1 /* $NetBSD: jobs.c,v 1.46 2002/05/15 16:33:35 christos 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 1.46 2002/05/15 16:33:35 christos 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 static int ttyfd = -1; 96 97 STATIC void restartjob __P((struct job *)); 98 STATIC void freejob __P((struct job *)); 99 STATIC struct job *getjob __P((char *)); 100 STATIC int dowait __P((int, struct job *)); 101 STATIC int onsigchild __P((void)); 102 STATIC int waitproc __P((int, struct job *, int *)); 103 STATIC void cmdtxt __P((union node *)); 104 STATIC void cmdputs __P((const char *)); 105 106 #ifdef OLD_TTY_DRIVER 107 static pid_t tcgetpgrp __P((int fd)); 108 static int tcsetpgrp __P((int fd, pid_t pgrp)); 109 110 static pid_t 111 tcgetpgrp(fd) 112 int fd; 113 { 114 pid_t pgrp; 115 if (ioctl(fd, TIOCGPGRP, (char *)&pgrp) == -1) 116 return -1; 117 else 118 return pgrp; 119 } 120 121 static int 122 tcsetpgrp(fd, pgrp) 123 int fd; 124 pid_t pgrp; 125 { 126 return ioctl(fd, TIOCSPGRP, (char *)&pgrp); 127 } 128 #endif 129 130 /* 131 * Turn job control on and off. 132 * 133 * Note: This code assumes that the third arg to ioctl is a character 134 * pointer, which is true on Berkeley systems but not System V. Since 135 * System V doesn't have job control yet, this isn't a problem now. 136 */ 137 138 MKINIT int jobctl; 139 140 void 141 setjobctl(on) 142 int on; 143 { 144 #ifdef OLD_TTY_DRIVER 145 int ldisc; 146 #endif 147 148 if (on == jobctl || rootshell == 0) 149 return; 150 if (on) { 151 #if defined(FIOCLEX) || defined(FD_CLOEXEC) 152 int err; 153 if (ttyfd != -1) 154 close(ttyfd); 155 if ((ttyfd = open("/dev/tty", O_RDWR)) == -1) { 156 int i; 157 for (i = 0; i < 3; i++) { 158 if (isatty(i) && (ttyfd = dup(i)) != -1) 159 break; 160 } 161 if (i == 3) 162 goto out; 163 } 164 #ifdef FIOCLEX 165 err = ioctl(ttyfd, FIOCLEX, 0); 166 #elif FD_CLOEXEC 167 err = fcntl(ttyfd, FD_CLOEXEC, 1); 168 #endif 169 if (err == -1) { 170 close(ttyfd); 171 ttyfd = -1; 172 goto out; 173 } 174 #else 175 out2str("sh: Need FIOCLEX or FD_CLOEXEC to support job control"); 176 goto out; 177 #endif 178 do { /* while we are in the background */ 179 if ((initialpgrp = tcgetpgrp(ttyfd)) < 0) { 180 out: 181 out2str("sh: can't access tty; job control turned off\n"); 182 mflag = 0; 183 return; 184 } 185 if (initialpgrp == -1) 186 initialpgrp = getpgrp(); 187 else if (initialpgrp != getpgrp()) { 188 killpg(0, SIGTTIN); 189 continue; 190 } 191 } while (0); 192 193 #ifdef OLD_TTY_DRIVER 194 if (ioctl(ttyfd, TIOCGETD, (char *)&ldisc) < 0 195 || ldisc != NTTYDISC) { 196 out2str("sh: need new tty driver to run job control; job control turned off\n"); 197 mflag = 0; 198 return; 199 } 200 #endif 201 setsignal(SIGTSTP); 202 setsignal(SIGTTOU); 203 setsignal(SIGTTIN); 204 setpgid(0, rootpid); 205 tcsetpgrp(ttyfd, rootpid); 206 } else { /* turning job control off */ 207 setpgid(0, initialpgrp); 208 tcsetpgrp(ttyfd, initialpgrp); 209 close(ttyfd); 210 ttyfd = -1; 211 setsignal(SIGTSTP); 212 setsignal(SIGTTOU); 213 setsignal(SIGTTIN); 214 } 215 jobctl = on; 216 } 217 218 219 #ifdef mkinit 220 INCLUDE <stdlib.h> 221 222 