| 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 | * %sccs.include.redist.c% |
| 9 | */ |
| 10 | |
| 11 | #ifndef lint |
| 12 | static char sccsid[] = "@(#)eval.c 5.1 (Berkeley) %G%"; |
| 13 | #endif /* not lint */ |
| 14 | |
| 15 | /* |
| 16 | * Evaluate a command. |
| 17 | */ |
| 18 | |
| 19 | #include "shell.h" |
| 20 | #include "nodes.h" |
| 21 | #include "syntax.h" |
| 22 | #include "expand.h" |
| 23 | #include "parser.h" |
| 24 | #include "jobs.h" |
| 25 | #include "eval.h" |
| 26 | #include "builtins.h" |
| 27 | #include "options.h" |
| 28 | #include "exec.h" |
| 29 | #include "redir.h" |
| 30 | #include "input.h" |
| 31 | #include "output.h" |
| 32 | #include "trap.h" |
| 33 | #include "var.h" |
| 34 | #include "memalloc.h" |
| 35 | #include "error.h" |
| 36 | #include "mystring.h" |
| 37 | #include <signal.h> |
| 38 | |
| 39 | |
| 40 | /* flags in argument to evaltree */ |
| 41 | #define EV_EXIT 01 /* exit after evaluating tree */ |
| 42 | #define EV_TESTED 02 /* exit status is checked; ignore -e flag */ |
| 43 | #define EV_BACKCMD 04 /* command executing within back quotes */ |
| 44 | |
| 45 | |
| 46 | /* reasons for skipping commands (see comment on breakcmd routine) */ |
| 47 | #define SKIPBREAK 1 |
| 48 | #define SKIPCONT 2 |
| 49 | #define SKIPFUNC 3 |
| 50 | |
| 51 | MKINIT int evalskip; /* set if we are skipping commands */ |
| 52 | STATIC int skipcount; /* number of levels to skip */ |
| 53 | MKINIT int loopnest; /* current loop nesting level */ |
| 54 | int funcnest; /* depth of function calls */ |
| 55 | |
| 56 | |
| 57 | char *commandname; |
| 58 | struct strlist *cmdenviron; |
| 59 | int exitstatus; /* exit status of last command */ |
| 60 | |
| 61 | |
| 62 | #ifdef __STDC__ |
| 63 | STATIC void evalloop(union node *); |
| 64 | STATIC void evalfor(union node *); |
| 65 | STATIC void evalcase(union node *, int); |
| 66 | STATIC void evalsubshell(union node *, int); |
| 67 | STATIC void expredir(union node *); |
| 68 | STATIC void evalpipe(union node *); |
| 69 | STATIC void evalcommand(union node *, int, struct backcmd *); |
| 70 | STATIC void prehash(union node *); |
| 71 | #else |
| 72 | STATIC void evalloop(); |
| 73 | STATIC void evalfor(); |
| 74 | STATIC void evalcase(); |
| 75 | STATIC void evalsubshell(); |
| 76 | STATIC void expredir(); |
| 77 | STATIC void evalpipe(); |
| 78 | STATIC void evalcommand(); |
| 79 | STATIC void prehash(); |
| 80 | #endif |
| 81 | |
| 82 | |
| 83 | |
| 84 | /* |
| 85 | * Called to reset things after an exception. |
| 86 | */ |
| 87 | |
| 88 | #ifdef mkinit |
| 89 | INCLUDE "eval.h" |
| 90 | |
| 91 | RESET { |
| 92 | evalskip = 0; |
| 93 | loopnest = 0; |
| 94 | funcnest = 0; |
| 95 | } |
| 96 | |
| 97 | SHELLPROC { |
| 98 | exitstatus = 0; |
| 99 | } |
| 100 | #endif |
| 101 | |
| 102 | |
| 103 | |
| 104 | /* |
| 105 | * The eval builtin. Do you want clean, straight-forward semantics for |
| 106 | * your eval command? If so, read on.... |
| 107 | */ |
| 108 | |
| 109 | #ifdef ELIGANT |
| 110 | evalcmd(argc, argv) char **argv; { |
| 111 | char **ap; |
| 112 | |
| 113 | for (ap = argv + 1 ; *ap ; ap++) { |
| 114 | evalstring(*ap); |
| 115 | } |
| 116 | return exitstatus; |
| 117 | } |
