xref: /dragonfly/contrib/tcsh-6/sh.exp.c (revision b97fef05)
1 /*
2  * sh.exp.c: Expression evaluations
3  */
4 /*-
5  * Copyright (c) 1980, 1991 The Regents of the University of California.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 #include "sh.h"
33 #include "tw.h"
34 
35 /*
36  * C shell
37  */
38 
39 #define	ADDOP	1
40 #define	MULOP	2
41 #define	EQOP	4
42 #define	RELOP	8
43 #define	RESTOP	16
44 #define	ANYOP	31
45 
46 #define	EQEQ	1
47 #define	GTR	2
48 #define	LSS	4
49 #define	NOTEQ	6
50 #define EQMATCH 7
51 #define NOTEQMATCH 8
52 
53 static	int	   sh_access	(const Char *, int);
54 static	tcsh_number_t  exp1		(Char ***, int);
55 static	tcsh_number_t  exp2x	(Char ***, int);
56 static	tcsh_number_t  exp2a	(Char ***, int);
57 static	tcsh_number_t  exp2b	(Char ***, int);
58 static	tcsh_number_t  exp2c	(Char ***, int);
59 static	Char 	  *exp3		(Char ***, int);
60 static	Char 	  *exp3a	(Char ***, int);
61 static	Char 	  *exp4		(Char ***, int);
62 static	Char 	  *exp5		(Char ***, int);
63 static	Char 	  *exp6		(Char ***, int);
64 static	void	   evalav	(Char **);
65 static	int	   isa		(Char *, int);
66 static	tcsh_number_t  egetn	(const Char *);
67 
68 #ifdef EDEBUG
69 static	void	   etracc	(const char *, const Char *, Char ***);
70 static	void	   etraci	(const char *, tcsh_number_t, Char ***);
71 #else /* !EDEBUG */
72 #define etracc(A, B, C) ((void)0)
73 #define etraci(A, B, C) ((void)0)
74 #endif /* !EDEBUG */
75 
76 /*
77  * shell access function according to POSIX and non POSIX
78  * From Beto Appleton (beto@aixwiz.aix.ibm.com)
79  */
80 static int
81 sh_access(const Char *fname, int mode)
82 {
83 #if defined(POSIX) && !defined(USE_ACCESS)
84     struct stat     statb;
85 #endif /* POSIX */
86     char *name = short2str(fname);
87 
88     if (*name == '\0')
89 	return 1;
90 
91 #if !defined(POSIX) || defined(USE_ACCESS)
92     return access(name, mode);
93 #else /* POSIX */
94 
95     /*
96      * POSIX 1003.2-d11.2
97      *	-r file		True if file exists and is readable.
98      *	-w file		True if file exists and is writable.
99      *			True shall indicate only that the write flag is on.
100      *			The file shall not be writable on a read-only file
101      *			system even if this test indicates true.
102      *	-x file		True if file exists and is executable.
103      *			True shall indicate only that the execute flag is on.
104      *			If file is a directory, true indicates that the file
105      *			can be searched.
106      */
107     if (mode != W_OK && mode != X_OK)
108 	return access(name, mode);
109 
110     if (stat(name, &statb) == -1)
111 	return 1;
112 
113     if (access(name, mode) == 0) {
114 #ifdef S_ISDIR
115 	if (S_ISDIR(statb.st_mode) && mode == X_OK)
116 	    return 0;
117 #endif /* S_ISDIR */
118 
119 	/* root needs permission for someone */
120 	switch (mode) {
121 	case W_OK:
122 	    mode = S_IWUSR | S_IWGRP | S_IWOTH;
123 	    break;
124 	case X_OK:
125 	    mode = S_IXUSR | S_IXGRP | S_IXOTH;
126 	    break;
127 	default:
128 	    abort();
129 	    break;
130 	}
131 
132     }
133 
134     else if (euid == statb.st_uid)
135 	mode <<= 6;
136 
137     else if (egid == statb.st_gid)
138 	mode <<= 3;
139 
140 # ifdef NGROUPS_MAX
141     else {
142 	/* you can be in several groups */
143 	long	n;
144 	GETGROUPS_T *groups;
145 
146 	/*
147 	 * Try these things to find a positive maximum groups value:
148 	 *   1) sysconf(_SC_NGROUPS_MAX)
149 	 *   2) NGROUPS_MAX
150 	 *   3) getgroups(0, unused)
151 	 * Then allocate and scan the groups array if one of these worked.