SHELLPROC { 223 backgndpid = -1; 224 #if JOBS 225 jobctl = 0; 226 #endif 227 } 228 229 #endif 230 231 232 233 #if JOBS 234 int 235 fgcmd(argc, argv) 236 int argc; 237 char **argv; 238 { 239 struct job *jp; 240 int pgrp; 241 int status; 242 243 jp = getjob(argv[1]); 244 if (jp->jobctl == 0) 245 error("job not created under job control"); 246 pgrp = jp->ps[0].pid; 247 tcsetpgrp(ttyfd, pgrp); 248 restartjob(jp); 249 INTOFF; 250 status = waitforjob(jp); 251 INTON; 252 return status; 253 } 254 255 256 int 257 bgcmd(argc, argv) 258 int argc; 259 char **argv; 260 { 261 struct job *jp; 262 263 do { 264 jp = getjob(*++argv); 265 if (jp->jobctl == 0) 266 error("job not created under job control"); 267 restartjob(jp); 268 } while (--argc > 1); 269 return 0; 270 } 271 272 273 STATIC void 274 restartjob(jp) 275 struct job *jp; 276 { 277 struct procstat *ps; 278 int i; 279 280 if (jp->state == JOBDONE) 281 return; 282 INTOFF; 283 killpg(jp->ps[0].pid, SIGCONT); 284 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 285 if (WIFSTOPPED(ps->status)) { 286 ps->status = -1; 287 jp->state = 0; 288 } 289 } 290 INTON; 291 } 292 #endif 293 294 295 int 296 jobscmd(argc, argv) 297 int argc; 298 char **argv; 299 { 300 showjobs(0); 301 return 0; 302 } 303 304 305 /* 306 * Print a list of jobs. If "change" is nonzero, only print jobs whose 307 * statuses have changed since the last call to showjobs. 308 * 309 * If the shell is interrupted in the process of creating a job, the 310 * result may be a job structure containing zero processes. Such structures 311 * will be freed here. 312 */ 313 314 void 315 showjobs(change) 316 int change; 317 { 318 int jobno; 319 int procno; 320 int i; 321 struct job *jp; 322 struct procstat *ps; 323 int col; 324 char s[64]; 325 326 TRACE(("showjobs(%d) called\n", change)); 327 while (dowait(0, (struct job *)NULL) > 0); 328 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 329 if (! jp->used) 330 continue; 331 if (jp->nprocs == 0) { 332 freejob(jp); 333 continue; 334 } 335 if (change && ! jp->changed) 336 continue; 337 procno = jp->nprocs; 338 for (ps = jp->ps ; ; ps++) { /* for each process */ 339 if (ps == jp->ps) 340 fmtstr(s, 64, "[%d] %ld ", jobno, 341 (long)ps->pid); 342 else 343 fmtstr(s, 64, " %ld ", 344 (long)ps->pid); 345 out1str(s); 346 col = strlen(s); 347 s[0] = '\0'; 348 if (ps->status == -1) { 349 /* don't print anything */ 350 } else if (WIFEXITED(ps->status)) { 351 fmtstr(s, 64, "Exit %d", 352 WEXITSTATUS(ps->status)); 353 } else { 354 #if JOBS 355 if (WIFSTOPPED(ps->status)) 356 i = WSTOPSIG(ps->status); 357 else /* WIFSIGNALED(ps->status) */ 358 #endif 359 i = WTERMSIG(ps->status); 360 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 361 scopy(sys_siglist[i & 0x7F], s); 362 else 363 fmtstr(s, 64, "Signal %d", i & 0x7F); 364 if (WCOREDUMP(ps->status)) 365 strcat(s, " (core dumped)"); 366 } 367 out1str(s); 368 col += strlen(s); 369 do { 370 out1c(' '); 371 col++; 372 } while (col < 30); 373 out1str(ps->cmd); 374 out1c('\n'); 375 if (--procno <= 0) 376 break; 377 } 378 jp->changed = 0; 379 if (jp->state == JOBDONE) { 380 freejob(jp); 381 } 382 } 383 } 384 385 386 /* 387 * Mark a job structure as unused. 