contrib/tcsh-6/sh.exp.c

   1 /* $Header: /p/tcsh/cvsroot/tcsh/sh.exp.c,v 3.53 2007/10/01 19:09:28 christos Exp $ */
   2 /*
   3  * sh.exp.c: Expression evaluations
   4  */
   5 /*-
   6  * Copyright (c) 1980, 1991 The Regents of the University of California.
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions
  11  * are met:
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33 #include "sh.h"
  34
  35 RCSID("$tcsh: sh.exp.c,v 3.53 2007/10/01 19:09:28 christos Exp $")
  36
  37 #include "tw.h"
  38
  39 /*
  40  * C shell
  41  */
  42
  43 #define TEXP_IGNORE 1   /* in ignore, it means to ignore value, just parse */
  44 #define TEXP_NOGLOB 2   /* in ignore, it means not to globone */
  45
  46 #define ADDOP   1
  47 #define MULOP   2
  48 #define EQOP    4
  49 #define RELOP   8
  50 #define RESTOP  16
  51 #define ANYOP   31
  52
  53 #define EQEQ    1
  54 #define GTR     2
  55 #define LSS     4
  56 #define NOTEQ   6
  57 #define EQMATCH 7
  58 #define NOTEQMATCH 8
  59
  60 static  int      sh_access      (const Char *, int);
  61 static  int      exp1           (Char ***, int);
  62 static  int      exp2x          (Char ***, int);
  63 static  int      exp2a          (Char ***, int);
  64 static  int      exp2b          (Char ***, int);
  65 static  int      exp2c          (Char ***, int);
  66 static  Char    *exp3           (Char ***, int);
  67 static  Char    *exp3a          (Char ***, int);
  68 static  Char    *exp4           (Char ***, int);
  69 static  Char    *exp5           (Char ***, int);
  70 static  Char    *exp6           (Char ***, int);
  71 static  void     evalav         (Char **);
  72 static  int      isa            (Char *, int);
  73 static  int      egetn          (Char *);
  74
  75 #ifdef EDEBUG
  76 static  void     etracc         (const char *, const Char *, Char ***);
  77 static  void     etraci         (const char *, int, Char ***);
  78 #else /* !EDEBUG */
  79 #define etracc(A, B, C) ((void)0)
  80 #define etraci(A, B, C) ((void)0)
  81 #endif /* !EDEBUG */
  82
  83 /*
  84  * shell access function according to POSIX and non POSIX
  85  * From Beto Appleton (beto@aixwiz.aix.ibm.com)
  86  */
  87 static int
  88 sh_access(const Char *fname, int mode)
  89 {
  90 #if defined(POSIX) && !defined(USE_ACCESS)
  91     struct stat     statb;
  92 #endif /* POSIX */
  93     char *name = short2str(fname);
  94
  95     if (*name == '\0')
  96         return 1;
  97
  98 #if !defined(POSIX) || defined(USE_ACCESS)
  99     return access(name, mode);
 100 #else /* POSIX */
 101
 102     /*
 103      * POSIX 1003.2-d11.2
 104      *  -r file         True if file exists and is readable.
 105      *  -w file         True if file exists and is writable.
 106      *                  True shall indicate only that the write flag is on.
 107      *                  The file shall not be writable on a read-only file
 108      *                  system even if this test indicates true.
 109      *  -x file         True if file exists and is executable.
 110      *                  True shall indicate only that the execute flag is on.
 111      *                  If file is a directory, true indicates that the file
 112      *                  can be searched.
 113      */
 114     if (mode != W_OK && mode != X_OK)
 115         return access(name, mode);
 116
 117     if (stat(name, &statb) == -1)
 118         return 1;
 119
 120     if (access(name, mode) == 0) {
 121 #ifdef S_ISDIR
 122         if (S_ISDIR(statb.st_mode) && mode == X_OK)
 123             return 0;
 124 #endif /* S_ISDIR */
 125
 126         /* root needs permission for someone */
 127         switch (mode) {
 128         case W_OK:
 129             mode = S_IWUSR | S_IWGRP | S_IWOTH;
 130             break;
 131         case X_OK:
 132             mode = S_IXUSR | S_IXGRP | S_IXOTH;
 133             break;
 134         default:
 135             abort();
 136             break;
 137         }
 138
 139     }
 140
 141     else if (euid == statb.st_uid)
 142         mode <<= 6;
 143
 144     else if (egid == statb.st_gid)
 145         mode <<= 3;
 146
 147 # ifdef NGROUPS_MAX
 148     else {
 149         /* you can be in several groups */
 150         long    n;
 151         GETGROUPS_T *groups;
 152
 153         /*
 154          * Try these things to find a positive maximum groups value:
 155          *   1) sysconf(_SC_NGROUPS_MAX)
 156          *   2) NGROUPS_MAX
 157          *   3) getgroups(0, unused)
 158          * Then allocate and scan the groups array if one of these worked.
