xref: /freebsd/contrib/tcsh/sh.exp.c (revision f0adf7f5cdd241db2f2c817683191a6ef64a4e95)
1 /* $Header: /src/pub/tcsh/sh.exp.c,v 3.40 2002/03/08 17:36:46 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("$Id: sh.exp.c,v 3.40 2002/03/08 17:36:46 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	__P((Char *, int));
61 static	int	 exp1		__P((Char ***, bool));
62 static	int	 exp2		__P((Char ***, bool));
63 static	int	 exp2a		__P((Char ***, bool));
64 static	int	 exp2b		__P((Char ***, bool));
65 static	int	 exp2c		__P((Char ***, bool));
66 static	Char 	*exp3		__P((Char ***, bool));
67 static	Char 	*exp3a		__P((Char ***, bool));
68 static	Char 	*exp4		__P((Char ***, bool));
69 static	Char 	*exp5		__P((Char ***, bool));
70 static	Char 	*exp6		__P((Char ***, bool));
71 static	void	 evalav		__P((Char **));
72 static	int	 isa		__P((Char *, int));
73 static	int	 egetn		__P((Char *));
74 
75 
76 #ifdef EDEBUG
77 static	void	 etracc		__P((char *, Char *, Char ***));
78 static	void	 etraci		__P((char *, int, Char ***));
79 #endif /* EDEBUG */
80 
81 
82 /*
83  * shell access function according to POSIX and non POSIX
84  * From Beto Appleton (beto@aixwiz.aix.ibm.com)
85  */
86 static int
87 sh_access(fname, mode)
88     Char *fname;
89     int mode;
90 {
91 #if defined(POSIX) && !defined(USE_ACCESS)
92     struct stat     statb;
93 #endif /* POSIX */
94     char *name = short2str(fname);
95 
96     if (*name == '\0')
97 	return 1;
98 
99 #if !defined(POSIX) || defined(USE_ACCESS)
100     return access(name, mode);
101 #else /* POSIX */
102 
103     /*
104      * POSIX 1003.2-d11.2
105      *	-r file		True if file exists and is readable.
106      *	-w file		True if file exists and is writable.
107      *			True shall indicate only that the write flag is on.
108      *			The file shall not be writable on a read-only file
109      *			system even if this test indicates true.
110      *	-x file		True if file exists and is executable.
111      *			True shall indicate only that the execute flag is on.
112      *			If file is a directory, true indicates that the file
113      *			can be searched.
114      */
115     if (mode != W_OK && mode != X_OK)
116 	return access(name, mode);
117 
118     if (stat(name, &statb) == -1)
119 	return 1;
120 
121     if (access(name, mode) == 0) {
122 #ifdef S_ISDIR
123 	if (S_ISDIR(statb.st_mode) && mode == X_OK)
124 	    return 0;
125 #endif /* S_ISDIR */
126 
127 	/* root needs permission for someone */
128 	switch (mode) {
129 	case W_OK:
130 	    mode = S_IWUSR | S_IWGRP | S_IWOTH;
131 	    break;
132 	case X_OK:
133 	    mode = S_IXUSR | S_IXGRP | S_IXOTH;
134 	    break;
135 	default:
136 	    abort();
137 	    break;
138 	}
139 
140     }
141 
142     else if (euid == statb.st_uid)
143 	mode <<= 6;
144 
145     else if (egid == statb.st_gid)
146 	mode <<= 3;
147 
148 # ifdef NGROUPS_MAX
149     else {
150 #  if defined(__386BSD__) || defined(BSD4_4)
151     /*
152      * These two decided that setgroup() should take an array of int's
153      * and they define _SC_NGROUPS_MAX without having sysconf
154      */
155 #   undef _SC_NGROUPS_MAX
156 #   if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__bsdi__)
157 #    define GID_T gid_t
158 #   else
159 #    define GID_T int
160 #   endif
161 #  else
162 #   define GID_T gid_t
163 #  endif /* __386BSD__ || BSD4_4 */
164 	/* you can be in several groups */
165 	long	n;
166 	GID_T	*groups;
167 
168 	/*
169 	 * Try these things to find a positive maximum groups value:
170 	 *   1) sysconf(_SC_NGROUPS_MAX)
171 	 *   2) NGROUPS_MAX
172 	 *   3) getgroups(0, unused)
173 	 * Then allocate and scan the groups array if one of these worked.