152 	 */
153 #  if defined (HAVE_SYSCONF) && defined (_SC_NGROUPS_MAX)
154 	if ((n = sysconf(_SC_NGROUPS_MAX)) == -1)
155 #  endif /* _SC_NGROUPS_MAX */
156 	    n = NGROUPS_MAX;
157 	if (n <= 0)
158 	    n = getgroups(0, (GETGROUPS_T *) NULL);
159 
160 	if (n > 0) {
161 	    groups = xmalloc(n * sizeof(*groups));
162 	    n = getgroups((int) n, groups);
163 	    while (--n >= 0)
164 		if (groups[n] == statb.st_gid) {
165 		    mode <<= 3;
166 		    break;
167 		}
168 	    xfree(groups);
169 	}
170     }
171 # endif /* NGROUPS_MAX */
172 
173     if (statb.st_mode & mode)
174 	return 0;
175     else
176 	return 1;
177 #endif /* !POSIX */
178 }
179 
180 tcsh_number_t
181 expr(Char ***vp)
182 {
183     return (exp0(vp, 0));
184 }
185 
186 tcsh_number_t
187 exp0(Char ***vp, int ignore)
188 {
189     tcsh_number_t p1 = exp1(vp, ignore);
190 
191     etraci("exp0 p1", p1, vp);
192     while (**vp && eq(**vp, STRor2)) {
193 	int p2;
194 
195 	(*vp)++;
196 
197 	p2 = compat_expr ?
198 	    exp0(vp, (ignore & TEXP_IGNORE) || p1) :
199 	    exp1(vp, (ignore & TEXP_IGNORE) || p1);
200 	if (compat_expr || !(ignore & TEXP_IGNORE))
201 	    p1 = (p1 || p2);
202 	etraci("exp0 p1", p1, vp);
203 	if (compat_expr)
204 	    break;
205     }
206     return (p1);
207 }
208 
209 static tcsh_number_t
210 exp1(Char ***vp, int ignore)
211 {
212     tcsh_number_t p1 = exp2x(vp, ignore);
213 
214     etraci("exp1 p1", p1, vp);
215     while (**vp && eq(**vp, STRand2)) {
216 	tcsh_number_t p2;
217 
218 	(*vp)++;
219 	p2 = compat_expr ?
220 	    exp1(vp, (ignore & TEXP_IGNORE) || !p1) :
221 	    exp2x(vp, (ignore & TEXP_IGNORE) || !p1);
222 
223 	etraci("exp1 p2", p2, vp);
224 	if (compat_expr || !(ignore & TEXP_IGNORE))
225 	    p1 = (p1 && p2);
226 	etraci("exp1 p1", p1, vp);
227 	if (compat_expr)
228 	    break;
229     }
230     return (p1);
231 }
232 
233 static tcsh_number_t
234 exp2x(Char ***vp, int ignore)
235 {
236     tcsh_number_t p1 = exp2a(vp, ignore);
237 
238     etraci("exp2x p1", p1, vp);
239     while (**vp && eq(**vp, STRor)) {
240 	tcsh_number_t p2;
241 
242 	(*vp)++;
243 	p2 = compat_expr ?
244 	    exp2x(vp, ignore) :
245 	    exp2a(vp, ignore);
246 	etraci("exp2x p2", p2, vp);
247 	if (compat_expr || !(ignore & TEXP_IGNORE))
248 		p1 = (p1 | p2);
249 	etraci("exp2x p1", p1, vp);
250 	if (compat_expr)
251 	    break;
252     }
253     return (p1);
254 }
255 
256 static tcsh_number_t
257 exp2a(Char ***vp, int ignore)
258 {
259     tcsh_number_t p1 = exp2b(vp, ignore);
260 
261     etraci("exp2a p1", p1, vp);
262     while (**vp && eq(**vp, STRcaret)) {
263 	tcsh_number_t p2;
264 
265 	(*vp)++;
266 	p2 = compat_expr ?