| 118 | #else |
| 119 | |
| 120 | /* |
| 121 | * If, on the other hand, you prefer downright bogus semantics in the |
| 122 | * name of compatibility, here it is... |
| 123 | */ |
| 124 | |
| 125 | evalcmd(argc, argv) char **argv; { |
| 126 | char **ap; |
| 127 | char *p, *q; |
| 128 | |
| 129 | if (argc <= 1) { |
| 130 | p = nullstr; |
| 131 | } else if (argc == 2) { |
| 132 | p = argv[1]; |
| 133 | } else { |
| 134 | STARTSTACKSTR(p); |
| 135 | ap = argv + 1; |
| 136 | for (;;) { |
| 137 | q = *ap++; |
| 138 | while (*q) { |
| 139 | STPUTC(*q++, p); |
| 140 | } |
| 141 | if (*ap == NULL) |
| 142 | break; |
| 143 | STPUTC(' ', p); |
| 144 | } |
| 145 | STPUTC('\0', p); |
| 146 | p = grabstackstr(p); |
| 147 | } |
| 148 | evalstring(p); |
| 149 | return exitstatus; |
| 150 | } |
| 151 | #endif |
| 152 | |
| 153 | |
| 154 | |
| 155 | /* |
| 156 | * Execute a command or commands contained in a string. |
| 157 | */ |
| 158 | |
| 159 | void |
| 160 | evalstring(s) |
| 161 | char *s; |
| 162 | { |
| 163 | union node *n; |
| 164 | struct stackmark smark; |
| 165 | |
| 166 | setstackmark(&smark); |
| 167 | setinputstring(s, 1); |
| 168 | while ((n = parsecmd(0)) != NEOF) { |
| 169 | evaltree(n, 0); |
| 170 | popstackmark(&smark); |
| 171 | } |
| 172 | popfile(); |
| 173 | popstackmark(&smark); |
| 174 | } |
| 175 | |
| 176 | |
| 177 | |
| 178 | /* |
| 179 | * Evaluate a parse tree. The value is left in the global variable |
| 180 | * exitstatus. |
| 181 | */ |
| 182 | |
| 183 | void |
| 184 | evaltree(n, flags) |
| 185 | union node *n; |
| 186 | { |
| 187 | if (n == NULL) { |
| 188 | TRACE(("evaltree(NULL) called\n")); |
| 189 | return; |
| 190 | } |
| 191 | TRACE(("evaltree(0x%x: %d) called\n", (int)n, n->type)); |
| 192 | switch (n->type) { |
| 193 | case NSEMI: |
| 194 | evaltree(n->nbinary.ch1, 0); |
| 195 | if (evalskip) |
| 196 | goto out; |
| 197 | evaltree(n->nbinary.ch2, flags); |
| 198 | break; |
| 199 | case NAND: |
| 200 | evaltree(n->nbinary.ch1, EV_TESTED); |
| 201 | if (evalskip || exitstatus != 0) |
| 202 | goto out; |
| 203 | evaltree(n->nbinary.ch2, flags); |
| 204 | break; |
| 205 | case NOR: |
| 206 | evaltree(n->nbinary.ch1, EV_TESTED); |
| 207 | if (evalskip || exitstatus == 0) |
| 208 | goto out; |
| 209 | evaltree(n->nbinary.ch2, flags); |
| 210 | break; |
| 211 | case NREDIR: |
| 212 | expredir(n->nredir.redirect); |
| 213 | redirect(n->nredir.redirect, REDIR_PUSH); |
| 214 | evaltree(n->nredir.n, flags); |
| 215 | popredir(); |
| 216 | break; |
| 217 | case NSUBSHELL: |
| 218 | evalsubshell(n, flags); |
| 219 | break; |
| 220 | case NBACKGND: |
| 221 | evalsubshell(n, flags); |
| 222 | break; |
| 223 | case NIF: |
| 224 | evaltree(n->nif.test, EV_TESTED); |
| 225 | if (evalskip) |
| 226 | goto out; |
| 227 | if (exitstatus == 0) { |
| 228 | evaltree(n->nif.ifpart, flags); |
| 229 | } else if (n->nif.elsepart) { |
| 230 | evaltree(n->nif.elsepart, flags); |
| 231 | } |
| 232 | break; |
| 233 | case NWHILE: |
| 234 | case NUNTIL: |
| 235 | evalloop(n); |
| 236 | break; |
| 237 | case NFOR: |
| 238 | evalfor(n); |
| 239 | break; |
| 240 | case NCASE: |
| 241 | evalcase(n, flags); |
| 242 | break; |
| 243 | case NDEFUN: |