174 	 */
175 #  ifdef _SC_NGROUPS_MAX
176 	if ((n = sysconf(_SC_NGROUPS_MAX)) == -1)
177 #  endif /* _SC_NGROUPS_MAX */
178 	    n = NGROUPS_MAX;
179 	if (n <= 0)
180 	    n = getgroups(0, (GID_T *) NULL);
181 
182 	if (n > 0) {
183 	    groups = (GID_T *) xmalloc((size_t) (n * sizeof(GID_T)));
184 	    n = getgroups((int) n, groups);
185 	    while (--n >= 0)
186 		if (groups[n] == statb.st_gid) {
187 		    mode <<= 3;
188 		    break;
189 		}
190 	}
191     }
192 # endif /* NGROUPS_MAX */
193 
194     if (statb.st_mode & mode)
195 	return 0;
196     else
197 	return 1;
198 #endif /* !POSIX */
199 }
200 
201 int
202 expr(vp)
203     register Char ***vp;
204 {
205     return (exp0(vp, 0));
206 }
207 
208 int
209 exp0(vp, ignore)
210     register Char ***vp;
211     bool    ignore;
212 {
213     register int p1 = exp1(vp, ignore);
214 
215 #ifdef EDEBUG
216     etraci("exp0 p1", p1, vp);
217 #endif /* EDEBUG */
218     if (**vp && eq(**vp, STRor2)) {
219 	register int p2;
220 
221 	(*vp)++;
222 	p2 = exp0(vp, (ignore & TEXP_IGNORE) || p1);
223 #ifdef EDEBUG
224 	etraci("exp0 p2", p2, vp);
225 #endif /* EDEBUG */
226 	return (p1 || p2);
227     }
228     return (p1);
229 }
230 
231 static int
232 exp1(vp, ignore)
233     register Char ***vp;
234     bool    ignore;
235 {
236     register int p1 = exp2(vp, ignore);
237 
238 #ifdef EDEBUG
239     etraci("exp1 p1", p1, vp);
240 #endif /* EDEBUG */
241     if (**vp && eq(**vp, STRand2)) {
242 	register int p2;
243 
244 	(*vp)++;
245 	p2 = exp1(vp, (ignore & TEXP_IGNORE) || !p1);
246 #ifdef EDEBUG
247 	etraci("exp1 p2", p2, vp);
248 #endif /* EDEBUG */
249 	return (p1 && p2);
250     }
251     return (p1);
252 }
253 
254 static int
255 exp2(vp, ignore)
256     register Char ***vp;
257     bool    ignore;
258 {
259     register int p1 = exp2a(vp, ignore);
260 
261 #ifdef EDEBUG
262     etraci("exp3 p1", p1, vp);
263 #endif /* EDEBUG */
264     if (**vp && eq(**vp, STRor)) {
265 	register int p2;
266 
267 	(*vp)++;
268 	p2 = exp2(vp, ignore);
269 #ifdef EDEBUG
270 	etraci("exp3 p2", p2, vp);
271 #endif /* EDEBUG */
272 	return (p1 | p2);
273     }
274     return (p1);
275 }
276 
277 static int
278 exp2a(vp, ignore)
279     register Char ***vp;
280     bool    ignore;
281 {
282     register int p1 = exp2b(vp, ignore);
283 
284 #ifdef EDEBUG
285     etraci("exp2a p1", p1, vp);
286 #endif /* EDEBUG */
287     if (**vp && eq(**vp, STRcaret)) {
288 	register int p2;
289 
290 	(*vp)++;
291 	p2 = exp2a(vp, ignore);
292 #ifdef EDEBUG
293 	etraci("exp2a p2", p2, vp);
294 #endif /* EDEBUG */
295 	return (p1 ^ p2);
296     }
297     return (p1);
298 }
299 
300 static int
301 exp2b(vp, ignore)
302     register Char ***vp;
303     bool    ignore;
304 {
305     register int p1 = exp2c(vp, ignore);
306 
307 #ifdef EDEBUG
308     etraci("exp2b p1", p1, vp);
309 #endif /* EDEBUG */
310     if (**vp && eq(**vp, STRand)) {
311 	register int p2;
312 
313 	(*vp)++;
314 	p2 = exp2b(vp, ignore);
315 #ifdef EDEBUG
316 	etraci("exp2b p2", p2, vp);
317 #endif /* EDEBUG */