267 	    exp2a(vp, ignore) :
268 	    exp2b(vp, ignore);
269 	etraci("exp2a p2", p2, vp);
270 	if (compat_expr || !(ignore & TEXP_IGNORE))
271 	    p1 = (p1 ^ p2);
272 	etraci("exp2a p1", p1, vp);
273 	if (compat_expr)
274 	    break;
275     }
276     return (p1);
277 }
278 
279 static tcsh_number_t
280 exp2b(Char ***vp, int ignore)
281 {
282     tcsh_number_t p1 = exp2c(vp, ignore);
283 
284     etraci("exp2b p1", p1, vp);
285     while (**vp && eq(**vp, STRand)) {
286 	tcsh_number_t p2;
287 
288 	(*vp)++;
289 	p2 = compat_expr ?
290 	    exp2b(vp, ignore) :
291 	    exp2c(vp, ignore);
292 	etraci("exp2b p2", p2, vp);
293 	if (compat_expr || !(ignore & TEXP_IGNORE))
294 	    p1 = (p1 & p2);
295 	etraci("exp2b p1", p1, vp);
296 	if (compat_expr)
297 	    break;
298     }
299     return (p1);
300 }
301 
302 static tcsh_number_t
303 exp2c(Char ***vp, int ignore)
304 {
305     Char *p1 = exp3(vp, ignore);
306     Char *p2;
307     tcsh_number_t i;
308 
309     cleanup_push(p1, xfree);
310     etracc("exp2c p1", p1, vp);
311     if ((i = isa(**vp, EQOP)) != 0) {
312 	(*vp)++;
313 	if (i == EQMATCH || i == NOTEQMATCH)
314 	    ignore |= TEXP_NOGLOB;
315 	p2 = exp3(vp, ignore);
316 	cleanup_push(p2, xfree);
317 	etracc("exp2c p2", p2, vp);
318 	if (!(ignore & TEXP_IGNORE))
319 	    switch ((int)i) {
320 
321 	    case EQEQ:
322 		i = eq(p1, p2);
323 		break;
324 
325 	    case NOTEQ:
326 		i = !eq(p1, p2);
327 		break;
328 
329 	    case EQMATCH:
330 		i = Gmatch(p1, p2);
331 		break;
332 
333 	    case NOTEQMATCH:
334 		i = !Gmatch(p1, p2);
335 		break;
336 	    }
337 	cleanup_until(p1);
338 	return (i);
339     }
340     i = egetn(p1);
341     cleanup_until(p1);
342     return (i);
343 }
344 
345 static Char *
346 exp3(Char ***vp, int ignore)
347 {
348     Char *p1, *p2;
349     tcsh_number_t i;
350 
351     p1 = exp3a(vp, ignore);
352     etracc("exp3 p1", p1, vp);
353     while ((i = isa(**vp, RELOP)) != 0) {
354 	(*vp)++;
355 	if (**vp && eq(**vp, STRequal))
356 	    i |= 1, (*vp)++;
357 	cleanup_push(p1, xfree);
358 	p2 = compat_expr ?
359 	    exp3(vp, ignore) :
360 	    exp3a(vp, ignore);
361 	cleanup_push(p2, xfree);
362 	etracc("exp3 p2", p2, vp);
363 	if (!(ignore & TEXP_IGNORE))
364 	    switch ((int)i) {
365 
366 	    case GTR:
367 		i = egetn(p1) > egetn(p2);
368 		break;
369 
370 	    case GTR | 1:
371 		i = egetn(p1) >= egetn(p2);
372 		break;
373 
374 	    case LSS:
375 		i = egetn(p1) < egetn(p2);
376 		break;
377 
378 	    case LSS | 1:
379 		i = egetn(p1) <= egetn(p2);
380 		break;
381 	    }
382 	cleanup_until(p1);
383 	p1 = putn(i);
384 	etracc("exp3 p1", p1, vp);
385 	if (compat_expr)
386 	    break;
387     }
388     return (p1);
389 }
390 
391 static Char *
392 exp3a(Char ***vp, int ignore)
393 {
394     Char *p1, *p2;
395     const Char *op;
396     tcsh_number_t i;
397 
398     p1 = exp4(vp, ignore);
399     etracc("exp3a p1", p1, vp);
400     op = **vp;
401     if (op && any("<>", op[0]) && op[0] == op[1]) {
402 	(*vp)++;
403 	cleanup_push(p1, xfree);
404 	p2 = compat_expr ?
