1 /*        $NetBSD: c_test.c,v 1.10 2021/09/16 19:44:01 christos Exp $ */
2 
3 /*
4  * test(1); version 7-like  --  author Erik Baalbergen
5  * modified by Eric Gisin to be used as built-in.
6  * modified by Arnold Robbins to add SVR3 compatibility
7  * (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
8  * modified by Michael Rendell to add Korn's [[ .. ]] expressions.
9  * modified by J.T. Conklin to add POSIX compatibility.
10  */
11 #include <sys/cdefs.h>
12 
13 #ifndef lint
14 __RCSID("$NetBSD: c_test.c,v 1.10 2021/09/16 19:44:01 christos Exp $");
15 #endif
16 
17 #include <sys/stat.h>
18 
19 #include "sh.h"
20 #include "c_test.h"
21 
22 /* test(1) accepts the following grammar:
23           oexpr     ::= aexpr | aexpr "-o" oexpr ;
24           aexpr     ::= nexpr | nexpr "-a" aexpr ;
25           nexpr     ::= primary | "!" nexpr ;
26           primary   ::= unary-operator operand
27                     | operand binary-operator operand
28                     | operand
29                     | "(" oexpr ")"
30                     ;
31 
32           unary-operator ::= "-a"|"-r"|"-w"|"-x"|"-e"|"-f"|"-d"|"-c"|"-b"|"-p"|
33                                  "-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|
34                                  "-L"|"-h"|"-S"|"-H";
35 
36           binary-operator ::= "="|"=="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
37                                   "-nt"|"-ot"|"-ef"|
38                                   "<"|">"         # rules used for [[ .. ]] expressions
39                                   ;
40           operand ::= <any thing>
41 */
42 
43 #define T_ERR_EXIT  2         /* POSIX says > 1 for errors */
44 
45 struct t_op {
46           char      op_text[4];
47           Test_op   op_num;
48 };
49 static const struct t_op u_ops [] = {
50           {"-a",    TO_FILAXST },
51           {"-b",    TO_FILBDEV },
52           {"-c",    TO_FILCDEV },
53           {"-d",    TO_FILID },
54           {"-e",    TO_FILEXST },
55           {"-f",    TO_FILREG },
56           {"-G",    TO_FILGID },
57           {"-g",    TO_FILSETG },
58           {"-h",    TO_FILSYM },
59           {"-H",    TO_FILCDF },
60           {"-k",    TO_FILSTCK },
61           {"-L",    TO_FILSYM },
62           {"-n",    TO_STNZE },
63           {"-O",    TO_FILUID },
64           {"-o",    TO_OPTION },
65           {"-p",    TO_FILFIFO },
66           {"-r",    TO_FILRD },
67           {"-s",    TO_FILGZ },
68           {"-S",    TO_FILSOCK },
69           {"-t",    TO_FILTT },
70           {"-u",    TO_FILSETU },
71           {"-w",    TO_FILWR },
72           {"-x",    TO_FILEX },
73           {"-z",    TO_STZER },
74           {"",      TO_NONOP }
75     };
76 static const struct t_op b_ops [] = {
77           {"=",     TO_STEQL },
78 #ifdef KSH
79           {"==",    TO_STEQL },
80 #endif /* KSH */
81           {"!=",    TO_STNEQ },
82           {"<",     TO_STLT },
83           {">",     TO_STGT },
84           {"-eq",   TO_INTEQ },
85           {"-ne",   TO_INTNE },
86           {"-gt",   TO_INTGT },
87           {"-ge",   TO_INTGE },
88           {"-lt",   TO_INTLT },
89           {"-le",   TO_INTLE },
90           {"-ef",   TO_FILEQ },
91           {"-nt",   TO_FILNT },
92           {"-ot",   TO_FILOT },
93           {"",      TO_NONOP }
94     };
95 
96 static int          test_stat ARGS((const char *, struct stat *));
97 static int          test_eaccess ARGS((const char *, int));
98 static int          test_oexpr ARGS((Test_env *, int));
99 static int          test_aexpr ARGS((Test_env *, int));
100 static int          test_nexpr ARGS((Test_env *, int));
101 static int          test_primary ARGS((Test_env *, int));
102 static int          ptest_isa ARGS((Test_env *, Test_meta));
103 static const char *ptest_getopnd ARGS((Test_env *, Test_op, int));
104 static int          ptest_eval ARGS((Test_env *, Test_op, const char *,
