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 * $Id: jobs.c,v 1.8 1996/10/16 02:30:39 steve Exp $ 37 */ 38 39 #ifndef lint 40 static char const sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 41 #endif /* not lint */ 42 43 #include <fcntl.h> 44 #include <signal.h> 45 #include <errno.h> 46 #include <unistd.h> 47 #include <stdlib.h> 48 #include <sys/types.h> 49 #include <sys/param.h> 50 #ifdef BSD 51 #include <sys/wait.h> 52 #include <sys/time.h> 53 #include <sys/resource.h> 54 #endif 55 #include <sys/ioctl.h> 56 57 #include "shell.h" 58 #if JOBS 59 #ifdef OLD_TTY_DRIVER 60 #include "sgtty.h" 61 #else 62 #include <termios.h> 63 #endif 64 #undef CEOF /* syntax.h redefines this */ 65 #endif 66 #include "redir.h" 67 #include "show.h" 68 #include "main.h" 69 #include "parser.h" 70 #include "nodes.h" 71 #include "jobs.h" 72 #include "options.h" 73 #include "trap.h" 74 #include "syntax.h" 75 #include "input.h" 76 #include "output.h" 77 #include "memalloc.h" 78 #include "error.h" 79 #include "mystring.h" 80 81 82 struct job *jobtab; /* array of jobs */ 83 int njobs; /* size of array */ 84 MKINIT short backgndpid = -1; /* pid of last background process */ 85 #if JOBS 86 int initialpgrp; /* pgrp of shell on invocation */ 87 short curjob; /* current job */ 88 #endif 89 90 #if JOBS 91 STATIC void restartjob __P((struct job *)); 92 #endif 93 STATIC void freejob __P((struct job *)); 94 STATIC struct job *getjob __P((char *)); 95 STATIC int dowait __P((int, struct job *)); 96 #if SYSV 97 STATIC int onsigchild __P((void)); 98 #endif 99 STATIC int waitproc __P((int, int *)); 100 STATIC void cmdtxt __P((union node *)); 101 STATIC void cmdputs __P((char *)); 102 103 104 /* 105 * Turn job control on and off. 106 * 107 * Note: This code assumes that the third arg to ioctl is a character 108 * pointer, which is true on Berkeley systems but not System V. Since 109 * System V doesn't have job control yet, this isn't a problem now. 110 */ 111 112 MKINIT int jobctl; 113 114 #if JOBS 115 void 116 setjobctl(on) 117 int on; 118 { 119 #ifdef OLD_TTY_DRIVER 120 int ldisc; 121 #endif 122 123 if (on == jobctl || rootshell == 0) 124 return; 125 if (on) { 126 do { /* while we are in the background */ 127 #ifdef OLD_TTY_DRIVER 128 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 129 #else 130 initialpgrp = tcgetpgrp(2); 131 if (initialpgrp < 0) { 132 #endif 133 out2str("sh: can't access tty; job control turned off\n"); 134 mflag = 0; 135 return; 136 } 137 if (initialpgrp == -1) 138 initialpgrp = getpgrp(); 139 else if (initialpgrp != getpgrp()) { 140 killpg(initialpgrp, SIGTTIN); 141 continue; 142 } 143 } while (0); 144 #ifdef OLD_TTY_DRIVER 145 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 146 out2str("sh: need new tty driver to run job control; job control turned off\n"); 147 mflag = 0; 148 return; 149 } 150 #endif 151 setsignal(SIGTSTP); 152 setsignal(SIGTTOU); 153 setsignal(SIGTTIN); 154 setpgid(0, rootpid); 155 #ifdef OLD_TTY_DRIVER 156 ioctl(2, TIOCSPGRP, (char *)&rootpid); 157 #else 158 tcsetpgrp(2, rootpid); 159 #endif 160 } else { /* turning job control off */ 161 setpgid(0, initialpgrp); 162 #ifdef OLD_TTY_DRIVER 163 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 