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15637ed4 RG |
1 | /*- |
2 | * Copyright (c) 1991 The Regents of the University of California. | |
3 | * All rights reserved. | |
4 | * | |
5 | * This code is derived from software contributed to Berkeley by | |
6 | * Kenneth Almquist. | |
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. All advertising materials mentioning features or use of this software | |
17 | * must display the following acknowledgement: | |
18 | * This product includes software developed by the University of | |
19 | * California, Berkeley and its contributors. | |
20 | * 4. Neither the name of the University nor the names of its contributors | |
21 | * may be used to endorse or promote products derived from this software | |
22 | * without specific prior written permission. | |
23 | * | |
24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND | |
25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE | |
28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
34 | * SUCH DAMAGE. | |
35 | */ | |
36 | ||
37 | #ifndef lint | |
78ed81a3 | 38 | /*static char sccsid[] = "from: @(#)eval.c 5.3 (Berkeley) 4/12/91";*/ |
39 | static char rcsid[] = "eval.c,v 1.5 1993/08/01 18:58:18 mycroft Exp"; | |
15637ed4 RG |
40 | #endif /* not lint */ |
41 | ||
42 | /* | |
43 | * Evaluate a command. | |
44 | */ | |
45 | ||
46 | #include "shell.h" | |
47 | #include "nodes.h" | |
48 | #include "syntax.h" | |
49 | #include "expand.h" | |
50 | #include "parser.h" | |
51 | #include "jobs.h" | |
52 | #include "eval.h" | |
53 | #include "builtins.h" | |
54 | #include "options.h" | |
55 | #include "exec.h" | |
56 | #include "redir.h" | |
57 | #include "input.h" | |
58 | #include "output.h" | |
59 | #include "trap.h" | |
60 | #include "var.h" | |
61 | #include "memalloc.h" | |
62 | #include "error.h" | |
63 | #include "mystring.h" | |
64 | #include <signal.h> | |
65 | ||
66 | ||
67 | /* flags in argument to evaltree */ | |
68 | #define EV_EXIT 01 /* exit after evaluating tree */ | |
69 | #define EV_TESTED 02 /* exit status is checked; ignore -e flag */ | |
70 | #define EV_BACKCMD 04 /* command executing within back quotes */ | |
71 | ||
72 | ||
73 | /* reasons for skipping commands (see comment on breakcmd routine) */ | |
74 | #define SKIPBREAK 1 | |
75 | #define SKIPCONT 2 | |
76 | #define SKIPFUNC 3 | |
77 | ||
78 | MKINIT int evalskip; /* set if we are skipping commands */ | |
79 | STATIC int skipcount; /* number of levels to skip */ | |
80 | MKINIT int loopnest; /* current loop nesting level */ | |
81 | int funcnest; /* depth of function calls */ | |
82 | ||
83 | ||
84 | char *commandname; | |
85 | struct strlist *cmdenviron; | |
86 | int exitstatus; /* exit status of last command */ | |
87 | ||
88 | ||
89 | #ifdef __STDC__ | |
90 | STATIC void evalloop(union node *); | |
91 | STATIC void evalfor(union node *); | |
92 | STATIC void evalcase(union node *, int); | |
93 | STATIC void evalsubshell(union node *, int); | |
94 | STATIC void expredir(union node *); | |
95 | STATIC void evalpipe(union node *); | |
96 | STATIC void evalcommand(union node *, int, struct backcmd *); | |
97 | STATIC void prehash(union node *); | |
98 | #else | |
99 | STATIC void evalloop(); | |
100 | STATIC void evalfor(); | |
101 | STATIC void evalcase(); | |