105                                         const char *, int));
106 static void         ptest_error ARGS((Test_env *, int, const char *));
107 
108 int
c_test(wp)109 c_test(wp)
110           char **wp;
111 {
112           int argc;
113           int res;
114           Test_env te;
115 
116           te.flags = 0;
117           te.isa = ptest_isa;
118           te.getopnd = ptest_getopnd;
119           te.eval = ptest_eval;
120           te.error = ptest_error;
121 
122           for (argc = 0; wp[argc]; argc++)
123                     ;
124 
125           if (strcmp(wp[0], "[") == 0) {
126                     if (strcmp(wp[--argc], "]") != 0) {
127                               bi_errorf("missing ]");
128                               return T_ERR_EXIT;
129                     }
130           }
131 
132           te.pos.wp = wp + 1;
133           te.wp_end = wp + argc;
134 
135           /*
136            * Handle the special cases from POSIX.2, section 4.62.4.
137            * Implementation of all the rules isn't necessary since
138            * our parser does the right thing for the omitted steps.
139            */
140           if (argc <= 5) {
141                     char **owp = wp;
142                     int invert = 0;
143                     Test_op   op;
144                     const char *opnd1, *opnd2;
145 
146                     while (--argc >= 0) {
147                               if ((*te.isa)(&te, TM_END))
148                                         return !0;
149                               if (argc == 3) {
150                                         opnd1 = (*te.getopnd)(&te, TO_NONOP, 1);
151                                         if ((op = (Test_op) (*te.isa)(&te, TM_BINOP))) {
152                                                   opnd2 = (*te.getopnd)(&te, op, 1);
153                                                   res = (*te.eval)(&te, op, opnd1, opnd2,
154                                                                       1);
155                                                   if (te.flags & TEF_ERROR)
156                                                             return T_ERR_EXIT;
157                                                   if (invert & 1)
158                                                             res = !res;
159                                                   return !res;
160                                         }
161                                         /* back up to opnd1 */
162                                         te.pos.wp--;
163                               }
164                               if (argc == 1) {
165                                         opnd1 = (*te.getopnd)(&te, TO_NONOP, 1);
166                                         /* Historically, -t by itself test if fd 1
167                                          * is a file descriptor, but POSIX says its
168                                          * a string test...
169                                          */
170                                         if (!Flag(FPOSIX) && strcmp(opnd1, "-t") == 0)
171                                             break;
172                                         res = (*te.eval)(&te, TO_STNZE, opnd1,
173                                                             (char *) 0, 1);
174                                         if (invert & 1)
175                                                   res = !res;
176                                         return !res;
177                               }
178                               if ((*te.isa)(&te, TM_NOT)) {
179                                         invert++;
180                               } else
181                                         break;
182                     }
183                     te.pos.wp = owp + 1;
184           }
185 
186           return test_parse(&te);
187 }
188 
189 /*
190  * Generic test routines.