164 #else 165 tcsetpgrp(2, initialpgrp); 166 #endif 167 setsignal(SIGTSTP); 168 setsignal(SIGTTOU); 169 setsignal(SIGTTIN); 170 } 171 jobctl = on; 172 } 173 #endif 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 ((ps->status & 0377) == 0177) { 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] %d ", jobno, ps->pid); 302 else 303 fmtstr(s, 64, " %d ", ps->pid); 304 out1str(s); 305 col = strlen(s); 306 s[0] = '\0'; 307 if (ps->status == -1) { 308 /* don't print anything */ 309 } else if ((ps->status & 0xFF) == 0) { 310 fmtstr(s, 64, "Exit %d", ps->status >> 8); 311 } else { 312 i = ps->status; 313 #if JOBS 314 if ((i & 0xFF) == 0177) 315 i >>= 8; 316 #endif 317 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 318 scopy(sys_siglist[i & 0x7F], s); 319 else 320 fmtstr(s, 64, "Signal %d", i & 0x7F); 321 if (i & 0x80) 322 strcat(s, " (core dumped)"); 323 } 324 out1str(s); 325 col += strlen(s); 326 do { 327 out1c(' '); 328 col++; 329 } while (col < 30); 330 out1str(ps->cmd); 331 out1c('\n'); 332 if (--procno <= 0) 333 break; 334 } 335 jp->changed = 0; 336 if (jp->state == JOBDONE) { 337 freejob(jp); 338 } 339 } 340 } 341 342 343 /* 344 * Mark a job structure as unused. 345 */ 346 347 STATIC void 348 freejob(jp) 349 struct job *jp; 350 { 351 struct procstat *ps; 352 int i; 353 354 INTOFF; 355 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 356 if (ps->cmd != nullstr) 357 ckfree(ps->cmd); 358 } 359 if (jp->ps != &jp->ps0) 360 ckfree(jp->ps); 361 jp->used = 0; 362 #if JOBS 363 if (curjob == jp - jobtab + 1) 364 curjob = 0; 365 #endif 366 INTON; 367 } 368 369 370 371 int 372 waitcmd(argc, argv) 373 int argc; 374 char **argv; 375 { 376 struct job *job; 377 int status; 378 struct job *jp; 379 380 if (argc > 1) { 381 job = getjob(argv[1]); 382 } else { 383 job = NULL; 384 } 385 for (;;) { /* loop until process terminated or stopped */ 386 if (job != NULL) { 387 if (job->state) { 388 status = job->ps[job->nprocs - 1].status; 389 if ((status & 0xFF) == 0) 390 status = status >> 8 & 0xFF; 391 #if JOBS 392 else if ((status & 0xFF) == 0177) 393 status = (status >> 8 & 0x7F) + 128; 394 #endif 395 else 396 status = (status & 0x7F) + 128; 397 if (! iflag) 398 freejob(job); 399 return status; 400 } 401 } else { 402 for (jp = jobtab ; ; jp++) { 403 if (jp >= jobtab + njobs) { /* no running procs */ 404 return 0; 405 } 406 if (jp->used && jp->state == 0) 407 break; 408 } 409 } 410 dowait(1, (struct job *)NULL); 411 } 412 } 413 414 415 416 int 417 jobidcmd(argc, argv) 418 int argc; 419 char **argv; 420 { 421 struct job *jp; 422 int i; 423 424 jp = getjob(argv[1]); 425 for (i = 0 ; i < jp->nprocs ; ) { 426 out1fmt("%d", jp->ps[i].pid); 427 out1c(++i < jp->nprocs? ' ' : '\n'); 428 } 429 return 0; 430 } 431 432 433 434 /* 435 * Convert a job name to a job structure. 