 159          */
 160 #  if defined (HAVE_SYSCONF) && defined (_SC_NGROUPS_MAX)
 161         if ((n = sysconf(_SC_NGROUPS_MAX)) == -1)
 162 #  endif /* _SC_NGROUPS_MAX */
 163             n = NGROUPS_MAX;
 164         if (n <= 0)
 165             n = getgroups(0, (GETGROUPS_T *) NULL);
 166
 167         if (n > 0) {
 168             groups = xmalloc(n * sizeof(*groups));
 169             n = getgroups((int) n, groups);
 170             while (--n >= 0)
 171                 if (groups[n] == statb.st_gid) {
 172                     mode <<= 3;
 173                     break;
 174                 }
 175         }
 176     }
 177 # endif /* NGROUPS_MAX */
 178
 179     if (statb.st_mode & mode)
 180         return 0;
 181     else
 182         return 1;
 183 #endif /* !POSIX */
 184 }
 185
 186 int
 187 expr(Char ***vp)
 188 {
 189     return (exp0(vp, 0));
 190 }
 191
 192 int
 193 exp0(Char ***vp, int ignore)
 194 {
 195     int p1 = exp1(vp, ignore);
 196
 197     etraci("exp0 p1", p1, vp);
 198     while (**vp && eq(**vp, STRor2)) {
 199         int p2;
 200
 201         (*vp)++;
 202
 203         p2 = compat_expr ?
 204             exp0(vp, (ignore & TEXP_IGNORE) || p1) :
 205             exp1(vp, (ignore & TEXP_IGNORE) || p1);
 206         if (compat_expr || !(ignore & TEXP_IGNORE))
 207             p1 = (p1 || p2);
 208         etraci("exp0 p1", p1, vp);
 209         if (compat_expr)
 210             break;
 211     }
 212     return (p1);
 213 }
 214
 215 static int
 216 exp1(Char ***vp, int ignore)
 217 {
 218     int p1 = exp2x(vp, ignore);
 219
 220     etraci("exp1 p1", p1, vp);
 221     while (**vp && eq(**vp, STRand2)) {
 222         int p2;
 223
 224         (*vp)++;
 225         p2 = compat_expr ?
 226             exp1(vp, (ignore & TEXP_IGNORE) || !p1) :
 227             exp2x(vp, (ignore & TEXP_IGNORE) || !p1);
 228
 229         etraci("exp1 p2", p2, vp);
 230         if (compat_expr || !(ignore & TEXP_IGNORE))
 231             p1 = (p1 && p2);
 232         etraci("exp1 p1", p1, vp);
 233         if (compat_expr)
 234             break;
 235     }
 236     return (p1);
 237 }
 238
 239 static int
 240 exp2x(Char ***vp, int ignore)
 241 {
 242     int p1 = exp2a(vp, ignore);
 243
 244     etraci("exp2x p1", p1, vp);
 245     while (**vp && eq(**vp, STRor)) {
 246         int p2;
 247
 248         (*vp)++;
 249         p2 = compat_expr ?
 250             exp2x(vp, ignore) :
 251             exp2a(vp, ignore);
 252         etraci("exp2x p2", p2, vp);
 253         if (compat_expr || !(ignore & TEXP_IGNORE))
 254                 p1 = (p1 | p2);
 255         etraci("exp2x p1", p1, vp);
 256         if (compat_expr)
 257             break;
 258     }
 259     return (p1);
 260 }
 261
 262 static int
 263 exp2a(Char ***vp, int ignore)
 264 {
 265     int p1 = exp2b(vp, ignore);
 266
 267     etraci("exp2a p1", p1, vp);
 268     while (**vp && eq(**vp, STRcaret)) {
 269         int p2;
 270
 271         (*vp)++;
 272         p2 = compat_expr ?
