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b3d7414a KB |
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 | * | |
93e07f49 MT |
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. | |
b3d7414a KB |
35 | */ |
36 | ||
37 | #ifndef lint | |
93e07f49 | 38 | static char sccsid[] = "@(#)eval.c 5.4 (Berkeley) 4/16/92"; |
b3d7414a KB |
39 | #endif /* not lint */ |
40 | ||
41 | /* | |
42 | * Evaluate a command. | |
43 | */ | |
44 | ||
45 | #include "shell.h" | |
46 | #include "nodes.h" | |
47 | #include "syntax.h" | |
48 | #include "expand.h" | |
49 | #include "parser.h" | |
50 | #include "jobs.h" | |
51 | #include "eval.h" | |
52 | #include "builtins.h" | |
53 | #include "options.h" | |
54 | #include "exec.h" | |
55 | #include "redir.h" | |
56 | #include "input.h" | |
57 | #include "output.h" | |
58 | #include "trap.h" | |
59 | #include "var.h" | |
60 | #include "memalloc.h" | |
61 | #include "error.h" | |
62 | #include "mystring.h" | |
63 | #include <signal.h> | |
64 | ||
65 | ||
66 | /* flags in argument to evaltree */ | |
67 | #define EV_EXIT 01 /* exit after evaluating tree */ | |
68 | #define EV_TESTED 02 /* exit status is checked; ignore -e flag */ | |
69 | #define EV_BACKCMD 04 /* command executing within back quotes */ | |
70 | ||
71 | ||
72 | /* reasons for skipping commands (see comment on breakcmd routine) */ | |
73 | #define SKIPBREAK 1 | |
74 | #define SKIPCONT 2 | |
75 | #define SKIPFUNC 3 | |
76 | ||
77 | MKINIT int evalskip; /* set if we are skipping commands */ | |
78 | STATIC int skipcount; /* number of levels to skip */ | |
79 | MKINIT int loopnest; /* current loop nesting level */ | |
80 | int funcnest; /* depth of function calls */ | |
81 | ||
82 | ||
83 | char *commandname; | |
84 | struct strlist *cmdenviron; | |
85 | int exitstatus; /* exit status of last command */ | |
86 | ||
87 | ||
88 | #ifdef __STDC__ | |
89 | STATIC void evalloop(union node *); | |
90 | STATIC void evalfor(union node *); | |
91 | STATIC void evalcase(union node *, int); | |
92 | STATIC void evalsubshell(union node *, int); | |
93 | STATIC void expredir(union node *); | |
94 | STATIC void evalpipe(union node *); | |
95 | STATIC void evalcommand(union node *, int, struct backcmd *); | |
96 | STATIC void prehash(union node *); | |
97 | #else | |
98 | STATIC void evalloop(); | |
99 | STATIC void evalfor(); | |
100 | STATIC void evalcase(); | |
101 | STATIC void evalsubshell(); | |
102 | STATIC void expredir(); | |
103 | STATIC void evalpipe(); | |
104 | STATIC void evalcommand(); | |
105 | STATIC void prehash(); | |
106 | #endif | |
107 | ||
108 | ||
109 | ||
110 | /* | |
111 | * Called to reset things after an exception. | |
112 | */ | |
113 | ||
114 | #ifdef mkinit | |
115 | INCLUDE "eval.h" | |
116 | ||
117 | RESET { | |
118 | evalskip = 0; | |
119 | loopnest = 0; | |
120 | funcnest = 0; | |
121 | } | |
122 | ||
123 | SHELLPROC { | |
124 | exitstatus = 0; | |
125 | } | |
126 | #endif | |
127 | ||
128 | ||
129 | ||
130 | /* | |
ddba57cd | 131 | * The eval commmand. |
b3d7414a KB |
132 | */ |
133 | ||
ddba57cd MT |
134 | evalcmd(argc, argv) |
135 | char **argv; | |
136 | { | |
137 | char *p; | |
138 | char *concat; | |
139 | char **ap; | |
140 | ||
141 | if (argc > 1) { | |