436 */ 437 438 STATIC struct job * 439 getjob(name) 440 char *name; 441 { 442 int jobno; 443 register struct job *jp; 444 int pid; 445 int i; 446 447 if (name == NULL) { 448 #if JOBS 449 currentjob: 450 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 451 error("No current job"); 452 return &jobtab[jobno - 1]; 453 #else 454 error("No current job"); 455 #endif 456 } else if (name[0] == '%') { 457 if (is_digit(name[1])) { 458 jobno = number(name + 1); 459 if (jobno > 0 && jobno <= njobs 460 && jobtab[jobno - 1].used != 0) 461 return &jobtab[jobno - 1]; 462 #if JOBS 463 } else if (name[1] == '%' && name[2] == '\0') { 464 goto currentjob; 465 #endif 466 } else { 467 register struct job *found = NULL; 468 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 469 if (jp->used && jp->nprocs > 0 470 && prefix(name + 1, jp->ps[0].cmd)) { 471 if (found) 472 error("%s: ambiguous", name); 473 found = jp; 474 } 475 } 476 if (found) 477 return found; 478 } 479 } else if (is_number(name)) { 480 pid = number(name); 481 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 482 if (jp->used && jp->nprocs > 0 483 && jp->ps[jp->nprocs - 1].pid == pid) 484 return jp; 485 } 486 } 487 error("No such job: %s", name); 488 /*NOTREACHED*/ 489 return NULL; 490 } 491 492 493 494 /* 495 * Return a new job structure, 496 */ 497 498 struct job * 499 makejob(node, nprocs) 500 union node *node; 501 int nprocs; 502 { 503 int i; 504 struct job *jp; 505 506 for (i = njobs, jp = jobtab ; ; jp++) { 507 if (--i < 0) { 508 INTOFF; 509 if (njobs == 0) { 510 jobtab = ckmalloc(4 * sizeof jobtab[0]); 511 } else { 512 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 513 memcpy(jp, jobtab, njobs * sizeof jp[0]); 514 /* Relocate `ps' pointers */ 515 for (i = 0; i < njobs; i++) 516 if (jp[i].ps == &jobtab[i].ps0) 517 jp[i].ps = &jp[i].ps0; 518 ckfree(jobtab); 519 jobtab = jp; 520 } 521 jp = jobtab + njobs; 522 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 523 INTON; 524 break; 525 } 526 if (jp->used == 0) 527 break; 528 } 529 INTOFF; 530 jp->state = 0; 531 jp->used = 1; 532 jp->changed = 0; 533 jp->nprocs = 0; 534 #if JOBS 535 jp->jobctl = jobctl; 536 #endif 537 if (nprocs > 1) { 538 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 539 } else { 540 jp->ps = &jp->ps0; 541 } 542 INTON; 543 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 544 jp - jobtab + 1)); 545 return jp; 546 } 547 548 549 /* 550 * Fork of a subshell. If we are doing job control, give the subshell its 551 * own process group. Jp is a job structure that the job is to be added to. 552 * N is the command that will be evaluated by the child. Both jp and n may 553 * be NULL. The mode parameter can be one of the following: 554 * FORK_FG - Fork off a foreground process. 555 * FORK_BG - Fork off a background process. 556 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 557 * process group even if job control is on. 558 * 559 * When job control is turned off, background processes have their standard 560 * input redirected to /dev/null (except for the second and later processes 561 * in a pipeline). 562 */ 563 564 int 565 forkshell(jp, n, mode) 566 union node *n; 567 struct job *jp; 568 int mode; 569 { 570 int pid; 571 int pgrp; 572 573 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 574 mode)); 575 INTOFF; 576 pid = fork(); 577 if (pid == -1) { 578 TRACE(("Fork failed, errno=%d\n", errno)); 579 INTON; 580 error("Cannot fork"); 581 } 582 if (pid == 0) { 583 struct job *p; 584 int wasroot; 585 int i; 586 587 TRACE(("Child shell %d\n", getpid())); 588 wasroot = rootshell; 589 