405 	    exp3a(vp, ignore) :
406 	    exp4(vp, ignore);
407 	cleanup_push(p2, xfree);
408 	etracc("exp3a p2", p2, vp);
409 	if (op[0] == '<')
410 	    i = egetn(p1) << egetn(p2);
411 	else
412 	    i = egetn(p1) >> egetn(p2);
413 	cleanup_until(p1);
414 	p1 = putn(i);
415 	etracc("exp3a p1", p1, vp);
416     }
417     return (p1);
418 }
419 
420 static Char *
421 exp4(Char ***vp, int ignore)
422 {
423     Char *p1, *p2;
424     tcsh_number_t i = 0;
425 
426     p1 = exp5(vp, ignore);
427     etracc("exp4 p1", p1, vp);
428     while (isa(**vp, ADDOP)) {
429 	const Char *op = *(*vp)++;
430 
431 	cleanup_push(p1, xfree);
432 	p2 = compat_expr ?
433 	    exp4(vp, ignore) :
434 	    exp5(vp, ignore);
435 	cleanup_push(p2, xfree);
436 	etracc("exp4 p2", p2, vp);
437 	if (!(ignore & TEXP_IGNORE))
438 	    switch (op[0]) {
439 
440 	    case '+':
441 		i = egetn(p1) + egetn(p2);
442 		break;
443 
444 	    case '-':
445 		i = egetn(p1) - egetn(p2);
446 		break;
447 	    }
448 	cleanup_until(p1);
449 	p1 = putn(i);
450 	etracc("exp4 p1", p1, vp);
451 	if (compat_expr)
452 	    break;
453     }
454     return (p1);
455 }
456 
457 static Char *
458 exp5(Char ***vp, int ignore)
459 {
460     Char *p1, *p2;
461     tcsh_number_t i = 0;
462 
463     p1 = exp6(vp, ignore);
464     etracc("exp5 p1", p1, vp);
465 
466     while (isa(**vp, MULOP)) {
467 	const Char *op = *(*vp)++;
468 	if ((ignore & TEXP_NOGLOB) != 0) {
469 	    /*
470 	     * We are just trying to get the right side of
471 	     * a =~ or !~ operator
472 	     */
473 	    xfree(p1);
474 	    return Strsave(op);
475 	}
476 
477 	cleanup_push(p1, xfree);
478 	p2 = compat_expr ?
479 	    exp5(vp, ignore) :
480 	    exp6(vp, ignore);
481 	cleanup_push(p2, xfree);
482 	etracc("exp5 p2", p2, vp);
483 	if (!(ignore & TEXP_IGNORE))
484 	    switch (op[0]) {
485 
486 	    case '*':
487 		i = egetn(p1) * egetn(p2);
488 		break;
489 
490 	    case '/':
491 		i = egetn(p2);
492 		if (i == 0)
493 		    stderror(ERR_DIV0);
494 		i = egetn(p1) / i;
495 		break;
496 
497 	    case '%':
498 		i = egetn(p2);
499 		if (i == 0)
500 		    stderror(ERR_MOD0);
501 		i = egetn(p1) % i;
502 		break;
503 	    }
504 	cleanup_until(p1);
505 	p1 = putn(i);
506 	etracc("exp5 p1", p1, vp);
507 	if (compat_expr)
508 	    break;
509     }
510     return (p1);
511 }
512 
513 static Char *
514 exp6(Char ***vp, int ignore)
515 {
516     tcsh_number_t ccode;
517     tcsh_number_t i = 0;
518     Char *cp;
519 
520     if (**vp == 0)
521 	stderror(ERR_NAME | ERR_EXPRESSION);
522     if (eq(**vp, STRbang)) {
523 	(*vp)++;
524 	cp = exp6(vp, ignore);
525 	cleanup_push(cp, xfree);
526 	etracc("exp6 ! cp", cp, vp);
527 	i = egetn(cp);
528 	cleanup_until(cp);
529 	return (putn(!i));
530     }
531     if (eq(**vp, STRtilde)) {
532 	(*vp)++;
533 	cp = exp6(vp, ignore);
534 	cleanup_push(cp, xfree);
535 	etracc("exp6 ~ cp", cp, vp);
536 	i = egetn(cp);
537 	cleanup_until(cp);
538 	return (putn(~i));
