=': /* can't assign to a vector */ 778 case '%': /* can't trim a vector (yet) */ 779 case '#': 780 return -1; 781 } 782 if (e->loc->argc == 0) { 783 xp->u.strv = NULL; 784 xp->str = null; 785 state = c == '@' ? XNULLSUB : XSUB; 786 } else { 787 char **t = &e->loc->argv[1]; 788 xp->u.strv = (void *)(uintptr_t)t; 789 xp->str = *xp->u.strv++; 790 xp->split = c == '@'; /* $@ */ 791 state = XARG; 792 } 793 } else { 794 if ((p=strchr(sp,'[')) && (p[1]=='*'||p[1]=='@') && p[2]==']') { 795 XPtrV wv; 796 797 switch (stype & 0x7f) { 798 case '=': /* can't assign to a vector */ 799 case '%': /* can't trim a vector (yet) */ 800 case '#': 801 return -1; 802 } 803 XPinit(wv, 32); 804 vp = global(arrayname(sp)); 805 for (; vp; vp = vp->u.array) { 806 if (!(vp->flag&ISSET)) 807 continue; 808 XPput(wv, str_val(vp)); 809 } 810 if (XPsize(wv) == 0) { 811 xp->str = null; 812 state = p[1] == '@' ? XNULLSUB : XSUB; 813 XPfree(wv); 814 } else { 815 XPput(wv, 0); 816 xp->u.strv = (const char **) XPptrv(wv); 817 xp->str = *xp->u.strv++; 818 xp->split = p[1] == '@'; /* ${foo[@]} */ 819 state = XARG; 820 } 821 } else { 822 /* Can't assign things like $! or $1 */ 823 if ((stype & 0x7f) == '=' 824 && (ctype(*sp, C_VAR1) || digit(*sp))) 825 return -1; 826 xp->var = global(sp); 827 xp->str = str_val(xp->var); 828 state = XSUB; 829 } 830 } 831 832 c = stype&0x7f; 833 /* test the compiler's code generator */ 834 if (ctype(c, C_SUBOP2) || 835 (((stype&0x80) ? *xp->str=='\0' : xp->str==null) ? /* undef? */ 836 c == '=' || c == '-' || c == '?' : c == '+')) 837 state = XBASE; /* expand word instead of variable value */ 838 if (Flag(FNOUNSET) && xp->str == null 839 && (ctype(c, C_SUBOP2) || (state != XBASE && c != '+'))) 840 errorf("%s: parameter not set", sp); 841 return state; 842 } 843 844 /* 845 * Run the command in $(...) and read its output. 846 */ 847 static int 848 comsub(xp, cp) 849 Expand *xp; 850 char *cp; 851 { 852 Source *s, *sold; 853 struct op *t; 854 struct shf *shf; 855 856 s = pushs(SSTRING, ATEMP); 857 s->start = s->str = cp; 858 sold = source; 859 t = compile(s); 860 afree(s, ATEMP); 861 source = sold; 862 863 if (t == NULL) 864 return XBASE; 865 866 if (t != NULL && t->type == TCOM && /* $(<file) */ 867 *t->args == NULL && *t->vars == NULL && t->ioact != NULL) { 868 struct ioword *io = *t->ioact; 869 char *name; 870 871 if ((io->flag&IOTYPE) != IOREAD) 872 errorf("funny $() command: %s", 873 snptreef((char *) 0, 32, "%R", io)); 874 shf = shf_open(name = evalstr(io->name, DOTILDE), O_RDONLY, 0, 875 SHF_MAPHI|SHF_CLEXEC); 876 if (shf == NULL) 877 errorf("%s: cannot open $() input", name); 878 xp->split = 0; /* no waitlast() */ 879 } else { 880 int ofd1, pv[2]; 881 openpipe(pv); 882 shf = shf_fdopen(pv[0], SHF_RD, (struct shf *) 0); 883 ofd1 = savefd(1, 0); /* fd 1 may be closed... */ 884 if (pv[1] != 1) { 885 ksh_dup2(pv[1], 1, false); 886 close(pv[1]); 887 } 888 execute(t, XFORK|XXCOM|XPIPEO); 889 restfd(1, ofd1); 890 startlast(); 891 xp->split = 1; /* waitlast() */ 892 } 893 894 xp->u.shf = shf; 895 return XCOM; 896 } 897 898 /* 899 * perform #pattern and %pattern substitution in ${} 900 */ 901 902 static char * 903 trimsub(str, pat, how) 904 char *str; 905 char *pat; 906 int how; 907 { 908 char *end = strchr(str, 0); 909 char *p, c; 910 911 switch (how&0xff) { /* UCHAR_MAX maybe? */ 912 case '#': /* shortest at beginning */ 913 for (p = str; p <= end; p++) { 914 c = *p; *p = '\0'; 915 if (gmatch(str, pat, false)) { 916 *p = c; 917 return p; 918 } 919 *p = c; 920 } 921 break; 922 case '#'|0x80: /* longest match at beginning */ 923 for (p = end; p >= str; p--) { 924 c = *p; *p = '\0'; 925 if (gmatch(str, pat, false)) { 926 *p = c; 927 return p; 928 } 929 *p = c; 930 } 931 break; 932 case '%': /* shortest match at end */ 933 for (p = end; p >= str; p--) { 934 if (gmatch(p, pat, false)) 935 return str_nsave(str, p - str, ATEMP); 936 } 937 break; 938 case '%'|0x80: /* longest match at end */ 939 for (p = str; p <= end; p++) { 940 if (gmatch(p, pat, false)) 941 return str_nsave(str, p - str, ATEMP); 942 } 943 break; 944 } 945 946 return str; /* no match, return string */ 947 } 948 949 /* 950 * ksh_glob 951 * Name derived from V6's /etc/glob, the program that expanded filenames. 952 */ 953 954 /* XXX cp not const 'cause slashes are temporarily replaced with nulls... */ 955 static void 956 ksh_glob(cp, wp, markdirs) 957 char *cp; 958 XPtrV *wp; 959 int markdirs; 960 { 961 int oldsize = XPsize(*wp); 962 963 if (glob_str(cp, wp, markdirs) == 0) 964 XPput(*wp, debunk(cp, cp, strlen(cp) + 1)); 965 else 966 qsortp(XPptrv(*wp) + oldsize, (size_t)(XPsize(*wp) - oldsize), 967 xstrcmp); 968 } 969 970 #define GF_NONE 0 971 #define GF_EXCHECK BIT(0) /* do existence check on file */ 972 #define GF_GLOBBED BIT(1) /* some globbing has been done */ 973 #define GF_MARKDIR BIT(2) /* add trailing / to directories */ 974 975 /* Apply file globbing to cp and store the matching files in wp. Returns 976 * the number of matches found. 977 */ 978 int 979 glob_str(cp, wp, markdirs) 980 char *cp; 981 XPtrV *wp; 982 int markdirs; 983 { 984 int oldsize = XPsize(*wp); 985 XString xs; 986 char *xp; 987 988 Xinit(xs, xp, 256, ATEMP); 989 globit(&xs, &xp, cp, wp, markdirs ? GF_MARKDIR : GF_NONE); 990 Xfree(xs, xp); 991 992 return XPsize(*wp) - oldsize; 993 } 994 995 static void 996 globit(xs, xpp, sp, wp, check) 997 XString *xs; /* dest string */ 998 char **xpp; /* ptr to dest end */ 999 char *sp; /* source path */ 1000 XPtrV *wp; /* output list */ 1001 int check; /* GF_* flags */ 1002 { 1003 char *np; /* next source component */ 1004 char *xp = *xpp; 1005 char *se; 1006 char odirsep; 1007 1008 /* This to allow long expansions to be interrupted */ 1009 intrcheck(); 1010 1011 if (sp == NULL) { /* end of source path */ 1012 /* We only need to check if the file exists if a pattern 1013 * is followed by a non-pattern (eg, foo*x/bar; no check 1014 * is needed for foo* since the match must exist) or if 1015 * any patterns were expanded and the markdirs option is set. 1016 * Symlinks make things a bit tricky... 