102 | STATIC void evalsubshell(); | |
103 | STATIC void expredir(); | |
104 | STATIC void evalpipe(); | |
105 | STATIC void evalcommand(); | |
106 | STATIC void prehash(); | |
107 | #endif | |
108 | ||
109 | ||
110 | ||
111 | /* | |
112 | * Called to reset things after an exception. | |
113 | */ | |
114 | ||
115 | #ifdef mkinit | |
116 | INCLUDE "eval.h" | |
117 | ||
118 | RESET { | |
119 | evalskip = 0; | |
120 | loopnest = 0; | |
121 | funcnest = 0; | |
122 | } | |
123 | ||
124 | SHELLPROC { | |
125 | exitstatus = 0; | |
126 | } | |
127 | #endif | |
128 | ||
129 | ||
130 | ||
131 | /* | |
132 | * The eval commmand. | |
133 | */ | |
134 | ||
135 | evalcmd(argc, argv) | |
136 | char **argv; | |
137 | { | |
138 | char *p; | |
139 | char *concat; | |
140 | char **ap; | |
141 | ||
142 | if (argc > 1) { | |
143 | p = argv[1]; | |
144 | if (argc > 2) { | |
145 | STARTSTACKSTR(concat); | |
146 | ap = argv + 2; | |
147 | for (;;) { | |
148 | while (*p) | |
149 | STPUTC(*p++, concat); | |
150 | if ((p = *ap++) == NULL) | |
151 | break; | |
152 | STPUTC(' ', concat); | |
153 | } | |
154 | STPUTC('\0', concat); | |
155 | p = grabstackstr(concat); | |
156 | } | |
157 | evalstring(p); | |
158 | } | |
159 | return exitstatus; | |
160 | } | |
161 | ||
162 | ||
163 | /* | |
164 | * Execute a command or commands contained in a string. | |
165 | */ | |
166 | ||
167 | void | |
168 | evalstring(s) | |
169 | char *s; | |
170 | { | |
171 | union node *n; | |
172 | struct stackmark smark; | |
173 | ||
174 | setstackmark(&smark); | |
175 | setinputstring(s, 1); | |
176 | while ((n = parsecmd(0)) != NEOF) { | |
177 | evaltree(n, 0); | |
178 | popstackmark(&smark); | |
179 | } | |
180 | popfile(); | |
181 | popstackmark(&smark); | |
182 | } | |
183 | ||
184 | ||
185 | ||
186 | /* | |
187 | * Evaluate a parse tree. The value is left in the global variable | |
188 | * exitstatus. | |
189 | */ | |
190 | ||
191 | void | |
192 | evaltree(n, flags) | |
193 | union node *n; | |
194 | { | |
195 | if (n == NULL) { | |
196 | TRACE(("evaltree(NULL) called\n")); | |
197 | return; | |
198 | } | |
199 | TRACE(("evaltree(0x%x: %d) called\n", (int)n, n->type)); | |
200 | switch (n->type) { | |
201 | case NSEMI: | |
202 | evaltree(n->nbinary.ch1, 0); | |
203 | if (evalskip) | |
204 | goto out; | |
205 | evaltree(n->nbinary.ch2, flags); | |
206 | break; | |
207 | case NAND: | |
208 | evaltree(n->nbinary.ch1, EV_TESTED); | |
209 | if (evalskip || exitstatus != 0) | |
210 | goto out; | |
211 | evaltree(n->nbinary.ch2, flags); | |
212 | break; | |
213 | case NOR: | |
214 | evaltree(n->nbinary.ch1, EV_TESTED); | |
215 | if (evalskip || exitstatus == 0) | |
216 | goto out; | |
217 | evaltree(n->nbinary.ch2, flags); | |
218 | break; | |
219 | case NREDIR: | |
220 | expredir(n->nredir.redirect); | |
221 | redirect(n->nredir.redirect, REDIR_PUSH); | |
222 | evaltree(n->nredir.n, flags); | |
223 | popredir(); | |
224 | break; | |
225 | case NSUBSHELL: | |
226 | evalsubshell(n, flags); | |
227 | break; | |
228 | case NBACKGND: | |
229 | evalsubshell(n, flags); | |
230 | break; | |
231 | case NIF: { | |
232 | int status = 0; | |
233 | ||
234 | evaltree(n->nif.test, EV_TESTED); | |
235 | if (evalskip) | |
236 | goto out; | |
237 | if (exitstatus == 0) { | |