142 | p = argv[1]; | |
143 | if (argc > 2) { | |
144 | STARTSTACKSTR(concat); | |
145 | ap = argv + 2; | |
146 | for (;;) { | |
147 | while (*p) | |
148 | STPUTC(*p++, concat); | |
149 | if ((p = *ap++) == NULL) | |
150 | break; | |
151 | STPUTC(' ', concat); | |
152 | } | |
153 | STPUTC('\0', concat); | |
154 | p = grabstackstr(concat); | |
155 | } | |
156 | evalstring(p); | |
157 | } | |
158 | return exitstatus; | |
b3d7414a | 159 | } |
b3d7414a KB |
160 | |
161 | ||
162 | /* | |
163 | * Execute a command or commands contained in a string. | |
164 | */ | |
165 | ||
166 | void | |
167 | evalstring(s) | |
168 | char *s; | |
169 | { | |
170 | union node *n; | |
171 | struct stackmark smark; | |
172 | ||
173 | setstackmark(&smark); | |
174 | setinputstring(s, 1); | |
175 | while ((n = parsecmd(0)) != NEOF) { | |
176 | evaltree(n, 0); | |
177 | popstackmark(&smark); | |
178 | } | |
179 | popfile(); | |
180 | popstackmark(&smark); | |
181 | } | |
182 | ||
183 | ||
184 | ||
185 | /* | |
186 | * Evaluate a parse tree. The value is left in the global variable | |
187 | * exitstatus. | |
188 | */ | |
189 | ||
190 | void | |
191 | evaltree(n, flags) | |
192 | union node *n; | |
193 | { | |
194 | if (n == NULL) { | |
195 | TRACE(("evaltree(NULL) called\n")); | |
196 | return; | |
197 | } | |
198 | TRACE(("evaltree(0x%x: %d) called\n", (int)n, n->type)); | |
199 | switch (n->type) { | |
200 | case NSEMI: | |
201 | evaltree(n->nbinary.ch1, 0); | |
202 | if (evalskip) | |
203 | goto out; | |
204 | evaltree(n->nbinary.ch2, flags); | |
205 | break; | |
206 | case NAND: | |
207 | evaltree(n->nbinary.ch1, EV_TESTED); | |
208 | if (evalskip || exitstatus != 0) | |
209 | goto out; | |
210 | evaltree(n->nbinary.ch2, flags); | |
211 | break; | |
212 | case NOR: | |
213 | evaltree(n->nbinary.ch1, EV_TESTED); | |
214 | if (evalskip || exitstatus == 0) | |
215 | goto out; | |
216 | evaltree(n->nbinary.ch2, flags); | |
217 | break; | |
218 | case NREDIR: | |
219 | expredir(n->nredir.redirect); | |
220 | redirect(n->nredir.redirect, REDIR_PUSH); | |
221 | evaltree(n->nredir.n, flags); | |
222 | popredir(); | |
223 | break; | |
224 | case NSUBSHELL: | |
225 | evalsubshell(n, flags); | |
226 | break; | |
227 | case NBACKGND: | |
228 | evalsubshell(n, flags); | |
229 | break; | |
932f34f0 MT |
230 | case NIF: { |
231 | int status = 0; | |
232 | ||
b3d7414a KB |
233 | evaltree(n->nif.test, EV_TESTED); |
234 | if (evalskip) | |
235 | goto out; | |
236 | if (exitstatus == 0) { | |
237 | evaltree(n->nif.ifpart, flags); | |
932f34f0 | 238 | status = exitstatus; |
b3d7414a KB |
239 | } else if (n->nif.elsepart) { |
240 | evaltree(n->nif.elsepart, flags); | |
932f34f0 | 241 | status = exitstatus; |
b3d7414a | 242 | } |
932f34f0 | 243 | exitstatus = status; |
b3d7414a | 244 | break; |
932f34f0 | 245 | } |
b3d7414a KB |
246 | case NWHILE: |
247 | case NUNTIL: | |
248 | evalloop(n); | |
249 | break; | |
250 | case NFOR: | |
251 | evalfor(n); | |
252 | break; | |
253 | case NCASE: | |
254 | evalcase(n, flags); | |
255 | break; | |
256 | case NDEFUN: | |
257 | defun(n->narg.text, n->narg.next); | |
258 | exitstatus = 0; | |
259 | break; | |
1545e6b2 MT |
260 | case NNOT: |
261 | evaltree(n->nnot.com, EV_TESTED); | |