| 244 | defun(n->narg.text, n->narg.next); |
| 245 | exitstatus = 0; |
| 246 | break; |
| 247 | case NPIPE: |
| 248 | evalpipe(n); |
| 249 | break; |
| 250 | case NCMD: |
| 251 | evalcommand(n, flags, (struct backcmd *)NULL); |
| 252 | break; |
| 253 | default: |
| 254 | out1fmt("Node type = %d\n", n->type); |
| 255 | flushout(&output); |
| 256 | break; |
| 257 | } |
| 258 | out: |
| 259 | if (pendingsigs) |
| 260 | dotrap(); |
| 261 | if ((flags & EV_EXIT) || (eflag && exitstatus && !(flags & EV_TESTED))) |
| 262 | exitshell(exitstatus); |
| 263 | } |
| 264 | |
| 265 | |
| 266 | STATIC void |
| 267 | evalloop(n) |
| 268 | union node *n; |
| 269 | { |
| 270 | int status; |
| 271 | |
| 272 | loopnest++; |
| 273 | status = 0; |
| 274 | for (;;) { |
| 275 | evaltree(n->nbinary.ch1, EV_TESTED); |
| 276 | if (evalskip) { |
| 277 | skipping: if (evalskip == SKIPCONT && --skipcount <= 0) { |
| 278 | evalskip = 0; |
| 279 | continue; |
| 280 | } |
| 281 | if (evalskip == SKIPBREAK && --skipcount <= 0) |
| 282 | evalskip = 0; |
| 283 | break; |
| 284 | } |
| 285 | if (n->type == NWHILE) { |
| 286 | if (exitstatus != 0) |
| 287 | break; |
| 288 | } else { |
| 289 | if (exitstatus == 0) |
| 290 | break; |
| 291 | } |
| 292 | evaltree(n->nbinary.ch2, 0); |
| 293 | status = exitstatus; |
| 294 | if (evalskip) |
| 295 | goto skipping; |
| 296 | } |
| 297 | loopnest--; |
| 298 | exitstatus = status; |
| 299 | } |
| 300 | |
| 301 | |
| 302 | |
| 303 | STATIC void |
| 304 | evalfor(n) |
| 305 | union node *n; |
| 306 | { |
| 307 | struct arglist arglist; |
| 308 | union node *argp; |
| 309 | struct strlist *sp; |
| 310 | struct stackmark smark; |
| 311 | |
| 312 | setstackmark(&smark); |
| 313 | arglist.lastp = &arglist.list; |
| 314 | for (argp = n->nfor.args ; argp ; argp = argp->narg.next) { |
| 315 | expandarg(argp, &arglist, 1); |
| 316 | if (evalskip) |
| 317 | goto out; |
| 318 | } |
| 319 | *arglist.lastp = NULL; |
| 320 | |
| 321 | exitstatus = 0; |
| 322 | loopnest++; |
| 323 | for (sp = arglist.list ; sp ; sp = sp->next) { |
| 324 | setvar(n->nfor.var, sp->text, 0); |
| 325 | evaltree(n->nfor.body, 0); |
| 326 | if (evalskip) { |
| 327 | if (evalskip == SKIPCONT && --skipcount <= 0) { |
| 328 | evalskip = 0; |
| 329 | continue; |
| 330 | } |
| 331 | if (evalskip == SKIPBREAK && --skipcount <= 0) |
| 332 | evalskip = 0; |
| 333 | break; |
| 334 | } |
| 335 | } |
| 336 | loopnest--; |
| 337 | out: |
| 338 | popstackmark(&smark); |
| 339 | } |
| 340 | |
| 341 | |
| 342 | |
| 343 | STATIC void |
| 344 | evalcase(n, flags) |
| 345 | union node *n; |
| 346 | { |
| 347 | union node *cp; |
| 348 | union node *patp; |
| 349 | struct arglist arglist; |
| 350 | struct stackmark smark; |
| 351 | |
| 352 | setstackmark(&smark); |
| 353 | arglist.lastp = &arglist.list; |
| 354 | expandarg(n->ncase.expr, &arglist, 0); |
| 355 | for (cp = n->ncase.cases ; cp && evalskip == 0 ; cp = cp->nclist.next) { |
| 356 | for (patp = cp->nclist.pattern ; patp ; patp = patp->narg.next) { |
| 357 | if (casematch(patp, arglist.list->text)) { |
| 358 | if (evalskip == 0) { |
| 359 | evaltree(cp->nclist.body, flags); |
| 360 | } |
| 361 | goto out; |
| 362 | } |
| 363 | } |
| 364 | } |
| 365 | out: |