238 | evaltree(n->nif.ifpart, flags); | |
239 | status = exitstatus; | |
240 | } else if (n->nif.elsepart) { | |
241 | evaltree(n->nif.elsepart, flags); | |
242 | status = exitstatus; | |
243 | } | |
244 | exitstatus = status; | |
245 | break; | |
246 | } | |
247 | case NWHILE: | |
248 | case NUNTIL: | |
249 | evalloop(n); | |
250 | break; | |
251 | case NFOR: | |
252 | evalfor(n); | |
253 | break; | |
254 | case NCASE: | |
255 | evalcase(n, flags); | |
256 | break; | |
257 | case NDEFUN: | |
258 | defun(n->narg.text, n->narg.next); | |
259 | exitstatus = 0; | |
260 | break; | |
261 | case NPIPE: | |
262 | evalpipe(n); | |
263 | break; | |
264 | case NCMD: | |
265 | evalcommand(n, flags, (struct backcmd *)NULL); | |
266 | break; | |
267 | default: | |
268 | out1fmt("Node type = %d\n", n->type); | |
269 | flushout(&output); | |
270 | break; | |
271 | } | |
272 | out: | |
273 | if (pendingsigs) | |
274 | dotrap(); | |
275 | if ((flags & EV_EXIT) || (eflag && exitstatus && !(flags & EV_TESTED))) | |
276 | exitshell(exitstatus); | |
277 | } | |
278 | ||
279 | ||
280 | STATIC void | |
281 | evalloop(n) | |
282 | union node *n; | |
283 | { | |
284 | int status; | |
285 | ||
286 | loopnest++; | |
287 | status = 0; | |
288 | for (;;) { | |
289 | evaltree(n->nbinary.ch1, EV_TESTED); | |
290 | if (evalskip) { | |
291 | skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { | |
292 | evalskip = 0; | |
293 | continue; | |
294 | } | |
295 | if (evalskip == SKIPBREAK && --skipcount <= 0) | |
296 | evalskip = 0; | |
297 | break; | |
298 | } | |
299 | if (n->type == NWHILE) { | |
300 | if (exitstatus != 0) | |
301 | break; | |
302 | } else { | |
303 | if (exitstatus == 0) | |
304 | break; | |
305 | } | |
306 | evaltree(n->nbinary.ch2, 0); | |
307 | status = exitstatus; | |
308 | if (evalskip) | |
309 | goto skipping; | |
310 | } | |
311 | loopnest--; | |
312 | exitstatus = status; | |
313 | } | |
314 | ||
315 | ||
316 | ||
317 | STATIC void | |
318 | evalfor(n) | |
319 | union node *n; | |
320 | { | |
321 | struct arglist arglist; | |
322 | union node *argp; | |
323 | struct strlist *sp; | |
324 | struct stackmark smark; | |
325 | ||
326 | setstackmark(&smark); | |
327 | arglist.lastp = &arglist.list; | |
328 | for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { | |
329 | expandarg(argp, &arglist, 1); | |
330 | if (evalskip) | |
331 | goto out; | |
332 | } | |
333 | *arglist.lastp = NULL; | |
334 | ||
335 | exitstatus = 0; | |
336 | loopnest++; | |
337 | for (sp = arglist.list ; sp ; sp = sp->next) { | |
338 | setvar(n->nfor.var, sp->text, 0); | |
339 | evaltree(n->nfor.body, 0); | |
340 | if (evalskip) { | |
341 | if (evalskip == SKIPCONT && --skipcount <= 0) { | |
342 | evalskip = 0; | |
343 | continue; | |
344 | } | |
345 | if (evalskip == SKIPBREAK && --skipcount <= 0) | |
346 | evalskip = 0; | |
347 | break; | |
348 | } | |
349 | } | |
350 | loopnest--; | |
351 | out: | |
352 | popstackmark(&smark); | |
353 | } | |
354 | ||
355 | ||
356 | ||
357 | STATIC void | |
358 | evalcase(n, flags) | |
359 | union node *n; | |
360 | { | |
361 | union node *cp; | |
362 | union node *patp; | |
363 | struct arglist arglist; | |
364 | struct stackmark smark; | |
365 | ||
366 | setstackmark(&smark); | |
367 | arglist.lastp = &arglist.list; | |