262 | exitstatus = !exitstatus; | |
263 | break; | |
264 | ||
b3d7414a KB |
265 | case NPIPE: |
266 | evalpipe(n); | |
267 | break; | |
268 | case NCMD: | |
269 | evalcommand(n, flags, (struct backcmd *)NULL); | |
270 | break; | |
271 | default: | |
272 | out1fmt("Node type = %d\n", n->type); | |
273 | flushout(&output); | |
274 | break; | |
275 | } | |
276 | out: | |
277 | if (pendingsigs) | |
278 | dotrap(); | |
279 | if ((flags & EV_EXIT) || (eflag && exitstatus && !(flags & EV_TESTED))) | |
280 | exitshell(exitstatus); | |
281 | } | |
282 | ||
283 | ||
284 | STATIC void | |
285 | evalloop(n) | |
286 | union node *n; | |
287 | { | |
288 | int status; | |
289 | ||
290 | loopnest++; | |
291 | status = 0; | |
292 | for (;;) { | |
293 | evaltree(n->nbinary.ch1, EV_TESTED); | |
294 | if (evalskip) { | |
295 | skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { | |
296 | evalskip = 0; | |
297 | continue; | |
298 | } | |
299 | if (evalskip == SKIPBREAK && --skipcount <= 0) | |
300 | evalskip = 0; | |
301 | break; | |
302 | } | |
303 | if (n->type == NWHILE) { | |
304 | if (exitstatus != 0) | |
305 | break; | |
306 | } else { | |
307 | if (exitstatus == 0) | |
308 | break; | |
309 | } | |
310 | evaltree(n->nbinary.ch2, 0); | |
311 | status = exitstatus; | |
312 | if (evalskip) | |
313 | goto skipping; | |
314 | } | |
315 | loopnest--; | |
316 | exitstatus = status; | |
317 | } | |
318 | ||
319 | ||
320 | ||
321 | STATIC void | |
322 | evalfor(n) | |
323 | union node *n; | |
324 | { | |
325 | struct arglist arglist; | |
326 | union node *argp; | |
327 | struct strlist *sp; | |
328 | struct stackmark smark; | |
329 | ||
330 | setstackmark(&smark); | |
331 | arglist.lastp = &arglist.list; | |
332 | for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { | |
93e07f49 | 333 | expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); |
b3d7414a KB |
334 | if (evalskip) |
335 | goto out; | |
336 | } | |
337 | *arglist.lastp = NULL; | |
338 | ||
339 | exitstatus = 0; | |
340 | loopnest++; | |
341 | for (sp = arglist.list ; sp ; sp = sp->next) { | |
342 | setvar(n->nfor.var, sp->text, 0); | |
343 | evaltree(n->nfor.body, 0); | |
344 | if (evalskip) { | |
345 | if (evalskip == SKIPCONT && --skipcount <= 0) { | |
346 | evalskip = 0; | |
347 | continue; | |
348 | } | |
349 | if (evalskip == SKIPBREAK && --skipcount <= 0) | |
350 | evalskip = 0; | |
351 | break; | |
352 | } | |
353 | } | |
354 | loopnest--; | |
355 | out: | |
356 | popstackmark(&smark); | |
357 | } | |
358 | ||
359 | ||
360 | ||
361 | STATIC void | |
362 | evalcase(n, flags) | |
363 | union node *n; | |
364 | { | |
365 | union node *cp; | |
366 | union node *patp; | |
367 | struct arglist arglist; | |
368 | struct stackmark smark; | |
369 | ||
370 | setstackmark(&smark); | |
371 | arglist.lastp = &arglist.list; | |
93e07f49 | 372 | expandarg(n->ncase.expr, &arglist, EXP_TILDE); |
b3d7414a KB |
373 | for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { |
374 | for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { | |
375 | if (casematch(patp, arglist.list->text)) { | |
376 | if (evalskip == 0) { | |
377 | evaltree(cp->nclist.body, flags); | |
378 | } | |
379 | goto out; | |
380 | } | |
381 | } | |
382 | } | |
383 | out: | |
