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