368 | expandarg(n->ncase.expr, &arglist, 0); | |
369 | for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { | |
370 | for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { | |
371 | if (casematch(patp, arglist.list->text)) { | |
372 | if (evalskip == 0) { | |
373 | evaltree(cp->nclist.body, flags); | |
374 | } | |
375 | goto out; | |
376 | } | |
377 | } | |
378 | } | |
379 | out: | |
380 | popstackmark(&smark); | |
381 | } | |
382 | ||
383 | ||
384 | ||
385 | /* | |
386 | * Kick off a subshell to evaluate a tree. | |
387 | */ | |
388 | ||
389 | STATIC void | |
390 | evalsubshell(n, flags) | |
391 | union node *n; | |
392 | { | |
393 | struct job *jp; | |
394 | int backgnd = (n->type == NBACKGND); | |
395 | ||
396 | expredir(n->nredir.redirect); | |
397 | jp = makejob(n, 1); | |
398 | if (forkshell(jp, n, backgnd) == 0) { | |
399 | if (backgnd) | |
400 | flags &=~ EV_TESTED; | |
401 | redirect(n->nredir.redirect, 0); | |
402 | evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ | |
403 | } | |
404 | if (! backgnd) { | |
405 | INTOFF; | |
406 | exitstatus = waitforjob(jp); | |
407 | INTON; | |
408 | } | |
409 | } | |
410 | ||
411 | ||
412 | ||
413 | /* | |
414 | * Compute the names of the files in a redirection list. | |
415 | */ | |
416 | ||
417 | STATIC void | |
418 | expredir(n) | |
419 | union node *n; | |
420 | { | |
421 | register union node *redir; | |
422 | ||
423 | for (redir = n ; redir ; redir = redir->nfile.next) { | |
424 | if (redir->type == NFROM | |
425 | || redir->type == NTO | |
426 | || redir->type == NAPPEND) { | |
427 | struct arglist fn; | |
428 | fn.lastp = &fn.list; | |
429 | expandarg(redir->nfile.fname, &fn, 0); | |
430 | redir->nfile.expfname = fn.list->text; | |
431 | } | |
432 | } | |
433 | } | |
434 | ||
435 | ||
436 | ||
437 | /* | |
438 | * Evaluate a pipeline. All the processes in the pipeline are children | |
439 | * of the process creating the pipeline. (This differs from some versions | |
440 | * of the shell, which make the last process in a pipeline the parent | |
441 | * of all the rest.) | |
442 | */ | |
443 | ||
444 | STATIC void | |
445 | evalpipe(n) | |
446 | union node *n; | |
447 | { | |
448 | struct job *jp; | |
449 | struct nodelist *lp; | |
450 | int pipelen; | |
451 | int prevfd; | |
452 | int pip[2]; | |
453 | ||
454 | TRACE(("evalpipe(0x%x) called\n", (int)n)); | |
455 | pipelen = 0; | |
456 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) | |
457 | pipelen++; | |
458 | INTOFF; | |
459 | jp = makejob(n, pipelen); | |
460 | prevfd = -1; | |
461 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { | |
462 | prehash(lp->n); | |
463 | pip[1] = -1; | |
464 | if (lp->next) { | |
465 | if (pipe(pip) < 0) { | |
466 | close(prevfd); | |
467 | error("Pipe call failed"); | |
468 | } | |
469 | } | |
470 | if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { | |
471 | INTON; | |
472 | if (prevfd > 0) { | |
473 | close(0); | |
474 | copyfd(prevfd, 0); | |
475 | close(prevfd); | |
476 | } | |
477 | if (pip[1] >= 0) { | |
478 | close(pip[0]); | |
479 | if (pip[1] != 1) { | |
480 | close(1); | |
481 | copyfd(pip[1], 1); | |
482 | close(pip[1]); | |
483 | } | |
484 | } | |
485 | evaltree(lp->n, EV_EXIT); | |
486 | } | |
487 | if (prevfd >= 0) | |
488 | close(prevfd); | |
489 | prevfd = pip[0]; | |