318 	return (p1 & p2);
319     }
320     return (p1);
321 }
322 
323 static int
324 exp2c(vp, ignore)
325     register Char ***vp;
326     bool    ignore;
327 {
328     register Char *p1 = exp3(vp, ignore);
329     register Char *p2;
330     register int i;
331 
332 #ifdef EDEBUG
333     etracc("exp2c p1", p1, vp);
334 #endif /* EDEBUG */
335     if ((i = isa(**vp, EQOP)) != 0) {
336 	(*vp)++;
337 	if (i == EQMATCH || i == NOTEQMATCH)
338 	    ignore |= TEXP_NOGLOB;
339 	p2 = exp3(vp, ignore);
340 #ifdef EDEBUG
341 	etracc("exp2c p2", p2, vp);
342 #endif /* EDEBUG */
343 	if (!(ignore & TEXP_IGNORE))
344 	    switch (i) {
345 
346 	    case EQEQ:
347 		i = eq(p1, p2);
348 		break;
349 
350 	    case NOTEQ:
351 		i = !eq(p1, p2);
352 		break;
353 
354 	    case EQMATCH:
355 		i = Gmatch(p1, p2);
356 		break;
357 
358 	    case NOTEQMATCH:
359 		i = !Gmatch(p1, p2);
360 		break;
361 	    }
362 	xfree((ptr_t) p1);
363 	xfree((ptr_t) p2);
364 	return (i);
365     }
366     i = egetn(p1);
367     xfree((ptr_t) p1);
368     return (i);
369 }
370 
371 static Char *
372 exp3(vp, ignore)
373     register Char ***vp;
374     bool    ignore;
375 {
376     register Char *p1, *p2;
377     register int i;
378 
379     p1 = exp3a(vp, ignore);
380 #ifdef EDEBUG
381     etracc("exp3 p1", p1, vp);
382 #endif /* EDEBUG */
383     if ((i = isa(**vp, RELOP)) != 0) {
384 	(*vp)++;
385 	if (**vp && eq(**vp, STRequal))
386 	    i |= 1, (*vp)++;
387 	p2 = exp3(vp, ignore);
388 #ifdef EDEBUG
389 	etracc("exp3 p2", p2, vp);
390 #endif /* EDEBUG */
391 	if (!(ignore & TEXP_IGNORE))
392 	    switch (i) {
393 
394 	    case GTR:
395 		i = egetn(p1) > egetn(p2);
396 		break;
397 
398 	    case GTR | 1:
399 		i = egetn(p1) >= egetn(p2);
400 		break;
401 
402 	    case LSS:
403 		i = egetn(p1) < egetn(p2);
404 		break;
405 
406 	    case LSS | 1:
407 		i = egetn(p1) <= egetn(p2);
408 		break;
409 	    }
410 	xfree((ptr_t) p1);
411 	xfree((ptr_t) p2);
412 	return (putn(i));
413     }
414     return (p1);
415 }
416 
417 static Char *
418 exp3a(vp, ignore)
419     register Char ***vp;
420     bool    ignore;
421 {
422     register Char *p1, *p2, *op;
423     register int i;
424 
425     p1 = exp4(vp, ignore);
426 #ifdef EDEBUG
427     etracc("exp3a p1", p1, vp);
428 #endif /* EDEBUG */
429     op = **vp;
430     if (op && any("<>", op[0]) && op[0] == op[1]) {
431 	(*vp)++;
432 	p2 = exp3a(vp, ignore);
433 #ifdef EDEBUG
434 	etracc("exp3a p2", p2, vp);
435 #endif /* EDEBUG */
436 	if (op[0] == '<')
437 	    i = egetn(p1) << egetn(p2);
438 	else
439 	    i = egetn(p1) >> egetn(p2);
440 	xfree((ptr_t) p1);
441 	xfree((ptr_t) p2);
442 	return (putn(i));
443     }
444     return (p1);
445 }
446 
447 static Char *
448 exp4(vp, ignore)
449     register Char ***vp;
450     bool    ignore;
451 {
452     register Char *p1, *p2;
453     register int i = 0;
454 
455     p1 = exp5(vp, ignore);
456 #ifdef EDEBUG
457     etracc("exp4 p1", p1, vp);
458 #endif /* EDEBUG */
459     if (isa(**vp, ADDOP)) {
460 	register Char *op = *(*vp)++;