 273             exp2a(vp, ignore) :
 274             exp2b(vp, ignore);
 275         etraci("exp2a p2", p2, vp);
 276         if (compat_expr || !(ignore & TEXP_IGNORE))
 277             p1 = (p1 ^ p2);
 278         etraci("exp2a p1", p1, vp);
 279         if (compat_expr)
 280             break;
 281     }
 282     return (p1);
 283 }
 284
 285 static int
 286 exp2b(Char ***vp, int ignore)
 287 {
 288     int p1 = exp2c(vp, ignore);
 289
 290     etraci("exp2b p1", p1, vp);
 291     while (**vp && eq(**vp, STRand)) {
 292         int p2;
 293
 294         (*vp)++;
 295         p2 = compat_expr ?
 296             exp2b(vp, ignore) :
 297             exp2c(vp, ignore);
 298         etraci("exp2b p2", p2, vp);
 299         if (compat_expr || !(ignore & TEXP_IGNORE))
 300             p1 = (p1 & p2);
 301         etraci("exp2b p1", p1, vp);
 302         if (compat_expr)
 303             break;
 304     }
 305     return (p1);
 306 }
 307
 308 static int
 309 exp2c(Char ***vp, int ignore)
 310 {
 311     Char *p1 = exp3(vp, ignore);
 312     Char *p2;
 313     int i;
 314
 315     cleanup_push(p1, xfree);
 316     etracc("exp2c p1", p1, vp);
 317     if ((i = isa(**vp, EQOP)) != 0) {
 318         (*vp)++;
 319         if (i == EQMATCH || i == NOTEQMATCH)
 320             ignore |= TEXP_NOGLOB;
 321         p2 = exp3(vp, ignore);
 322         cleanup_push(p2, xfree);
 323         etracc("exp2c p2", p2, vp);
 324         if (!(ignore & TEXP_IGNORE))
 325             switch (i) {
 326
 327             case EQEQ:
 328                 i = eq(p1, p2);
 329                 break;
 330
 331             case NOTEQ:
 332                 i = !eq(p1, p2);
 333                 break;
 334
 335             case EQMATCH:
 336                 i = Gmatch(p1, p2);
 337                 break;
 338
 339             case NOTEQMATCH:
 340                 i = !Gmatch(p1, p2);
 341                 break;
 342             }
 343         cleanup_until(p1);
 344         return (i);
 345     }
 346     i = egetn(p1);
 347     cleanup_until(p1);
 348     return (i);
 349 }
 350
 351 static Char *
 352 exp3(Char ***vp, int ignore)
 353 {
 354     Char *p1, *p2;
 355     int i;
 356
 357     p1 = exp3a(vp, ignore);
 358     etracc("exp3 p1", p1, vp);
 359     while ((i = isa(**vp, RELOP)) != 0) {
 360         (*vp)++;
 361         if (**vp && eq(**vp, STRequal))
 362             i |= 1, (*vp)++;
 363         cleanup_push(p1, xfree);
 364         p2 = compat_expr ?
 365             exp3(vp, ignore) :
 366             exp3a(vp, ignore);
 367         cleanup_push(p2, xfree);
 368         etracc("exp3 p2", p2, vp);
 369         if (!(ignore & TEXP_IGNORE))
 370             switch (i) {
 371
 372             case GTR:
 373                 i = egetn(p1) > egetn(p2);
 374                 break;
 375
 376             case GTR | 1:
 377                 i = egetn(p1) >= egetn(p2);
 378                 break;
 379
 380             case LSS:
 381                 i = egetn(p1) < egetn(p2);
 382                 break;
 383
 384             case LSS | 1:
 385                 i = egetn(p1) <= egetn(p2);
 386                 break;
 387             }
 388         cleanup_until(p1);
 389         p1 = putn(i);
 390         etracc("exp3 p1", p1, vp);
 391         if (compat_expr)
 392             break;
 393     }
 394     return (p1);
 395 }
 396
 397 static Char *
 398 exp3a(Char ***vp, int ignore)
 399 {
 400     Char *p1, *p2;
 401     const Char *op;
 402     int i;
 403
 404     p1 = exp4(vp, ignore);
 405     etracc("exp3a p1", p1, vp);
 406     op = **vp;
 407     if (op && any("<>", op[0]) && op[0] == op[1]) {
 408         (*vp)++;
 409         cleanup_push(p1, xfree);
 410         p2 = compat_expr ?
