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 * $Id$ 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 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 604 /*** this causes superfluous TIOCSPGRPS ***/ 605 #ifdef OLD_TTY_DRIVER 606 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 607 error("TIOCSPGRP failed, errno=%d", errno); 608 #else 609 if (tcsetpgrp(2, pgrp) < 0) 610 error("tcsetpgrp failed, errno=%d", errno); 611 #endif 612 } 613 setsignal(SIGTSTP); 614 setsignal(SIGTTOU); 615 } else if (mode == FORK_BG) { 616 ignoresig(SIGINT); 617 ignoresig(SIGQUIT); 618 if ((jp == NULL || jp->nprocs == 0) && 619 ! fd0_redirected_p ()) { 620 close(0); 621 if (open("/dev/null", O_RDONLY) != 0) 622 error("Can't open /dev/null"); 623 } 624 } 625 #else 626 if (mode == FORK_BG) { 627 ignoresig(SIGINT); 628 ignoresig(SIGQUIT); 629 if ((jp == NULL || jp->nprocs == 0) && 630 ! fd0_redirected_p ()) { 631 close(0); 632 if (open("/dev/null", O_RDONLY) != 0) 633 error("Can't open /dev/null"); 634 } 635 } 636 #endif 637 if (wasroot && iflag) { 638 setsignal(SIGINT); 639 setsignal(SIGQUIT); 640 setsignal(SIGTERM); 641 } 642 return pid; 643 } 644 if (rootshell && mode != FORK_NOJOB && mflag) { 645 if (jp == NULL || jp->nprocs == 0) 646 pgrp = pid; 647 else 648 pgrp = jp->ps[0].pid; 649 setpgid(pid, pgrp); 650 } 651 if (mode == FORK_BG) 652 backgndpid = pid; /* set $! */ 653 if (jp) { 654 struct procstat *ps = &jp->ps[jp->nprocs++]; 655 ps->pid = pid; 656 ps->status = -1; 657 ps->cmd = nullstr; 658 if (iflag && rootshell && n) 659 ps->cmd = commandtext(n); 660 } 661 INTON; 662 TRACE(("In parent shell: child = %d\n", pid)); 663 return pid; 664 } 665 666 667 668 /* 669 * Wait for job to finish. 670 * 671 * Under job control we have the problem that while a child process is 672 * running interrupts generated by the user are sent to the child but not 673 * to the shell. This means that an infinite loop started by an inter- 674 * active user may be hard to kill. With job control turned off, an 675 * interactive user may place an interactive program inside a loop. If 676 * the interactive program catches interrupts, the user doesn't want 677 * these interrupts to also abort the loop. The approach we take here 678 * is to have the shell ignore interrupt signals while waiting for a 679 * forground process to terminate, and then send itself an interrupt 680 * signal if the child process was terminated by an interrupt signal. 681 * Unfortunately, some programs want to do a bit of cleanup and then 682 * exit on interrupt; unless these processes terminate themselves by 683 * sending a signal to themselves (instead of calling exit) they will 684 * confuse this approach. 685 */ 686 687 int 688 waitforjob(jp) 689 register struct job *jp; 690 { 691 #if JOBS 692 int mypgrp = getpgrp(); 693 #endif 694 int status; 695 int st; 696 697 INTOFF; 698 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 699 while (jp->state == 0) { 700 dowait(1, jp); 701 } 702 #if JOBS 703 if (jp->jobctl) { 704 #ifdef OLD_TTY_DRIVER 705 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 706 error("TIOCSPGRP failed, errno=%d\n", errno); 707 #else 708 if (tcsetpgrp(2, mypgrp) < 0) 709 error("tcsetpgrp failed, errno=%d\n", errno); 710 #endif 711 } 712 if (jp->state == JOBSTOPPED) 713 curjob = jp - jobtab + 1; 714 #endif 715 status = jp->ps[jp->nprocs - 1].status; 716 /* convert to 8 bits */ 717 if ((status & 0xFF) == 0) 718 st = status >> 8 & 0xFF; 719 #if JOBS 720 else if ((status & 0xFF) == 0177) 721 st = (status >> 8 & 0x7F) + 128; 722 #endif 723 else 724 st = (status & 0x7F) + 128; 725 if (! JOBS || jp->state == JOBDONE) 726 freejob(jp); 727 CLEAR_PENDING_INT; 728 if ((status & 0x7F) == SIGINT) 729 kill(getpid(), SIGINT); 730 INTON; 731 return st; 732 } 733 734 735 736 /* 737 * Wait for a process to terminate. 