461 
462 	p2 = exp4(vp, ignore);
463 #ifdef EDEBUG
464 	etracc("exp4 p2", p2, vp);
465 #endif /* EDEBUG */
466 	if (!(ignore & TEXP_IGNORE))
467 	    switch (op[0]) {
468 
469 	    case '+':
470 		i = egetn(p1) + egetn(p2);
471 		break;
472 
473 	    case '-':
474 		i = egetn(p1) - egetn(p2);
475 		break;
476 	    }
477 	xfree((ptr_t) p1);
478 	xfree((ptr_t) p2);
479 	return (putn(i));
480     }
481     return (p1);
482 }
483 
484 static Char *
485 exp5(vp, ignore)
486     register Char ***vp;
487     bool    ignore;
488 {
489     register Char *p1, *p2;
490     register int i = 0;
491 
492     p1 = exp6(vp, ignore);
493 #ifdef EDEBUG
494     etracc("exp5 p1", p1, vp);
495 #endif /* EDEBUG */
496 
497     if (isa(**vp, MULOP)) {
498 	register Char *op = *(*vp)++;
499 	if ((ignore & TEXP_NOGLOB) != 0)
500 	    /*
501 	     * We are just trying to get the right side of
502 	     * a =~ or !~ operator
503 	     */
504 	    return Strsave(op);
505 
506 	p2 = exp5(vp, ignore);
507 #ifdef EDEBUG
508 	etracc("exp5 p2", p2, vp);
509 #endif /* EDEBUG */
510 	if (!(ignore & TEXP_IGNORE))
511 	    switch (op[0]) {
512 
513 	    case '*':
514 		i = egetn(p1) * egetn(p2);
515 		break;
516 
517 	    case '/':
518 		i = egetn(p2);
519 		if (i == 0)
520 		    stderror(ERR_DIV0);
521 		i = egetn(p1) / i;
522 		break;
523 
524 	    case '%':
525 		i = egetn(p2);
526 		if (i == 0)
527 		    stderror(ERR_MOD0);
528 		i = egetn(p1) % i;
529 		break;
530 	    }
531 	xfree((ptr_t) p1);
532 	xfree((ptr_t) p2);
533 	return (putn(i));
534     }
535     return (p1);
536 }
537 
538 static Char *
539 exp6(vp, ignore)
540     register Char ***vp;
541     bool    ignore;
542 {
543     int     ccode, i = 0;
544     register Char *cp;
545 
546     if (**vp == 0)
547 	stderror(ERR_NAME | ERR_EXPRESSION);
548     if (eq(**vp, STRbang)) {
549 	(*vp)++;
550 	cp = exp6(vp, ignore);
551 #ifdef EDEBUG
552 	etracc("exp6 ! cp", cp, vp);
553 #endif /* EDEBUG */
554 	i = egetn(cp);
555 	xfree((ptr_t) cp);
556 	return (putn(!i));
557     }
558     if (eq(**vp, STRtilde)) {
559 	(*vp)++;
560 	cp = exp6(vp, ignore);
561 #ifdef EDEBUG
562 	etracc("exp6 ~ cp", cp, vp);
563 #endif /* EDEBUG */
564 	i = egetn(cp);
565 	xfree((ptr_t) cp);
566 	return (putn(~i));
567     }
568     if (eq(**vp, STRLparen)) {
569 	(*vp)++;
570 	ccode = exp0(vp, ignore);
571 #ifdef EDEBUG
572 	etraci("exp6 () ccode", ccode, vp);
573 #endif /* EDEBUG */
574 	if (*vp == 0 || **vp == 0 || ***vp != ')')
575 	    stderror(ERR_NAME | ERR_EXPRESSION);
576 	(*vp)++;
577 	return (putn(ccode));
578     }
579     if (eq(**vp, STRLbrace)) {
580 	register Char **v;
581 	struct command faket;
582 	Char   *fakecom[2];
583 
584 	faket.t_dtyp = NODE_COMMAND;
585 	faket.t_dflg = F_BACKQ;
586 	faket.t_dcar = faket.t_dcdr = faket.t_dspr = NULL;
587 	faket.t_dcom = fakecom;
588 	fakecom[0] = STRfakecom;
589 	fakecom[1] = NULL;
590 	(*vp)++;
591 	v = *vp;
592 	for (;;) {
593 	    if (!**vp)
594 		stderror(ERR_NAME | ERR_MISSING, '}');
595 	    if (eq(*(*vp)++, STRRbrace))