388 */ 389 390 STATIC void 391 freejob(jp) 392 struct job *jp; 393 { 394 struct procstat *ps; 395 int i; 396 397 INTOFF; 398 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 399 if (ps->cmd != nullstr) 400 ckfree(ps->cmd); 401 } 402 if (jp->ps != &jp->ps0) { 403 ckfree(jp->ps); 404 jp->ps = &jp->ps0; 405 } 406 jp->nprocs = 0; 407 jp->used = 0; 408 #if JOBS 409 if (curjob == jp - jobtab + 1) 410 curjob = 0; 411 #endif 412 INTON; 413 } 414 415 416 417 int 418 waitcmd(argc, argv) 419 int argc; 420 char **argv; 421 { 422 struct job *job; 423 int status, retval; 424 struct job *jp; 425 426 if (argc > 1) { 427 job = getjob(argv[1]); 428 } else { 429 job = NULL; 430 } 431 for (;;) { /* loop until process terminated or stopped */ 432 if (job != NULL) { 433 if (job->state) { 434 status = job->ps[job->nprocs - 1].status; 435 if (WIFEXITED(status)) 436 retval = WEXITSTATUS(status); 437 #if JOBS 438 else if (WIFSTOPPED(status)) 439 retval = WSTOPSIG(status) + 128; 440 #endif 441 else { 442 /* XXX: limits number of signals */ 443 retval = WTERMSIG(status) + 128; 444 } 445 if (! iflag) 446 freejob(job); 447 return retval; 448 } 449 } else { 450 for (jp = jobtab ; ; jp++) { 451 if (jp >= jobtab + njobs) { /* no running procs */ 452 return 0; 453 } 454 if (jp->used && jp->state == 0) 455 break; 456 } 457 } 458 if (dowait(1, (struct job *)NULL) == -1) 459 return 128 + SIGINT; 460 } 461 } 462 463 464 465 int 466 jobidcmd(argc, argv) 467 int argc; 468 char **argv; 469 { 470 struct job *jp; 471 int i; 472 473 jp = getjob(argv[1]); 474 for (i = 0 ; i < jp->nprocs ; ) { 475 out1fmt("%ld", (long)jp->ps[i].pid); 476 out1c(++i < jp->nprocs? ' ' : '\n'); 477 } 478 return 0; 479 } 480 481 482 483 /* 484 * Convert a job name to a job structure. 485 */ 486 487 STATIC struct job * 488 getjob(name) 489 char *name; 490 { 491 int jobno; 492 struct job *jp; 493 int pid; 494 int i; 495 496 if (name == NULL) { 497 #if JOBS 498 currentjob: 499 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 500 error("No current job"); 501 return &jobtab[jobno - 1]; 502 #else 503 error("No current job"); 504 #endif 505 } else if (name[0] == '%') { 506 if (is_digit(name[1])) { 507 jobno = number(name + 1); 508 if (jobno > 0 && jobno <= njobs 509 && jobtab[jobno - 1].used != 0) 510 return &jobtab[jobno - 1]; 511 #if JOBS 512 } else if (name[1] == '%' && name[2] == '\0') { 513 goto currentjob; 514 #endif 515 } else { 516 struct job *found = NULL; 517 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 518 if (jp->used && jp->nprocs > 0 519 && prefix(name + 1, jp->ps[0].cmd)) { 520 if (found) 521 error("%s: ambiguous", name); 522 found = jp; 523 } 524 } 525 if (found) 526 return found; 527 } 528 } else if (is_number(name)) { 529 pid = number(name); 530 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 531 if (jp->used && jp->nprocs > 0 532 && jp->ps[jp->nprocs - 1].pid == pid) 533 return jp; 534 } 535 } 536 error("No such job: %s", name); 537 /* NOTREACHED */ 538 } 539 540 541 542 /* 543 * Return a new job structure, 544 */ 545 546 