jobs.c revision 1.43.2.1
1 /* $NetBSD: jobs.c,v 1.43.2.1 2002/03/27 20:37:38 elric Exp $ */ 2 3 /*- 4 * Copyright (c) 1991, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley by 8 * Kenneth Almquist. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 #ifndef lint 41 #if 0 42 static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 43 #else 44 __RCSID("$NetBSD: jobs.c,v 1.43.2.1 2002/03/27 20:37:38 elric Exp $"); 45 #endif 46 #endif /* not lint */ 47 48 #include <fcntl.h> 49 #include <signal.h> 50 #include <errno.h> 51 #include <unistd.h> 52 #include <stdlib.h> 53 #include <paths.h> 54 #include <sys/types.h> 55 #include <sys/param.h> 56 #ifdef BSD 57 #include <sys/wait.h> 58 #include <sys/time.h> 59 #include <sys/resource.h> 60 #endif 61 #include <sys/ioctl.h> 62 63 #include "shell.h" 64 #if JOBS 65 #if OLD_TTY_DRIVER 66 #include "sgtty.h" 67 #else 68 #include <termios.h> 69 #endif 70 #undef CEOF /* syntax.h redefines this */ 71 #endif 72 #include "redir.h" 73 #include "show.h" 74 #include "main.h" 75 #include "parser.h" 76 #include "nodes.h" 77 #include "jobs.h" 78 #include "options.h" 79 #include "trap.h" 80 #include "syntax.h" 81 #include "input.h" 82 #include "output.h" 83 #include "memalloc.h" 84 #include "error.h" 85 #include "mystring.h" 86 87 88 struct job *jobtab; /* array of jobs */ 89 int njobs; /* size of array */ 90 MKINIT short backgndpid = -1; /* pid of last background process */ 91 #if JOBS 92 int initialpgrp; /* pgrp of shell on invocation */ 93 short curjob; /* current job */ 94 #endif 95 96 STATIC void restartjob __P((struct job *)); 97 STATIC void freejob __P((struct job *)); 98 STATIC struct job *getjob __P((char *)); 99 STATIC int dowait __P((int, struct job *)); 100 STATIC int onsigchild __P((void)); 101 STATIC int waitproc __P((int, struct job *, int *)); 102 STATIC void cmdtxt __P((union node *)); 103 STATIC void cmdputs __P((const char *)); 104 105 106 /* 107 * Turn job control on and off. 108 * 109 * Note: This code assumes that the third arg to ioctl is a character 110 * pointer, which is true on Berkeley systems but not System V. Since 111 * System V doesn't have job control yet, this isn't a problem now. 112 */ 113 114 MKINIT int jobctl; 115 116 void 117 setjobctl(on) 118 int on; 119 { 120 #ifdef OLD_TTY_DRIVER 121 int ldisc; 122 #endif 123 124 if (on == jobctl || rootshell == 0) 125 return; 126 if (on) { 127 do { /* while we are in the background */ 128 #ifdef OLD_TTY_DRIVER 129 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 130 #else 131 initialpgrp = tcgetpgrp(2); 132 if (initialpgrp < 0) { 133 #endif 134 out2str("sh: can't access tty; job control turned off\n"); 135 mflag = 0; 136 return; 137 } 138 if (initialpgrp == -1) 139 initialpgrp = getpgrp(); 140 else if (initialpgrp != getpgrp()) { 141 killpg(initialpgrp, SIGTTIN); 142 continue; 143 } 144 } while (0); 145 #ifdef OLD_TTY_DRIVER 146 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 147 out2str("sh: need new tty driver to run job control; job control turned off\n"); 148 mflag = 0; 149 return; 150 } 151 #endif 152 setsignal(SIGTSTP, 0); 153 setsignal(SIGTTOU, 0); 154 setsignal(SIGTTIN, 0); 155 setpgid(0, rootpid); 156 #ifdef OLD_TTY_DRIVER 157 ioctl(2, TIOCSPGRP, (char *)&rootpid); 158 #else 159 tcsetpgrp(2, rootpid); 160 #endif 