596 		break;
597 	}
598 	if (ignore & TEXP_IGNORE)
599 	    return (Strsave(STRNULL));
600 	psavejob();
601 	if (pfork(&faket, -1) == 0) {
602 	    *--(*vp) = 0;
603 	    evalav(v);
604 	    exitstat();
605 	}
606 	pwait();
607 	prestjob();
608 #ifdef EDEBUG
609 	etraci("exp6 {} status", egetn(varval(STRstatus)), vp);
610 #endif /* EDEBUG */
611 	return (putn(egetn(varval(STRstatus)) == 0));
612     }
613     if (isa(**vp, ANYOP))
614 	return (Strsave(STRNULL));
615     cp = *(*vp)++;
616 #ifdef convex
617 # define FILETESTS "erwxfdzoplstSXLbcugkmKR"
618 #else
619 # define FILETESTS "erwxfdzoplstSXLbcugkmK"
620 #endif /* convex */
621 #define FILEVALS  "ZAMCDIUGNFPL"
622     if (*cp == '-' && (any(FILETESTS, cp[1]) || any(FILEVALS, cp[1])))
623         return(filetest(cp, vp, ignore));
624 #ifdef EDEBUG
625     etracc("exp6 default", cp, vp);
626 #endif /* EDEBUG */
627     return (ignore & TEXP_NOGLOB ? Strsave(cp) : globone(cp, G_APPEND));
628 }
629 
630 
631 /*
632  * Extended file tests
633  * From: John Rowe <rowe@excc.exeter.ac.uk>
634  */
635 Char *
636 filetest(cp, vp, ignore)
637     Char *cp, ***vp;
638     bool ignore;
639 {
640 #ifdef convex
641     struct cvxstat stb, *st = NULL;
642 # define TCSH_STAT	stat64
643 #else
644 # define TCSH_STAT	stat
645     struct stat stb, *st = NULL;
646 #endif /* convex */
647 
648 #ifdef S_IFLNK
649 # ifdef convex
650     struct cvxstat lstb, *lst = NULL;
651 #  define TCSH_LSTAT lstat64
652 # else
653 #  define TCSH_LSTAT lstat
654     struct stat lstb, *lst = NULL;
655 # endif /* convex */
656     char *filnam;
657 #endif /* S_IFLNK */
658 
659     int i = 0;
660     unsigned pmask = 0xffff;
661     bool altout = 0;
662     Char *ft = cp, *dp, *ep, *strdev, *strino, *strF, *str, valtest = '\0',
663     *errval = STR0;
664     char *string, string0[8];
665     time_t footime;
666     struct passwd *pw;
667     struct group *gr;
668 
669     while(any(FILETESTS, *++ft))
670 	continue;
671 
672     if (!*ft && *(ft - 1) == 'L')
673 	--ft;
674 
675     if (any(FILEVALS, *ft)) {
676 	valtest = *ft++;
677 	/*
678 	 * Value tests return '-1' on failure as 0 is
679 	 * a legitimate value for many of them.
680 	 * 'F' returns ':' for compatibility.
681 	 */
682 	errval = valtest == 'F' ? STRcolon : STRminus1;
683 
684 	if (valtest == 'P' && *ft >= '0' && *ft <= '7') {
685 	    pmask = (char) *ft - '0';
686 	    while ( *++ft >= '0' && *ft <= '7' )
687 		pmask = 8 * pmask + ((char) *ft - '0');
688 	}
689 	if (Strcmp(ft, STRcolon) == 0 && any("AMCUGP", valtest)) {
690 	    altout = 1;
691 	    ++ft;
692 	}
693     }
694 
695     if (*ft || ft == cp + 1)
696 	stderror(ERR_NAME | ERR_FILEINQ);
697 
698     /*
699      * Detect missing file names by checking for operator in the file name
700      * position.  However, if an operator name appears there, we must make
701      * sure that there's no file by that name (e.g., "/") before announcing
702      * an error.  Even this check isn't quite right, since it doesn't take
703      * globbing into account.