 411             exp3a(vp, ignore) :
 412             exp4(vp, ignore);
 413         cleanup_push(p2, xfree);
 414         etracc("exp3a p2", p2, vp);
 415         if (op[0] == '<')
 416             i = egetn(p1) << egetn(p2);
 417         else
 418             i = egetn(p1) >> egetn(p2);
 419         cleanup_until(p1);
 420         p1 = putn(i);
 421         etracc("exp3a p1", p1, vp);
 422     }
 423     return (p1);
 424 }
 425
 426 static Char *
 427 exp4(Char ***vp, int ignore)
 428 {
 429     Char *p1, *p2;
 430     int i = 0;
 431
 432     p1 = exp5(vp, ignore);
 433     etracc("exp4 p1", p1, vp);
 434     while (isa(**vp, ADDOP)) {
 435         const Char *op = *(*vp)++;
 436
 437         cleanup_push(p1, xfree);
 438         p2 = compat_expr ?
 439             exp4(vp, ignore) :
 440             exp5(vp, ignore);
 441         cleanup_push(p2, xfree);
 442         etracc("exp4 p2", p2, vp);
 443         if (!(ignore & TEXP_IGNORE))
 444             switch (op[0]) {
 445
 446             case '+':
 447                 i = egetn(p1) + egetn(p2);
 448                 break;
 449
 450             case '-':
 451                 i = egetn(p1) - egetn(p2);
 452                 break;
 453             }
 454         cleanup_until(p1);
 455         p1 = putn(i);
 456         etracc("exp4 p1", p1, vp);
 457         if (compat_expr)
 458             break;
 459     }
 460     return (p1);
 461 }
 462
 463 static Char *
 464 exp5(Char ***vp, int ignore)
 465 {
 466     Char *p1, *p2;
 467     int i = 0;
 468
 469     p1 = exp6(vp, ignore);
 470     etracc("exp5 p1", p1, vp);
 471
 472     while (isa(**vp, MULOP)) {
 473         const Char *op = *(*vp)++;
 474         if ((ignore & TEXP_NOGLOB) != 0) {
 475             /*
 476              * We are just trying to get the right side of
 477              * a =~ or !~ operator
 478              */
 479             xfree(p1);
 480             return Strsave(op);
 481         }
 482
 483         cleanup_push(p1, xfree);
 484         p2 = compat_expr ?
 485             exp5(vp, ignore) :
 486             exp6(vp, ignore);
 487         cleanup_push(p2, xfree);
 488         etracc("exp5 p2", p2, vp);
 489         if (!(ignore & TEXP_IGNORE))
 490             switch (op[0]) {
 491
 492             case '*':
 493                 i = egetn(p1) * egetn(p2);
 494                 break;
 495
 496             case '/':
 497                 i = egetn(p2);
 498                 if (i == 0)
 499                     stderror(ERR_DIV0);
 500                 i = egetn(p1) / i;
 501                 break;
 502
 503             case '%':
 504                 i = egetn(p2);
 505                 if (i == 0)
 506                     stderror(ERR_MOD0);
 507                 i = egetn(p1) % i;
 508                 break;
 509             }
 510         cleanup_until(p1);
 511         p1 = putn(i);
 512         etracc("exp5 p1", p1, vp);
 513         if (compat_expr)
 514             break;
 515     }
 516     return (p1);
 517 }
 518
 519 static Char *
 520 exp6(Char ***vp, int ignore)
 521 {
 522     int     ccode, i = 0;
 523     Char *cp;
 524
 525     if (**vp == 0)
 526         stderror(ERR_NAME | ERR_EXPRESSION);
 527     if (eq(**vp, STRbang)) {
 528         (*vp)++;
 529         cp = exp6(vp, ignore);
 530         cleanup_push(cp, xfree);
 531         etracc("exp6 ! cp", cp, vp);
 532         i = egetn(cp);
 533         cleanup_until(cp);
 534         return (putn(!i));
 535     }
 536     if (eq(**vp, STRtilde)) {
 537         (*vp)++;
 538         cp = exp6(vp, ignore);