161 } else { /* turning job control off */ 162 setpgid(0, initialpgrp); 163 #ifdef OLD_TTY_DRIVER 164 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 165 #else 166 tcsetpgrp(2, initialpgrp); 167 #endif 168 setsignal(SIGTSTP, 0); 169 setsignal(SIGTTOU, 0); 170 setsignal(SIGTTIN, 0); 171 } 172 jobctl = on; 173 } 174 175 176 #ifdef mkinit 177 INCLUDE <stdlib.h> 178 179 SHELLPROC { 180 backgndpid = -1; 181 #if JOBS 182 jobctl = 0; 183 #endif 184 } 185 186 #endif 187 188 189 190 #if JOBS 191 int 192 fgcmd(argc, argv) 193 int argc; 194 char **argv; 195 { 196 struct job *jp; 197 int pgrp; 198 int status; 199 200 jp = getjob(argv[1]); 201 if (jp->jobctl == 0) 202 error("job not created under job control"); 203 pgrp = jp->ps[0].pid; 204 #ifdef OLD_TTY_DRIVER 205 ioctl(2, TIOCSPGRP, (char *)&pgrp); 206 #else 207 tcsetpgrp(2, pgrp); 208 #endif 209 restartjob(jp); 210 INTOFF; 211 status = waitforjob(jp); 212 INTON; 213 return status; 214 } 215 216 217 int 218 bgcmd(argc, argv) 219 int argc; 220 char **argv; 221 { 222 struct job *jp; 223 224 do { 225 jp = getjob(*++argv); 226 if (jp->jobctl == 0) 227 error("job not created under job control"); 228 restartjob(jp); 229 } while (--argc > 1); 230 return 0; 231 } 232 233 234 STATIC void 235 restartjob(jp) 236 struct job *jp; 237 { 238 struct procstat *ps; 239 int i; 240 241 if (jp->state == JOBDONE) 242 return; 243 INTOFF; 244 killpg(jp->ps[0].pid, SIGCONT); 245 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 246 if (WIFSTOPPED(ps->status)) { 247 ps->status = -1; 248 jp->state = 0; 249 } 250 } 251 INTON; 252 } 253 #endif 254 255 256 int 257 jobscmd(argc, argv) 258 int argc; 259 char **argv; 260 { 261 showjobs(0); 262 return 0; 263 } 264 265 266 /* 267 * Print a list of jobs. If "change" is nonzero, only print jobs whose 268 * statuses have changed since the last call to showjobs. 269 * 270 * If the shell is interrupted in the process of creating a job, the 271 * result may be a job structure containing zero processes. Such structures 272 * will be freed here. 273 */ 274 275 void 276 showjobs(change) 277 int change; 278 { 279 int jobno; 280 int procno; 281 int i; 282 struct job *jp; 283 struct procstat *ps; 284 int col; 285 char s[64]; 286 287 TRACE(("showjobs(%d) called\n", change)); 288 while (dowait(0, (struct job *)NULL) > 0); 289 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 290 if (! jp->used) 291 continue; 292 if (jp->nprocs == 0) { 293 freejob(jp); 294 continue; 295 } 296 if (change && ! jp->changed) 297 continue; 298 procno = jp->nprocs; 299 for (ps = jp->ps ; ; ps++) { /* for each process */ 300 if (ps == jp->ps) 301 fmtstr(s, 64, "[%d] %ld ", jobno, 302 (long)ps->pid); 303 else 304 fmtstr(s, 64, " %ld ", 305 (long)ps->pid); 306 out1str(s); 307 col = strlen(s); 308 s[0] = '\0'; 309 if (ps->status == -1) { 310 /* don't print anything */ 311 } else if (WIFEXITED(ps->status)) { 312 fmtstr(s, 64, "Exit %d", 313 WEXITSTATUS(ps->status)); 314 } else { 315 #if JOBS 316 if (WIFSTOPPED(ps->status)) 317 i = WSTOPSIG(ps->status); 318 else /* WIFSIGNALED(ps->status) */ 319 #endif 320 i = WTERMSIG(ps->status); 321 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 322 scopy(sys_siglist[i & 0x7F], s); 323 else 324 fmtstr(s, 64, "Signal %d", i & 0x7F); 325 if (WCOREDUMP(ps->status)) 326 strcat(s, " (core dumped)"); 327 } 328 out1str(s); 329 col += strlen(s); 330 do { 331 out1c(' '); 332 col++; 333 } while (col < 30); 334 out1str(ps->cmd); 335 out1c('\n'); 336 if (--procno <= 0) 337 break; 338 } 339 jp->changed = 0; 340 if (jp->state == JOBDONE) { 341 freejob(jp); 342 } 343 } 344 } 345 346 347 /* 348 * Mark a job structure as unused. 