jobs.c revision 1.35
1 /* $NetBSD: jobs.c,v 1.35 2000/05/15 03:42:48 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 1.35 2000/05/15 03:42:48 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, 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->used = 0; 366 #if JOBS 367 if (curjob == jp - jobtab + 1) 368 curjob = 0; 369 #endif 370 INTON; 371 } 372 373 374 375 int 376 waitcmd(argc, argv) 377 int argc; 378 char **argv; 379 { 380 struct job *job; 381 int status, retval; 382 struct job *jp; 383 384 if (argc > 1) { 385 job = getjob(argv[1]); 386 } else { 387 job = NULL; 388 } 389 for (;;) { /* loop until process terminated or stopped */ 390 if (job != NULL) { 391 if (job->state) { 392 status = job->ps[job->nprocs - 1].status; 393 if (WIFEXITED(status)) 394 retval = WEXITSTATUS(status); 395 #if JOBS 396 else if (WIFSTOPPED(status)) 397 retval = WSTOPSIG(status) + 128; 398 #endif 399 else { 400 /* XXX: limits number of signals */ 401 retval = WTERMSIG(status) + 128; 402 } 403 if (! iflag) 404 freejob(job); 405 return retval; 406 } 407 } else { 408 for (jp = jobtab ; ; jp++) { 409 if (jp >= jobtab + njobs) { /* no running procs */ 410 return 0; 411 } 412 if (jp->used && jp->state == 0) 413 break; 414 } 415 } 416 dowait(1, (struct job *)NULL); 417 } 418 } 419 420 421 422 int 423 jobidcmd(argc, argv) 424 int argc; 425 char **argv; 426 { 427 struct job *jp; 428 int i; 429 430 jp = getjob(argv[1]); 431 for (i = 0 ; i < jp->nprocs ; ) { 432 out1fmt("%ld", (long)jp->ps[i].pid); 433 out1c(++i < jp->nprocs? ' ' : '\n'); 434 } 435 return 0; 436 } 437 438 439 440 /* 441 * Convert a job name to a job structure. 442 */ 443 444 STATIC struct job * 445 getjob(name) 446 char *name; 447 { 448 int jobno; 449 struct job *jp; 450 int pid; 451 int i; 452 453 if (name == NULL) { 454 #if JOBS 455 currentjob: 456 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 457 error("No current job"); 458 return &jobtab[jobno - 1]; 459 #else 460 error("No current job"); 461 #endif 462 } else if (name[0] == '%') { 463 if (is_digit(name[1])) { 464 jobno = number(name + 1); 465 if (jobno > 0 && jobno <= njobs 466 && jobtab[jobno - 1].used != 0) 467 return &jobtab[jobno - 1]; 468 #if JOBS 469 } else if (name[1] == '%' && name[2] == '\0') { 470 goto currentjob; 471 #endif 472 } else { 473 struct job *found = NULL; 474 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 475 if (jp->used && jp->nprocs > 0 476 && prefix(name + 1, jp->ps[0].cmd)) { 477 if (found) 478 error("%s: ambiguous", name); 479 found = jp; 480 } 481 } 482 if (found) 483 return found; 484 } 485 } else if (is_number(name)) { 486 pid = number(name); 487 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 488 if (jp->used && jp->nprocs > 0 489 && jp->ps[jp->nprocs - 1].pid == pid) 490 return jp; 491 } 492 } 493 error("No such job: %s", name); 494 /* NOTREACHED */ 495 } 496 497 498 499 /* 500 * Return a new job structure, 501 */ 502 503 struct job * 504 makejob(node, nprocs) 505 union node *node; 506 int nprocs; 507 { 508 int i; 509 struct job *jp; 510 511 for (i = njobs, jp = jobtab ; ; jp++) { 512 if (--i < 0) { 513 INTOFF; 514 if (njobs == 0) { 515 jobtab = ckmalloc(4 * sizeof jobtab[0]); 516 } else { 517 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 518 memcpy(jp, jobtab, njobs * sizeof jp[0]); 519 /* Relocate `ps' pointers */ 520 for (i = 0; i < njobs; i++) 521 if (jp[i].ps == &jobtab[i].ps0) 522 jp[i].ps = &jp[i].ps0; 523 ckfree(jobtab); 524 jobtab = jp; 525 } 526 jp = jobtab + njobs; 527 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 528 INTON; 529 break; 530 } 531 if (jp->used == 0) 532 break; 533 } 534 INTOFF; 535 jp->state = 0; 536 jp->used = 1; 537 jp->changed = 0; 538 jp->nprocs = 0; 539 #if JOBS 540 jp->jobctl = jobctl; 541 #endif 542 if (nprocs > 1) { 543 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 544 } else { 545 jp->ps = &jp->ps0; 546 } 547 INTON; 548 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 549 jp - jobtab + 1)); 550 return jp; 551 } 552 553 554 /* 555 * Fork of a subshell. If we are doing job control, give the subshell its 556 * own process group. Jp is a job structure that the job is to be added to. 557 * N is the command that will be evaluated by the child. Both jp and n may 558 * be NULL. The mode parameter can be one of the following: 559 * FORK_FG - Fork off a foreground process. 560 * FORK_BG - Fork off a background process. 561 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 562 * process group even if job control is on. 563 * 564 * When job control is turned off, background processes have their standard 565 * input redirected to /dev/null (except for the second and later processes 566 * in a pipeline). 567 */ 568 569 int 570 forkshell(jp, n, mode) 571 union node *n; 572 struct job *jp; 573 int mode; 574 { 575 int pid; 576 577 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 578 mode)); 579 INTOFF; 580 switch (pid = fork()) { 581 case -1: 582 TRACE(("Fork failed, errno=%d\n", errno)); 583 INTON; 584 error("Cannot fork"); 585 break; 586 case 0: 587 forkchild(jp, n, mode, 0); 588 return 0; 589 default: 590 return forkparent(jp, n, mode, pid); 591 } 592 } 593 594 int 595 forkparent(jp, n, mode, pid) 596 union node *n; 597 struct job *jp; 598 int mode; 599 pid_t pid; 600 { 601 int pgrp; 602 603 if (rootshell && mode != FORK_NOJOB && mflag) { 604 if (jp == NULL || jp->nprocs == 0) 605 pgrp = pid; 606 else 607 pgrp = jp->ps[0].pid; 608 setpgid(pid, pgrp); 609 } 610 if (mode == FORK_BG) 611 backgndpid = pid; /* set $! */ 612 if (jp) { 613 struct procstat *ps = &jp->ps[jp->nprocs++]; 614 ps->pid = pid; 615 ps->status = -1; 616 ps->cmd = nullstr; 617 if (iflag && rootshell && n) 618 ps->cmd = commandtext(n); 619 } 620 INTON; 621 TRACE(("In parent shell: child = %d\n", pid)); 622 return pid; 623 } 624 625 void 626 forkchild(jp, n, mode, vforked) 627 union node *n; 628 struct job *jp; 629 int mode; 630 int vforked; 631 { 632 struct job *p; 633 int wasroot; 634 int i; 635 int pgrp; 636 const char *devnull = _PATH_DEVNULL; 637 const char *nullerr = "Can't open %s"; 638 639 TRACE(("Child shell %d\n", getpid())); 640 wasroot = rootshell; 641 if (!vforked) { 642 rootshell = 0; 643 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 644 if (p->used) 645 freejob(p); 646 } 647 closescript(vforked); 648 if (!vforked) { 649 INTON; 650 } 651 clear_traps(vforked); 652 #if JOBS 