384 | popstackmark(&smark); | |
385 | } | |
386 | ||
387 | ||
388 | ||
389 | /* | |
390 | * Kick off a subshell to evaluate a tree. | |
391 | */ | |
392 | ||
393 | STATIC void | |
394 | evalsubshell(n, flags) | |
395 | union node *n; | |
396 | { | |
397 | struct job *jp; | |
398 | int backgnd = (n->type == NBACKGND); | |
399 | ||
400 | expredir(n->nredir.redirect); | |
401 | jp = makejob(n, 1); | |
402 | if (forkshell(jp, n, backgnd) == 0) { | |
403 | if (backgnd) | |
404 | flags &=~ EV_TESTED; | |
405 | redirect(n->nredir.redirect, 0); | |
406 | evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ | |
407 | } | |
408 | if (! backgnd) { | |
409 | INTOFF; | |
410 | exitstatus = waitforjob(jp); | |
411 | INTON; | |
412 | } | |
413 | } | |
414 | ||
415 | ||
416 | ||
417 | /* | |
418 | * Compute the names of the files in a redirection list. | |
419 | */ | |
420 | ||
421 | STATIC void | |
422 | expredir(n) | |
423 | union node *n; | |
424 | { | |
425 | register union node *redir; | |
426 | ||
427 | for (redir = n ; redir ; redir = redir->nfile.next) { | |
428 | if (redir->type == NFROM | |
429 | || redir->type == NTO | |
430 | || redir->type == NAPPEND) { | |
431 | struct arglist fn; | |
432 | fn.lastp = &fn.list; | |
93e07f49 | 433 | expandarg(redir->nfile.fname, &fn, EXP_TILDE | EXP_REDIR); |
b3d7414a KB |
434 | redir->nfile.expfname = fn.list->text; |
435 | } | |
436 | } | |
437 | } | |
438 | ||
439 | ||
440 | ||
441 | /* | |
442 | * Evaluate a pipeline. All the processes in the pipeline are children | |
443 | * of the process creating the pipeline. (This differs from some versions | |
444 | * of the shell, which make the last process in a pipeline the parent | |
445 | * of all the rest.) | |
446 | */ | |
447 | ||
448 | STATIC void | |
449 | evalpipe(n) | |
450 | union node *n; | |
451 | { | |
452 | struct job *jp; | |
453 | struct nodelist *lp; | |
454 | int pipelen; | |
455 | int prevfd; | |
456 | int pip[2]; | |
457 | ||
458 | TRACE(("evalpipe(0x%x) called\n", (int)n)); | |
459 | pipelen = 0; | |
460 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) | |
461 | pipelen++; | |
462 | INTOFF; | |
463 | jp = makejob(n, pipelen); | |
464 | prevfd = -1; | |
465 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { | |
466 | prehash(lp->n); | |
467 | pip[1] = -1; | |
468 | if (lp->next) { | |
469 | if (pipe(pip) < 0) { | |
470 | close(prevfd); | |
471 | error("Pipe call failed"); | |
472 | } | |
473 | } | |
474 | if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { | |
475 | INTON; | |
476 | if (prevfd > 0) { | |
477 | close(0); | |
478 | copyfd(prevfd, 0); | |
479 | close(prevfd); | |
480 | } | |
481 | if (pip[1] >= 0) { | |
482 | close(pip[0]); | |
483 | if (pip[1] != 1) { | |
484 | close(1); | |
485 | copyfd(pip[1], 1); | |
486 | close(pip[1]); | |
487 | } | |
488 | } | |
489 | evaltree(lp->n, EV_EXIT); | |
490 | } | |
491 | if (prevfd >= 0) | |
492 | close(prevfd); | |
493 | prevfd = pip[0]; | |
494 | close(pip[1]); | |
495 | } | |
496 | INTON; | |
497 | if (n->npipe.backgnd == 0) { | |
498 | INTOFF; | |
499 | exitstatus = waitforjob(jp); | |
500 | TRACE(("evalpipe: job done exit status %d\n", exitstatus)); | |
501 | INTON; | |
502 | } | |
503 | } | |
504 | ||
505 | ||
506 | ||
507 | /* | |