191  */
192 
193 Test_op
test_isop(te,meta,s)194 test_isop(te, meta, s)
195           Test_env *te;
196           Test_meta meta;
197           const char *s;
198 {
199           char sc1;
200           const struct t_op *otab;
201 
202           otab = meta == TM_UNOP ? u_ops : b_ops;
203           if (*s) {
204                     sc1 = s[1];
205                     for (; otab->op_text[0]; otab++)
206                               if (sc1 == otab->op_text[1]
207                                   && strcmp(s, otab->op_text) == 0
208                                   && ((te->flags & TEF_DBRACKET)
209                                         || (otab->op_num != TO_STLT
210                                             && otab->op_num != TO_STGT)))
211                                         return otab->op_num;
212           }
213           return TO_NONOP;
214 }
215 
216 int
test_eval(te,op,opnd1,opnd2,do_eval)217 test_eval(te, op, opnd1, opnd2, do_eval)
218           Test_env *te;
219           Test_op op;
220           const char *opnd1;
221           const char *opnd2;
222           int do_eval;
223 {
224           int res;
225           int not;
226           struct stat b1, b2;
227 
228           if (!do_eval)
229                     return 0;
230 
231           switch ((int) op) {
232           /*
233            * Unary Operators
234            */
235             case TO_STNZE: /* -n */
236                     return *opnd1 != '\0';
237             case TO_STZER: /* -z */
238                     return *opnd1 == '\0';
239             case TO_OPTION: /* -o */
240                     if ((not = *opnd1 == '!'))
241                               opnd1++;
242                     if ((res = option(opnd1)) < 0)
243                               res = 0;
244                     else {
245                               res = Flag(res);
246                               if (not)
247                                         res = !res;
248                     }
249                     return res;
250             case TO_FILRD: /* -r */
251                     return test_eaccess(opnd1, R_OK) == 0;
252             case TO_FILWR: /* -w */
253                     return test_eaccess(opnd1, W_OK) == 0;
254             case TO_FILEX: /* -x */
255                     return test_eaccess(opnd1, X_OK) == 0;
256             case TO_FILAXST: /* -a */
257                     return test_stat(opnd1, &b1) == 0;
258             case TO_FILEXST: /* -e */
259                     /* at&t ksh does not appear to do the /dev/fd/ thing for
260                      * this (unless the os itself handles it)
261                      */
262                     return stat(opnd1, &b1) == 0;
263             case TO_FILREG: /* -r */
264                     return test_stat(opnd1, &b1) == 0 && S_ISREG(b1.st_mode);
265             case TO_FILID: /* -d */
266                     return test_stat(opnd1, &b1) == 0 && S_ISDIR(b1.st_mode);
267             case TO_FILCDEV: /* -c */
268 #ifdef S_ISCHR
269                     return test_stat(opnd1, &b1) == 0 && S_ISCHR(b1.st_mode);
270 #else
271                     return 0;
272 #endif
273             case TO_FILBDEV: /* -b */
274 #ifdef S_ISBLK
275                     return test_stat(opnd1, &b1) == 0 && S_ISBLK(b1.st_mode);
276 #else
277                     return 0;
278 #endif
279             case TO_FILFIFO: /* -p */
280 #ifdef S_ISFIFO
281                     return test_stat(opnd1, &b1) == 0 && S_ISFIFO(b1.st_mode);
282 #else
283                     return 0;
284 #endif
285             case TO_FILSYM: /* -h -L */
286 #ifdef S_ISLNK
287                     return lstat(opnd1, &b1) == 0 && S_ISLNK(b1.st_mode);
288 #else
289                     return 0;
290 #endif
291             case TO_FILSOCK: /* -S */
292 #ifdef S_ISSOCK
293                     return test_stat(opnd1, &b1) == 0 && S_ISSOCK(b1.st_mode);
294 #else
295                     return 0;
296 #endif
297             case TO_FILCDF:/* -H HP context dependent files (directories) */
298 #ifdef S_ISCDF
299             {
300                     /* Append a + to filename and check to see if result is a
301                      * setuid directory.  CDF stuff in general is hookey, since
302                      * it breaks for the following sequence: echo hi > foo+;
303                      * mkdir foo; echo bye > foo/default; chmod u+s foo
304                      * (foo+ refers to the file with hi in it, there is no way
305                      * to get at the file with bye in it - please correct me if
306                      * I'm wrong about this).