490 | close(pip[1]); | |
491 | } | |
492 | INTON; | |
493 | if (n->npipe.backgnd == 0) { | |
494 | INTOFF; | |
495 | exitstatus = waitforjob(jp); | |
496 | TRACE(("evalpipe: job done exit status %d\n", exitstatus)); | |
497 | INTON; | |
498 | } | |
499 | } | |
500 | ||
501 | ||
502 | ||
503 | /* | |
504 | * Execute a command inside back quotes. If it's a builtin command, we | |
505 | * want to save its output in a block obtained from malloc. Otherwise | |
506 | * we fork off a subprocess and get the output of the command via a pipe. | |
507 | * Should be called with interrupts off. | |
508 | */ | |
509 | ||
510 | void | |
511 | evalbackcmd(n, result) | |
512 | union node *n; | |
513 | struct backcmd *result; | |
514 | { | |
515 | int pip[2]; | |
516 | struct job *jp; | |
517 | struct stackmark smark; /* unnecessary */ | |
518 | ||
519 | setstackmark(&smark); | |
520 | result->fd = -1; | |
521 | result->buf = NULL; | |
522 | result->nleft = 0; | |
523 | result->jp = NULL; | |
524 | if (n->type == NCMD) { | |
525 | evalcommand(n, EV_BACKCMD, result); | |
526 | } else { | |
527 | if (pipe(pip) < 0) | |
528 | error("Pipe call failed"); | |
529 | jp = makejob(n, 1); | |
530 | if (forkshell(jp, n, FORK_NOJOB) == 0) { | |
531 | FORCEINTON; | |
532 | close(pip[0]); | |
533 | if (pip[1] != 1) { | |
534 | close(1); | |
535 | copyfd(pip[1], 1); | |
536 | close(pip[1]); | |
537 | } | |
538 | evaltree(n, EV_EXIT); | |
539 | } | |
540 | close(pip[1]); | |
541 | result->fd = pip[0]; | |
542 | result->jp = jp; | |
543 | } | |
544 | popstackmark(&smark); | |
545 | TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", | |
546 | result->fd, result->buf, result->nleft, result->jp)); | |
547 | } | |
548 | ||
549 | ||
550 | ||
551 | /* | |
552 | * Execute a simple command. | |
553 | */ | |
554 | ||
555 | STATIC void | |
556 | evalcommand(cmd, flags, backcmd) | |
557 | union node *cmd; | |
558 | struct backcmd *backcmd; | |
559 | { | |
560 | struct stackmark smark; | |
561 | union node *argp; | |
562 | struct arglist arglist; | |
563 | struct arglist varlist; | |
564 | char **argv; | |
565 | int argc; | |
566 | char **envp; | |
567 | int varflag; | |
568 | struct strlist *sp; | |
569 | register char *p; | |
570 | int mode; | |
571 | int pip[2]; | |
572 | struct cmdentry cmdentry; | |
573 | struct job *jp; | |
574 | struct jmploc jmploc; | |
575 | struct jmploc *volatile savehandler; | |
576 | char *volatile savecmdname; | |
577 | volatile struct shparam saveparam; | |
578 | struct localvar *volatile savelocalvars; | |
579 | volatile int e; | |
580 | char *lastarg; | |
581 | ||
582 | /* First expand the arguments. */ | |
583 | TRACE(("evalcommand(0x%x, %d) called\n", (int)cmd, flags)); | |
584 | setstackmark(&smark); | |
585 | arglist.lastp = &arglist.list; | |
586 | varlist.lastp = &varlist.list; | |
587 | varflag = 1; | |
588 | for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { | |
589 | p = argp->narg.text; | |
590 | if (varflag && is_name(*p)) { | |
591 | do { | |
592 | p++; | |
593 | } while (is_in_name(*p)); | |
594 | if (*p == '=') { | |
595 | expandarg(argp, &varlist, 0); | |
596 | continue; | |
597 | } | |
598 | } | |
599 | expandarg(argp, &arglist, 1); | |
600 | varflag = 0; | |
601 | } | |
602 | *arglist.lastp = NULL; | |