| 366 | popstackmark(&smark); |
| 367 | } |
| 368 | |
| 369 | |
| 370 | |
| 371 | /* |
| 372 | * Kick off a subshell to evaluate a tree. |
| 373 | */ |
| 374 | |
| 375 | STATIC void |
| 376 | evalsubshell(n, flags) |
| 377 | union node *n; |
| 378 | { |
| 379 | struct job *jp; |
| 380 | int backgnd = (n->type == NBACKGND); |
| 381 | |
| 382 | expredir(n->nredir.redirect); |
| 383 | jp = makejob(n, 1); |
| 384 | if (forkshell(jp, n, backgnd) == 0) { |
| 385 | if (backgnd) |
| 386 | flags &=~ EV_TESTED; |
| 387 | redirect(n->nredir.redirect, 0); |
| 388 | evaltree(n->nredir.n, flags | EV_EXIT); /* never returns */ |
| 389 | } |
| 390 | if (! backgnd) { |
| 391 | INTOFF; |
| 392 | exitstatus = waitforjob(jp); |
| 393 | INTON; |
| 394 | } |
| 395 | } |
| 396 | |
| 397 | |
| 398 | |
| 399 | /* |
| 400 | * Compute the names of the files in a redirection list. |
| 401 | */ |
| 402 | |
| 403 | STATIC void |
| 404 | expredir(n) |
| 405 | union node *n; |
| 406 | { |
| 407 | register union node *redir; |
| 408 | |
| 409 | for (redir = n ; redir ; redir = redir->nfile.next) { |
| 410 | if (redir->type == NFROM |
| 411 | || redir->type == NTO |
| 412 | || redir->type == NAPPEND) { |
| 413 | struct arglist fn; |
| 414 | fn.lastp = &fn.list; |
| 415 | expandarg(redir->nfile.fname, &fn, 0); |
| 416 | redir->nfile.expfname = fn.list->text; |
| 417 | } |
| 418 | } |
| 419 | } |
| 420 | |
| 421 | |
| 422 | |
| 423 | /* |
| 424 | * Evaluate a pipeline. All the processes in the pipeline are children |
| 425 | * of the process creating the pipeline. (This differs from some versions |
| 426 | * of the shell, which make the last process in a pipeline the parent |
| 427 | * of all the rest.) |
| 428 | */ |
| 429 | |
| 430 | STATIC void |
| 431 | evalpipe(n) |
| 432 | union node *n; |
| 433 | { |
| 434 | struct job *jp; |
| 435 | struct nodelist *lp; |
| 436 | int pipelen; |
| 437 | int prevfd; |
| 438 | int pip[2]; |
| 439 | |
| 440 | TRACE(("evalpipe(0x%x) called\n", (int)n)); |
| 441 | pipelen = 0; |
| 442 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) |
| 443 | pipelen++; |
| 444 | INTOFF; |
| 445 | jp = makejob(n, pipelen); |
| 446 | prevfd = -1; |
| 447 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { |
| 448 | prehash(lp->n); |
| 449 | pip[1] = -1; |
| 450 | if (lp->next) { |
| 451 | if (pipe(pip) < 0) { |
| 452 | close(prevfd); |
| 453 | error("Pipe call failed"); |
| 454 | } |
| 455 | } |
| 456 | if (forkshell(jp, lp->n, n->npipe.backgnd) == 0) { |
| 457 | INTON; |
| 458 | if (prevfd > 0) { |
| 459 | close(0); |
| 460 | copyfd(prevfd, 0); |
| 461 | close(prevfd); |
| 462 | } |
| 463 | if (pip[1] >= 0) { |
| 464 | close(pip[0]); |
| 465 | if (pip[1] != 1) { |
| 466 | close(1); |
| 467 | copyfd(pip[1], 1); |
| 468 | close(pip[1]); |
| 469 | } |
| 470 | } |
| 471 | evaltree(lp->n, EV_EXIT); |
| 472 | } |
| 473 | if (prevfd >= 0) |
| 474 | close(prevfd); |
| 475 | prevfd = pip[0]; |
| 476 | close(pip[1]); |
| 477 | } |
| 478 | INTON; |
| 479 | if (n->npipe.backgnd == 0) { |
| 480 | INTOFF; |
| 481 | exitstatus = waitforjob(jp); |
| 482 | TRACE(("evalpipe: job done exit status %d\n", exitstatus)); |
| 483 | INTON; |
| 484 | } |
| 485 | } |
| 486 | |
| 487 | |