738 */ 739 740 STATIC int 741 dowait(block, job) 742 int block; 743 struct job *job; 744 { 745 int pid; 746 int status; 747 struct procstat *sp; 748 struct job *jp; 749 struct job *thisjob; 750 int done; 751 int stopped; 752 int core; 753 754 TRACE(("dowait(%d) called\n", block)); 755 do { 756 pid = waitproc(block, &status); 757 TRACE(("wait returns %d, status=%d\n", pid, status)); 758 } while (pid == -1 && errno == EINTR); 759 if (pid <= 0) 760 return pid; 761 INTOFF; 762 thisjob = NULL; 763 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 764 if (jp->used) { 765 done = 1; 766 stopped = 1; 767 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 768 if (sp->pid == -1) 769 continue; 770 if (sp->pid == pid) { 771 TRACE(("Changin status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 772 sp->status = status; 773 thisjob = jp; 774 } 775 if (sp->status == -1) 776 stopped = 0; 777 else if ((sp->status & 0377) == 0177) 778 done = 0; 779 } 780 if (stopped) { /* stopped or done */ 781 int state = done? JOBDONE : JOBSTOPPED; 782 if (jp->state != state) { 783 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 784 jp->state = state; 785 #if JOBS 786 if (done && curjob == jp - jobtab + 1) 787 curjob = 0; /* no current job */ 788 #endif 789 } 790 } 791 } 792 } 793 INTON; 794 if (! rootshell || ! iflag || (job && thisjob == job)) { 795 #if JOBS 796 if ((status & 0xFF) == 0177) 797 status >>= 8; 798 #endif 799 core = status & 0x80; 800 status &= 0x7F; 801 if (status != 0 && status != SIGINT && status != SIGPIPE) { 802 if (thisjob != job) 803 outfmt(out2, "%d: ", pid); 804 #if JOBS 805 if (status == SIGTSTP && rootshell && iflag) 806 outfmt(out2, "%%%d ", job - jobtab + 1); 807 #endif 808 if (status < NSIG && sys_siglist[status]) 809 out2str(sys_siglist[status]); 810 else 811 outfmt(out2, "Signal %d", status); 812 if (core) 813 out2str(" - core dumped"); 814 out2c('\n'); 815 flushout(&errout); 816 } else { 817 TRACE(("Not printing status: status=%d\n", status)); 818 } 819 } else { 820 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 821 if (thisjob) 822 thisjob->changed = 1; 823 } 824 return pid; 825 } 826 827 828 829 /* 830 * Do a wait system call. If job control is compiled in, we accept 831 * stopped processes. If block is zero, we return a value of zero 832 * rather than blocking. 833 * 834 * System V doesn't have a non-blocking wait system call. It does 835 * have a SIGCLD signal that is sent to a process when one of it's 836 * children dies. The obvious way to use SIGCLD would be to install 837 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 838 * was received, and have waitproc bump another counter when it got 839 * the status of a process. Waitproc would then know that a wait 840 * system call would not block if the two counters were different. 841 * This approach doesn't work because if a process has children that 842 * have not been waited for, System V will send it a SIGCLD when it 843 * installs a signal handler for SIGCLD. What this means is that when 844 * a child exits, the shell will be sent SIGCLD signals continuously 845 * until is runs out of stack space, unless it does a wait call before 846 * restoring the signal handler. The code below takes advantage of 847 * this (mis)feature by installing a signal handler for SIGCLD and 848 * then checking to see whether it was called. If there are any 849 * children to be waited for, it will be. 850 * 851 * If neither SYSV nor BSD is defined, we don't implement nonblocking 852 * waits at all. In this case, the user will not be informed when 853 * a background process until the next time she runs a real program 854 * (as opposed to running a builtin command or just typing return), 855 * and the jobs command may give out of date information. 856 */ 857 858 #ifdef SYSV 859 STATIC int gotsigchild; 860 861 STATIC int onsigchild() { 862 gotsigchild = 1; 863 } 864 #endif 865 866 867 STATIC int 868 waitproc(block, status) 869 int block; 870 int *status; 871 { 872 #ifdef BSD 873 int flags; 874 875 #if JOBS 876 flags = WUNTRACED; 877 #else 878 flags = 0; 879 #endif 880 if (block == 0) 881 flags |= WNOHANG; 882 return wait3(status, flags, (struct rusage *)NULL); 883 #else 884 #ifdef SYSV 885 int (*save)(); 886 887 if (block == 0) { 888 gotsigchild = 0; 889 save = signal(SIGCLD, onsigchild); 890 signal(SIGCLD, save); 891 if (gotsigchild == 0) 892 return 0; 893 } 894 return wait(status); 895 #else 896 if (block == 0) 897 return 0; 898 return wait(status); 899 #endif 900 #endif 901 } 902 903 /* 904 * return 1 if there are stopped jobs, otherwise 0 905 */ 906 int job_warning = 0; 907 int 908 stoppedjobs() 909 { 910 register int jobno; 911 register struct job *jp; 912 913 if (job_warning) 914 return (0); 915 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 916 if (jp->used == 0) 917 continue; 918 if (jp->state == JOBSTOPPED) { 919 out2str("You have stopped jobs.