508 | * Execute a command inside back quotes. If it's a builtin command, we | |
509 | * want to save its output in a block obtained from malloc. Otherwise | |
510 | * we fork off a subprocess and get the output of the command via a pipe. | |
511 | * Should be called with interrupts off. | |
512 | */ | |
513 | ||
514 | void | |
515 | evalbackcmd(n, result) | |
516 | union node *n; | |
517 | struct backcmd *result; | |
518 | { | |
519 | int pip[2]; | |
520 | struct job *jp; | |
521 | struct stackmark smark; /* unnecessary */ | |
522 | ||
523 | setstackmark(&smark); | |
524 | result->fd = -1; | |
525 | result->buf = NULL; | |
526 | result->nleft = 0; | |
527 | result->jp = NULL; | |
528 | if (n->type == NCMD) { | |
529 | evalcommand(n, EV_BACKCMD, result); | |
530 | } else { | |
531 | if (pipe(pip) < 0) | |
532 | error("Pipe call failed"); | |
533 | jp = makejob(n, 1); | |
534 | if (forkshell(jp, n, FORK_NOJOB) == 0) { | |
535 | FORCEINTON; | |
536 | close(pip[0]); | |
537 | if (pip[1] != 1) { | |
538 | close(1); | |
539 | copyfd(pip[1], 1); | |
540 | close(pip[1]); | |
541 | } | |
542 | evaltree(n, EV_EXIT); | |
543 | } | |
544 | close(pip[1]); | |
545 | result->fd = pip[0]; | |
546 | result->jp = jp; | |
547 | } | |
548 | popstackmark(&smark); | |
549 | TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", | |
550 | result->fd, result->buf, result->nleft, result->jp)); | |
551 | } | |
552 | ||
553 | ||
554 | ||
555 | /* | |
556 | * Execute a simple command. | |
557 | */ | |
558 | ||
559 | STATIC void | |
560 | evalcommand(cmd, flags, backcmd) | |
561 | union node *cmd; | |
562 | struct backcmd *backcmd; | |
563 | { | |
564 | struct stackmark smark; | |
565 | union node *argp; | |
566 | struct arglist arglist; | |
567 | struct arglist varlist; | |
568 | char **argv; | |
569 | int argc; | |
570 | char **envp; | |
571 | int varflag; | |
572 | struct strlist *sp; | |
573 | register char *p; | |
574 | int mode; | |
575 | int pip[2]; | |
576 | struct cmdentry cmdentry; | |
577 | struct job *jp; | |
578 | struct jmploc jmploc; | |
579 | struct jmploc *volatile savehandler; | |
580 | char *volatile savecmdname; | |
581 | volatile struct shparam saveparam; | |
582 | struct localvar *volatile savelocalvars; | |
583 | volatile int e; | |
584 | char *lastarg; | |
585 | ||
586 | /* First expand the arguments. */ | |
587 | TRACE(("evalcommand(0x%x, %d) called\n", (int)cmd, flags)); | |
588 | setstackmark(&smark); | |
589 | arglist.lastp = &arglist.list; | |
590 | varlist.lastp = &varlist.list; | |
591 | varflag = 1; | |
592 | for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { | |
593 | p = argp->narg.text; | |
594 | if (varflag && is_name(*p)) { | |
595 | do { | |
596 | p++; | |
597 | } while (is_in_name(*p)); | |
598 | if (*p == '=') { | |
93e07f49 | 599 | expandarg(argp, &varlist, EXP_VARTILDE); |
b3d7414a KB |
600 | continue; |
601 | } | |
602 | } | |
93e07f49 | 603 | expandarg(argp, &arglist, EXP_FULL | EXP_TILDE); |
b3d7414a KB |
604 | varflag = 0; |
605 | } | |
606 | *arglist.lastp = NULL; | |
607 | *varlist.lastp = NULL; | |
608 | expredir(cmd->ncmd.redirect); | |
609 | argc = 0; | |
610 | for (sp = arglist.list ; sp ; sp = sp->next) | |
611 | argc++; | |