349 */ 350 351 STATIC void 352 freejob(jp) 353 struct job *jp; 354 { 355 struct procstat *ps; 356 int i; 357 358 INTOFF; 359 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 360 if (ps->cmd != nullstr) 361 ckfree(ps->cmd); 362 } 363 if (jp->ps != &jp->ps0) { 364 ckfree(jp->ps); 365 jp->ps = &jp->ps0; 366 } 367 jp->nprocs = 0; 368 jp->used = 0; 369 #if JOBS 370 if (curjob == jp - jobtab + 1) 371 curjob = 0; 372 #endif 373 INTON; 374 } 375 376 377 378 int 379 waitcmd(argc, argv) 380 int argc; 381 char **argv; 382 { 383 struct job *job; 384 int status, retval; 385 struct job *jp; 386 387 if (argc > 1) { 388 job = getjob(argv[1]); 389 } else { 390 job = NULL; 391 } 392 for (;;) { /* loop until process terminated or stopped */ 393 if (job != NULL) { 394 if (job->state) { 395 status = job->ps[job->nprocs - 1].status; 396 if (WIFEXITED(status)) 397 retval = WEXITSTATUS(status); 398 #if JOBS 399 else if (WIFSTOPPED(status)) 400 retval = WSTOPSIG(status) + 128; 401 #endif 402 else { 403 /* XXX: limits number of signals */ 404 retval = WTERMSIG(status) + 128; 405 } 406 if (! iflag) 407 freejob(job); 408 return retval; 409 } 410 } else { 411 for (jp = jobtab ; ; jp++) { 412 if (jp >= jobtab + njobs) { /* no running procs */ 413 return 0; 414 } 415 if (jp->used && jp->state == 0) 416 break; 417 } 418 } 419 if (dowait(1, (struct job *)NULL) == -1) 420 return 128 + SIGINT; 421 } 422 } 423 424 425 426 int 427 jobidcmd(argc, argv) 428 int argc; 429 char **argv; 430 { 431 struct job *jp; 432 int i; 433 434 jp = getjob(argv[1]); 435 for (i = 0 ; i < jp->nprocs ; ) { 436 out1fmt("%ld", (long)jp->ps[i].pid); 437 out1c(++i < jp->nprocs? ' ' : '\n'); 438 } 439 return 0; 440 } 441 442 443 444 /* 445 * Convert a job name to a job structure. 446 */ 447 448 STATIC struct job * 449 getjob(name) 450 char *name; 451 { 452 int jobno; 453 struct job *jp; 454 int pid; 455 int i; 456 457 if (name == NULL) { 458 #if JOBS 459 currentjob: 460 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 461 error("No current job"); 462 return &jobtab[jobno - 1]; 463 #else 464 error("No current job"); 465 #endif 466 } else if (name[0] == '%') { 467 if (is_digit(name[1])) { 468 jobno = number(name + 1); 469 if (jobno > 0 && jobno <= njobs 470 && jobtab[jobno - 1].used != 0) 471 return &jobtab[jobno - 1]; 472 #if JOBS 473 } else if (name[1] == '%' && name[2] == '\0') { 474 goto currentjob; 475 #endif 476 } else { 477 struct job *found = NULL; 478 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 479 if (jp->used && jp->nprocs > 0 480 && prefix(name + 1, jp->ps[0].cmd)) { 481 if (found) 482 error("%s: ambiguous", name); 483 found = jp; 484 } 485 } 486 if (found) 487 return found; 488 } 489 } else if (is_number(name)) { 490 pid = number(name); 491 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 492 if (jp->used && jp->nprocs > 0 493 && jp->ps[jp->nprocs - 1].pid == pid) 494 return jp; 495 } 496 } 497 error("No such