1017 */ 1018 if ((check & GF_EXCHECK) 1019 || ((check & GF_MARKDIR) && (check & GF_GLOBBED))) 1020 { 1021 #define stat_check() (stat_done ? stat_done : \ 1022 (stat_done = stat(Xstring(*xs, xp), &statb) < 0 \ 1023 ? -1 : 1)) 1024 struct stat lstatb, statb; 1025 int stat_done = 0; /* -1: failed, 1 ok */ 1026 1027 if (lstat(Xstring(*xs, xp), &lstatb) < 0) 1028 return; 1029 /* special case for systems which strip trailing 1030 * slashes from regular files (eg, /etc/passwd/). 1031 * SunOS 4.1.3 does this... 1032 */ 1033 if ((check & GF_EXCHECK) && xp > Xstring(*xs, xp) 1034 && ISDIRSEP(xp[-1]) && !S_ISDIR(lstatb.st_mode) 1035 #ifdef S_ISLNK 1036 && (!S_ISLNK(lstatb.st_mode) 1037 || stat_check() < 0 1038 || !S_ISDIR(statb.st_mode)) 1039 #endif /* S_ISLNK */ 1040 ) 1041 return; 1042 /* Possibly tack on a trailing / if there isn't already 1043 * one and if the file is a directory or a symlink to a 1044 * directory 1045 */ 1046 if (((check & GF_MARKDIR) && (check & GF_GLOBBED)) 1047 && xp > Xstring(*xs, xp) && !ISDIRSEP(xp[-1]) 1048 && (S_ISDIR(lstatb.st_mode) 1049 #ifdef S_ISLNK 1050 || (S_ISLNK(lstatb.st_mode) 1051 && stat_check() > 0 1052 && S_ISDIR(statb.st_mode)) 1053 #endif /* S_ISLNK */ 1054 )) 1055 { 1056 *xp++ = DIRSEP; 1057 *xp = '\0'; 1058 } 1059 } 1060 # define KLUDGE_VAL 0 1061 XPput(*wp, str_nsave(Xstring(*xs, xp), Xlength(*xs, xp) 1062 + KLUDGE_VAL, ATEMP)); 1063 return; 1064 } 1065 1066 if (xp > Xstring(*xs, xp)) 1067 *xp++ = DIRSEP; 1068 while (ISDIRSEP(*sp)) { 1069 Xcheck(*xs, xp); 1070 *xp++ = *sp++; 1071 } 1072 np = ksh_strchr_dirsep(sp); 1073 if (np != NULL) { 1074 se = np; 1075 odirsep = *np; /* don't assume DIRSEP, can be multiple kinds */ 1076 *np++ = '\0'; 1077 } else { 1078 odirsep = '\0'; /* keep gcc quiet */ 1079 se = sp + strlen(sp); 1080 } 1081 1082 1083 /* Check if sp needs globbing - done to avoid pattern checks for strings 1084 * containing MAGIC characters, open ['s without the matching close ], 1085 * etc. (otherwise opendir() will be called which may fail because the 1086 * directory isn't readable - if no globbing is needed, only execute 1087 * permission should be required (as per POSIX)). 1088 */ 1089 if (!has_globbing(sp, se)) { 1090 XcheckN(*xs, xp, se - sp + 1); 1091 debunk(xp, sp, Xnleft(*xs, xp)); 1092 xp += strlen(xp); 1093 *xpp = xp; 1094 globit(xs, xpp, np, wp, check); 1095 } else { 1096 DIR *dirp; 1097 struct dirent *d; 1098 char *name; 1099 int len; 1100 int prefix_len; 1101 1102 /* xp = *xpp; copy_non_glob() may have re-alloc'd xs */ 1103 *xp = '\0'; 1104 prefix_len = Xlength(*xs, xp); 1105 dirp = ksh_opendir(prefix_len ? Xstring(*xs, xp) : "."); 1106 if (dirp == NULL) 1107 goto Nodir; 1108 while ((d = readdir(dirp)) != NULL) { 1109 name = d->d_name; 1110 if ((*name == '.' && *sp != '.') 