653 if (!vforked) 654 jobctl = 0; /* do job control only in root shell */ 655 if (wasroot && mode != FORK_NOJOB && mflag) { 656 if (jp == NULL || jp->nprocs == 0) 657 pgrp = getpid(); 658 else 659 pgrp = jp->ps[0].pid; 660 setpgid(0, pgrp); 661 if (mode == FORK_FG) { 662 /*** this causes superfluous TIOCSPGRPS ***/ 663 #ifdef OLD_TTY_DRIVER 664 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 665 error("TIOCSPGRP failed, errno=%d", errno); 666 #else 667 if (tcsetpgrp(2, pgrp) < 0) 668 error("tcsetpgrp failed, errno=%d", errno); 669 #endif 670 } 671 setsignal(SIGTSTP, vforked); 672 setsignal(SIGTTOU, vforked); 673 } else if (mode == FORK_BG) { 674 ignoresig(SIGINT, vforked); 675 ignoresig(SIGQUIT, vforked); 676 if ((jp == NULL || jp->nprocs == 0) && 677 ! fd0_redirected_p ()) { 678 close(0); 679 if (open(devnull, O_RDONLY) != 0) 680 error(nullerr, devnull); 681 } 682 } 683 #else 684 if (mode == FORK_BG) { 685 ignoresig(SIGINT, vforked); 686 ignoresig(SIGQUIT, vforked); 687 if ((jp == NULL || jp->nprocs == 0) && 688 ! fd0_redirected_p ()) { 689 close(0); 690 if (open(devnull, O_RDONLY) != 0) 691 error(nullerr, devnull); 692 } 693 } 694 #endif 695 if (wasroot && iflag) { 696 setsignal(SIGINT, vforked); 697 setsignal(SIGQUIT, vforked); 698 setsignal(SIGTERM, vforked); 699 } 700 } 701 702 703 704 /* 705 * Wait for job to finish. 706 * 707 * Under job control we have the problem that while a child process is 708 * running interrupts generated by the user are sent to the child but not 709 * to the shell. This means that an infinite loop started by an inter- 710 * active user may be hard to kill. With job control turned off, an 711 * interactive user may place an interactive program inside a loop. If 712 * the interactive program catches interrupts, the user doesn't want 713 * these interrupts to also abort the loop. The approach we take here 714 * is to have the shell ignore interrupt signals while waiting for a 715 * forground process to terminate, and then send itself an interrupt 716 * signal if the child process was terminated by an interrupt signal. 717 * Unfortunately, some programs want to do a bit of cleanup and then 718 * exit on interrupt; unless these processes terminate themselves by 719 * sending a signal to themselves (instead of calling exit) they will 720 * confuse this approach. 721 */ 722 723 int 724 waitforjob(jp) 725 struct job *jp; 726 { 727 #if JOBS 728 int mypgrp = getpgrp(); 729 #endif 730 int status; 731 int st; 732 733 INTOFF; 734 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 735 while (jp->state == 0) { 736 dowait(1, jp); 737 } 738 #if JOBS 739 if (jp->jobctl) { 740 #ifdef OLD_TTY_DRIVER 741 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 742 error("TIOCSPGRP failed, errno=%d\n", errno); 743 #else 744 if (tcsetpgrp(2, mypgrp) < 0) 745 error("tcsetpgrp failed, errno=%d\n", errno); 746 #endif 747 } 748 if (jp->state == JOBSTOPPED) 749 curjob = jp - jobtab + 1; 750 #endif 751 status = jp->ps[jp->nprocs - 1].status; 752 /* convert to 8 bits */ 753 if (WIFEXITED(status)) 754 st = WEXITSTATUS(status); 755 #if JOBS 756 else if (WIFSTOPPED(status)) 757 st = WSTOPSIG(status) + 128; 758 #endif 759 else 760 st = WTERMSIG(status) + 128; 761 #if JOBS 762 if (jp->jobctl) { 763 /* 764 * This is truly gross. 