\n"); 920 job_warning = 2; 921 return (1); 922 } 923 } 924 925 return (0); 926 } 927 928 /* 929 * Return a string identifying a command (to be printed by the 930 * jobs command. 931 */ 932 933 STATIC char *cmdnextc; 934 STATIC int cmdnleft; 935 STATIC void cmdtxt(), cmdputs(); 936 #define MAXCMDTEXT 200 937 938 char * 939 commandtext(n) 940 union node *n; 941 { 942 char *name; 943 944 cmdnextc = name = ckmalloc(MAXCMDTEXT); 945 cmdnleft = MAXCMDTEXT - 4; 946 cmdtxt(n); 947 *cmdnextc = '\0'; 948 return name; 949 } 950 951 952 STATIC void 953 cmdtxt(n) 954 union node *n; 955 { 956 union node *np; 957 struct nodelist *lp; 958 char *p; 959 int i; 960 char s[2]; 961 962 if (n == NULL) 963 return; 964 switch (n->type) { 965 case NSEMI: 966 cmdtxt(n->nbinary.ch1); 967 cmdputs("; "); 968 cmdtxt(n->nbinary.ch2); 969 break; 970 case NAND: 971 cmdtxt(n->nbinary.ch1); 972 cmdputs(" && "); 973 cmdtxt(n->nbinary.ch2); 974 break; 975 case NOR: 976 cmdtxt(n->nbinary.ch1); 977 cmdputs(" || "); 978 cmdtxt(n->nbinary.ch2); 979 break; 980 case NPIPE: 981 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 982 cmdtxt(lp->n); 983 if (lp->next) 984 cmdputs(" | "); 985 } 986 break; 987 case NSUBSHELL: 988 cmdputs("("); 989 cmdtxt(n->nredir.n); 990 cmdputs(")"); 991 break; 992 case NREDIR: 993 case NBACKGND: 994 cmdtxt(n->nredir.n); 995 break; 996 case NIF: 997 cmdputs("if "); 998 cmdtxt(n->nif.test); 999 cmdputs("; then "); 1000 cmdtxt(n->nif.ifpart); 1001 cmdputs("..."); 1002 break; 1003 case NWHILE: 1004 cmdputs("while "); 1005 goto until; 1006 case NUNTIL: 1007 cmdputs("until "); 1008 until: 1009 cmdtxt(n->nbinary.ch1); 1010 cmdputs("; do "); 1011 cmdtxt(n->nbinary.ch2); 1012 cmdputs("; done"); 1013 break; 1014 case NFOR: 1015 cmdputs("for "); 1016 cmdputs(n->nfor.var); 1017 cmdputs(" in ..."); 1018 break; 1019 case NCASE: 1020 cmdputs("case "); 1021 cmdputs(n->ncase.expr->narg.text); 1022 cmdputs(" in ..."); 1023 break; 1024 case NDEFUN: 1025 cmdputs(n->narg.text); 1026 cmdputs("() ..."); 1027 break; 1028 case NCMD: 1029 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1030 cmdtxt(np); 1031 if (np->narg.next) 1032 cmdputs(" "); 1033 } 1034 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1035 cmdputs(" "); 1036 cmdtxt(np); 1037 } 1038 break; 1039 case NARG: 1040 cmdputs(n->narg.text); 1041 break; 1042 case NTO: 1043 p = ">"; i = 1; goto redir; 1044 case NAPPEND: 1045 p = ">>"; i = 1; goto redir; 1046 case NTOFD: 1047 p = ">&"; i = 1; goto redir; 1048 case NFROM: 1049 p = "<"; i = 0; goto redir; 1050 case NFROMFD: 1051 p = "<&"; i = 0; goto redir; 1052 redir: 1053 if (n->nfile.fd != i) { 1054 s[0] = n->nfile.fd + '0'; 1055 s[1] = '\0'; 1056 cmdputs(s); 1057 } 1058 cmdputs(p); 1059 if (n->type == NTOFD || n->type == NFROMFD) { 1060 s[0] = n->ndup.dupfd + '0'; 1061 s[1] = '\0'; 1062 cmdputs(s); 1063 } else { 1064 cmdtxt(n->nfile.fname); 1065 } 1066 break; 1067 case NHERE: 1068 case NXHERE: 1069 cmdputs("<<..."); 1070 break; 1071 default: 1072 cmdputs("???"); 1073 break; 1074 } 1075 } 1076 1077 1078 1079 STATIC void 1080 cmdputs(s) 1081 char *s; 1082 { 1083 register char *p, *q; 1084 register char c; 1085 int subtype = 0; 1086 1087 if (cmdnleft <= 0) 1088 return; 1089 p = s; 1090 q = cmdnextc; 1091 while ((c = *p++) != '\0') { 1092 if (c == CTLESC) 1093 *q++ = *p++; 1094 else if (c == CTLVAR) { 1095 *q++ = '$'; 1096 if (--cmdnleft > 0) 1097 *q++ = '{'; 1098 subtype = *p++; 1099 } else if (c == '=' && subtype != 0) { 1100 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1101 subtype = 0; 1102 } else if (c == CTLENDVAR) { 1103 *q++ = '}'; 1104 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1105 cmdnleft++; /* ignore it */ 1106 else 1107 *q++ = c; 1108 if (--cmdnleft <= 0) { 1109 *q++ = '.'; 1110 *q++ = '.'; 1111 *q++ = '.'; 1112 break; 1113 } 1114 } 1115 cmdnextc = q; 1116 } 1117