| 488 | |
| 489 | /* |
| 490 | * Execute a command inside back quotes. If it's a builtin command, we |
| 491 | * want to save its output in a block obtained from malloc. Otherwise |
| 492 | * we fork off a subprocess and get the output of the command via a pipe. |
| 493 | * Should be called with interrupts off. |
| 494 | */ |
| 495 | |
| 496 | void |
| 497 | evalbackcmd(n, result) |
| 498 | union node *n; |
| 499 | struct backcmd *result; |
| 500 | { |
| 501 | int pip[2]; |
| 502 | struct job *jp; |
| 503 | struct stackmark smark; /* unnecessary */ |
| 504 | |
| 505 | setstackmark(&smark); |
| 506 | result->fd = -1; |
| 507 | result->buf = NULL; |
| 508 | result->nleft = 0; |
| 509 | result->jp = NULL; |
| 510 | if (n->type == NCMD) { |
| 511 | evalcommand(n, EV_BACKCMD, result); |
| 512 | } else { |
| 513 | if (pipe(pip) < 0) |
| 514 | error("Pipe call failed"); |
| 515 | jp = makejob(n, 1); |
| 516 | if (forkshell(jp, n, FORK_NOJOB) == 0) { |
| 517 | FORCEINTON; |
| 518 | close(pip[0]); |
| 519 | if (pip[1] != 1) { |
| 520 | close(1); |
| 521 | copyfd(pip[1], 1); |
| 522 | close(pip[1]); |
| 523 | } |
| 524 | evaltree(n, EV_EXIT); |
| 525 | } |
| 526 | close(pip[1]); |
| 527 | result->fd = pip[0]; |
| 528 | result->jp = jp; |
| 529 | } |
| 530 | popstackmark(&smark); |
| 531 | TRACE(("evalbackcmd done: fd=%d buf=0x%x nleft=%d jp=0x%x\n", |
| 532 | result->fd, result->buf, result->nleft, result->jp)); |
| 533 | } |
| 534 | |
| 535 | |
| 536 | |
| 537 | /* |
| 538 | * Execute a simple command. |
| 539 | */ |
| 540 | |
| 541 | STATIC void |
| 542 | evalcommand(cmd, flags, backcmd) |
| 543 | union node *cmd; |
| 544 | struct backcmd *backcmd; |
| 545 | { |
| 546 | struct stackmark smark; |
| 547 | union node *argp; |
| 548 | struct arglist arglist; |
| 549 | struct arglist varlist; |
| 550 | char **argv; |
| 551 | int argc; |
| 552 | char **envp; |
| 553 | int varflag; |
| 554 | struct strlist *sp; |
| 555 | register char *p; |
| 556 | int mode; |
| 557 | int pip[2]; |
| 558 | struct cmdentry cmdentry; |
| 559 | struct job *jp; |
| 560 | struct jmploc jmploc; |
| 561 | struct jmploc *volatile savehandler; |
| 562 | char *volatile savecmdname; |
| 563 | volatile struct shparam saveparam; |
| 564 | struct localvar *volatile savelocalvars; |
| 565 | volatile int e; |
| 566 | char *lastarg; |
| 567 | |
| 568 | /* First expand the arguments. */ |
| 569 | TRACE(("evalcommand(0x%x, %d) called\n", (int)cmd, flags)); |
| 570 | setstackmark(&smark); |
| 571 | arglist.lastp = &arglist.list; |
| 572 | varlist.lastp = &varlist.list; |
| 573 | varflag = 1; |
| 574 | for (argp = cmd->ncmd.args ; argp ; argp = argp->narg.next) { |
| 575 | p = argp->narg.text; |
| 576 | if (varflag && is_name(*p)) { |
| 577 | do { |
| 578 | p++; |
| 579 | } while (is_in_name(*p)); |
| 580 | if (*p == '=') { |
| 581 | expandarg(argp, &varlist, 0); |
| 582 | continue; |
| 583 | } |
| 584 | } |
| 585 | expandarg(argp, &arglist, 1); |
| 586 | varflag = 0; |
| 587 | } |
| 588 | *arglist.lastp = NULL; |
| 589 | *varlist.lastp = NULL; |
| 590 | expredir(cmd->ncmd.redirect); |
| 591 | argc = 0; |
| 592 | for (sp = arglist.list ; sp ; sp = sp->next) |
| 593 | argc++; |