765 * If we're doing job control, then we did a TIOCSPGRP which 766 * caused us (the shell) to no longer be in the controlling 767 * session -- so we wouldn't have seen any ^C/SIGINT. So, we 768 * intuit from the subprocess exit status whether a SIGINT 769 * occured, and if so interrupt ourselves. Yuck. - mycroft 770 */ 771 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 772 raise(SIGINT); 773 } 774 #endif 775 if (! JOBS || jp->state == JOBDONE) 776 freejob(jp); 777 INTON; 778 return st; 779 } 780 781 782 783 /* 784 * Wait for a process to terminate. 785 */ 786 787 STATIC int 788 dowait(block, job) 789 int block; 790 struct job *job; 791 { 792 int pid; 793 int status; 794 struct procstat *sp; 795 struct job *jp; 796 struct job *thisjob; 797 int done; 798 int stopped; 799 int core; 800 int sig; 801 802 TRACE(("dowait(%d) called\n", block)); 803 do { 804 pid = waitproc(block, &status); 805 TRACE(("wait returns %d, status=%d\n", pid, status)); 806 } while (pid == -1 && errno == EINTR); 807 if (pid <= 0) 808 return pid; 809 INTOFF; 810 thisjob = NULL; 811 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 812 if (jp->used) { 813 done = 1; 814 stopped = 1; 815 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 816 if (sp->pid == -1) 817 continue; 818 if (sp->pid == pid) { 819 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 820 sp->status = status; 821 thisjob = jp; 822 } 823 if (sp->status == -1) 824 stopped = 0; 825 else if (WIFSTOPPED(sp->status)) 826 done = 0; 827 } 828 if (stopped) { /* stopped or done */ 829 int state = done? JOBDONE : JOBSTOPPED; 830 if (jp->state != state) { 831 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 832 jp->state = state; 833 #if JOBS 834 if (done && curjob == jp - jobtab + 1) 835 curjob = 0; /* no current job */ 836 #endif 837 } 838 } 839 } 840 } 841 INTON; 842 if (! rootshell || ! iflag || (job && thisjob == job)) { 843 core = WCOREDUMP(status); 844 #if JOBS 845 if (WIFSTOPPED(status)) sig = WSTOPSIG(status); 846 else 847 #endif 848 if (WIFEXITED(status)) sig = 0; 849 else sig = WTERMSIG(status); 850 851 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 852 if (thisjob != job) 853 outfmt(out2, "%d: ", pid); 854 #if JOBS 855 if (sig == SIGTSTP && rootshell && iflag) 856 outfmt(out2, "%%%ld ", 857 (long)(job - jobtab + 1)); 858 #endif 859 if (sig < NSIG && sys_siglist[sig]) 860 out2str(sys_siglist[sig]); 861 else 862 outfmt(out2, "Signal %d", sig); 863 if (core) 864 out2str(" - core dumped"); 865 out2c('\n'); 866 flushout(&errout); 867 } else { 868 TRACE(("Not printing status: status=%d, sig=%d\n", 869 status, sig)); 870 } 871 } else { 872 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 873 if (thisjob) 874 thisjob->changed = 1; 875 } 876 return pid; 877 } 878 879 880 881 /* 882 * Do a wait system call. If job control is compiled in, we accept 883 * stopped processes. If block is zero, we return a value of zero 884 * rather than blocking. 