rootshell = 0; 590 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 591 if (p->used) 592 freejob(p); 593 closescript(); 594 INTON; 595 clear_traps(); 596 #if JOBS 597 jobctl = 0; /* do job control only in root shell */ 598 if (wasroot && mode != FORK_NOJOB && mflag) { 599 if (jp == NULL || jp->nprocs == 0) 600 pgrp = getpid(); 601 else 602 pgrp = jp->ps[0].pid; 603 setpgid(0, pgrp); 604 if (mode == FORK_FG) { 605 /*** this causes superfluous TIOCSPGRPS ***/ 606 #ifdef OLD_TTY_DRIVER 607 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 608 error("TIOCSPGRP failed, errno=%d", errno); 609 #else 610 if (tcsetpgrp(2, pgrp) < 0) 611 error("tcsetpgrp failed, errno=%d", errno); 612 #endif 613 } 614 setsignal(SIGTSTP); 615 setsignal(SIGTTOU); 616 } else if (mode == FORK_BG) { 617 ignoresig(SIGINT); 618 ignoresig(SIGQUIT); 619 if ((jp == NULL || jp->nprocs == 0) && 620 ! fd0_redirected_p ()) { 621 close(0); 622 if (open("/dev/null", O_RDONLY) != 0) 623 error("Can't open /dev/null"); 624 } 625 } 626 #else 627 if (mode == FORK_BG) { 628 ignoresig(SIGINT); 629 ignoresig(SIGQUIT); 630 if ((jp == NULL || jp->nprocs == 0) && 631 ! fd0_redirected_p ()) { 632 close(0); 633 if (open("/dev/null", O_RDONLY) != 0) 634 error("Can't open /dev/null"); 635 } 636 } 637 #endif 638 if (wasroot && iflag) { 639 setsignal(SIGINT); 640 setsignal(SIGQUIT); 641 setsignal(SIGTERM); 642 } 643 return pid; 644 } 645 if (rootshell && mode != FORK_NOJOB && mflag) { 646 if (jp == NULL || jp->nprocs == 0) 647 pgrp = pid; 648 else 649 pgrp = jp->ps[0].pid; 650 setpgid(pid, pgrp); 651 } 652 if (mode == FORK_BG) 653 backgndpid = pid; /* set $! */ 654 if (jp) { 655 struct procstat *ps = &jp->ps[jp->nprocs++]; 656 ps->pid = pid; 657 ps->status = -1; 658 ps->cmd = nullstr; 659 if (iflag && rootshell && n) 660 ps->cmd = commandtext(n); 661 } 662 INTON; 663 TRACE(("In parent shell: child = %d\n", pid)); 664 return pid; 665 } 666 667 668 669 /* 670 * Wait for job to finish. 671 * 672 * Under job control we have the problem that while a child process is 673 * running interrupts generated by the user are sent to the child but not 674 * to the shell. This means that an infinite loop started by an inter- 675 * active user may be hard to kill. With job control turned off, an 676 * interactive user may place an interactive program inside a loop. If 677 * the interactive program catches interrupts, the user doesn't want 678 * these interrupts to also abort the loop. The approach we take here 679 * is to have the shell ignore interrupt signals while waiting for a 680 * forground process to terminate, and then send itself an interrupt 681 * signal if the child process was terminated by an interrupt signal. 682 * Unfortunately, some programs want to do a bit of cleanup and then 683 * exit on interrupt; unless these processes terminate themselves by 684 * sending a signal to themselves (instead of calling exit) they will 685 * confuse this approach. 