704      */
705 
706     if (isa(**vp, ANYOP) && TCSH_STAT(short2str(**vp), &stb))
707 	stderror(ERR_NAME | ERR_FILENAME);
708 
709     dp = *(*vp)++;
710     if (ignore & TEXP_IGNORE)
711 	return (Strsave(STRNULL));
712     ep = globone(dp, G_APPEND);
713     ft = &cp[1];
714     do
715 	switch (*ft) {
716 
717 	case 'r':
718 	    i = !sh_access(ep, R_OK);
719 	    break;
720 
721 	case 'w':
722 	    i = !sh_access(ep, W_OK);
723 	    break;
724 
725 	case 'x':
726 	    i = !sh_access(ep, X_OK);
727 	    break;
728 
729 	case 'X':	/* tcsh extension, name is an executable in the path
730 			 * or a tcsh builtin command
731 			 */
732 	    i = find_cmd(ep, 0);
733 	    break;
734 
735 	case 't':	/* SGI extension, true when file is a tty */
736 	    i = isatty(atoi(short2str(ep)));
737 	    break;
738 
739 	default:
740 
741 #ifdef S_IFLNK
742 	    if (tolower(*ft) == 'l') {
743 		/*
744 		 * avoid convex compiler bug.
745 		 */
746 		if (!lst) {
747 		    lst = &lstb;
748 		    if (TCSH_LSTAT(short2str(ep), lst) == -1) {
749 			xfree((ptr_t) ep);
750 			return (Strsave(errval));
751 		    }
752 		}
753 		if (*ft == 'L')
754 		    st = lst;
755 	    }
756 	    else
757 #endif /* S_IFLNK */
758 		/*
759 		 * avoid convex compiler bug.
760 		 */
761 		if (!st) {
762 		    st = &stb;
763 		    if (TCSH_STAT(short2str(ep), st) == -1) {
764 			xfree((ptr_t) ep);
765 			return (Strsave(errval));
766 		    }
767 		}
768 
769 	    switch (*ft) {
770 
771 	    case 'f':
772 #ifdef S_ISREG
773 		i = S_ISREG(st->st_mode);
774 #else /* !S_ISREG */
775 		i = 0;
776 #endif /* S_ISREG */
777 		break;
778 
779 	    case 'd':
780 #ifdef S_ISDIR
781 		i = S_ISDIR(st->st_mode);
782 #else /* !S_ISDIR */
783 		i = 0;
784 #endif /* S_ISDIR */
785 		break;
786 
787 	    case 'p':
788 #ifdef S_ISFIFO
789 		i = S_ISFIFO(st->st_mode);
790 #else /* !S_ISFIFO */
791 		i = 0;
792 #endif /* S_ISFIFO */
793 		break;
794 
795 	    case 'm' :
796 #ifdef S_ISOFL
797 	      i = S_ISOFL(st->st_dm_mode);
798 #else /* !S_ISOFL */
799 	      i = 0;
800 #endif /* S_ISOFL */
801 	      break ;
802 
803 	    case 'K' :
804 #ifdef S_ISOFL
805 	      i = stb.st_dm_key;
806 #else /* !S_ISOFL */
807 	      i = 0;
808 #endif /* S_ISOFL */
809 	      break ;
810 
811 
812 	    case 'l':
813 #ifdef S_ISLNK
814 		i = S_ISLNK(lst->st_mode);
815 #else /* !S_ISLNK */
816 		i = 0;
817 #endif /* S_ISLNK */
818 		break;
819 
820 	    case 'S':
821 # ifdef S_ISSOCK
822 		i = S_ISSOCK(st->st_mode);
823 # else /* !S_ISSOCK */
824 		i = 0;
825 # endif /* S_ISSOCK */
826 		break;
827 
828 	    case 'b':
829 #ifdef S_ISBLK
830 		i = S_ISBLK(st->st_mode);
831 #else /* !S_ISBLK */
832 		i = 0;
833 #endif /* S_ISBLK */
834 		break;
835 
836 	    case 'c':
837 #ifdef S_ISCHR
838 		i = S_ISCHR(st->st_mode);
839 #else /* !S_ISCHR */
840 		i = 0;
841 #endif /* S_ISCHR */
842 		break;
843 
844 	    case 'u':
845 		i = (S_ISUID & st->st_mode) != 0;
846 		break;
847 
848 	    case 'g':
849 		i = (S_ISGID & st->st_mode) != 0;
850 		break;
851 
852 	    case 'k':
853 		i = (S_ISVTX & st->st_mode) != 0;
854 		break;
855 
856 	    case 'z':
857 		i = st->st_size == 0;
858 		break;
859 
860 #ifdef convex
861 	    case 'R':
862 		i = (stb.st_dmonflags & IMIGRATED) == IMIGRATED;
863 		break;
864 #endif /* convex */
865 
866 	    case 's':
867 		i = stb.st_size != 0;
868 		break;
869 
870 	    case 'e':
871 		i = 1;
872 		break;
873 
874 	    case 'o':
875 		i = st->st_uid == uid;
876 		break;
877 
878 		/*
879 		 * Value operators are a tcsh extension.