612 | argv = stalloc(sizeof (char *) * (argc + 1)); | |
93e07f49 MT |
613 | for (sp = arglist.list ; sp ; sp = sp->next) { |
614 | TRACE(("evalcommand arg: %s\n", sp->text)); | |
b3d7414a | 615 | *argv++ = sp->text; |
93e07f49 | 616 | } |
b3d7414a KB |
617 | *argv = NULL; |
618 | lastarg = NULL; | |
619 | if (iflag && funcnest == 0 && argc > 0) | |
620 | lastarg = argv[-1]; | |
621 | argv -= argc; | |
622 | ||
623 | /* Print the command if xflag is set. */ | |
624 | if (xflag) { | |
625 | outc('+', &errout); | |
626 | for (sp = varlist.list ; sp ; sp = sp->next) { | |
627 | outc(' ', &errout); | |
628 | out2str(sp->text); | |
629 | } | |
630 | for (sp = arglist.list ; sp ; sp = sp->next) { | |
631 | outc(' ', &errout); | |
632 | out2str(sp->text); | |
633 | } | |
634 | outc('\n', &errout); | |
635 | flushout(&errout); | |
636 | } | |
637 | ||
638 | /* Now locate the command. */ | |
639 | if (argc == 0) { | |
640 | cmdentry.cmdtype = CMDBUILTIN; | |
641 | cmdentry.u.index = BLTINCMD; | |
642 | } else { | |
643 | find_command(argv[0], &cmdentry, 1); | |
644 | if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ | |
645 | exitstatus = 2; | |
646 | flushout(&errout); | |
647 | return; | |
648 | } | |
649 | /* implement the bltin builtin here */ | |
650 | if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { | |
651 | for (;;) { | |
652 | argv++; | |
653 | if (--argc == 0) | |
654 | break; | |
655 | if ((cmdentry.u.index = find_builtin(*argv)) < 0) { | |
656 | outfmt(&errout, "%s: not found\n", *argv); | |
657 | exitstatus = 2; | |
658 | flushout(&errout); | |
659 | return; | |
660 | } | |
661 | if (cmdentry.u.index != BLTINCMD) | |
662 | break; | |
663 | } | |
664 | } | |
665 | } | |
666 | ||
667 | /* Fork off a child process if necessary. */ | |
668 | if (cmd->ncmd.backgnd | |
669 | || cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0 | |
670 | || (flags & EV_BACKCMD) != 0 | |
671 | && (cmdentry.cmdtype != CMDBUILTIN | |
672 | || cmdentry.u.index == DOTCMD | |
673 | || cmdentry.u.index == EVALCMD)) { | |
674 | jp = makejob(cmd, 1); | |
675 | mode = cmd->ncmd.backgnd; | |
676 | if (flags & EV_BACKCMD) { | |
677 | mode = FORK_NOJOB; | |
678 | if (pipe(pip) < 0) | |
679 | error("Pipe call failed"); | |
680 | } | |
681 | if (forkshell(jp, cmd, mode) != 0) | |
682 | goto parent; /* at end of routine */ | |
683 | if (flags & EV_BACKCMD) { | |
684 | FORCEINTON; | |
685 | close(pip[0]); | |
686 | if (pip[1] != 1) { | |
687 | close(1); | |
688 | copyfd(pip[1], 1); | |
689 | close(pip[1]); | |
690 | } | |
691 | } | |
692 | flags |= EV_EXIT; | |
693 | } | |
694 | ||
695 | /* This is the child process if a fork occurred. */ | |
696 | /* Execute the command. */ | |
697 | if (cmdentry.cmdtype == CMDFUNCTION) { | |
698 | trputs("Shell function: "); trargs(argv); | |
699 | redirect(cmd->ncmd.redirect, REDIR_PUSH); | |
700 | saveparam = shellparam; | |
701 | shellparam.malloc = 0; | |
702 | shellparam.nparam = argc - 1; | |
703 | shellparam.p = argv + 1; | |
704 | shellparam.optnext = NULL; | |
705 | INTOFF; | |
706 | savelocalvars = localvars; | |
707 | localvars = NULL; | |
708 | INTON; | |
709 | if (setjmp(jmploc.loc)) { | |
710 | if (exception == EXSHELLPROC) | |
711 | freeparam((struct shparam *)&saveparam); | |