| 594 | argv = stalloc(sizeof (char *) * (argc + 1)); |
| 595 | for (sp = arglist.list ; sp ; sp = sp->next) |
| 596 | *argv++ = sp->text; |
| 597 | *argv = NULL; |
| 598 | lastarg = NULL; |
| 599 | if (iflag && funcnest == 0 && argc > 0) |
| 600 | lastarg = argv[-1]; |
| 601 | argv -= argc; |
| 602 | |
| 603 | /* Print the command if xflag is set. */ |
| 604 | if (xflag) { |
| 605 | outc('+', &errout); |
| 606 | for (sp = varlist.list ; sp ; sp = sp->next) { |
| 607 | outc(' ', &errout); |
| 608 | out2str(sp->text); |
| 609 | } |
| 610 | for (sp = arglist.list ; sp ; sp = sp->next) { |
| 611 | outc(' ', &errout); |
| 612 | out2str(sp->text); |
| 613 | } |
| 614 | outc('\n', &errout); |
| 615 | flushout(&errout); |
| 616 | } |
| 617 | |
| 618 | /* Now locate the command. */ |
| 619 | if (argc == 0) { |
| 620 | cmdentry.cmdtype = CMDBUILTIN; |
| 621 | cmdentry.u.index = BLTINCMD; |
| 622 | } else { |
| 623 | find_command(argv[0], &cmdentry, 1); |
| 624 | if (cmdentry.cmdtype == CMDUNKNOWN) { /* command not found */ |
| 625 | exitstatus = 2; |
| 626 | flushout(&errout); |
| 627 | return; |
| 628 | } |
| 629 | /* implement the bltin builtin here */ |
| 630 | if (cmdentry.cmdtype == CMDBUILTIN && cmdentry.u.index == BLTINCMD) { |
| 631 | for (;;) { |
| 632 | argv++; |
| 633 | if (--argc == 0) |
| 634 | break; |
| 635 | if ((cmdentry.u.index = find_builtin(*argv)) < 0) { |
| 636 | outfmt(&errout, "%s: not found\n", *argv); |
| 637 | exitstatus = 2; |
| 638 | flushout(&errout); |
| 639 | return; |
| 640 | } |
| 641 | if (cmdentry.u.index != BLTINCMD) |
| 642 | break; |
| 643 | } |
| 644 | } |
| 645 | } |
| 646 | |
| 647 | /* Fork off a child process if necessary. */ |
| 648 | if (cmd->ncmd.backgnd |
| 649 | || cmdentry.cmdtype == CMDNORMAL && (flags & EV_EXIT) == 0 |
| 650 | || (flags & EV_BACKCMD) != 0 |
| 651 | && (cmdentry.cmdtype != CMDBUILTIN |
| 652 | || cmdentry.u.index == DOTCMD |
| 653 | || cmdentry.u.index == EVALCMD)) { |
| 654 | jp = makejob(cmd, 1); |
| 655 | mode = cmd->ncmd.backgnd; |
| 656 | if (flags & EV_BACKCMD) { |
| 657 | mode = FORK_NOJOB; |
| 658 | if (pipe(pip) < 0) |
| 659 | error("Pipe call failed"); |
| 660 | } |
| 661 | if (forkshell(jp, cmd, mode) != 0) |
| 662 | goto parent; /* at end of routine */ |
| 663 | if (flags & EV_BACKCMD) { |
| 664 | FORCEINTON; |
| 665 | close(pip[0]); |
| 666 | if (pip[1] != 1) { |
| 667 | close(1); |
| 668 | copyfd(pip[1], 1); |
| 669 | close(pip[1]); |
| 670 | } |
| 671 | } |
| 672 | flags |= EV_EXIT; |
| 673 | } |
| 674 | |
| 675 | /* This is the child process if a fork occurred. */ |
| 676 | /* Execute the command. */ |
| 677 | if (cmdentry.cmdtype == CMDFUNCTION) { |
| 678 | trputs("Shell function: "); trargs(argv); |
| 679 | redirect(cmd->ncmd.redirect, REDIR_PUSH); |
| 680 | saveparam = shellparam; |
| 681 | shellparam.malloc = 0; |
| 682 | shellparam.nparam = argc - 1; |
| 683 | shellparam.p = argv + 1; |
| 684 | shellparam.optnext = NULL; |
| 685 | INTOFF; |
| 686 | savelocalvars = localvars; |
| 687 | localvars = NULL; |
| 688 | INTON; |
| 689 | if (setjmp(jmploc.loc)) { |
| 690 | if (exception == EXSHELLPROC) |
| 691 | freeparam((struct shparam *)&saveparam); |
| 692 | else { |
| 693 | freeparam(&shellparam); |