539     }
540     if (eq(**vp, STRLparen)) {
541 	(*vp)++;
542 	ccode = exp0(vp, ignore);
543 	etraci("exp6 () ccode", ccode, vp);
544 	if (**vp == 0 || ***vp != ')')
545 	    stderror(ERR_NAME | ERR_EXPRESSION);
546 	(*vp)++;
547 	return (putn(ccode));
548     }
549     if (eq(**vp, STRLbrace)) {
550 	Char **v;
551 	struct command faket;
552 	Char   *fakecom[2];
553 
554 	faket.t_dtyp = NODE_COMMAND;
555 	faket.t_dflg = F_BACKQ;
556 	faket.t_dcar = faket.t_dcdr = faket.t_dspr = NULL;
557 	faket.t_dcom = fakecom;
558 	fakecom[0] = STRfakecom;
559 	fakecom[1] = NULL;
560 	(*vp)++;
561 	v = *vp;
562 	for (;;) {
563 	    if (!**vp)
564 		stderror(ERR_NAME | ERR_MISSING, '}');
565 	    if (eq(*(*vp)++, STRRbrace))
566 		break;
567 	}
568 	if (ignore & TEXP_IGNORE)
569 	    return (Strsave(STRNULL));
570 	psavejob();
571 	cleanup_push(&faket, psavejob_cleanup); /* faket is only a marker */
572 	if (pfork(&faket, -1) == 0) {
573 	    *--(*vp) = 0;
574 	    evalav(v);
575 	    exitstat();
576 	}
577 	pwait();
578 	cleanup_until(&faket);
579 	etraci("exp6 {} status", getstatus(), vp);
580 	return putn(getstatus() == 0);
581     }
582     if (isa(**vp, ANYOP))
583 	return (Strsave(STRNULL));
584     cp = *(*vp)++;
585 #ifdef convex
586 # define FILETESTS "erwxfdzoplstSXLbcugkmKR"
587 #else
588 # define FILETESTS "erwxfdzoplstSXLbcugkmK"
589 #endif /* convex */
590 #define FILEVALS  "ZAMCDIUGNFPL"
591     if (*cp == '-' && (any(FILETESTS, cp[1]) || any(FILEVALS, cp[1])))
592         return(filetest(cp, vp, ignore));
593     etracc("exp6 default", cp, vp);
594     return (ignore & TEXP_NOGLOB ? Strsave(cp) : globone(cp, G_APPEND));
595 }
596 
597 
598 /*
599  * Extended file tests
600  * From: John Rowe <rowe@excc.exeter.ac.uk>
601  */
602 Char *
603 filetest(Char *cp, Char ***vp, int ignore)
604 {
605 #ifdef convex
606     struct cvxstat stb, *st = NULL;
607 # define TCSH_STAT	stat64
608 #else
609 # define TCSH_STAT	stat
610     struct stat stb, *st = NULL;
611 #endif /* convex */
612 
613 #ifdef S_IFLNK
614 # ifdef convex
615     struct cvxstat lstb, *lst = NULL;
616 #  define TCSH_LSTAT lstat64
617 # else
618 #  define TCSH_LSTAT lstat
619     struct stat lstb, *lst = NULL;
620 # endif /* convex */
621     char *filnam;
622 #endif /* S_IFLNK */
623 
624     tcsh_number_t i = 0;
625     unsigned pmask = 0xffff;
626     int altout = 0;
627     Char *ft = cp, *dp, *ep, *strdev, *strino, *strF, *str, valtest = '\0',
628     *errval = STR0;
629     char *string, string0[22 + MB_LEN_MAX + 1];	/* space for 64 bit octal */
630     time_t footime;
631     struct passwd *pw;
632     struct group *gr;
633 
634     while (any(FILETESTS, *++ft))
635 	continue;
636 
637     if (!*ft && *(ft - 1) == 'L')
638 	--ft;
639 
640     if (any(FILEVALS, *ft)) {
641 	valtest = *ft++;
642 	/*
643 	 * Value tests return '-1' on failure as 0 is
644 	 * a legitimate value for many of them.
645 	 * 'F' returns ':' for compatibility.