712 | else { | |
713 | freeparam(&shellparam); | |
714 | shellparam = saveparam; | |
715 | } | |
716 | poplocalvars(); | |
717 | localvars = savelocalvars; | |
718 | handler = savehandler; | |
719 | longjmp(handler->loc, 1); | |
720 | } | |
721 | savehandler = handler; | |
722 | handler = &jmploc; | |
723 | for (sp = varlist.list ; sp ; sp = sp->next) | |
724 | mklocal(sp->text); | |
725 | funcnest++; | |
726 | evaltree(cmdentry.u.func, 0); | |
727 | funcnest--; | |
728 | INTOFF; | |
729 | poplocalvars(); | |
730 | localvars = savelocalvars; | |
731 | freeparam(&shellparam); | |
732 | shellparam = saveparam; | |
733 | handler = savehandler; | |
734 | popredir(); | |
735 | INTON; | |
736 | if (evalskip == SKIPFUNC) { | |
737 | evalskip = 0; | |
738 | skipcount = 0; | |
739 | } | |
740 | if (flags & EV_EXIT) | |
741 | exitshell(exitstatus); | |
742 | } else if (cmdentry.cmdtype == CMDBUILTIN) { | |
743 | trputs("builtin command: "); trargs(argv); | |
744 | mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; | |
745 | if (flags == EV_BACKCMD) { | |
746 | memout.nleft = 0; | |
747 | memout.nextc = memout.buf; | |
748 | memout.bufsize = 64; | |
749 | mode |= REDIR_BACKQ; | |
750 | } | |
751 | redirect(cmd->ncmd.redirect, mode); | |
752 | savecmdname = commandname; | |
753 | cmdenviron = varlist.list; | |
754 | e = -1; | |
755 | if (setjmp(jmploc.loc)) { | |
756 | e = exception; | |
757 | exitstatus = (e == EXINT)? SIGINT+128 : 2; | |
758 | goto cmddone; | |
759 | } | |
760 | savehandler = handler; | |
761 | handler = &jmploc; | |
762 | commandname = argv[0]; | |
763 | argptr = argv + 1; | |
764 | optptr = NULL; /* initialize nextopt */ | |
765 | exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); | |
766 | flushall(); | |
767 | cmddone: | |
768 | out1 = &output; | |
769 | out2 = &errout; | |
770 | freestdout(); | |
771 | if (e != EXSHELLPROC) { | |
772 | commandname = savecmdname; | |
773 | if (flags & EV_EXIT) { | |
774 | exitshell(exitstatus); | |
775 | } | |
776 | } | |
777 | handler = savehandler; | |
778 | if (e != -1) { | |
779 | if (e != EXERROR || cmdentry.u.index == BLTINCMD | |
780 | || cmdentry.u.index == DOTCMD | |
781 | || cmdentry.u.index == EVALCMD | |
782 | || cmdentry.u.index == EXECCMD) | |
783 | exraise(e); | |
784 | FORCEINTON; | |
785 | } | |
786 | if (cmdentry.u.index != EXECCMD) | |
787 | popredir(); | |
788 | if (flags == EV_BACKCMD) { | |
789 | backcmd->buf = memout.buf; | |
790 | backcmd->nleft = memout.nextc - memout.buf; | |
791 | memout.buf = NULL; | |
792 | } | |
793 | } else { | |
794 | trputs("normal command: "); trargs(argv); | |
795 | clearredir(); | |
796 | redirect(cmd->ncmd.redirect, 0); | |
797 | if (varlist.list) { | |
798 | p = stalloc(strlen(pathval()) + 1); | |
799 | scopy(pathval(), p); | |
800 | } else { | |
801 | p = pathval(); | |
802 | } | |
803 | for (sp = varlist.list ; sp ; sp = sp->next) | |
804 | setvareq(sp->text, VEXPORT|VSTACK); | |
805 | envp = environment(); | |
806 | shellexec(argv, envp, p, cmdentry.u.index); | |
807 | /*NOTREACHED*/ | |
808 | } | |
809 | goto out; | |
810 | ||
811 | parent: /* parent process gets here (if we forked) */ | |
812 | if (mode == 0) { /* argument to fork */ | |
813 | INTOFF; | |