603 | *varlist.lastp = NULL; | |
604 | expredir(cmd->ncmd.redirect); | |
605 | argc = 0; | |
606 | for (sp = arglist.list ; sp ; sp = sp->next) | |
607 | argc++; | |
608 | argv = stalloc(sizeof (char *) * (argc + 1)); | |
609 | for (sp = arglist.list ; sp ; sp = sp->next) | |
610 | *argv++ = sp->text; | |
611 | *argv = NULL; | |
612 | lastarg = NULL; | |
613 | if (iflag && funcnest == 0 && argc > 0) | |
614 | lastarg = argv[-1]; | |
615 | argv -= argc; | |
616 | ||
617 | /* Print the command if xflag is set. */ | |
618 | if (xflag) { | |
619 | outc('+', &errout); | |
620 | for (sp = varlist.list ; sp ; sp = sp->next) { | |
621 | outc(' ', &errout); | |
622 | out2str(sp->text); | |
623 | } | |
624 | for (sp = arglist.list ; sp ; sp = sp->next) { | |
625 | outc(' ', &errout); | |
626 | out2str(sp->text); | |
627 | } | |
628 | outc('\n', &errout); | |
629 | flushout(&errout); | |
630 | } | |
631 | ||
632 | /* Now locate the command. */ | |
633 | if (argc == 0) { | |
634 | cmdentry.cmdtype = CMDBUILTIN; | |
635 | cmdentry.u.index = BLTINCMD; | |
636 | } else { | |
637 | find_command(argv[0], &cmdentry, 1); | |
638 | if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ | |
639 | exitstatus = 2; | |
640 | flushout(&errout); | |
641 | return; | |
642 | } | |
643 | /* implement the bltin builtin here */ | |
644 | if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { | |
645 | for (;;) { | |
646 | argv++; | |
647 | if (--argc == 0) | |
648 | break; | |
649 | if ((cmdentry.u.index = find_builtin(*argv)) < 0) { | |
650 | outfmt(&errout, "%s: not found\n", *argv); | |
651 | exitstatus = 2; | |
652 | flushout(&errout); | |
653 | return; | |
654 | } | |
655 | if (cmdentry.u.index != BLTINCMD) | |
656 | break; | |
657 | } | |
658 | } | |
659 | } | |
660 | ||
661 | /* Fork off a child process if necessary. */ | |
662 | if (cmd->ncmd.backgnd | |
663 | || cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0 | |
664 | || (flags & EV_BACKCMD) != 0 | |
665 | && (cmdentry.cmdtype != CMDBUILTIN | |
666 | || cmdentry.u.index == DOTCMD | |
667 | || cmdentry.u.index == EVALCMD)) { | |
668 | jp = makejob(cmd, 1); | |
669 | mode = cmd->ncmd.backgnd; | |
670 | if (flags & EV_BACKCMD) { | |
671 | mode = FORK_NOJOB; | |
672 | if (pipe(pip) < 0) | |
673 | error("Pipe call failed"); | |
674 | } | |
675 | if (forkshell(jp, cmd, mode) != 0) | |
676 | goto parent; /* at end of routine */ | |
677 | if (flags & EV_BACKCMD) { | |
678 | FORCEINTON; | |
679 | close(pip[0]); | |
680 | if (pip[1] != 1) { | |
681 | close(1); | |
682 | copyfd(pip[1], 1); | |
683 | close(pip[1]); | |
684 | } | |
685 | } | |
686 | flags |= EV_EXIT; | |
687 | } | |
688 | ||
689 | /* This is the child process if a fork occurred. */ | |
690 | /* Execute the command. */ | |
691 | if (cmdentry.cmdtype == CMDFUNCTION) { | |
692 | trputs("Shell function: "); trargs(argv); | |
693 | redirect(cmd->ncmd.redirect, REDIR_PUSH); | |
694 | saveparam = shellparam; | |
695 | shellparam.malloc = 0; | |
696 | shellparam.nparam = argc - 1; | |
697 | shellparam.p = argv + 1; | |
698 | shellparam.optnext = NULL; | |
699 | INTOFF; | |
700 | savelocalvars = localvars; | |
701 | localvars = NULL; | |
702 | INTON; | |
703 | if (setjmp(jmploc.loc)) { | |
704 | if (exception == EXSHELLPROC) | |