job: %s", name); 498 /* NOTREACHED */ 499 } 500 501 502 503 /* 504 * Return a new job structure, 505 */ 506 507 struct job * 508 makejob(node, nprocs) 509 union node *node; 510 int nprocs; 511 { 512 int i; 513 struct job *jp; 514 515 for (i = njobs, jp = jobtab ; ; jp++) { 516 if (--i < 0) { 517 INTOFF; 518 if (njobs == 0) { 519 jobtab = ckmalloc(4 * sizeof jobtab[0]); 520 } else { 521 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 522 memcpy(jp, jobtab, njobs * sizeof jp[0]); 523 /* Relocate `ps' pointers */ 524 for (i = 0; i < njobs; i++) 525 if (jp[i].ps == &jobtab[i].ps0) 526 jp[i].ps = &jp[i].ps0; 527 ckfree(jobtab); 528 jobtab = jp; 529 } 530 jp = jobtab + njobs; 531 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 532 INTON; 533 break; 534 } 535 if (jp->used == 0) 536 break; 537 } 538 INTOFF; 539 jp->state = 0; 540 jp->used = 1; 541 jp->changed = 0; 542 jp->nprocs = 0; 543 #if JOBS 544 jp->jobctl = jobctl; 545 #endif 546 if (nprocs > 1) { 547 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 548 } else { 549 jp->ps = &jp->ps0; 550 } 551 INTON; 552 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 553 jp - jobtab + 1)); 554 return jp; 555 } 556 557 558 /* 559 * Fork off a subshell. If we are doing job control, give the subshell its 560 * own process group. Jp is a job structure that the job is to be added to. 561 * N is the command that will be evaluated by the child. Both jp and n may 562 * be NULL. The mode parameter can be one of the following: 563 * FORK_FG - Fork off a foreground process. 564 * FORK_BG - Fork off a background process. 565 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 566 * process group even if job control is on. 567 * 568 * When job control is turned off, background processes have their standard 569 * input redirected to /dev/null (except for the second and later processes 570 * in a pipeline). 571 */ 572 573 int 574 forkshell(jp, n, mode) 575 union node *n; 576 struct job *jp; 577 int mode; 578 { 579 int pid; 580 581 TRACE(("forkshell(%%%d, %p, %d) called\n", jp - jobtab, n, mode)); 582 INTOFF; 583 switch ((pid = fork())) { 584 case -1: 585 TRACE(("Fork failed, errno=%d\n", errno)); 586 INTON; 587 error("Cannot fork"); 588 break; 589 case 0: 590 forkchild(jp, n, mode, 0); 591 return 0; 592 default: 593 return forkparent(jp, n, mode, pid); 594 } 595 } 596 597 int 598 forkparent(jp, n, mode, pid) 599 union node *n; 600 struct job *jp; 601 int mode; 602 pid_t pid; 603 { 604 int pgrp; 605 606 if (rootshell && mode != FORK_NOJOB && mflag) { 607 if (jp == NULL || jp->nprocs == 0) 608 pgrp = pid; 609 else 610 pgrp = jp->ps[0].pid; 611 setpgid(pid, pgrp); 612 } 613 if (mode == FORK_BG) 614 backgndpid = pid; /* set $! */ 615 if (jp) { 616 struct procstat *ps = &jp->ps[jp->nprocs++]; 617 ps->pid = pid; 618 ps->status = -1; 619 ps->cmd = nullstr; 620 if (iflag && rootshell && n) 621 ps->cmd = commandtext(n); 622 } 623 INTON; 624 TRACE(("In parent shell: child = %d\n", pid)); 625 return pid; 626 } 627 628 void 629 forkchild(jp, n, mode, vforked) 630 union node *n; 631 struct job *jp; 632 int mode; 633 int vforked; 634 { 635 struct job *p; 636 int wasroot; 637 int i; 638 int pgrp; 639 const char *devnull = _PATH_DEVNULL; 640 const char *nullerr = "Can't open %s"; 641 642 TRACE(("Child shell %d\n", getpid())); 643 wasroot = rootshell; 644 if (!vforked) { 645 rootshell = 0; 646 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 647 if (p->used) 648 freejob(p); 649 } 650 closescript(vforked); 651 if (!vforked) { 652 INTON; 653 } 654 clear_traps(vforked); 655 #if JOBS 656 if (!vforked) 657 jobctl = 0; /* do job control only in root shell */ 658 if (wasroot && mode != FORK_NOJOB && mflag) { 659 if (jp == NULL || jp->nprocs == 0) 660 pgrp = getpid(); 661 else 662 pgrp = jp->ps[0].pid; 663 setpgid(0, pgrp); 664 if (mode == FORK_FG) { 665 /*** this causes superfluous TIOCSPGRPS ***/ 666 #ifdef OLD_TTY_DRIVER 667 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 668 error("TIOCSPGRP failed, errno=%d", errno); 669 #else 670 if (tcsetpgrp(2, pgrp) < 0) 671 error("tcsetpgrp failed, errno=%d", errno); 672 #endif 673 } 674 setsignal(SIGTSTP, vforked); 675 setsignal(SIGTTOU, vforked); 676 } else if (mode == FORK_BG) { 677 ignoresig(SIGINT, vforked); 678 ignoresig(SIGQUIT, vforked); 679 if ((jp == NULL || jp->nprocs == 0) && 680 ! fd0_redirected_p ()) { 681 close(0); 682 if (open(devnull, O_RDONLY) != 0) 683 error(nullerr, devnull); 684 } 685 } 686 #else 687 if (mode == FORK_BG) { 688 ignoresig(SIGINT, vforked); 689 ignoresig(SIGQUIT, vforked); 690 if ((jp == NULL || jp->nprocs == 0) && 691 ! fd0_redirected_p ()) { 692 close(0); 693 if (open(devnull, O_RDONLY) != 0) 694 error(nullerr, devnull); 695 } 696 } 697 #endif 698 if (wasroot && iflag) { 699 setsignal(SIGINT, vforked); 700 setsignal(SIGQUIT, vforked); 701 setsignal(SIGTERM, vforked); 702 } 703 } 704 705 706 707 /* 708 * Wait for job to finish. 709 * 710 * Under job control we have the problem that while a child process is 711 * running interrupts generated by the user are sent to the child but not 712 * to the shell. This means that an infinite loop started by an inter- 713 * active user may be hard to kill. With job control turned off, an 714 * interactive user may place an interactive program inside a loop. If 715 * the interactive program catches interrupts, the user doesn't want 716 * these interrupts to also abort the loop. The approach we take here 717 * is to have the shell ignore interrupt signals while waiting for a 718 * forground process to terminate, and then send itself an interrupt 719 * signal if the child process was terminated by an interrupt signal. 720 * Unfortunately, some programs want to do a bit of cleanup and then 721 * exit on interrupt; unless these processes terminate themselves by 722 * sending a signal to themselves (instead of calling exit) they will 723 * confuse this approach. 724 */ 725 726 int 727 waitforjob(jp) 728 struct job *jp; 729 { 730 #if JOBS 731 int mypgrp = getpgrp(); 732 #endif 733 int status; 734 int st; 735 736 INTOFF; 737 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 738 while (jp->state == 0) { 739 dowait(1, jp); 740 } 741 #if JOBS 742 if (jp->jobctl) { 743 #ifdef OLD_TTY_DRIVER 744 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 745 error("TIOCSPGRP failed, errno=%d\n", errno); 746 #else 747 if (tcsetpgrp(2, mypgrp) < 0) 748 error("tcsetpgrp failed, errno=%d\n", errno); 749 #endif 750 } 751 if (jp->state == JOBSTOPPED) 752 curjob = jp - jobtab + 1; 753 #endif 754 status = jp->ps[jp->nprocs - 1].status; 755 /* convert to 8 bits */ 756 if (WIFEXITED(status)) 757 st = WEXITSTATUS(status); 758 #if JOBS 759 else if (WIFSTOPPED(status)) 760 st = WSTOPSIG(status) + 128; 761 #endif 762 else 763 st = WTERMSIG(status) + 128; 764 #if JOBS 765 if (jp->jobctl) { 766 /* 767 * This is truly gross. 