814 | exitstatus = waitforjob(jp); | |
815 | INTON; | |
816 | } else if (mode == 2) { | |
817 | backcmd->fd = pip[0]; | |
818 | close(pip[1]); | |
819 | backcmd->jp = jp; | |
820 | } | |
821 | ||
822 | out: | |
823 | if (lastarg) | |
824 | setvar("_", lastarg, 0); | |
825 | popstackmark(&smark); | |
826 | } | |
827 | ||
828 | ||
829 | ||
830 | /* | |
831 | * Search for a command. This is called before we fork so that the | |
832 | * location of the command will be available in the parent as well as | |
833 | * the child. The check for "goodname" is an overly conservative | |
834 | * check that the name will not be subject to expansion. | |
835 | */ | |
836 | ||
837 | STATIC void | |
838 | prehash(n) | |
839 | union node *n; | |
840 | { | |
841 | struct cmdentry entry; | |
842 | ||
843 | if (n->type == NCMD && goodname(n->ncmd.args->narg.text)) | |
844 | find_command(n->ncmd.args->narg.text, &entry, 0); | |
845 | } | |
846 | ||
847 | ||
848 | ||
849 | /* | |
850 | * Builtin commands. Builtin commands whose functions are closely | |
851 | * tied to evaluation are implemented here. | |
852 | */ | |
853 | ||
854 | /* | |
855 | * No command given, or a bltin command with no arguments. Set the | |
856 | * specified variables. | |
857 | */ | |
858 | ||
859 | bltincmd(argc, argv) char **argv; { | |
860 | listsetvar(cmdenviron); | |
861 | return exitstatus; | |
862 | } | |
863 | ||
864 | ||
865 | /* | |
866 | * Handle break and continue commands. Break, continue, and return are | |
867 | * all handled by setting the evalskip flag. The evaluation routines | |
868 | * above all check this flag, and if it is set they start skipping | |
869 | * commands rather than executing them. The variable skipcount is | |
870 | * the number of loops to break/continue, or the number of function | |
871 | * levels to return. (The latter is always 1.) It should probably | |
872 | * be an error to break out of more loops than exist, but it isn't | |
873 | * in the standard shell so we don't make it one here. | |
874 | */ | |
875 | ||
876 | breakcmd(argc, argv) char **argv; { | |
877 | int n; | |
878 | ||
879 | n = 1; | |
880 | if (argc > 1) | |
881 | n = number(argv[1]); | |
882 | if (n > loopnest) | |
883 | n = loopnest; | |
884 | if (n > 0) { | |
885 | evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; | |
886 | skipcount = n; | |
887 | } | |
888 | return 0; | |
889 | } | |
890 | ||
891 | ||
892 | /* | |
893 | * The return command. | |
894 | */ | |
895 | ||
896 | returncmd(argc, argv) char **argv; { | |
897 | int ret; | |
898 | ||
899 | ret = exitstatus; | |
900 | if (argc > 1) | |
901 | ret = number(argv[1]); | |
902 | if (funcnest) { | |
903 | evalskip = SKIPFUNC; | |
904 | skipcount = 1; | |
905 | } | |
906 | return ret; | |
907 | } | |
908 | ||
909 | ||
910 | truecmd(argc, argv) char **argv; { | |
911 | return 0; | |
912 | } | |
913 | ||
914 | ||
915 | execcmd(argc, argv) char **argv; { | |
916 | if (argc > 1) { | |
917 | iflag = 0; /* exit on error */ | |
918 | setinteractive(0); | |
7e5f3556 | 919 | histedit(); |
b3d7414a KB |
920 | #if JOBS |
921 | jflag = 0; | |
922 | setjobctl(0); | |
923 | #endif | |
924 | shellexec(argv + 1, environment(), pathval(), 0); | |
925 | ||
926 | } | |
927 | return 0; | |
928 | } |