686 */ 687 688 int 689 waitforjob(jp) 690 register struct job *jp; 691 { 692 #if JOBS 693 int mypgrp = getpgrp(); 694 #endif 695 int status; 696 int st; 697 698 INTOFF; 699 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 700 while (jp->state == 0) { 701 dowait(1, jp); 702 } 703 #if JOBS 704 if (jp->jobctl) { 705 #ifdef OLD_TTY_DRIVER 706 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 707 error("TIOCSPGRP failed, errno=%d\n", errno); 708 #else 709 if (tcsetpgrp(2, mypgrp) < 0) 710 error("tcsetpgrp failed, errno=%d\n", errno); 711 #endif 712 } 713 if (jp->state == JOBSTOPPED) 714 curjob = jp - jobtab + 1; 715 #endif 716 status = jp->ps[jp->nprocs - 1].status; 717 /* convert to 8 bits */ 718 if ((status & 0xFF) == 0) 719 st = status >> 8 & 0xFF; 720 #if JOBS 721 else if ((status & 0xFF) == 0177) 722 st = (status >> 8 & 0x7F) + 128; 723 #endif 724 else 725 st = (status & 0x7F) + 128; 726 if (! JOBS || jp->state == JOBDONE) 727 freejob(jp); 728 CLEAR_PENDING_INT; 729 if ((status & 0x7F) == SIGINT) 730 kill(getpid(), SIGINT); 731 INTON; 732 return st; 733 } 734 735 736 737 /* 738 * Wait for a process to terminate. 739 */ 740 741 STATIC int 742 dowait(block, job) 743 int block; 744 struct job *job; 745 { 746 int pid; 747 int status; 748 struct procstat *sp; 749 struct job *jp; 750 struct job *thisjob; 751 int done; 752 int stopped; 753 int core; 754 755 TRACE(("dowait(%d) called\n", block)); 756 do { 757 pid = waitproc(block, &status); 758 TRACE(("wait returns %d, status=%d\n", pid, status)); 759 } while (pid == -1 && errno == EINTR); 760 if (pid <= 0) 761 return pid; 762 INTOFF; 763 thisjob = NULL; 764 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 765 if (jp->used) { 766 done = 1; 767 stopped = 1; 768 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 769 if (sp->pid == -1) 770 continue; 771 if (sp->pid == pid) { 772 TRACE(("Changin status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 773 sp->status = status; 774 thisjob = jp; 775 } 776 if (sp->status == -1) 777 stopped = 0; 778 else if ((sp->status & 0377) == 0177) 779 done = 0; 780 } 781 if (stopped) { /* stopped or done */ 782 int state = done? JOBDONE : JOBSTOPPED; 783 if (jp->state != state) { 784 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 785 jp->state = state; 786 #if JOBS 787 if (done && curjob == jp - jobtab + 1) 788 curjob = 0; /* no current job */ 789 #endif 790 } 791 } 792 } 793 } 794 INTON; 795 if (! rootshell || ! iflag || (job && thisjob == job)) { 796 #if JOBS 797 if ((status & 0xFF) == 0177) 798 status >>= 8; 799 #endif 800 core = status & 0x80; 801 status &= 0x7F; 802 if (status != 0 && status != SIGINT && status != SIGPIPE) { 803 if (thisjob != job) 804 outfmt(out2, "%d: ", pid); 805 #if JOBS 806 if (status == SIGTSTP && rootshell && iflag) 807 outfmt(out2, "%%%d ", job - jobtab + 1); 808 #endif 809 if (status < NSIG && sys_siglist[status]) 810 out2str(sys_siglist[status]); 811 else 812 outfmt(out2, "Signal %d", status); 813 if (core) 814 out2str(" - core dumped"); 815 out2c('\n'); 816 flushout(&errout); 817 } else { 818 TRACE(("Not printing status: status=%d\n", status)); 819 } 820 } else { 821 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 822 if (thisjob) 823 thisjob->changed = 1; 824 } 825 return pid; 826 } 827 828 829 830 /* 831 * Do a wait system call. If job control is compiled in, we accept 832 * stopped processes. If block is zero, we return a value of zero 833 * rather than blocking. 