sh.exp.c revision 100616 
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
35RCSID("$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
60static	int	 sh_access	__P((Char *, int));
61static	int	 exp1		__P((Char ***, bool));
62static	int	 exp2		__P((Char ***, bool));
63static	int	 exp2a		__P((Char ***, bool));
64static	int	 exp2b		__P((Char ***, bool));
65static	int	 exp2c		__P((Char ***, bool));
66static	Char 	*exp3		__P((Char ***, bool));
67static	Char 	*exp3a		__P((Char ***, bool));
68static	Char 	*exp4		__P((Char ***, bool));
69static	Char 	*exp5		__P((Char ***, bool));
70static	Char 	*exp6		__P((Char ***, bool));
71static	void	 evalav		__P((Char **));
72static	int	 isa		__P((Char *, int));
73static	int	 egetn		__P((Char *));
74
75
76#ifdef EDEBUG
77static	void	 etracc		__P((char *, Char *, Char ***));
78static	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 */
86static int
87sh_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
201int
202expr(vp)
203    register Char ***vp;
204{
205    return (exp0(vp, 0));
206}
207
208int
209exp0(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
231static int
232exp1(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
254static int
255exp2(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
277static int
278exp2a(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
300static int
301exp2b(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
323static int
324exp2c(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
371static Char *
372exp3(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
417static Char *
418exp3a(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
447static Char *
448exp4(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
484static Char *
485exp5(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
538static Char *
539exp6(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 */
635Char *
636filetest(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
991static void
992evalav(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
1022static int
1023isa(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
1073static int
1074egetn(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
1085static void
1086etraci(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}
1095static void
1096etracc(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