705 | freeparam((struct shparam *)&saveparam); | |
706 | else { | |
707 | freeparam(&shellparam); | |
708 | shellparam = saveparam; | |
709 | } | |
710 | poplocalvars(); | |
711 | localvars = savelocalvars; | |
712 | handler = savehandler; | |
713 | longjmp(handler->loc, 1); | |
714 | } | |
715 | savehandler = handler; | |
716 | handler = &jmploc; | |
717 | for (sp = varlist.list ; sp ; sp = sp->next) | |
718 | mklocal(sp->text); | |
719 | funcnest++; | |
720 | evaltree(cmdentry.u.func, 0); | |
721 | funcnest--; | |
722 | INTOFF; | |
723 | poplocalvars(); | |
724 | localvars = savelocalvars; | |
725 | freeparam(&shellparam); | |
726 | shellparam = saveparam; | |
727 | handler = savehandler; | |
728 | popredir(); | |
729 | INTON; | |
730 | if (evalskip == SKIPFUNC) { | |
731 | evalskip = 0; | |
732 | skipcount = 0; | |
733 | } | |
734 | if (flags & EV_EXIT) | |
735 | exitshell(exitstatus); | |
736 | } else if (cmdentry.cmdtype == CMDBUILTIN) { | |
737 | trputs("builtin command: "); trargs(argv); | |
738 | mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; | |
739 | if (flags == EV_BACKCMD) { | |
740 | memout.nleft = 0; | |
741 | memout.nextc = memout.buf; | |
742 | memout.bufsize = 64; | |
743 | mode |= REDIR_BACKQ; | |
744 | } | |
745 | redirect(cmd->ncmd.redirect, mode); | |
746 | savecmdname = commandname; | |
747 | cmdenviron = varlist.list; | |
748 | e = -1; | |
749 | if (setjmp(jmploc.loc)) { | |
750 | e = exception; | |
751 | exitstatus = (e == EXINT)? SIGINT+128 : 2; | |
752 | goto cmddone; | |
753 | } | |
754 | savehandler = handler; | |
755 | handler = &jmploc; | |
756 | commandname = argv[0]; | |
757 | argptr = argv + 1; | |
758 | optptr = NULL; /* initialize nextopt */ | |
759 | exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); | |
760 | flushall(); | |
761 | cmddone: | |
762 | out1 = &output; | |
763 | out2 = &errout; | |
764 | freestdout(); | |
765 | if (e != EXSHELLPROC) { | |
766 | commandname = savecmdname; | |
767 | if (flags & EV_EXIT) { | |
768 | exitshell(exitstatus); | |
769 | } | |
770 | } | |
771 | handler = savehandler; | |
772 | if (e != -1) { | |
773 | if (e != EXERROR || cmdentry.u.index == BLTINCMD | |
774 | || cmdentry.u.index == DOTCMD | |
775 | || cmdentry.u.index == EVALCMD | |
776 | || cmdentry.u.index == EXECCMD) | |
777 | exraise(e); | |
778 | FORCEINTON; | |
779 | } | |
780 | if (cmdentry.u.index != EXECCMD) | |
781 | popredir(); | |
782 | if (flags == EV_BACKCMD) { | |
783 | backcmd->buf = memout.buf; | |
784 | backcmd->nleft = memout.nextc - memout.buf; | |
785 | memout.buf = NULL; | |
786 | } | |
787 | } else { | |
788 | trputs("normal command: "); trargs(argv); | |
789 | clearredir(); | |
790 | redirect(cmd->ncmd.redirect, 0); | |
791 | if (varlist.list) { | |
792 | p = stalloc(strlen(pathval()) + 1); | |
793 | scopy(pathval(), p); | |
794 | } else { | |
795 | p = pathval(); | |
796 | } | |
797 | for (sp = varlist.list ; sp ; sp = sp->next) | |
798 | setvareq(sp->text, VEXPORT|VSTACK); | |
799 | envp = environment(); | |
800 | shellexec(argv, envp, p, cmdentry.u.index); | |
801 | /*NOTREACHED*/ | |
802 | } | |
803 | goto out; | |
804 | ||
805 | parent: /* parent process gets here (if we forked) */ | |
806 | if (mode == 0) { /* argument to fork */ | |
807 | INTOFF; | |
808 | exitstatus = waitforjob(jp); | |