834 * 835 * System V doesn't have a non-blocking wait system call. It does 836 * have a SIGCLD signal that is sent to a process when one of it's 837 * children dies. The obvious way to use SIGCLD would be to install 838 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 839 * was received, and have waitproc bump another counter when it got 840 * the status of a process. Waitproc would then know that a wait 841 * system call would not block if the two counters were different. 842 * This approach doesn't work because if a process has children that 843 * have not been waited for, System V will send it a SIGCLD when it 844 * installs a signal handler for SIGCLD. What this means is that when 845 * a child exits, the shell will be sent SIGCLD signals continuously 846 * until is runs out of stack space, unless it does a wait call before 847 * restoring the signal handler. The code below takes advantage of 848 * this (mis)feature by installing a signal handler for SIGCLD and 849 * then checking to see whether it was called. If there are any 850 * children to be waited for, it will be. 851 * 852 * If neither SYSV nor BSD is defined, we don't implement nonblocking 853 * waits at all. In this case, the user will not be informed when 854 * a background process until the next time she runs a real program 855 * (as opposed to running a builtin command or just typing return), 856 * and the jobs command may give out of date information. 857 */ 858 859 #ifdef SYSV 860 STATIC int gotsigchild; 861 862 STATIC int onsigchild() { 863 gotsigchild = 1; 864 } 865 #endif 866 867 868 STATIC int 869 waitproc(block, status) 870 int block; 871 int *status; 872 { 873 #ifdef BSD 874 int flags; 875 876 #if JOBS 877 flags = WUNTRACED; 878 #else 879 flags = 0; 880 #endif 881 if (block == 0) 882 flags |= WNOHANG; 883 return wait3(status, flags, (struct rusage *)NULL); 884 #else 885 #ifdef SYSV 886 int (*save)(); 887 888 if (block == 0) { 889 gotsigchild = 0; 890 save = signal(SIGCLD, onsigchild); 891 signal(SIGCLD, save); 892 if (gotsigchild == 0) 893 return 0; 894 } 895 return wait(status); 896 #else 897 if (block == 0) 898 return 0; 899 return wait(status); 900 #endif 901 #endif 902 } 903 904 /* 905 * return 1 if there are stopped jobs, otherwise 0 906 */ 907 int job_warning = 0; 908 int 909 stoppedjobs() 910 { 911 register int jobno; 912 register struct job *jp; 913 914 if (job_warning) 915 return (0); 916 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 917 if (jp->used == 0) 918 continue; 919 if (jp->state == JOBSTOPPED) { 920 out2str("You have stopped jobs.\n"); 921 job_warning = 2; 922 return (1); 923 } 924 } 925 926 return (0); 927 } 928 929 /* 930 * Return a string identifying a command (to be printed by the 931 * jobs command. 