struct job * 547 makejob(node, nprocs) 548 union node *node; 549 int nprocs; 550 { 551 int i; 552 struct job *jp; 553 554 for (i = njobs, jp = jobtab ; ; jp++) { 555 if (--i < 0) { 556 INTOFF; 557 if (njobs == 0) { 558 jobtab = ckmalloc(4 * sizeof jobtab[0]); 559 } else { 560 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 561 memcpy(jp, jobtab, njobs * sizeof jp[0]); 562 /* Relocate `ps' pointers */ 563 for (i = 0; i < njobs; i++) 564 if (jp[i].ps == &jobtab[i].ps0) 565 jp[i].ps = &jp[i].ps0; 566 ckfree(jobtab); 567 jobtab = jp; 568 } 569 jp = jobtab + njobs; 570 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 571 INTON; 572 break; 573 } 574 if (jp->used == 0) 575 break; 576 } 577 INTOFF; 578 jp->state = 0; 579 jp->used = 1; 580 jp->changed = 0; 581 jp->nprocs = 0; 582 #if JOBS 583 jp->jobctl = jobctl; 584 #endif 585 if (nprocs > 1) { 586 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 587 } else { 588 jp->ps = &jp->ps0; 589 } 590 INTON; 591 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 592 jp - jobtab + 1)); 593 return jp; 594 } 595 596 597 /* 598 * Fork off a subshell. If we are doing job control, give the subshell its 599 * own process group. Jp is a job structure that the job is to be added to. 600 * N is the command that will be evaluated by the child. Both jp and n may 601 * be NULL. The mode parameter can be one of the following: 602 * FORK_FG - Fork off a foreground process. 603 * FORK_BG - Fork off a background process. 604 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 605 * process group even if job control is on. 606 * 607 * When job control is turned off, background processes have their standard 608 * input redirected to /dev/null (except for the second and later processes 609 * in a pipeline). 610 */ 611 612 int 613 forkshell(jp, n, mode) 614 union node *n; 615 struct job *jp; 616 int mode; 617 { 618 int pid; 619 int pgrp; 620 const char *devnull = _PATH_DEVNULL; 621 const char *nullerr = "Can't open %s"; 622 623 TRACE(("forkshell(%%%d, %p, %d) called\n", jp - jobtab, n, mode)); 624 INTOFF; 625 pid = fork(); 626 if (pid == -1) { 627 TRACE(("Fork failed, errno=%d", errno)); 628 INTON; 629 error("Cannot fork"); 630 } 631 if (pid == 0) { 632 struct job *p; 633 int wasroot; 634 int i; 635 636 TRACE(("Child shell %d\n", getpid())); 637 wasroot = rootshell; 638 rootshell = 0; 639 for (i = njobs, p = jobtab ; --i >= 0 ; p++) { 640 if (p == jp) 641 continue; /* don't free current job */ 642 if (p->used) 643 freejob(p); 644 } 645 closescript(); 646 INTON; 647 clear_traps(); 648 #if JOBS 649 jobctl = 0; /* do job control only in root shell */ 650 if (wasroot && mode != FORK_NOJOB && mflag) { 651 if (jp == NULL || jp->nprocs == 0) 652 pgrp = getpid(); 653 else 654 pgrp = jp->ps[0].pid; 655 setpgid(0, pgrp); 656 if (mode == FORK_FG) { 657 /*** this causes superfluous TIOCSPGRPS ***/ 658 if (tcsetpgrp(ttyfd, pgrp) < 0) 659 error("tcsetpgrp failed, errno=%d", errno); 660 } 661 setsignal(SIGTSTP); 662 setsignal(SIGTTOU); 663 } else if (mode == FORK_BG) { 664 ignoresig(SIGINT); 665 ignoresig(SIGQUIT); 666 if ((jp == NULL || jp->nprocs == 0) && 667 ! fd0_redirected_p ()) { 668 close(0); 669 if (open(devnull, O_RDONLY) != 0) 670 error(nullerr, devnull); 671 } 672 } 673 #else 674 if (mode == FORK_BG) { 675 ignoresig(SIGINT); 676 ignoresig(SIGQUIT); 677 if ((jp == NULL || jp->nprocs == 0) && 678 ! fd0_redirected_p ()) { 679 close(0); 680 if (open(devnull, O_RDONLY) != 0) 681 error(nullerr, devnull); 682 } 683 } 684 #endif 685 if (wasroot && iflag) { 686 setsignal(SIGINT); 687 setsignal(SIGQUIT); 688 setsignal(SIGTERM); 689 } 690 return pid; 691 } 692 if (rootshell && mode != FORK_NOJOB && mflag) { 693 if (jp == NULL || jp->nprocs == 0) 694 pgrp = pid; 695 else 696 pgrp = jp->ps[0].pid; 697 setpgid(pid, pgrp); 698 } 699 if (mode == FORK_BG) 700 backgndpid = pid; /* set $! */ 701 if (jp) { 702 struct procstat *ps = &jp->ps[jp->nprocs++]; 703 ps->pid = pid; 704 ps->status = -1; 705 ps->cmd = nullstr; 706 if (iflag && rootshell && n) 707 ps->cmd = commandtext(n); 708 } 709 INTON; 710 TRACE(("In parent shell: child = %d\n", pid)); 711 return pid; 712 } 713 714 715 716 /* 717 * Wait for job to finish. 718 * 719 * Under job control we have the problem that while a child process is 720 * running interrupts generated by the user are sent to the child but not 721 * to the shell. This means that an infinite loop started by an inter- 722 * active user may be hard to kill. With job control turned off, an 723 * interactive user may place an interactive program inside a loop. If 724 * the interactive program catches interrupts, the user doesn't want 725 * these interrupts to also abort the loop. The approach we take here 726 * is to have the shell ignore interrupt signals while waiting for a 727 * forground process to terminate, and then send itself an interrupt 728 * signal if the child process was terminated by an interrupt signal. 729 * Unfortunately, some programs want to do a bit of cleanup and then 730 * exit on interrupt; unless these processes terminate themselves by 731 * sending a signal to themselves (instead of calling exit) they will 732 * confuse this approach. 733 */ 734 735 int 736 waitforjob(jp) 737 struct job *jp; 738 { 739 #if JOBS 740 int mypgrp = getpgrp(); 741 #endif 742 int status; 743 int st; 744 745 INTOFF; 746 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 747 while (jp->state == 0) { 748 dowait(1, jp); 749 } 750 #if JOBS 751 if (jp->jobctl) { 752 if (tcsetpgrp(ttyfd, mypgrp) < 0) 753 error("tcsetpgrp failed, errno=%d\n", errno); 754 } 755 if (jp->state == JOBSTOPPED) 756 curjob = jp - jobtab + 1; 757 #endif 758 status = jp->ps[jp->nprocs - 1].status; 759 /* convert to 8 bits */ 760 if (WIFEXITED(status)) 761 st = WEXITSTATUS(status); 762 #if JOBS 763 else if (WIFSTOPPED(status)) 764 st = WSTOPSIG(status) + 128; 765 #endif 766 else 767 st = WTERMSIG(status) + 128; 768 #if JOBS 769 if (jp->jobctl) { 770 /* 771 * This is truly gross. 