 539         cleanup_push(cp, xfree);
 540         etracc("exp6 ~ cp", cp, vp);
 541         i = egetn(cp);
 542         cleanup_until(cp);
 543         return (putn(~i));
 544     }
 545     if (eq(**vp, STRLparen)) {
 546         (*vp)++;
 547         ccode = exp0(vp, ignore);
 548         etraci("exp6 () ccode", ccode, vp);
 549         if (**vp == 0 || ***vp != ')')
 550             stderror(ERR_NAME | ERR_EXPRESSION);
 551         (*vp)++;
 552         return (putn(ccode));
 553     }
 554     if (eq(**vp, STRLbrace)) {
 555         Char **v;
 556         struct command faket;
 557         Char   *fakecom[2];
 558
 559         faket.t_dtyp = NODE_COMMAND;
 560         faket.t_dflg = F_BACKQ;
 561         faket.t_dcar = faket.t_dcdr = faket.t_dspr = NULL;
 562         faket.t_dcom = fakecom;
 563         fakecom[0] = STRfakecom;
 564         fakecom[1] = NULL;
 565         (*vp)++;
 566         v = *vp;
 567         for (;;) {
 568             if (!**vp)
 569                 stderror(ERR_NAME | ERR_MISSING, '}');
 570             if (eq(*(*vp)++, STRRbrace))
 571                 break;
 572         }
 573         if (ignore & TEXP_IGNORE)
 574             return (Strsave(STRNULL));
 575         psavejob();
 576         cleanup_push(&faket, psavejob_cleanup); /* faket is only a marker */
 577         if (pfork(&faket, -1) == 0) {
 578             *--(*vp) = 0;
 579             evalav(v);
 580             exitstat();
 581         }
 582         pwait();
 583         cleanup_until(&faket);
 584         etraci("exp6 {} status", egetn(varval(STRstatus)), vp);
 585         return (putn(egetn(varval(STRstatus)) == 0));
 586     }
 587     if (isa(**vp, ANYOP))
 588         return (Strsave(STRNULL));
 589     cp = *(*vp)++;
 590 #ifdef convex
 591 # define FILETESTS "erwxfdzoplstSXLbcugkmKR"
 592 #else
 593 # define FILETESTS "erwxfdzoplstSXLbcugkmK"
 594 #endif /* convex */
 595 #define FILEVALS  "ZAMCDIUGNFPL"
 596     if (*cp == '-' && (any(FILETESTS, cp[1]) || any(FILEVALS, cp[1])))
 597         return(filetest(cp, vp, ignore));
 598     etracc("exp6 default", cp, vp);
 599     return (ignore & TEXP_NOGLOB ? Strsave(cp) : globone(cp, G_APPEND));
 600 }
 601
 602
 603 /*
 604  * Extended file tests
 605  * From: John Rowe <rowe@excc.exeter.ac.uk>
 606  */
 607 Char *
 608 filetest(Char *cp, Char ***vp, int ignore)
 609 {
 610 #ifdef convex
 611     struct cvxstat stb, *st = NULL;
 612 # define TCSH_STAT      stat64
 613 #else
 614 # define TCSH_STAT      stat
 615     struct stat stb, *st = NULL;
 616 #endif /* convex */
 617
 618 #ifdef S_IFLNK
 619 # ifdef convex
 620     struct cvxstat lstb, *lst = NULL;
 621 #  define TCSH_LSTAT lstat64
 622 # else
 623 #  define TCSH_LSTAT lstat
 624     struct stat lstb, *lst = NULL;
 625 # endif /* convex */
 626     char *filnam;
 627 #endif /* S_IFLNK */
 628
 629     int i = 0;
 630     unsigned pmask = 0xffff;
 631     int altout = 0;
 632     Char *ft = cp, *dp, *ep, *strdev, *strino, *strF, *str, valtest = '\0',
 633     *errval = STR0;
 634     char *string, string0[8];
 635     time_t footime;
 636     struct passwd *pw;
 637     struct group *gr;
 638
 639     while(any(FILETESTS, *++ft))
 640         continue;
 641
 642     if (!*ft && *(ft - 1) == 'L')
 643         --ft;
 644
 645     if (any(FILEVALS, *ft)) {
 646         valtest = *ft++;
 647         /*
 648          * Value tests return '-1' on failure as 0 is
 649          * a legitimate value for many of them.
 650          * 'F' returns ':' for compatibility.