809 | INTON; | |
810 | } else if (mode == 2) { | |
811 | backcmd->fd = pip[0]; | |
812 | close(pip[1]); | |
813 | backcmd->jp = jp; | |
814 | } | |
815 | ||
816 | out: | |
817 | if (lastarg) | |
818 | setvar("_", lastarg, 0); | |
819 | popstackmark(&smark); | |
820 | } | |
821 | ||
822 | ||
823 | ||
824 | /* | |
825 | * Search for a command. This is called before we fork so that the | |
826 | * location of the command will be available in the parent as well as | |
827 | * the child. The check for "goodname" is an overly conservative | |
828 | * check that the name will not be subject to expansion. | |
829 | */ | |
830 | ||
831 | STATIC void | |
832 | prehash(n) | |
833 | union node *n; | |
834 | { | |
835 | struct cmdentry entry; | |
836 | ||
837 | if (n->type == NCMD && goodname(n->ncmd.args->narg.text)) | |
838 | find_command(n->ncmd.args->narg.text, &entry, 0); | |
839 | } | |
840 | ||
841 | ||
842 | ||
843 | /* | |
844 | * Builtin commands. Builtin commands whose functions are closely | |
845 | * tied to evaluation are implemented here. | |
846 | */ | |
847 | ||
848 | /* | |
849 | * No command given, or a bltin command with no arguments. Set the | |
850 | * specified variables. | |
851 | */ | |
852 | ||
853 | bltincmd(argc, argv) char **argv; { | |
854 | listsetvar(cmdenviron); | |
855 | return exitstatus; | |
856 | } | |
857 | ||
858 | ||
859 | /* | |
860 | * Handle break and continue commands. Break, continue, and return are | |
861 | * all handled by setting the evalskip flag. The evaluation routines | |
862 | * above all check this flag, and if it is set they start skipping | |
863 | * commands rather than executing them. The variable skipcount is | |
864 | * the number of loops to break/continue, or the number of function | |
865 | * levels to return. (The latter is always 1.) It should probably | |
866 | * be an error to break out of more loops than exist, but it isn't | |
867 | * in the standard shell so we don't make it one here. | |
868 | */ | |
869 | ||
870 | breakcmd(argc, argv) char **argv; { | |
871 | int n; | |
872 | ||
873 | n = 1; | |
874 | if (argc > 1) | |
875 | n = number(argv[1]); | |
876 | if (n > loopnest) | |
877 | n = loopnest; | |
878 | if (n > 0) { | |
879 | evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; | |
880 | skipcount = n; | |
881 | } | |
882 | return 0; | |
883 | } | |
884 | ||
885 | ||
886 | /* | |
887 | * The return command. | |
888 | */ | |
889 | ||
890 | returncmd(argc, argv) char **argv; { | |
891 | int ret; | |
892 | ||
893 | ret = exitstatus; | |
894 | if (argc > 1) | |
895 | ret = number(argv[1]); | |
896 | if (funcnest) { | |
897 | evalskip = SKIPFUNC; | |
898 | skipcount = 1; | |
899 | } | |
900 | return ret; | |
901 | } | |
902 | ||
78ed81a3 | 903 | falsecmd(argc, argv) char **argv; { |
904 | return 1; | |
905 | } | |
15637ed4 RG |
906 | |
907 | truecmd(argc, argv) char **argv; { | |
908 | return 0; | |
909 | } | |
910 | ||
911 | ||
912 | execcmd(argc, argv) char **argv; { | |
913 | if (argc > 1) { | |
914 | iflag = 0; /* exit on error */ | |
915 | setinteractive(0); | |
916 | #if JOBS | |
917 | jflag = 0; | |
918 | setjobctl(0); | |
919 | #endif | |
920 | shellexec(argv + 1, environment(), pathval(), 0); | |
921 | ||
922 | } | |
923 | return 0; | |
924 | } |