772 * If we're doing job control, then we did a TIOCSPGRP which 773 * caused us (the shell) to no longer be in the controlling 774 * session -- so we wouldn't have seen any ^C/SIGINT. So, we 775 * intuit from the subprocess exit status whether a SIGINT 776 * occurred, and if so interrupt ourselves. Yuck. - mycroft 777 */ 778 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 779 raise(SIGINT); 780 } 781 #endif 782 if (! JOBS || jp->state == JOBDONE) 783 freejob(jp); 784 INTON; 785 return st; 786 } 787 788 789 790 /* 791 * Wait for a process to terminate. 792 */ 793 794 STATIC int 795 dowait(block, job) 796 int block; 797 struct job *job; 798 { 799 int pid; 800 int status; 801 struct procstat *sp; 802 struct job *jp; 803 struct job *thisjob; 804 int done; 805 int stopped; 806 int core; 807 int sig; 808 extern volatile char gotsig[]; 809 810 TRACE(("dowait(%d) called\n", block)); 811 do { 812 pid = waitproc(block, job, &status); 813 TRACE(("wait returns %d, status=%d\n", pid, status)); 814 } while (pid == -1 && errno == EINTR && gotsig[SIGINT - 1] == 0); 815 if (pid <= 0) 816 return pid; 817 INTOFF; 818 thisjob = NULL; 819 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 820 if (jp->used) { 821 done = 1; 822 stopped = 1; 823 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 824 if (sp->pid == -1) 825 continue; 826 if (sp->pid == pid) { 827 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 828 sp->status = status; 829 thisjob = jp; 830 } 831 if (sp->status == -1) 832 stopped = 0; 833 else if (WIFSTOPPED(sp->status)) 834 done = 0; 835 } 836 if (stopped) { /* stopped or done */ 837 int state = done? JOBDONE : JOBSTOPPED; 838 if (jp->state != state) { 839 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 840 jp->state = state; 841 #if JOBS 842 if (done && curjob == jp - jobtab + 1) 843 curjob = 0; /* no current job */ 844 #endif 845 } 846 } 847 } 848 } 849 INTON; 850 if (! rootshell || ! iflag || (job && thisjob == job)) { 851 core = WCOREDUMP(status); 852 #if JOBS 853 if (WIFSTOPPED(status)) sig = WSTOPSIG(status); 854 else 855 #endif 856 if (WIFEXITED(status)) sig = 0; 857 else sig = WTERMSIG(status); 858 859 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 860 if (thisjob != job) 861 outfmt(out2, "%d: ", pid); 862 #if JOBS 863 if (sig == SIGTSTP && rootshell && iflag) 864 outfmt(out2, "%%%ld ", 865 (long)(job - jobtab + 1)); 866 #endif 867 if (sig < NSIG && sys_siglist[sig]) 868 out2str(sys_siglist[sig]); 869 else 870 outfmt(out2, "Signal %d", sig); 871 if (core) 872 out2str(" - core dumped"); 873 out2c('\n'); 874 flushout(&errout); 875 } else { 876 TRACE(("Not printing status: status=%d, sig=%d\n", 877 status, sig)); 878 } 879 } else { 880 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 881 if (thisjob) 882 thisjob->changed = 1; 883 } 884 return pid; 885 } 886 887 888 889 /* 890 * Do a wait system call. If job control is compiled in, we accept 891 * stopped processes. If block is zero, we return a value of zero 892 * rather than blocking. 893 * 894 * System V doesn't have a non-blocking wait system call. It does 895 * have a SIGCLD signal that is sent to a process when one of it's 896 * children dies. The obvious way to use SIGCLD would be to install 897 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 898 * was received, and have waitproc bump another counter when it got 899 * the status of a process. Waitproc would then know that a wait 900 * system call would not block if the two counters were different. 