 651          */
 652         errval = valtest == 'F' ? STRcolon : STRminus1;
 653
 654         if (valtest == 'P' && *ft >= '0' && *ft <= '7') {
 655             pmask = (char) *ft - '0';
 656             while ( *++ft >= '0' && *ft <= '7' )
 657                 pmask = 8 * pmask + ((char) *ft - '0');
 658         }
 659         if (Strcmp(ft, STRcolon) == 0 && any("AMCUGP", valtest)) {
 660             altout = 1;
 661             ++ft;
 662         }
 663     }
 664
 665     if (*ft || ft == cp + 1)
 666         stderror(ERR_NAME | ERR_FILEINQ);
 667
 668     /*
 669      * Detect missing file names by checking for operator in the file name
 670      * position.  However, if an operator name appears there, we must make
 671      * sure that there's no file by that name (e.g., "/") before announcing
 672      * an error.  Even this check isn't quite right, since it doesn't take
 673      * globbing into account.
 674      */
 675
 676     if (isa(**vp, ANYOP) && TCSH_STAT(short2str(**vp), &stb))
 677         stderror(ERR_NAME | ERR_FILENAME);
 678
 679     dp = *(*vp)++;
 680     if (ignore & TEXP_IGNORE)
 681         return (Strsave(STRNULL));
 682     ep = globone(dp, G_APPEND);
 683     cleanup_push(ep, xfree);
 684     ft = &cp[1];
 685     do
 686         switch (*ft) {
 687
 688         case 'r':
 689             i = !sh_access(ep, R_OK);
 690             break;
 691
 692         case 'w':
 693             i = !sh_access(ep, W_OK);
 694             break;
 695
 696         case 'x':
 697             i = !sh_access(ep, X_OK);
 698             break;
 699
 700         case 'X':       /* tcsh extension, name is an executable in the path
 701                          * or a tcsh builtin command
 702                          */
 703             i = find_cmd(ep, 0);
 704             break;
 705
 706         case 't':       /* SGI extension, true when file is a tty */
 707             i = isatty(atoi(short2str(ep)));
 708             break;
 709
 710         default:
 711
 712 #ifdef S_IFLNK
 713             if (tolower(*ft) == 'l') {
 714                 /*
 715                  * avoid convex compiler bug.
 716                  */
 717                 if (!lst) {
 718                     lst = &lstb;
 719                     if (TCSH_LSTAT(short2str(ep), lst) == -1) {
 720                         cleanup_until(ep);
 721                         return (Strsave(errval));
 722                     }
 723                 }
 724                 if (*ft == 'L')
 725                     st = lst;
 726             }
 727             else
 728 #endif /* S_IFLNK */
 729                 /*
 730                  * avoid convex compiler bug.
 731                  */
 732                 if (!st) {
 733                     st = &stb;
 734                     if (TCSH_STAT(short2str(ep), st) == -1) {
 735                         cleanup_until(ep);
 736                         return (Strsave(errval));
 737                     }
 738                 }
 739
 740             switch (*ft) {
 741
 742             case 'f':
 743 #ifdef S_ISREG
 744                 i = S_ISREG(st->st_mode);
 745 #else /* !S_ISREG */
 746                 i = 0;
 747 #endif /* S_ISREG */
 748                 break;
 749
 750             case 'd':
 751 #ifdef S_ISDIR
 752                 i = S_ISDIR(st->st_mode);
 753 #else /* !S_ISDIR */
 754                 i = 0;
 755 #endif /* S_ISDIR */
 756                 break;
 757
 758             case 'p':
 759 #ifdef S_ISFIFO
 760                 i = S_ISFIFO(st->st_mode);
 761 #else /* !S_ISFIFO */
 762                 i = 0;
 763 #endif /* S_ISFIFO */
 764                 break;
 765
 766             case 'm' :
 767 #ifdef S_ISOFL
 768               i = S_ISOFL(st->st_dm_mode);
 769 #else /* !S_ISOFL */
 770               i = 0;
 771 #endif /* S_ISOFL */
 772               break ;
 773
 774             case 'K' :
 775 #ifdef S_ISOFL
 776               i = stb.st_dm_key;
 777 #else /* !S_ISOFL */
 778               i = 0;
 779 #endif /* S_ISOFL */
 780               break ;
 781
 782
 783             case 'l':
 784 #ifdef S_ISLNK