307                      */
308                     int len = strlen(opnd1);
309                     char *p = str_nsave(opnd1, len + 1, ATEMP);
310 
311                     p[len++] = '+';
312                     p[len] = '\0';
313                     return stat(p, &b1) == 0 && S_ISCDF(b1.st_mode);
314             }
315 #else
316                     return 0;
317 #endif
318             case TO_FILSETU: /* -u */
319 #ifdef S_ISUID
320                     return test_stat(opnd1, &b1) == 0
321                               && (b1.st_mode & S_ISUID) == S_ISUID;
322 #else
323                     return 0;
324 #endif
325             case TO_FILSETG: /* -g */
326 #ifdef S_ISGID
327                     return test_stat(opnd1, &b1) == 0
328                               && (b1.st_mode & S_ISGID) == S_ISGID;
329 #else
330                     return 0;
331 #endif
332             case TO_FILSTCK: /* -k */
333                     return test_stat(opnd1, &b1) == 0
334                               && (b1.st_mode & S_ISVTX) == S_ISVTX;
335             case TO_FILGZ: /* -s */
336                     return test_stat(opnd1, &b1) == 0 && b1.st_size > 0L;
337             case TO_FILTT: /* -t */
338                     if (opnd1 && !bi_getn(opnd1, &res)) {
339                               te->flags |= TEF_ERROR;
340                               res = 0;
341                     } else {
342                               /* generate error if in FPOSIX mode? */
343                               res = isatty(opnd1 ? res : 0);
344                     }
345                     return res;
346             case TO_FILUID: /* -O */
347                     return test_stat(opnd1, &b1) == 0 && b1.st_uid == ksheuid;
348             case TO_FILGID: /* -G */
349                     return test_stat(opnd1, &b1) == 0 && b1.st_gid == getegid();
350           /*
351            * Binary Operators
352            */
353             case TO_STEQL: /* = */
354                     if (te->flags & TEF_DBRACKET)
355                               return gmatch(opnd1, opnd2, false);
356                     return strcmp(opnd1, opnd2) == 0;
357             case TO_STNEQ: /* != */
358                     if (te->flags & TEF_DBRACKET)
359                               return !gmatch(opnd1, opnd2, false);
360                     return strcmp(opnd1, opnd2) != 0;
361             case TO_STLT: /* < */
362                     return strcmp(opnd1, opnd2) < 0;
363             case TO_STGT: /* > */
364                     return strcmp(opnd1, opnd2) > 0;
365             case TO_INTEQ: /* -eq */
366             case TO_INTNE: /* -ne */
367             case TO_INTGE: /* -ge */
368             case TO_INTGT: /* -gt */
369             case TO_INTLE: /* -le */
370             case TO_INTLT: /* -lt */
371                     {
372                               long v1, v2;
373 
374                               if (!evaluate(opnd1, &v1, KSH_RETURN_ERROR)
375                                   || !evaluate(opnd2, &v2, KSH_RETURN_ERROR))
376                               {
377                                         /* error already printed.. */
378                                         te->flags |= TEF_ERROR;
379                                         return 1;
380                               }
381                               switch ((int) op) {
382                                 case TO_INTEQ:
383                                         return v1 == v2;
384                                 case TO_INTNE:
385                                         return v1 != v2;
386                                 case TO_INTGE:
387                                         return v1 >= v2;
388                                 case TO_INTGT:
389                                         return v1 > v2;
390                                 case TO_INTLE:
391                                         return v1 <= v2;
392                                 case TO_INTLT:
393                                         return v1 < v2;
394                               }
395                     }
396                     abort();
397             case TO_FILNT: /* -nt */
398                     {
399                               int s2;
400                               /* ksh88/ksh93 succeed if file2 can't be stated
401                                * (subtly different from `does not exist').