646 	 */
647 	errval = valtest == 'F' ? STRcolon : STRminus1;
648 
649 	if (valtest == 'P' && *ft >= '0' && *ft <= '7') {
650 	    pmask = (char) *ft - '0';
651 	    while ( *++ft >= '0' && *ft <= '7' )
652 		pmask = 8 * pmask + ((char) *ft - '0');
653 	}
654 	if (Strcmp(ft, STRcolon) == 0 && any("AMCUGP", valtest)) {
655 	    altout = 1;
656 	    ++ft;
657 	}
658     }
659 
660     if (*ft || ft == cp + 1)
661 	stderror(ERR_NAME | ERR_FILEINQ);
662 
663     /*
664      * Detect missing file names by checking for operator in the file name
665      * position.  However, if an operator name appears there, we must make
666      * sure that there's no file by that name (e.g., "/") before announcing
667      * an error.  Even this check isn't quite right, since it doesn't take
668      * globbing into account.
669      */
670 
671     if (isa(**vp, ANYOP) && TCSH_STAT(short2str(**vp), &stb))
672 	stderror(ERR_NAME | ERR_FILENAME);
673 
674     dp = *(*vp)++;
675     if (ignore & TEXP_IGNORE)
676 	return (Strsave(STRNULL));
677     if ((ignore & TEXP_NOGLOB) == 0) {
678 	ep = globone(dp, G_APPEND);
679     } else {
680 	ep = Strsave(dp);
681     }
682     cleanup_push(ep, xfree);
683     ft = &cp[1];
684     do
685 	switch (*ft) {
686 
687 	case 'r':
688 	    i = !sh_access(ep, R_OK);
689 	    break;
690 
691 	case 'w':
692 	    i = !sh_access(ep, W_OK);
693 	    break;
694 
695 	case 'x':
696 	    i = !sh_access(ep, X_OK);
697 	    break;
698 
699 	case 'X':	/* tcsh extension, name is an executable in the path
700 			 * or a tcsh builtin command
701 			 */
702 	    i = find_cmd(ep, 0);
703 	    break;
704 
705 	case 't':	/* SGI extension, true when file is a tty */
706 	    i = isatty(atoi(short2str(ep)));
707 	    break;
708 
709 	default:
710 
711 #ifdef S_IFLNK
712 	    if (tolower(*ft) == 'l') {
713 		/*
714 		 * avoid convex compiler bug.
715 		 */
716 		if (!lst) {
717 		    lst = &lstb;
718 		    if (TCSH_LSTAT(short2str(ep), lst) == -1) {
719 			cleanup_until(ep);
720 			return (Strsave(errval));
721 		    }
722 		}
723 		if (*ft == 'L')
724 		    st = lst;
725 	    }
726 	    else
727 #endif /* S_IFLNK */
728 		/*
729 		 * avoid convex compiler bug.
730 		 */
731 		if (!st) {
732 		    st = &stb;
733 		    if (TCSH_STAT(short2str(ep), st) == -1) {
734 			cleanup_until(ep);
735 			return (Strsave(errval));
736 		    }
737 		}
738 
739 	    switch (*ft) {
740 
741 	    case 'f':
742 #ifdef S_ISREG
743 		i = S_ISREG(st->st_mode);
744 #else /* !S_ISREG */
745 		i = 0;
746 #endif /* S_ISREG */
747 		break;
748 
749 	    case 'd':
750 #ifdef S_ISDIR
751 		i = S_ISDIR(st->st_mode);
752 #else /* !S_ISDIR */
753 		i = 0;
754 #endif /* S_ISDIR */
755 		break;
756 
757 	    case 'p':
758 #ifdef S_ISFIFO
759 		i = S_ISFIFO(st->st_mode);
760 #else /* !S_ISFIFO */
761 		i = 0;
762 #endif /* S_ISFIFO */
763 		break;
764 
765 	    case 'm' :
766 #ifdef S_ISOFL
767 	      i = S_ISOFL(st->st_dm_mode);
768 #else /* !S_ISOFL */
769 	      i = 0;
770 #endif /* S_ISOFL */
771 	      break ;
772 
773 	    case 'K' :
774 #ifdef S_ISOFL
775 	      i = stb.st_dm_key;
776 #else /* !S_ISOFL */
777 	      i = 0;
778 #endif /* S_ISOFL */
779 	      break ;