 785                 i = S_ISLNK(lst->st_mode);
 786 #else /* !S_ISLNK */
 787                 i = 0;
 788 #endif /* S_ISLNK */
 789                 break;
 790
 791             case 'S':
 792 # ifdef S_ISSOCK
 793                 i = S_ISSOCK(st->st_mode);
 794 # else /* !S_ISSOCK */
 795                 i = 0;
 796 # endif /* S_ISSOCK */
 797                 break;
 798
 799             case 'b':
 800 #ifdef S_ISBLK
 801                 i = S_ISBLK(st->st_mode);
 802 #else /* !S_ISBLK */
 803                 i = 0;
 804 #endif /* S_ISBLK */
 805                 break;
 806
 807             case 'c':
 808 #ifdef S_ISCHR
 809                 i = S_ISCHR(st->st_mode);
 810 #else /* !S_ISCHR */
 811                 i = 0;
 812 #endif /* S_ISCHR */
 813                 break;
 814
 815             case 'u':
 816                 i = (S_ISUID & st->st_mode) != 0;
 817                 break;
 818
 819             case 'g':
 820                 i = (S_ISGID & st->st_mode) != 0;
 821                 break;
 822
 823             case 'k':
 824                 i = (S_ISVTX & st->st_mode) != 0;
 825                 break;
 826
 827             case 'z':
 828                 i = st->st_size == 0;
 829                 break;
 830
 831 #ifdef convex
 832             case 'R':
 833                 i = (stb.st_dmonflags & IMIGRATED) == IMIGRATED;
 834                 break;
 835 #endif /* convex */
 836
 837             case 's':
 838                 i = stb.st_size != 0;
 839                 break;
 840
 841             case 'e':
 842                 i = 1;
 843                 break;
 844
 845             case 'o':
 846                 i = st->st_uid == uid;
 847                 break;
 848
 849                 /*
 850                  * Value operators are a tcsh extension.
 851                  */
 852
 853             case 'D':
 854                 i = (int) st->st_dev;
 855                 break;
 856
 857             case 'I':
 858                 i = (int) st->st_ino;
 859                 break;
 860
 861             case 'F':
 862                 strdev = putn( (int) st->st_dev);
 863                 strino = putn( (int) st->st_ino);
 864                 strF = xmalloc((2 + Strlen(strdev) + Strlen(strino))
 865                                * sizeof(Char));
 866                 (void) Strcat(Strcat(Strcpy(strF, strdev), STRcolon), strino);
 867                 xfree(strdev);
 868                 xfree(strino);
 869                 cleanup_until(ep);
 870                 return(strF);
 871
 872             case 'L':
 873                 if ( *(ft + 1) ) {
 874                     i = 1;
 875                     break;
 876                 }
 877 #ifdef S_ISLNK
 878                 filnam = short2str(ep);
 879                 string = areadlink(filnam);
 880                 strF = string == NULL ? errval : str2short(string);
 881                 xfree(string);
 882                 cleanup_until(ep);
 883                 return(Strsave(strF));
 884
 885 #else /* !S_ISLNK */
 886                 i = 0;
 887                 break;
 888 #endif /* S_ISLNK */
 889
 890
 891             case 'N':
 892                 i = (int) st->st_nlink;
 893                 break;
 894
 895             case 'P':
 896                 string = string0 + 1;
 897                 (void) xsnprintf(string, sizeof(string0) - 1, "%o",
 898                     pmask & (unsigned int)
 899                     ((S_IRWXU|S_IRWXG|S_IRWXO|S_ISUID|S_ISGID) & st->st_mode));
 900                 if (altout && *string != '0')
 901                     *--string = '0';
 902                 cleanup_until(ep);
 903                 return(Strsave(str2short(string)));
 904
 905             case 'U':
 906                 if (altout && (pw = xgetpwuid(st->st_uid))) {
 907                     cleanup_until(ep);
 908                     return(Strsave(str2short(pw->pw_name)));
 909                 }
 910                 i = (int) st->st_uid;
 911                 break;
 912
 913             case 'G':
 914                 if (altout && (gr = xgetgrgid(st->st_gid))) {