402                                */
403                               return stat(opnd1, &b1) == 0
404                                         && (((s2 = stat(opnd2, &b2)) == 0
405                                               && b1.st_mtime > b2.st_mtime) || s2 < 0);
406                     }
407             case TO_FILOT: /* -ot */
408                     {
409                               int s1;
410                               /* ksh88/ksh93 succeed if file1 can't be stated
411                                * (subtly different from `does not exist').
412                                */
413                               return stat(opnd2, &b2) == 0
414                                         && (((s1 = stat(opnd1, &b1)) == 0
415                                               && b1.st_mtime < b2.st_mtime) || s1 < 0);
416                     }
417             case TO_FILEQ: /* -ef */
418                     return stat (opnd1, &b1) == 0 && stat (opnd2, &b2) == 0
419                            && b1.st_dev == b2.st_dev
420                            && b1.st_ino == b2.st_ino;
421           }
422           (*te->error)(te, 0, "internal error: unknown op");
423           return 1;
424 }
425 
426 static int
test_stat(pathx,statb)427 test_stat(pathx, statb)
428           const char *pathx;
429           struct stat *statb;
430 {
431           return stat(pathx, statb);
432 }
433 
434 /* Routine to handle Korn's /dev/fd hack, and to deal with X_OK on
435  * non-directories when running as root.
436  */
437 static int
test_eaccess(pathx,mode)438 test_eaccess(pathx, mode)
439           const char *pathx;
440           int mode;
441 {
442           int res;
443 
444           res = eaccess(pathx, mode);
445           /*
446            * On most (all?) unixes, access() says everything is executable for
447            * root - avoid this on files by using stat().
448            */
449           if (res == 0 && ksheuid == 0 && (mode & X_OK)) {
450                     struct stat statb;
451 
452                     if (stat(pathx, &statb) < 0)
453                               res = -1;
454                     else if (S_ISDIR(statb.st_mode))
455                               res = 0;
456                     else
457                               res = (statb.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH))
458                                         ? 0 : -1;
459           }
460 
461           return res;
462 }
463 
464 int
test_parse(te)465 test_parse(te)
466           Test_env *te;
467 {
468           int res;
469 
470           res = test_oexpr(te, 1);
471 
472           if (!(te->flags & TEF_ERROR) && !(*te->isa)(te, TM_END))
473                     (*te->error)(te, 0, "unexpected operator/operand");
474 
475           return (te->flags & TEF_ERROR) ? T_ERR_EXIT : !res;
476 }
477 
478 static int
test_oexpr(te,do_eval)479 test_oexpr(te, do_eval)
480           Test_env *te;
481           int do_eval;
482 {
483           int res;
484 
485           res = test_aexpr(te, do_eval);
486           if (res)
487                     do_eval = 0;
488           if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_OR))
489                     return test_oexpr(te, do_eval) || res;
490           return res;
491 }
492 
493 static int
test_aexpr(te,do_eval)494 test_aexpr(te, do_eval)
495           Test_env *te;
496           int do_eval;
497 {
498           int res;
499 
500           res = test_nexpr(te, do_eval);
501           if (!res)
502                     do_eval = 0;
503           if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_AND))
504                     return test_aexpr(te, do_eval) && res;
505           return res;
506 }
507 
508 static int
test_nexpr(te,do_eval)509 test_nexpr(te, do_eval)
510           Test_env *te;
511           int do_eval;
512 {
513           if (!(te->flags & TEF_ERROR) && (*te->isa)(te, TM_NOT))
514                     return !test_nexpr(te, do_eval);
515           return test_primary(te, do_eval);
516 }
517 
518 static int
test_primary(te,do_eval)519 test_primary(te, do_eval)
520           Test_env *te;
521           int do_eval;
522 {
523           const char *opnd1, *opnd2;
524           int res;
525           Test_op op;
526 
527           if (te->flags & TEF_ERROR)