768 * If we're doing job control, then we did a TIOCSPGRP which 769 * caused us (the shell) to no longer be in the controlling 770 * session -- so we wouldn't have seen any ^C/SIGINT. So, we 771 * intuit from the subprocess exit status whether a SIGINT 772 * occurred, and if so interrupt ourselves. Yuck. - mycroft 773 */ 774 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 775 raise(SIGINT); 776 } 777 #endif 778 if (! JOBS || jp->state == JOBDONE) 779 freejob(jp); 780 INTON; 781 return st; 782 } 783 784 785 786 /* 787 * Wait for a process to terminate. 788 */ 789 790 STATIC int 791 dowait(block, job) 792 int block; 793 struct job *job; 794 { 795 int pid; 796 int status; 797 struct procstat *sp; 798 struct job *jp; 799 struct job *thisjob; 800 int done; 801 int stopped; 802 int core; 803 int sig; 804 extern volatile char gotsig[]; 805 806 TRACE(("dowait(%d) called\n", block)); 807 do { 808 pid = waitproc(block, job, &status); 809 TRACE(("wait returns %d, status=%d\n", pid, status)); 810 } while (pid == -1 && errno == EINTR && gotsig[SIGINT - 1] == 0); 811 if (pid <= 0) 812 return pid; 813 INTOFF; 814 thisjob = NULL; 815 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 816 if (jp->used) { 817 done = 1; 818 stopped = 1; 819 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 820 if (sp->pid == -1) 821 continue; 822 if (sp->pid == pid) { 823 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 824 sp->status = status; 825 thisjob = jp; 826 } 827 if (sp->status == -1) 828 stopped = 0; 829 else if (WIFSTOPPED(sp->status)) 830 done = 0; 831 } 832 if (stopped) { /* stopped or done */ 833 int state = done? JOBDONE : JOBSTOPPED; 834 if (jp->state != state) { 835 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 836 jp->state = state; 837 #if JOBS 838 if (done && curjob == jp - jobtab + 1) 839 curjob = 0; /* no current job */ 840 #endif 841 } 842 } 843 } 844 } 845 INTON; 846 if (! rootshell || ! iflag || (job && thisjob == job)) { 847 core = WCOREDUMP(status); 848 #if JOBS 849 if (WIFSTOPPED(status)) sig = WSTOPSIG(status); 850 else 851 #endif 852 if (WIFEXITED(status)) sig = 0; 853 else sig = WTERMSIG(status); 854 855 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 856 if (thisjob != job) 857 outfmt(out2, "%d: ", pid); 858 #if JOBS 859 if (sig == SIGTSTP && rootshell && iflag) 860 outfmt(out2, "%%%ld ", 861 (long)(job - jobtab + 1)); 862 #endif 863 if (sig < NSIG && sys_siglist[sig]) 864 out2str(sys_siglist[sig]); 865 else 866 outfmt(out2, "Signal %d", sig); 867 if (core) 868 out2str(" - core dumped"); 869 out2c('\n'); 870 flushout(&errout); 871 } else { 872 TRACE(("Not printing status: status=%d, sig=%d\n", 873 status, sig)); 874 } 875 } else { 876 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 877 if (thisjob) 878 thisjob->changed = 1; 879 } 880 return pid; 881 } 882 883 884 885 /* 886 * Do a wait system call. If job control is compiled in, we accept 887 * stopped processes. If block is zero, we return a value of zero 888 * rather than blocking. 