901 * This approach doesn't work because if a process has children that 902 * have not been waited for, System V will send it a SIGCLD when it 903 * installs a signal handler for SIGCLD. What this means is that when 904 * a child exits, the shell will be sent SIGCLD signals continuously 905 * until is runs out of stack space, unless it does a wait call before 906 * restoring the signal handler. The code below takes advantage of 907 * this (mis)feature by installing a signal handler for SIGCLD and 908 * then checking to see whether it was called. If there are any 909 * children to be waited for, it will be. 910 * 911 * If neither SYSV nor BSD is defined, we don't implement nonblocking 912 * waits at all. In this case, the user will not be informed when 913 * a background process until the next time she runs a real program 914 * (as opposed to running a builtin command or just typing return), 915 * and the jobs command may give out of date information. 916 */ 917 918 #ifdef SYSV 919 STATIC int gotsigchild; 920 921 STATIC int onsigchild() { 922 gotsigchild = 1; 923 } 924 #endif 925 926 927 STATIC int 928 waitproc(block, jp, status) 929 int block; 930 struct job *jp; 931 int *status; 932 { 933 #ifdef BSD 934 int flags = 0; 935 936 #if JOBS 937 if (jp != NULL && jp->jobctl) 938 flags |= WUNTRACED; 939 #endif 940 if (block == 0) 941 flags |= WNOHANG; 942 return wait3(status, flags, (struct rusage *)NULL); 943 #else 944 #ifdef SYSV 945 int (*save)(); 946 947 if (block == 0) { 948 gotsigchild = 0; 949 save = signal(SIGCLD, onsigchild); 950 signal(SIGCLD, save); 951 if (gotsigchild == 0) 952 return 0; 953 } 954 return wait(status); 955 #else 956 if (block == 0) 957 return 0; 958 return wait(status); 959 #endif 960 #endif 961 } 962 963 /* 964 * return 1 if there are stopped jobs, otherwise 0 965 */ 966 int job_warning = 0; 967 int 968 stoppedjobs() 969 { 970 int jobno; 971 struct job *jp; 972 973 if (job_warning) 974 return (0); 975 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 976 if (jp->used == 0) 977 continue; 978 if (jp->state == JOBSTOPPED) { 979 out2str("You have stopped jobs.\n"); 980 job_warning = 2; 981 return (1); 982 } 983 } 984 985 return (0); 986 } 987 988 /* 989 * Return a string identifying a command (to be printed by the 990 * jobs command. 991 */ 992 993 STATIC char *cmdnextc; 994 STATIC int cmdnleft; 995 #define MAXCMDTEXT 200 996 997 char * 998 commandtext(n) 999 union node *n; 1000 { 1001 char *name; 1002 1003 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1004 cmdnleft = MAXCMDTEXT - 4; 1005 cmdtxt(n); 1006 *cmdnextc = '\0'; 1007 return name; 1008 } 1009 1010 1011 STATIC void 1012 cmdtxt(n) 1013 union node *n; 1014 { 1015 union node *np; 1016 struct nodelist *lp; 1017 const char *p; 1018 int i; 1019 char s[2]; 1020 1021 if (n == NULL) 1022 return; 1023 switch (n->type) { 1024 case NSEMI: 1025 cmdtxt(n->nbinary.ch1); 1026 cmdputs("; "); 1027 cmdtxt(n->nbinary.ch2); 1028 break; 1029 case NAND: 1030 cmdtxt(n->nbinary.ch1); 