885 * 886 * System V doesn't have a non-blocking wait system call. It does 887 * have a SIGCLD signal that is sent to a process when one of it's 888 * children dies. The obvious way to use SIGCLD would be to install 889 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 890 * was received, and have waitproc bump another counter when it got 891 * the status of a process. Waitproc would then know that a wait 892 * system call would not block if the two counters were different. 893 * This approach doesn't work because if a process has children that 894 * have not been waited for, System V will send it a SIGCLD when it 895 * installs a signal handler for SIGCLD. What this means is that when 896 * a child exits, the shell will be sent SIGCLD signals continuously 897 * until is runs out of stack space, unless it does a wait call before 898 * restoring the signal handler. The code below takes advantage of 899 * this (mis)feature by installing a signal handler for SIGCLD and 900 * then checking to see whether it was called. If there are any 901 * children to be waited for, it will be. 902 * 903 * If neither SYSV nor BSD is defined, we don't implement nonblocking 904 * waits at all. In this case, the user will not be informed when 905 * a background process until the next time she runs a real program 906 * (as opposed to running a builtin command or just typing return), 907 * and the jobs command may give out of date information. 908 */ 909 910 #ifdef SYSV 911 STATIC int gotsigchild; 912 913 STATIC int onsigchild() { 914 gotsigchild = 1; 915 } 916 #endif 917 918 919 STATIC int 920 waitproc(block, status) 921 int block; 922 int *status; 923 { 924 #ifdef BSD 925 int flags; 926 927 #if JOBS 928 flags = WUNTRACED; 929 #else 930 flags = 0; 931 #endif 932 if (block == 0) 933 flags |= WNOHANG; 934 return wait3(status, flags, (struct rusage *)NULL); 935 #else 936 #ifdef SYSV 937 int (*save)(); 938 939 if (block == 0) { 940 gotsigchild = 0; 941 save = signal(SIGCLD, onsigchild); 942 signal(SIGCLD, save); 943 if (gotsigchild == 0) 944 return 0; 945 } 946 return wait(status); 947 #else 948 if (block == 0) 949 return 0; 950 return wait(status); 951 #endif 952 #endif 953 } 954 955 /* 956 * return 1 if there are stopped jobs, otherwise 0 957 */ 958 int job_warning = 0; 959 int 960 stoppedjobs() 961 { 962 int jobno; 963 struct job *jp; 964 965 if (job_warning) 966 return (0); 967 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 968 if (jp->used == 0) 969 continue; 970 if (jp->state == JOBSTOPPED) { 971 out2str("You have stopped jobs.\n"); 972 job_warning = 2; 973 return (1); 974 } 975 } 976 977 return (0); 978 } 979 980 /* 981 * Return a string identifying a command (to be printed by the 982 * jobs command. 983 */ 984 985 STATIC char *cmdnextc; 986 STATIC int cmdnleft; 987 #define MAXCMDTEXT 200 988 989 char * 990 commandtext(n) 991 union node *n; 992 { 993 char *name; 994 995 cmdnextc = name = ckmalloc(MAXCMDTEXT); 996 cmdnleft = MAXCMDTEXT - 4; 997 cmdtxt(n); 998 *cmdnextc = '\0'; 999 return name; 1000 } 1001 1002 1003 STATIC void 1004 cmdtxt(n) 1005 union node *n; 1006 { 1007 union node *np; 1008 struct nodelist *lp; 1009 const char *p; 1010 int i; 1011 char s[2]; 1012 1013 if (n == NULL) 1014 return; 1015 switch (n->type) { 1016 case NSEMI: 1017 cmdtxt(n->nbinary.ch1); 1018 cmdputs("; "); 