880 		 */
881 
882 	    case 'D':
883 		i = (int) st->st_dev;
884 		break;
885 
886 	    case 'I':
887 		i = (int) st->st_ino;
888 		break;
889 
890 	    case 'F':
891 		strdev = putn( (int) st->st_dev);
892 		strino = putn( (int) st->st_ino);
893 		strF = (Char *) xmalloc((size_t) (2 + Strlen(strdev) +
894 					 Strlen(strino)) * sizeof(Char));
895 		(void) Strcat(Strcat(Strcpy(strF, strdev), STRcolon), strino);
896 		xfree((ptr_t) strdev);
897 		xfree((ptr_t) strino);
898 		xfree((ptr_t) ep);
899 		return(strF);
900 
901 	    case 'L':
902 		if ( *(ft + 1) ) {
903 		    i = 1;
904 		    break;
905 		}
906 #ifdef S_ISLNK
907 		filnam = short2str(ep);
908 #ifdef PATH_MAX
909 # define MY_PATH_MAX PATH_MAX
910 #else /* !PATH_MAX */
911 /*
912  * I can't think of any more sensible alterative; readlink doesn't give
913  * us an errno if the buffer isn't large enough :-(
914  */
915 # define MY_PATH_MAX  2048
916 #endif /* PATH_MAX */
917 		i = readlink(filnam, string = (char *)
918 		      xmalloc((size_t) (1 + MY_PATH_MAX) * sizeof(char)),
919 			MY_PATH_MAX);
920 		if (i >= 0 && i <= MY_PATH_MAX)
921 		    string[i] = '\0'; /* readlink does not null terminate */
922 		strF = (i < 0) ? errval : str2short(string);
923 		xfree((ptr_t) string);
924 		xfree((ptr_t) ep);
925 		return(Strsave(strF));
926 
927 #else /* !S_ISLNK */
928 		i = 0;
929 		break;
930 #endif /* S_ISLNK */
931 
932 
933 	    case 'N':
934 		i = (int) st->st_nlink;
935 		break;
936 
937 	    case 'P':
938 		string = string0 + 1;
939 		(void) xsnprintf(string, sizeof(string0) - 1, "%o",
940 		    pmask & (unsigned int)
941 		    ((S_IRWXU|S_IRWXG|S_IRWXO|S_ISUID|S_ISGID) & st->st_mode));
942 		if (altout && *string != '0')
943 		    *--string = '0';
944 		xfree((ptr_t) ep);
945 		return(Strsave(str2short(string)));
946 
947 	    case 'U':
948 		if (altout && (pw = getpwuid(st->st_uid))) {
949 		    xfree((ptr_t) ep);
950 		    return(Strsave(str2short(pw->pw_name)));
951 		}
952 		i = (int) st->st_uid;
953 		break;
954 
955 	    case 'G':
956 		if ( altout && (gr = getgrgid(st->st_gid))) {
957 		    xfree((ptr_t) ep);
958 		    return(Strsave(str2short(gr->gr_name)));
959 		}
960 		i = (int) st->st_gid;
961 		break;
962 
963 	    case 'Z':
964 		i = (int) st->st_size;
965 		break;
966 
967 	    case 'A': case 'M': case 'C':
968 		footime = *ft == 'A' ? st->st_atime :
969 		    *ft == 'M' ? st->st_mtime : st->st_ctime;
970 		if (altout) {
971 		    strF = str2short(ctime(&footime));
972 		    if ((str = Strchr(strF, '\n')) != NULL)
973 			*str = (Char) '\0';
974 		    xfree((ptr_t) ep);
975 		    return(Strsave(strF));
976 		}
977 		i = (int) footime;
978 		break;
979 
980 	    }
981 	}
982     while (*++ft && i);
983 #ifdef EDEBUG
984     etraci("exp6 -? i", i, vp);
985 #endif /* EDEBUG */
986     xfree((ptr_t) ep);
987     return (putn(i));