1031 cmdputs(" && "); 1032 cmdtxt(n->nbinary.ch2); 1033 break; 1034 case NOR: 1035 cmdtxt(n->nbinary.ch1); 1036 cmdputs(" || "); 1037 cmdtxt(n->nbinary.ch2); 1038 break; 1039 case NPIPE: 1040 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1041 cmdtxt(lp->n); 1042 if (lp->next) 1043 cmdputs(" | "); 1044 } 1045 break; 1046 case NSUBSHELL: 1047 cmdputs("("); 1048 cmdtxt(n->nredir.n); 1049 cmdputs(")"); 1050 break; 1051 case NREDIR: 1052 case NBACKGND: 1053 cmdtxt(n->nredir.n); 1054 break; 1055 case NIF: 1056 cmdputs("if "); 1057 cmdtxt(n->nif.test); 1058 cmdputs("; then "); 1059 cmdtxt(n->nif.ifpart); 1060 cmdputs("..."); 1061 break; 1062 case NWHILE: 1063 cmdputs("while "); 1064 goto until; 1065 case NUNTIL: 1066 cmdputs("until "); 1067 until: 1068 cmdtxt(n->nbinary.ch1); 1069 cmdputs("; do "); 1070 cmdtxt(n->nbinary.ch2); 1071 cmdputs("; done"); 1072 break; 1073 case NFOR: 1074 cmdputs("for "); 1075 cmdputs(n->nfor.var); 1076 cmdputs(" in ..."); 1077 break; 1078 case NCASE: 1079 cmdputs("case "); 1080 cmdputs(n->ncase.expr->narg.text); 1081 cmdputs(" in ..."); 1082 break; 1083 case NDEFUN: 1084 cmdputs(n->narg.text); 1085 cmdputs("() ..."); 1086 break; 1087 case NCMD: 1088 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1089 cmdtxt(np); 1090 if (np->narg.next) 1091 cmdputs(" "); 1092 } 1093 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1094 cmdputs(" "); 1095 cmdtxt(np); 1096 } 1097 break; 1098 case NARG: 1099 cmdputs(n->narg.text); 1100 break; 1101 case NTO: 1102 p = ">"; i = 1; goto redir; 1103 case NCLOBBER: 1104 p = ">|"; i = 1; goto redir; 1105 case NAPPEND: 1106 p = ">>"; i = 1; goto redir; 1107 case NTOFD: 1108 p = ">&"; i = 1; goto redir; 1109 case NFROM: 1110 p = "<"; i = 0; goto redir; 1111 case NFROMFD: 1112 p = "<&"; i = 0; goto redir; 1113 case NFROMTO: 1114 p = "<>"; i = 0; goto redir; 1115 redir: 1116 if (n->nfile.fd != i) { 1117 s[0] = n->nfile.fd + '0'; 1118 s[1] = '\0'; 1119 cmdputs(s); 1120 } 1121 cmdputs(p); 1122 if (n->type == NTOFD || n->type == NFROMFD) { 1123 s[0] = n->ndup.dupfd + '0'; 1124 s[1] = '\0'; 1125 cmdputs(s); 1126 } else { 1127 cmdtxt(n->nfile.fname); 1128 } 1129 break; 1130 case NHERE: 1131 case NXHERE: 1132 cmdputs("<<..."); 1133 break; 1134 default: 1135 cmdputs("???"); 1136 break; 1137 } 1138 } 1139 1140 1141 1142 STATIC void 1143 cmdputs(s) 1144 const char *s; 1145 { 1146 const char *p; 1147 char *q; 1148 char c; 1149 int subtype = 0; 1150 1151 if (cmdnleft <= 0) 1152 return; 1153 p = s; 1154 q = cmdnextc; 1155 while ((c = *p++) != '\0') { 1156 if (c == CTLESC) 1157 *q++ = *p++; 1158 else if (c == CTLVAR) { 1159 *q++ = '$'; 1160 if (--cmdnleft > 0) 1161 *q++ = '{'; 1162 subtype = *p++; 1163 } else if (c == '=' && subtype != 0) { 1164 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1165 subtype = 0; 1166 } else if (c == CTLENDVAR) { 1167 *q++ = '}'; 1168 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1169 cmdnleft++; /* ignore it */ 1170 else 1171 *q++ = c; 1172 if (--cmdnleft <= 0) { 1173 *q++ = '.'; 1174 *q++ = '.'; 1175 *q++ = '.'; 1176 break; 1177 } 1178 } 1179 cmdnextc = q; 1180 } 1181