780 
781 
782 	    case 'l':
783 #ifdef S_ISLNK
784 		i = S_ISLNK(lst->st_mode);
785 #else /* !S_ISLNK */
786 		i = 0;
787 #endif /* S_ISLNK */
788 		break;
789 
790 	    case 'S':
791 # ifdef S_ISSOCK
792 		i = S_ISSOCK(st->st_mode);
793 # else /* !S_ISSOCK */
794 		i = 0;
795 # endif /* S_ISSOCK */
796 		break;
797 
798 	    case 'b':
799 #ifdef S_ISBLK
800 		i = S_ISBLK(st->st_mode);
801 #else /* !S_ISBLK */
802 		i = 0;
803 #endif /* S_ISBLK */
804 		break;
805 
806 	    case 'c':
807 #ifdef S_ISCHR
808 		i = S_ISCHR(st->st_mode);
809 #else /* !S_ISCHR */
810 		i = 0;
811 #endif /* S_ISCHR */
812 		break;
813 
814 	    case 'u':
815 		i = (S_ISUID & st->st_mode) != 0;
816 		break;
817 
818 	    case 'g':
819 		i = (S_ISGID & st->st_mode) != 0;
820 		break;
821 
822 	    case 'k':
823 		i = (S_ISVTX & st->st_mode) != 0;
824 		break;
825 
826 	    case 'z':
827 		i = st->st_size == 0;
828 		break;
829 
830 #ifdef convex
831 	    case 'R':
832 		i = (stb.st_dmonflags & IMIGRATED) == IMIGRATED;
833 		break;
834 #endif /* convex */
835 
836 	    case 's':
837 		i = stb.st_size != 0;
838 		break;
839 
840 	    case 'e':
841 		i = 1;
842 		break;
843 
844 	    case 'o':
845 		i = st->st_uid == uid;
846 		break;
847 
848 		/*
849 		 * Value operators are a tcsh extension.
850 		 */
851 
852 	    case 'D':
853 		i = (tcsh_number_t) st->st_dev;
854 		break;
855 
856 	    case 'I':
857 		i = (tcsh_number_t) st->st_ino;
858 		break;
859 
860 	    case 'F':
861 		strdev = putn( (int) st->st_dev);
862 		strino = putn( (int) st->st_ino);
863 		strF = xmalloc((2 + Strlen(strdev) + Strlen(strino))
864 			       * sizeof(Char));
865 		(void) Strcat(Strcat(Strcpy(strF, strdev), STRcolon), strino);
866 		xfree(strdev);
867 		xfree(strino);
868 		cleanup_until(ep);
869 		return(strF);
870 
871 	    case 'L':
872 		if ( *(ft + 1) ) {
873 		    i = 1;
874 		    break;
875 		}
876 #ifdef S_ISLNK
877 		filnam = short2str(ep);
878 		string = areadlink(filnam);
879 		strF = string == NULL ? errval : str2short(string);
880 		xfree(string);
881 		cleanup_until(ep);
882 		return(Strsave(strF));
883 
884 #else /* !S_ISLNK */
885 		i = 0;
886 		break;
887 #endif /* S_ISLNK */
888 
889 
890 	    case 'N':
891 		i = (tcsh_number_t) st->st_nlink;
892 		break;
893 
894 	    case 'P':
895 		string = string0 + 1;
896 		(void) xsnprintf(string, sizeof(string0) - 1, "%o",
897 		    pmask & (unsigned int)
898 		    ((S_IRWXU|S_IRWXG|S_IRWXO|S_ISUID|S_ISGID) & st->st_mode));
899 		if (altout && *string != '0')
900 		    *--string = '0';
901 		cleanup_until(ep);
902 		return(Strsave(str2short(string)));
903 
904 	    case 'U':
905 		if (altout && (pw = xgetpwuid(st->st_uid))) {
906 		    cleanup_until(ep);
907 		    return(Strsave(str2short(pw->pw_name)));
908 		}
909 		i = (tcsh_number_t) st->st_uid;
910 		break;
911 
912 	    case 'G':
913 		if (altout && (gr = xgetgrgid(st->st_gid))) {
914 		    cleanup_until(ep);
915 		    return(Strsave(str2short(gr->gr_name)));
916 		}
917 		i = (tcsh_number_t) st->st_gid;
918 		break;
919 
920 	    case 'Z':
921 		i = (tcsh_number_t) st->st_size;
922 		break;
923 
924 	    case 'A': case 'M': case 'C':