528                     return 0;
529           if ((*te->isa)(te, TM_OPAREN)) {
530                     res = test_oexpr(te, do_eval);
531                     if (te->flags & TEF_ERROR)
532                               return 0;
533                     if (!(*te->isa)(te, TM_CPAREN)) {
534                               (*te->error)(te, 0, "missing closing paren");
535                               return 0;
536                     }
537                     return res;
538           }
539           if ((op = (Test_op) (*te->isa)(te, TM_UNOP))) {
540                     /* unary expression */
541                     opnd1 = (*te->getopnd)(te, op, do_eval);
542                     if (!opnd1) {
543                               (*te->error)(te, -1, "missing argument");
544                               return 0;
545                     }
546 
547                     return (*te->eval)(te, op, opnd1, (const char *) 0, do_eval);
548           }
549           opnd1 = (*te->getopnd)(te, TO_NONOP, do_eval);
550           if (!opnd1) {
551                     (*te->error)(te, 0, "expression expected");
552                     return 0;
553           }
554           if ((op = (Test_op) (*te->isa)(te, TM_BINOP))) {
555                     /* binary expression */
556                     opnd2 = (*te->getopnd)(te, op, do_eval);
557                     if (!opnd2) {
558                               (*te->error)(te, -1, "missing second argument");
559                               return 0;
560                     }
561 
562                     return (*te->eval)(te, op, opnd1, opnd2, do_eval);
563           }
564           if (te->flags & TEF_DBRACKET) {
565                     (*te->error)(te, -1, "missing expression operator");
566                     return 0;
567           }
568           return (*te->eval)(te, TO_STNZE, opnd1, (const char *) 0, do_eval);
569 }
570 
571 /*
572  * Plain test (test and [ .. ]) specific routines.
573  */
574 
575 /* Test if the current token is a whatever.  Accepts the current token if
576  * it is.  Returns 0 if it is not, non-zero if it is (in the case of
577  * TM_UNOP and TM_BINOP, the returned value is a Test_op).
578  */
579 static int
ptest_isa(te,meta)580 ptest_isa(te, meta)
581           Test_env *te;
582           Test_meta meta;
583 {
584           /* Order important - indexed by Test_meta values */
585           static const char *const tokens[] = {
586                                         "-o", "-a", "!", "(", ")"
587                               };
588           int ret;
589 
590           if (te->pos.wp >= te->wp_end)
591                     return meta == TM_END;
592 
593           if (meta == TM_UNOP || meta == TM_BINOP)
594                     ret = (int) test_isop(te, meta, *te->pos.wp);
595           else if (meta == TM_END)
596                     ret = 0;
597           else
598                     ret = strcmp(*te->pos.wp, tokens[(int) meta]) == 0;
599 
600           /* Accept the token? */
601           if (ret)
602                     te->pos.wp++;
603 
604           return ret;
605 }
606 
607 static const char *
ptest_getopnd(te,op,do_eval)608 ptest_getopnd(te, op, do_eval)
609           Test_env *te;
610           Test_op op;
611           int do_eval;
612 {
613           if (te->pos.wp >= te->wp_end)
614                     return op == TO_FILTT ? "1" : (const char *) 0;
615           return *te->pos.wp++;
616 }
617 
618 static int
ptest_eval(te,op,opnd1,opnd2,do_eval)619 ptest_eval(te, op, opnd1, opnd2, do_eval)
620           Test_env *te;
621           Test_op op;
622           const char *opnd1;
623           const char *opnd2;
624           int do_eval;
625 {
626           return test_eval(te, op, opnd1, opnd2, do_eval);
627 }
628 
629 static void
ptest_error(te,offset,msg)630 ptest_error(te, offset, msg)
631           Test_env *te;
632           int offset;
633           const char *msg;
634 {
635           const char *op = te->pos.wp + offset >= te->wp_end ?
636                                         (const char *) 0 : te->pos.wp[offset];
637 
638           te->flags |= TEF_ERROR;
639           if (op)
640                     bi_errorf("%s: %s", op, msg);
641           else
642                     bi_errorf("%s", msg);
643 }
644