889 * 890 * System V doesn't have a non-blocking wait system call. It does 891 * have a SIGCLD signal that is sent to a process when one of it's 892 * children dies. The obvious way to use SIGCLD would be to install 893 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 894 * was received, and have waitproc bump another counter when it got 895 * the status of a process. Waitproc would then know that a wait 896 * system call would not block if the two counters were different. 897 * This approach doesn't work because if a process has children that 898 * have not been waited for, System V will send it a SIGCLD when it 899 * installs a signal handler for SIGCLD. What this means is that when 900 * a child exits, the shell will be sent SIGCLD signals continuously 901 * until is runs out of stack space, unless it does a wait call before 902 * restoring the signal handler. The code below takes advantage of 903 * this (mis)feature by installing a signal handler for SIGCLD and 904 * then checking to see whether it was called. If there are any 905 * children to be waited for, it will be. 906 * 907 * If neither SYSV nor BSD is defined, we don't implement nonblocking 908 * waits at all. In this case, the user will not be informed when 909 * a background process until the next time she runs a real program 910 * (as opposed to running a builtin command or just typing return), 911 * and the jobs command may give out of date information. 912 */ 913 914 #ifdef SYSV 915 STATIC int gotsigchild; 916 917 STATIC int onsigchild() { 918 gotsigchild = 1; 919 } 920 #endif 921 922 923 STATIC int 924 waitproc(block, jp, status) 925 int block; 926 struct job *jp; 927 int *status; 928 { 929 #ifdef BSD 930 int flags = 0; 931 932 #if JOBS 933 if (jp != NULL && jp->jobctl) 934 flags |= WUNTRACED; 935 #endif 936 if (block == 0) 937 flags |= WNOHANG; 938 return wait3(status, flags, (struct rusage *)NULL); 939 #else 940 #ifdef SYSV 941 int (*save)(); 942 943 if (block == 0) { 944 gotsigchild = 0; 945 save = signal(SIGCLD, onsigchild); 946 signal(SIGCLD, save); 947 if (gotsigchild == 0) 948 return 0; 949 } 950 return wait(status); 951 #else 952 if (block == 0) 953 return 0; 954 return wait(status); 955 #endif 956 #endif 957 } 958 959 /* 960 * return 1 if there are stopped jobs, otherwise 0 961 */ 962 int job_warning = 0; 963 int 964 stoppedjobs() 965 { 966 int jobno; 967 struct job *jp; 968 969 if (job_warning) 970 return (0); 971 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 972 if (jp->used == 0) 973 continue; 974 if (jp->state == JOBSTOPPED) { 975 out2str("You have stopped jobs.\n"); 976 job_warning = 2; 977 return (1); 978 } 979 } 980 981 return (0); 982 } 983 984 /* 985 * Return a string identifying a command (to be printed by the 986 * jobs command. 987 */ 988 989 STATIC char *cmdnextc; 990 STATIC int cmdnleft; 991 #define MAXCMDTEXT 200 992 993 char * 994 commandtext(n) 995 union node *n; 996 { 997 char *name; 998 999 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1000 cmdnleft = MAXCMDTEXT - 4; 1001 cmdtxt(n); 1002 *cmdnextc = '\0'; 1003 return name; 1004 } 1005 1006 1007 STATIC void 1008 cmdtxt(n) 1009 union node *n; 1010 { 1011 union node *np; 1012 struct nodelist *lp; 1013 const char *p; 1014 int i; 1015 char s[2]; 1016 1017 if (n == NULL) 