925 		footime = *ft == 'A' ? st->st_atime :
926 		    *ft == 'M' ? st->st_mtime : st->st_ctime;
927 		if (altout) {
928 		    strF = str2short(ctime(&footime));
929 		    if ((str = Strchr(strF, '\n')) != NULL)
930 			*str = (Char) '\0';
931 		    cleanup_until(ep);
932 		    return(Strsave(strF));
933 		}
934 		i = (tcsh_number_t) footime;
935 		break;
936 
937 	    }
938 	}
939     while (*++ft && i);
940     etraci("exp6 -? i", i, vp);
941     cleanup_until(ep);
942     return (putn(i));
943 }
944 
945 
946 static void
947 evalav(Char **v)
948 {
949     struct wordent paraml1;
950     struct wordent *hp = &paraml1;
951     struct command *t;
952     struct wordent *wdp = hp;
953 
954     setstatus(0);
955     initlex(hp);
956     while (*v) {
957 	struct wordent *new = xcalloc(1, sizeof *wdp);
958 
959 	new->prev = wdp;
960 	new->next = hp;
961 	wdp->next = new;
962 	wdp = new;
963 	wdp->word = Strsave(*v++);
964     }
965     hp->prev = wdp;
966     cleanup_push(&paraml1, lex_cleanup);
967     alias(&paraml1);
968     t = syntax(paraml1.next, &paraml1, 0);
969     cleanup_push(t, syntax_cleanup);
970     if (seterr)
971 	stderror(ERR_OLD);
972     execute(t, -1, NULL, NULL, TRUE);
973     cleanup_until(&paraml1);
974 }
975 
976 static int
977 isa(Char *cp, int what)
978 {
979     if (cp == 0)
980 	return ((what & RESTOP) != 0);
981     if (*cp == '\0')
982     	return 0;
983     if (cp[1] == 0) {
984 	if (what & ADDOP && (*cp == '+' || *cp == '-'))
985 	    return (1);
986 	if (what & MULOP && (*cp == '*' || *cp == '/' || *cp == '%'))
987 	    return (1);
988 	if (what & RESTOP && (*cp == '(' || *cp == ')' || *cp == '!' ||
989 			      *cp == '~' || *cp == '^' || *cp == '"'))
990 	    return (1);
991     }
992     else if (cp[2] == 0) {
993 	if (what & RESTOP) {
994 	    if (cp[0] == '|' && cp[1] == '&')
995 		return (1);
996 	    if (cp[0] == '<' && cp[1] == '<')
997 		return (1);
998 	    if (cp[0] == '>' && cp[1] == '>')
999 		return (1);
1000 	}
1001 	if (what & EQOP) {
1002 	    if (cp[0] == '=') {
1003 		if (cp[1] == '=')
1004 		    return (EQEQ);
1005 		if (cp[1] == '~')
1006 		    return (EQMATCH);
1007 	    }
1008 	    else if (cp[0] == '!') {
1009 		if (cp[1] == '=')
1010 		    return (NOTEQ);
1011 		if (cp[1] == '~')
1012 		    return (NOTEQMATCH);
1013 	    }
1014 	}
1015     }
1016     if (what & RELOP) {
1017 	if (*cp == '<')
1018 	    return (LSS);
1019 	if (*cp == '>')
1020 	    return (GTR);
1021     }
1022     return (0);
1023 }
1024 
1025 static tcsh_number_t
1026 egetn(const Char *cp)
1027 {
1028     if (*cp && *cp != '-' && !Isdigit(*cp))
1029 	stderror(ERR_NAME | ERR_EXPRESSION);
1030     return (getn(cp));
1031 }
1032 
1033 /* Phew! */
1034 
1035 #ifdef EDEBUG
1036 static void
1037 etraci(const char *str, tcsh_number_t i, Char ***vp)
1038 {
1039 #ifdef HAVE_LONG_LONG
1040     xprintf("%s=%lld\t", str, i);
1041 #else
1042     xprintf("%s=%ld\t", str, i);
1043 #endif
1044     blkpr(*vp);
1045     xputchar('\n');
1046 }
1047 static void
1048 etracc(const char *str, const Char *cp, Char ***vp)
1049 {
1050     xprintf("%s=%S\t", str, cp);
1051     blkpr(*vp);
1052     xputchar('\n');
1053 }
1054 #endif /* EDEBUG */
1055