1111 || !gmatch(name, sp, true)) 1112 continue; 1113 1114 len = NLENGTH(d) + 1; 1115 XcheckN(*xs, xp, len); 1116 memcpy(xp, name, len); 1117 *xpp = xp + len - 1; 1118 globit(xs, xpp, np, wp, 1119 (check & GF_MARKDIR) | GF_GLOBBED 1120 | (np ? GF_EXCHECK : GF_NONE)); 1121 xp = Xstring(*xs, xp) + prefix_len; 1122 } 1123 closedir(dirp); 1124 Nodir:; 1125 } 1126 1127 if (np != NULL) 1128 *--np = odirsep; 1129 } 1130 1131 #if 0 1132 /* Check if p contains something that needs globbing; if it does, 0 is 1133 * returned; if not, p is copied into xs/xp after stripping any MAGICs 1134 */ 1135 static int copy_non_glob ARGS((XString *xs, char **xpp, char *p)); 1136 static int 1137 copy_non_glob(xs, xpp, p) 1138 XString *xs; 1139 char **xpp; 1140 char *p; 1141 { 1142 char *xp; 1143 int len = strlen(p); 1144 1145 XcheckN(*xs, *xpp, len); 1146 xp = *xpp; 1147 for (; *p; p++) { 1148 if (ISMAGIC(*p)) { 1149 int c = *++p; 1150 1151 if (c == '*' || c == '?') 1152 return 0; 1153 if (*p == '[') { 1154 char *q = p + 1; 1155 1156 if (ISMAGIC(*q) && q[1] == NOT) 1157 q += 2; 1158 if (ISMAGIC(*q) && q[1] == ']') 1159 q += 2; 1160 for (; *q; q++) 1161 if (ISMAGIC(*q) && *++q == ']') 1162 return 0; 1163 /* pass a literal [ through */ 1164 } 1165 /* must be a MAGIC-MAGIC, or MAGIC-!, MAGIC--, etc. */ 1166 } 1167 *xp++ = *p; 1168 } 1169 *xp = '\0'; 1170 *xpp = xp; 1171 return 1; 1172 } 1173 #endif /* 0 */ 1174 1175 /* remove MAGIC from string */ 1176 char * 1177 debunk(dp, sp, dlen) 1178 char *dp; 1179 const char *sp; 1180 size_t dlen; 1181 { 1182 char *d; 1183 const char *s; 1184 1185 if ((s = strchr(sp, MAGIC))) { 1186 if (s - sp >= (ptrdiff_t)dlen) 1187 return dp; 1188 memcpy(dp, sp, s - sp); 1189 for (d = dp + (s - sp); *s && (d - dp < (ptrdiff_t)dlen); s++) 1190 if (!ISMAGIC(*s) || !(*++s & 0x80) 1191 || !strchr("*+?@! ", *s & 0x7f)) 1192 *d++ = *s; 1193 else { 1194 /* extended pattern operators: *+?@! */ 1195 if ((*s & 0x7f) != ' ') 1196 *d++ = *s & 0x7f; 1197 if (d - dp < (ptrdiff_t)dlen) 1198 *d++ = '('; 1199 } 1200 *d = '\0'; 1201 } else if (dp != sp) 1202 strlcpy(dp, sp, dlen); 1203 return dp; 1204 } 1205 1206 /* Check if p is an unquoted name, possibly followed by a / or :. If so 1207 * puts the expanded version in *dcp,dp and returns a pointer in p just 1208 * past the name, otherwise returns 0. 1209 */ 1210 static char * 1211 maybe_expand_tilde(p, dsp, dpp, isassign) 1212 char *p; 1213 XString *dsp; 1214 char **dpp; 1215 int isassign; 1216 { 1217 XString ts; 1218 char *dp = *dpp; 1219 char *tp, *r; 1220 1221 Xinit(ts, tp, 16, ATEMP); 1222 /* : only for DOASNTILDE form */ 1223 while (p[0] == CHAR && !ISDIRSEP(p[1]) 1224 && (!isassign || p[1] != PATHSEP)) 1225 { 1226 Xcheck(ts, tp); 1227 *tp++ = p[1]; 1228 p += 2; 1229 } 1230 *tp = '\0'; 1231 r = (p[0] == EOS || p[0] == CHAR || p[0] == CSUBST) ? tilde(Xstring(ts, tp)) : (char *) 0; 1232 Xfree(ts, tp); 1233 if (r) { 1234 while (*r) { 1235 Xcheck(*dsp, dp); 1236 if (ISMAGIC(*r)) 1237 *dp++ = MAGIC; 1238 *dp++ = *r++; 1239 } 1240 *dpp = dp; 1241 r = p; 1242 } 1243 return r; 1244 } 1245 1246 /* 1247 * tilde expansion 1248 * 1249 * based on a version by Arnold Robbins 1250 */ 1251 1252 static char * 1253 tilde(cp) 1254 char *cp; 1255 { 1256 char *dp; 1257 1258 if (cp[0] == '\0') 1259 dp = str_val(global("HOME")); 1260 else if (cp[0] == '+' && cp[1] == '\0') 1261 dp = str_val(global("PWD")); 1262 else if (cp[0] == '-' && cp[1] == '\0') 1263 dp = str_val(global("OLDPWD")); 1264 else 1265 dp = homedir(cp); 1266 /* If HOME, PWD or OLDPWD are not set, don't expand ~ */ 1267 if (dp == null) 1268 dp = (char *) 0; 1269 return dp; 1270 } 1271 1272 /* 1273 * map userid to user's home directory. 