 915                     cleanup_until(ep);
 916                     return(Strsave(str2short(gr->gr_name)));
 917                 }
 918                 i = (int) st->st_gid;
 919                 break;
 920
 921             case 'Z':
 922                 i = (int) st->st_size;
 923                 break;
 924
 925             case 'A': case 'M': case 'C':
 926                 footime = *ft == 'A' ? st->st_atime :
 927                     *ft == 'M' ? st->st_mtime : st->st_ctime;
 928                 if (altout) {
 929                     strF = str2short(ctime(&footime));
 930                     if ((str = Strchr(strF, '\n')) != NULL)
 931                         *str = (Char) '\0';
 932                     cleanup_until(ep);
 933                     return(Strsave(strF));
 934                 }
 935                 i = (int) footime;
 936                 break;
 937
 938             }
 939         }
 940     while (*++ft && i);
 941     etraci("exp6 -? i", i, vp);
 942     cleanup_until(ep);
 943     return (putn(i));
 944 }
 945
 946
 947 static void
 948 evalav(Char **v)
 949 {
 950     struct wordent paraml1;
 951     struct wordent *hp = &paraml1;
 952     struct command *t;
 953     struct wordent *wdp = hp;
 954
 955     setcopy(STRstatus, STR0, VAR_READWRITE);
 956     hp->prev = hp->next = hp;
 957     hp->word = STRNULL;
 958     while (*v) {
 959         struct wordent *new = xcalloc(1, sizeof *wdp);
 960
 961         new->prev = wdp;
 962         new->next = hp;
 963         wdp->next = new;
 964         wdp = new;
 965         wdp->word = Strsave(*v++);
 966     }
 967     hp->prev = wdp;
 968     cleanup_push(&paraml1, lex_cleanup);
 969     alias(&paraml1);
 970     t = syntax(paraml1.next, &paraml1, 0);
 971     cleanup_push(t, syntax_cleanup);
 972     if (seterr)
 973         stderror(ERR_OLD);
 974     execute(t, -1, NULL, NULL, TRUE);
 975     cleanup_until(&paraml1);
 976 }
 977
 978 static int
 979 isa(Char *cp, int what)
 980 {
 981     if (cp == 0)
 982         return ((what & RESTOP) != 0);
 983     if (*cp == '\0')
 984         return 0;
 985     if (cp[1] == 0) {
 986         if (what & ADDOP && (*cp == '+' || *cp == '-'))
 987             return (1);
 988         if (what & MULOP && (*cp == '*' || *cp == '/' || *cp == '%'))
 989             return (1);
 990         if (what & RESTOP && (*cp == '(' || *cp == ')' || *cp == '!' ||
 991                               *cp == '~' || *cp == '^' || *cp == '"'))
 992             return (1);
 993     }
 994     else if (cp[2] == 0) {
 995         if (what & RESTOP) {
 996             if (cp[0] == '|' && cp[1] == '&')
 997                 return (1);
 998             if (cp[0] == '<' && cp[1] == '<')
 999                 return (1);
1000             if (cp[0] == '>' && cp[1] == '>')
1001                 return (1);
1002         }
1003         if (what & EQOP) {
1004             if (cp[0] == '=') {
1005                 if (cp[1] == '=')
1006                     return (EQEQ);
1007                 if (cp[1] == '~')
1008                     return (EQMATCH);
1009             }
1010             else if (cp[0] == '!') {
1011                 if (cp[1] == '=')
1012                     return (NOTEQ);
1013                 if (cp[1] == '~')
1014                     return (NOTEQMATCH);
1015             }
1016         }
1017     }
1018     if (what & RELOP) {
1019         if (*cp == '<')
1020             return (LSS);
1021         if (*cp == '>')
1022             return (GTR);
1023     }
1024     return (0);
1025 }
1026
1027 static int
1028 egetn(Char *cp)
1029 {
1030     if (*cp && *cp != '-' && !Isdigit(*cp))
1031         stderror(ERR_NAME | ERR_EXPRESSION);
1032     return (getn(cp));
1033 }
1034
1035 /* Phew! */
1036
1037 #ifdef EDEBUG
1038 static void
1039 etraci(const char *str, int i, Char ***vp)
1040 {
1041     xprintf("%s=%d\t", str, i);
1042     blkpr(*vp);
1043     xputchar('\n');
1044 }
1045 static void
1046 etracc(const char *str, const Char *cp, Char ***vp)
1047 {
1048     xprintf("%s=%S\t", str, cp);
1049     blkpr(*vp);
1050     xputchar('\n');
1051 }
1052 #endif /* EDEBUG */