1018 return; 1019 switch (n->type) { 1020 case NSEMI: 1021 cmdtxt(n->nbinary.ch1); 1022 cmdputs("; "); 1023 cmdtxt(n->nbinary.ch2); 1024 break; 1025 case NAND: 1026 cmdtxt(n->nbinary.ch1); 1027 cmdputs(" && "); 1028 cmdtxt(n->nbinary.ch2); 1029 break; 1030 case NOR: 1031 cmdtxt(n->nbinary.ch1); 1032 cmdputs(" || "); 1033 cmdtxt(n->nbinary.ch2); 1034 break; 1035 case NPIPE: 1036 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1037 cmdtxt(lp->n); 1038 if (lp->next) 1039 cmdputs(" | "); 1040 } 1041 break; 1042 case NSUBSHELL: 1043 cmdputs("("); 1044 cmdtxt(n->nredir.n); 1045 cmdputs(")"); 1046 break; 1047 case NREDIR: 1048 case NBACKGND: 1049 cmdtxt(n->nredir.n); 1050 break; 1051 case NIF: 1052 cmdputs("if "); 1053 cmdtxt(n->nif.test); 1054 cmdputs("; then "); 1055 cmdtxt(n->nif.ifpart); 1056 cmdputs("..."); 1057 break; 1058 case NWHILE: 1059 cmdputs("while "); 1060 goto until; 1061 case NUNTIL: 1062 cmdputs("until "); 1063 until: 1064 cmdtxt(n->nbinary.ch1); 1065 cmdputs("; do "); 1066 cmdtxt(n->nbinary.ch2); 1067 cmdputs("; done"); 1068 break; 1069 case NFOR: 1070 cmdputs("for "); 1071 cmdputs(n->nfor.var); 1072 cmdputs(" in ..."); 1073 break; 1074 case NCASE: 1075 cmdputs("case "); 1076 cmdputs(n->ncase.expr->narg.text); 1077 cmdputs(" in ..."); 1078 break; 1079 case NDEFUN: 1080 cmdputs(n->narg.text); 1081 cmdputs("() ..."); 1082 break; 1083 case NCMD: 1084 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1085 cmdtxt(np); 1086 if (np->narg.next) 1087 cmdputs(" "); 1088 } 1089 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1090 cmdputs(" "); 1091 cmdtxt(np); 1092 } 1093 break; 1094 case NARG: 1095 cmdputs(n->narg.text); 1096 break; 1097 case NTO: 1098 p = ">"; i = 1; goto redir; 1099 case NAPPEND: 1100 p = ">>"; i = 1; goto redir; 1101 case NTOFD: 1102 p = ">&"; i = 1; goto redir; 1103 case NFROM: 1104 p = "<"; i = 0; goto redir; 1105 case NFROMFD: 1106 p = "<&"; i = 0; goto redir; 1107 case NFROMTO: 1108 p = "<>"; i = 0; goto redir; 1109 redir: 1110 if (n->nfile.fd != i) { 1111 s[0] = n->nfile.fd + '0'; 1112 s[1] = '\0'; 1113 cmdputs(s); 1114 } 1115 cmdputs(p); 1116 if (n->type == NTOFD || n->type == NFROMFD) { 1117 s[0] = n->ndup.dupfd + '0'; 1118 s[1] = '\0'; 1119 cmdputs(s); 1120 } else { 1121 cmdtxt(n->nfile.fname); 1122 } 1123 break; 1124 case NHERE: 1125 case NXHERE: 1126 cmdputs("<<..."); 1127 break; 1128 default: 1129 cmdputs("???"); 1130 break; 1131 } 1132 } 1133 1134 1135 1136 STATIC void 1137 cmdputs(s) 1138 const char *s; 1139 { 1140 const char *p; 1141 char *q; 1142 char c; 1143 int subtype = 0; 1144 1145 if (cmdnleft <= 0) 1146 return; 1147 p = s; 1148 q = cmdnextc; 1149 while ((c = *p++) != '\0') { 1150 if (c == CTLESC) 1151 *q++ = *p++; 1152 else if (c == CTLVAR) { 1153 *q++ = '$'; 1154 if (--cmdnleft > 0) 1155 *q++ = '{'; 1156 subtype = *p++; 1157 } else if (c == '=' && subtype != 0) { 1158 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1159 subtype = 0; 1160 } else if (c == CTLENDVAR) { 1161 *q++ = '}'; 1162 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1163 cmdnleft++; /* ignore it */ 1164 else 1165 *q++ = c; 1166 if (--cmdnleft <= 0) { 1167 *q++ = '.'; 1168 *q++ = '.'; 1169 *q++ = '.'; 1170 break; 1171 } 1172 } 1173 cmdnextc = q; 1174 } 1175
Indexes created Sun Oct 26 21:10:03 GMT 2025