| 694 | shellparam = saveparam; |
| 695 | } |
| 696 | poplocalvars(); |
| 697 | localvars = savelocalvars; |
| 698 | handler = savehandler; |
| 699 | longjmp(handler->loc, 1); |
| 700 | } |
| 701 | savehandler = handler; |
| 702 | handler = &jmploc; |
| 703 | for (sp = varlist.list ; sp ; sp = sp->next) |
| 704 | mklocal(sp->text); |
| 705 | funcnest++; |
| 706 | evaltree(cmdentry.u.func, 0); |
| 707 | funcnest--; |
| 708 | INTOFF; |
| 709 | poplocalvars(); |
| 710 | localvars = savelocalvars; |
| 711 | freeparam(&shellparam); |
| 712 | shellparam = saveparam; |
| 713 | handler = savehandler; |
| 714 | popredir(); |
| 715 | INTON; |
| 716 | if (evalskip == SKIPFUNC) { |
| 717 | evalskip = 0; |
| 718 | skipcount = 0; |
| 719 | } |
| 720 | if (flags & EV_EXIT) |
| 721 | exitshell(exitstatus); |
| 722 | } else if (cmdentry.cmdtype == CMDBUILTIN) { |
| 723 | trputs("builtin command: "); trargs(argv); |
| 724 | mode = (cmdentry.u.index == EXECCMD)? 0 : REDIR_PUSH; |
| 725 | if (flags == EV_BACKCMD) { |
| 726 | memout.nleft = 0; |
| 727 | memout.nextc = memout.buf; |
| 728 | memout.bufsize = 64; |
| 729 | mode |= REDIR_BACKQ; |
| 730 | } |
| 731 | redirect(cmd->ncmd.redirect, mode); |
| 732 | savecmdname = commandname; |
| 733 | cmdenviron = varlist.list; |
| 734 | e = -1; |
| 735 | if (setjmp(jmploc.loc)) { |
| 736 | e = exception; |
| 737 | exitstatus = (e == EXINT)? SIGINT+128 : 2; |
| 738 | goto cmddone; |
| 739 | } |
| 740 | savehandler = handler; |
| 741 | handler = &jmploc; |
| 742 | commandname = argv[0]; |
| 743 | argptr = argv + 1; |
| 744 | optptr = NULL; /* initialize nextopt */ |
| 745 | exitstatus = (*builtinfunc[cmdentry.u.index])(argc, argv); |
| 746 | flushall(); |
| 747 | cmddone: |
| 748 | out1 = &output; |
| 749 | out2 = &errout; |
| 750 | freestdout(); |
| 751 | if (e != EXSHELLPROC) { |
| 752 | commandname = savecmdname; |
| 753 | if (flags & EV_EXIT) { |
| 754 | exitshell(exitstatus); |
| 755 | } |
| 756 | } |
| 757 | handler = savehandler; |
| 758 | if (e != -1) { |
| 759 | if (e != EXERROR || cmdentry.u.index == BLTINCMD |
| 760 | || cmdentry.u.index == DOTCMD |
| 761 | || cmdentry.u.index == EVALCMD |
| 762 | || cmdentry.u.index == EXECCMD) |
| 763 | exraise(e); |
| 764 | FORCEINTON; |
| 765 | } |
| 766 | if (cmdentry.u.index != EXECCMD) |
| 767 | popredir(); |
| 768 | if (flags == EV_BACKCMD) { |
| 769 | backcmd->buf = memout.buf; |
| 770 | backcmd->nleft = memout.nextc - memout.buf; |
| 771 | memout.buf = NULL; |
| 772 | } |
| 773 | } else { |
| 774 | trputs("normal command: "); trargs(argv); |
| 775 | clearredir(); |
| 776 | redirect(cmd->ncmd.redirect, 0); |
| 777 | if (varlist.list) { |
| 778 | p = stalloc(strlen(pathval()) + 1); |
| 779 | scopy(pathval(), p); |
| 780 | } else { |
| 781 | p = pathval(); |
| 782 | } |
| 783 | for (sp = varlist.list ; sp ; sp = sp->next) |
| 784 | setvareq(sp->text, VEXPORT|VSTACK); |
| 785 | envp = environment(); |
| 786 | shellexec(argv, envp, p, cmdentry.u.index); |
| 787 | /*NOTREACHED*/ |
| 788 | } |
| 789 | goto out; |
| 790 | |
| 791 | parent: /* parent process gets here (if we forked) */ |
| 792 | if (mode == 0) { /* argument to fork */ |
| 793 | INTOFF; |
| 794 | exitstatus = waitforjob(jp); |