988 }
989 
990 
991 static void
992 evalav(v)
993     register Char **v;
994 {
995     struct wordent paraml1;
996     register struct wordent *hp = &paraml1;
997     struct command *t;
998     register struct wordent *wdp = hp;
999 
1000     set(STRstatus, Strsave(STR0), VAR_READWRITE);
1001     hp->prev = hp->next = hp;
1002     hp->word = STRNULL;
1003     while (*v) {
1004 	register struct wordent *new =
1005 	(struct wordent *) xcalloc(1, sizeof *wdp);
1006 
1007 	new->prev = wdp;
1008 	new->next = hp;
1009 	wdp->next = new;
1010 	wdp = new;
1011 	wdp->word = Strsave(*v++);
1012     }
1013     hp->prev = wdp;
1014     alias(&paraml1);
1015     t = syntax(paraml1.next, &paraml1, 0);
1016     if (seterr)
1017 	stderror(ERR_OLD);
1018     execute(t, -1, NULL, NULL, TRUE);
1019     freelex(&paraml1), freesyn(t);
1020 }
1021 
1022 static int
1023 isa(cp, what)
1024     register Char *cp;
1025     register int what;
1026 {
1027     if (cp == 0)
1028 	return ((what & RESTOP) != 0);
1029     if (*cp == '\0')
1030     	return 0;
1031     if (cp[1] == 0) {
1032 	if (what & ADDOP && (*cp == '+' || *cp == '-'))
1033 	    return (1);
1034 	if (what & MULOP && (*cp == '*' || *cp == '/' || *cp == '%'))
1035 	    return (1);
1036 	if (what & RESTOP && (*cp == '(' || *cp == ')' || *cp == '!' ||
1037 			      *cp == '~' || *cp == '^' || *cp == '"'))
1038 	    return (1);
1039     }
1040     else if (cp[2] == 0) {
1041 	if (what & RESTOP) {
1042 	    if (cp[0] == '|' && cp[1] == '&')
1043 		return (1);
1044 	    if (cp[0] == '<' && cp[1] == '<')
1045 		return (1);
1046 	    if (cp[0] == '>' && cp[1] == '>')
1047 		return (1);
1048 	}
1049 	if (what & EQOP) {
1050 	    if (cp[0] == '=') {
1051 		if (cp[1] == '=')
1052 		    return (EQEQ);
1053 		if (cp[1] == '~')
1054 		    return (EQMATCH);
1055 	    }
1056 	    else if (cp[0] == '!') {
1057 		if (cp[1] == '=')
1058 		    return (NOTEQ);
1059 		if (cp[1] == '~')
1060 		    return (NOTEQMATCH);
1061 	    }
1062 	}
1063     }
1064     if (what & RELOP) {
1065 	if (*cp == '<')
1066 	    return (LSS);
1067 	if (*cp == '>')
1068 	    return (GTR);
1069     }
1070     return (0);
1071 }
1072 
1073 static int
1074 egetn(cp)
1075     register Char *cp;
1076 {
1077     if (*cp && *cp != '-' && !Isdigit(*cp))
1078 	stderror(ERR_NAME | ERR_EXPRESSION);
1079     return (getn(cp));
1080 }
1081 
1082 /* Phew! */
1083 
1084 #ifdef EDEBUG
1085 static void
1086 etraci(str, i, vp)
1087     char   *str;
1088     int     i;
1089     Char ***vp;
1090 {
1091     xprintf("%s=%d\t", str, i);
1092     blkpr(*vp);
1093     xputchar('\n');
1094 }
1095 static void
1096 etracc(str, cp, vp)
1097     char   *str;
1098     Char   *cp;
1099     Char ***vp;
1100 {
1101     xprintf("%s=%s\t", str, cp);
1102     blkpr(*vp);
1103     xputchar('\n');
1104 }
1105 #endif /* EDEBUG */
1106