1274 * note that 4.3's getpw adds more than 6K to the shell, 1275 * and the YP version probably adds much more. 1276 * we might consider our own version of getpwnam() to keep the size down. 1277 */ 1278 1279 static char * 1280 homedir(name) 1281 char *name; 1282 { 1283 struct tbl *ap; 1284 1285 ap = tenter(&homedirs, name, hash(name)); 1286 if (!(ap->flag & ISSET)) { 1287 struct passwd *pw; 1288 size_t n; 1289 1290 pw = getpwnam(name); 1291 if (pw == NULL) 1292 return NULL; 1293 n = strlen(pw->pw_dir); 1294 if (n > 0 && '/' != pw->pw_dir[n - 1]) { 1295 ap->val.s = str_nsave(pw->pw_dir, n + 1, APERM); 1296 ap->val.s[n] = '/'; 1297 ap->val.s[n + 1] = '\0'; 1298 } else { 1299 ap->val.s = str_save(pw->pw_dir, APERM); 1300 } 1301 ap->flag |= DEFINED|ISSET|ALLOC; 1302 } 1303 return ap->val.s; 1304 } 1305 1306 #ifdef BRACE_EXPAND 1307 static void 1308 alt_expand(wp, start, exp_start, end, fdo) 1309 XPtrV *wp; 1310 char *start, *exp_start; 1311 char *end; 1312 int fdo; 1313 { 1314 int UNINITIALIZED(count); 1315 char *brace_start, *brace_end, *UNINITIALIZED(comma); 1316 char *field_start; 1317 char *p; 1318 1319 /* search for open brace */ 1320 for (p = exp_start; (p = strchr(p, MAGIC)) && p[1] != OBRACE; p += 2) 1321 ; 1322 brace_start = p; 1323 1324 /* find matching close brace, if any */ 1325 if (p) { 1326 comma = (char *) 0; 1327 count = 1; 1328 for (p += 2; *p && count; p++) { 1329 if (ISMAGIC(*p)) { 1330 if (*++p == OBRACE) 1331 count++; 1332 else if (*p == CBRACE) 1333 --count; 1334 else if (*p == ',' && count == 1) 1335 comma = p; 1336 } 1337 } 1338 } 1339 /* no valid expansions... */ 1340 if (!p || count != 0) { 1341 /* Note that given a{{b,c} we do not expand anything (this is 1342 * what at&t ksh does. This may be changed to do the {b,c} 1343 * expansion. } 1344 */ 1345 if (fdo & DOGLOB) 1346 ksh_glob(start, wp, fdo & DOMARKDIRS); 1347 else 1348 XPput(*wp, debunk(start, start, end - start)); 1349 return; 1350 } 1351 brace_end = p; 1352 if (!comma) { 1353 alt_expand(wp, start, brace_end, end, fdo); 1354 return; 1355 } 1356 1357 /* expand expression */ 1358 field_start = brace_start + 2; 1359 count = 1; 1360 for (p = brace_start + 2; p != brace_end; p++) { 1361 if (ISMAGIC(*p)) { 1362 if (*++p == OBRACE) 1363 count++; 1364 else if ((*p == CBRACE && --count == 0) 1365 || (*p == ',' && count == 1)) 1366 { 1367 char *new; 1368 int l1, l2, l3; 1369 1370 l1 = brace_start - start; 1371 l2 = (p - 1) - field_start; 1372 l3 = end - brace_end; 1373 new = (char *) alloc(l1 + l2 + l3 + 1, ATEMP); 1374 memcpy(new, start, l1); 1375 memcpy(new + l1, field_start, l2); 1376 memcpy(new + l1 + l2, brace_end, l3); 1377 new[l1 + l2 + l3] = '\0'; 1378 alt_expand(wp, new, new + l1, 1379 new + l1 + l2 + l3, fdo); 1380 field_start = p + 1; 1381 } 1382 } 1383 } 1384 return; 1385 } 1386 #endif /* BRACE_EXPAND */ 1387
Indexes created Sat Sep 20 22:09:52 GMT 2025