1019 cmdtxt(n->nbinary.ch2); 1020 break; 1021 case NAND: 1022 cmdtxt(n->nbinary.ch1); 1023 cmdputs(" && "); 1024 cmdtxt(n->nbinary.ch2); 1025 break; 1026 case NOR: 1027 cmdtxt(n->nbinary.ch1); 1028 cmdputs(" || "); 1029 cmdtxt(n->nbinary.ch2); 1030 break; 1031 case NPIPE: 1032 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1033 cmdtxt(lp->n); 1034 if (lp->next) 1035 cmdputs(" | "); 1036 } 1037 break; 1038 case NSUBSHELL: 1039 cmdputs("("); 1040 cmdtxt(n->nredir.n); 1041 cmdputs(")"); 1042 break; 1043 case NREDIR: 1044 case NBACKGND: 1045 cmdtxt(n->nredir.n); 1046 break; 1047 case NIF: 1048 cmdputs("if "); 1049 cmdtxt(n->nif.test); 1050 cmdputs("; then "); 1051 cmdtxt(n->nif.ifpart); 1052 cmdputs("..."); 1053 break; 1054 case NWHILE: 1055 cmdputs("while "); 1056 goto until; 1057 case NUNTIL: 1058 cmdputs("until "); 1059 until: 1060 cmdtxt(n->nbinary.ch1); 1061 cmdputs("; do "); 1062 cmdtxt(n->nbinary.ch2); 1063 cmdputs("; done"); 1064 break; 1065 case NFOR: 1066 cmdputs("for "); 1067 cmdputs(n->nfor.var); 1068 cmdputs(" in ..."); 1069 break; 1070 case NCASE: 1071 cmdputs("case "); 1072 cmdputs(n->ncase.expr->narg.text); 1073 cmdputs(" in ..."); 1074 break; 1075 case NDEFUN: 1076 cmdputs(n->narg.text); 1077 cmdputs("() ..."); 1078 break; 1079 case NCMD: 1080 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1081 cmdtxt(np); 1082 if (np->narg.next) 1083 cmdputs(" "); 1084 } 1085 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1086 cmdputs(" "); 1087 cmdtxt(np); 1088 } 1089 break; 1090 case NARG: 1091 cmdputs(n->narg.text); 1092 break; 1093 case NTO: 1094 p = ">"; i = 1; goto redir; 1095 case NAPPEND: 1096 p = ">>"; i = 1; goto redir; 1097 case NTOFD: 1098 p = ">&"; i = 1; goto redir; 1099 case NFROM: 1100 p = "<"; i = 0; goto redir; 1101 case NFROMFD: 1102 p = "<&"; i = 0; goto redir; 1103 case NFROMTO: 1104 p = "<>"; i = 0; goto redir; 1105 redir: 1106 if (n->nfile.fd != i) { 1107 s[0] = n->nfile.fd + '0'; 1108 s[1] = '\0'; 1109 cmdputs(s); 1110 } 1111 cmdputs(p); 1112 if (n->type == NTOFD || n->type == NFROMFD) { 1113 s[0] = n->ndup.dupfd + '0'; 1114 s[1] = '\0'; 1115 cmdputs(s); 1116 } else { 1117 cmdtxt(n->nfile.fname); 1118 } 1119 break; 1120 case NHERE: 1121 case NXHERE: 1122 cmdputs("<<..."); 1123 break; 1124 default: 1125 cmdputs("???"); 1126 break; 1127 } 1128 } 1129 1130 1131 1132 STATIC void 1133 cmdputs(s) 1134 const char *s; 1135 { 1136 const char *p; 1137 char *q; 1138 char c; 1139 int subtype = 0; 1140 1141 if (cmdnleft <= 0) 1142 return; 1143 p = s; 1144 q = cmdnextc; 1145 while ((c = *p++) != '\0') { 1146 if (c == CTLESC) 1147 *q++ = *p++; 1148 else if (c == CTLVAR) { 1149 *q++ = '$'; 1150 if (--cmdnleft > 0) 1151 *q++ = '{'; 1152 subtype = *p++; 1153 } else if (c == '=' && subtype != 0) { 1154 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1155 subtype = 0; 1156 } else if (c == CTLENDVAR) { 1157 *q++ = '}'; 1158 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1159 cmdnleft++; /* ignore it */ 1160 else 1161 *q++ = c; 1162 if (--cmdnleft <= 0) { 1163 *q++ = '.'; 1164 *q++ = '.'; 1165 *q++ = '.'; 1166 break; 1167 } 1168 } 1169 cmdnextc = q; 1170 } 1171
Indexes created Thu Oct 23 22:10:10 GMT 2025