932 */ 933 934 STATIC char *cmdnextc; 935 STATIC int cmdnleft; 936 STATIC void cmdtxt(), cmdputs(); 937 #define MAXCMDTEXT 200 938 939 char * 940 commandtext(n) 941 union node *n; 942 { 943 char *name; 944 945 cmdnextc = name = ckmalloc(MAXCMDTEXT); 946 cmdnleft = MAXCMDTEXT - 4; 947 cmdtxt(n); 948 *cmdnextc = '\0'; 949 return name; 950 } 951 952 953 STATIC void 954 cmdtxt(n) 955 union node *n; 956 { 957 union node *np; 958 struct nodelist *lp; 959 char *p; 960 int i; 961 char s[2]; 962 963 if (n == NULL) 964 return; 965 switch (n->type) { 966 case NSEMI: 967 cmdtxt(n->nbinary.ch1); 968 cmdputs("; "); 969 cmdtxt(n->nbinary.ch2); 970 break; 971 case NAND: 972 cmdtxt(n->nbinary.ch1); 973 cmdputs(" && "); 974 cmdtxt(n->nbinary.ch2); 975 break; 976 case NOR: 977 cmdtxt(n->nbinary.ch1); 978 cmdputs(" || "); 979 cmdtxt(n->nbinary.ch2); 980 break; 981 case NPIPE: 982 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 983 cmdtxt(lp->n); 984 if (lp->next) 985 cmdputs(" | "); 986 } 987 break; 988 case NSUBSHELL: 989 cmdputs("("); 990 cmdtxt(n->nredir.n); 991 cmdputs(")"); 992 break; 993 case NREDIR: 994 case NBACKGND: 995 cmdtxt(n->nredir.n); 996 break; 997 case NIF: 998 cmdputs("if "); 999 cmdtxt(n->nif.test); 1000 cmdputs("; then "); 1001 cmdtxt(n->nif.ifpart); 1002 cmdputs("..."); 1003 break; 1004 case NWHILE: 1005 cmdputs("while "); 1006 goto until; 1007 case NUNTIL: 1008 cmdputs("until "); 1009 until: 1010 cmdtxt(n->nbinary.ch1); 1011 cmdputs("; do "); 1012 cmdtxt(n->nbinary.ch2); 1013 cmdputs("; done"); 1014 break; 1015 case NFOR: 1016 cmdputs("for "); 1017 cmdputs(n->nfor.var); 1018 cmdputs(" in ..."); 1019 break; 1020 case NCASE: 1021 cmdputs("case "); 1022 cmdputs(n->ncase.expr->narg.text); 1023 cmdputs(" in ..."); 1024 break; 1025 case NDEFUN: 1026 cmdputs(n->narg.text); 1027 cmdputs("() ..."); 1028 break; 1029 case NCMD: 1030 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1031 cmdtxt(np); 1032 if (np->narg.next) 1033 cmdputs(" "); 1034 } 1035 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1036 cmdputs(" "); 1037 cmdtxt(np); 1038 } 1039 break; 1040 case NARG: 1041 cmdputs(n->narg.text); 1042 break; 1043 case NTO: 1044 p = ">"; i = 1; goto redir; 1045 case NAPPEND: 1046 p = ">>"; i = 1; goto redir; 1047 case NTOFD: 1048 p = ">&"; i = 1; goto redir; 1049 case NFROM: 1050 p = "<"; i = 0; goto redir; 1051 case NFROMFD: 1052 p = "<&"; i = 0; goto redir; 1053 redir: 1054 if (n->nfile.fd != i) { 1055 s[0] = n->nfile.fd + '0'; 1056 s[1] = '\0'; 1057 cmdputs(s); 1058 } 1059 cmdputs(p); 1060 if (n->type == NTOFD || n->type == NFROMFD) { 1061 s[0] = n->ndup.dupfd + '0'; 1062 s[1] = '\0'; 1063 cmdputs(s); 1064 } else { 1065 cmdtxt(n->nfile.fname); 1066 } 1067 break; 1068 case NHERE: 1069 case NXHERE: 1070 cmdputs("<<..."); 1071 break; 1072 default: 1073 cmdputs("???"); 1074 break; 1075 } 1076 } 1077 1078 1079 1080 STATIC void 1081 cmdputs(s) 1082 char *s; 1083 { 1084 register char *p, *q; 1085 register char c; 1086 int subtype = 0; 1087 1088 if (cmdnleft <= 0) 1089 return; 1090 p = s; 1091 q = cmdnextc; 1092 while ((c = *p++) != '\0') { 1093 if (c == CTLESC) 1094 *q++ = *p++; 1095 else if (c == CTLVAR) { 1096 *q++ = '$'; 1097 if (--cmdnleft > 0) 1098 *q++ = '{'; 1099 subtype = *p++; 1100 } else if (c == '=' && subtype != 0) { 1101 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1102 subtype = 0; 1103 } else if (c == CTLENDVAR) { 1104 *q++ = '}'; 1105 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1106 cmdnleft++; /* ignore it */ 1107 else 1108 *q++ = c; 1109 if (--cmdnleft <= 0) { 1110 *q++ = '.'; 1111 *q++ = '.'; 1112 *q++ = '.'; 1113 break; 1114 } 1115 } 1116 cmdnextc = q; 1117 } 1118