| 795 | INTON; |
| 796 | } else if (mode == 2) { |
| 797 | backcmd->fd = pip[0]; |
| 798 | close(pip[1]); |
| 799 | backcmd->jp = jp; |
| 800 | } |
| 801 | |
| 802 | out: |
| 803 | if (lastarg) |
| 804 | setvar("_", lastarg, 0); |
| 805 | popstackmark(&smark); |
| 806 | } |
| 807 | |
| 808 | |
| 809 | |
| 810 | /* |
| 811 | * Search for a command. This is called before we fork so that the |
| 812 | * location of the command will be available in the parent as well as |
| 813 | * the child. The check for "goodname" is an overly conservative |
| 814 | * check that the name will not be subject to expansion. |
| 815 | */ |
| 816 | |
| 817 | STATIC void |
| 818 | prehash(n) |
| 819 | union node *n; |
| 820 | { |
| 821 | struct cmdentry entry; |
| 822 | |
| 823 | if (n->type == NCMD && goodname(n->ncmd.args->narg.text)) |
| 824 | find_command(n->ncmd.args->narg.text, &entry, 0); |
| 825 | } |
| 826 | |
| 827 | |
| 828 | |
| 829 | /* |
| 830 | * Builtin commands. Builtin commands whose functions are closely |
| 831 | * tied to evaluation are implemented here. |
| 832 | */ |
| 833 | |
| 834 | /* |
| 835 | * No command given, or a bltin command with no arguments. Set the |
| 836 | * specified variables. |
| 837 | */ |
| 838 | |
| 839 | bltincmd(argc, argv) char **argv; { |
| 840 | listsetvar(cmdenviron); |
| 841 | return exitstatus; |
| 842 | } |
| 843 | |
| 844 | |
| 845 | /* |
| 846 | * Handle break and continue commands. Break, continue, and return are |
| 847 | * all handled by setting the evalskip flag. The evaluation routines |
| 848 | * above all check this flag, and if it is set they start skipping |
| 849 | * commands rather than executing them. The variable skipcount is |
| 850 | * the number of loops to break/continue, or the number of function |
| 851 | * levels to return. (The latter is always 1.) It should probably |
| 852 | * be an error to break out of more loops than exist, but it isn't |
| 853 | * in the standard shell so we don't make it one here. |
| 854 | */ |
| 855 | |
| 856 | breakcmd(argc, argv) char **argv; { |
| 857 | int n; |
| 858 | |
| 859 | n = 1; |
| 860 | if (argc > 1) |
| 861 | n = number(argv[1]); |
| 862 | if (n > loopnest) |
| 863 | n = loopnest; |
| 864 | if (n > 0) { |
| 865 | evalskip = (**argv == 'c')? SKIPCONT : SKIPBREAK; |
| 866 | skipcount = n; |
| 867 | } |
| 868 | return 0; |
| 869 | } |
| 870 | |
| 871 | |
| 872 | /* |
| 873 | * The return command. |
| 874 | */ |
| 875 | |
| 876 | returncmd(argc, argv) char **argv; { |
| 877 | int ret; |
| 878 | |
| 879 | ret = exitstatus; |
| 880 | if (argc > 1) |
| 881 | ret = number(argv[1]); |
| 882 | if (funcnest) { |
| 883 | evalskip = SKIPFUNC; |
| 884 | skipcount = 1; |
| 885 | } |
| 886 | return ret; |
| 887 | } |
| 888 | |
| 889 | |
| 890 | truecmd(argc, argv) char **argv; { |
| 891 | return 0; |
| 892 | } |
| 893 | |
| 894 | |
| 895 | execcmd(argc, argv) char **argv; { |
| 896 | if (argc > 1) { |
| 897 | iflag = 0; /* exit on error */ |
| 898 | setinteractive(0); |
| 899 | #if JOBS |
| 900 | jflag = 0; |
| 901 | setjobctl(0); |
| 902 | #endif |
| 903 | shellexec(argv + 1, environment(), pathval(), 0); |
| 904 | |
| 905 | } |
| 906 | return 0; |
| 907 | } |