jobs.c revision 1.25
1 /* $NetBSD: jobs.c,v 1.25 1998/02/04 23:49:25 thorpej 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 1.25 1998/02/04 23:49:25 thorpej 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 <sys/types.h> 54 #include <sys/param.h> 55 #ifdef BSD 56 #include <sys/wait.h> 57 #include <sys/time.h> 58 #include <sys/resource.h> 59 #endif 60 #include <sys/ioctl.h> 61 62 #include "shell.h" 63 #if JOBS 64 #if OLD_TTY_DRIVER 65 #include "sgtty.h" 66 #else 67 #include <termios.h> 68 #endif 69 #undef CEOF /* syntax.h redefines this */ 70 #endif 71 #include "redir.h" 72 #include "show.h" 73 #include "main.h" 74 #include "parser.h" 75 #include "nodes.h" 76 #include "jobs.h" 77 #include "options.h" 78 #include "trap.h" 79 #include "syntax.h" 80 #include "input.h" 81 #include "output.h" 82 #include "memalloc.h" 83 #include "error.h" 84 #include "mystring.h" 85 86 87 struct job *jobtab; /* array of jobs */ 88 int njobs; /* size of array */ 89 MKINIT short backgndpid = -1; /* pid of last background process */ 90 #if JOBS 91 int initialpgrp; /* pgrp of shell on invocation */ 92 short curjob; /* current job */ 93 #endif 94 95 STATIC void restartjob __P((struct job *)); 96 STATIC void freejob __P((struct job *)); 97 STATIC struct job *getjob __P((char *)); 98 STATIC int dowait __P((int, struct job *)); 99 STATIC int onsigchild __P((void)); 100 STATIC int waitproc __P((int, int *)); 101 STATIC void cmdtxt __P((union node *)); 102 STATIC void cmdputs __P((char *)); 103 104 105 /* 106 * Turn job control on and off. 107 * 108 * Note: This code assumes that the third arg to ioctl is a character 109 * pointer, which is true on Berkeley systems but not System V. Since 110 * System V doesn't have job control yet, this isn't a problem now. 111 */ 112 113 MKINIT int jobctl; 114 115 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 } 173 174 175 #ifdef mkinit 176 INCLUDE <stdlib.h> 177 178 SHELLPROC { 179 backgndpid = -1; 180 #if JOBS 181 jobctl = 0; 182 #endif 183 } 184 185 #endif 186 187 188 189 #if JOBS 190 int 191 fgcmd(argc, argv) 192 int argc; 193 char **argv; 194 { 195 struct job *jp; 196 int pgrp; 197 int status; 198 199 jp = getjob(argv[1]); 200 if (jp->jobctl == 0) 201 error("job not created under job control"); 202 pgrp = jp->ps[0].pid; 203 #ifdef OLD_TTY_DRIVER 204 ioctl(2, TIOCSPGRP, (char *)&pgrp); 205 #else 206 tcsetpgrp(2, pgrp); 207 #endif 208 restartjob(jp); 209 INTOFF; 210 status = waitforjob(jp); 211 INTON; 212 return status; 213 } 214 215 216 int 217 bgcmd(argc, argv) 218 int argc; 219 char **argv; 220 { 221 struct job *jp; 222 223 do { 224 jp = getjob(*++argv); 225 if (jp->jobctl == 0) 226 error("job not created under job control"); 227 restartjob(jp); 228 } while (--argc > 1); 229 return 0; 230 } 231 232 233 STATIC void 234 restartjob(jp) 235 struct job *jp; 236 { 237 struct procstat *ps; 238 int i; 239 240 if (jp->state == JOBDONE) 241 return; 242 INTOFF; 243 killpg(jp->ps[0].pid, SIGCONT); 244 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 245 if (WIFSTOPPED(ps->status)) { 246 ps->status = -1; 247 jp->state = 0; 248 } 249 } 250 INTON; 251 } 252 #endif 253 254 255 int 256 jobscmd(argc, argv) 257 int argc; 258 char **argv; 259 { 260 showjobs(0); 261 return 0; 262 } 263 264 265 /* 266 * Print a list of jobs. If "change" is nonzero, only print jobs whose 267 * statuses have changed since the last call to showjobs. 268 * 269 * If the shell is interrupted in the process of creating a job, the 270 * result may be a job structure containing zero processes. Such structures 271 * will be freed here. 272 */ 273 274 void 275 showjobs(change) 276 int change; 277 { 278 int jobno; 279 int procno; 280 int i; 281 struct job *jp; 282 struct procstat *ps; 283 int col; 284 char s[64]; 285 286 TRACE(("showjobs(%d) called\n", change)); 287 while (dowait(0, (struct job *)NULL) > 0); 288 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 289 if (! jp->used) 290 continue; 291 if (jp->nprocs == 0) { 292 freejob(jp); 293 continue; 294 } 295 if (change && ! jp->changed) 296 continue; 297 procno = jp->nprocs; 298 for (ps = jp->ps ; ; ps++) { /* for each process */ 299 if (ps == jp->ps) 300 fmtstr(s, 64, "[%d] %d ", jobno, ps->pid); 301 else 302 fmtstr(s, 64, " %d ", ps->pid); 303 out1str(s); 304 col = strlen(s); 305 s[0] = '\0'; 306 if (ps->status == -1) { 307 /* don't print anything */ 308 } else if (WIFEXITED(ps->status)) { 309 fmtstr(s, 64, "Exit %d", 310 WEXITSTATUS(ps->status)); 311 } else { 312 #if JOBS 313 if (WIFSTOPPED(ps->status)) 314 i = WSTOPSIG(ps->status); 315 else /* WIFSIGNALED(ps->status) */ 316 #endif 317 i = WTERMSIG(ps->status); 318 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 319 scopy(sys_siglist[i & 0x7F], s); 320 else 321 fmtstr(s, 64, "Signal %d", i & 0x7F); 322 if (WCOREDUMP(ps->status)) 323 strcat(s, " (core dumped)"); 324 } 325 out1str(s); 326 col += strlen(s); 327 do { 328 out1c(' '); 329 col++; 330 } while (col < 30); 331 out1str(ps->cmd); 332 out1c('\n'); 333 if (--procno <= 0) 334 break; 335 } 336 jp->changed = 0; 337 if (jp->state == JOBDONE) { 338 freejob(jp); 339 } 340 } 341 } 342 343 344 /* 345 * Mark a job structure as unused. 346 */ 347 348 STATIC void 349 freejob(jp) 350 struct job *jp; 351 { 352 struct procstat *ps; 353 int i; 354 355 INTOFF; 356 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 357 if (ps->cmd != nullstr) 358 ckfree(ps->cmd); 359 } 360 if (jp->ps != &jp->ps0) 361 ckfree(jp->ps); 362 jp->used = 0; 363 #if JOBS 364 if (curjob == jp - jobtab + 1) 365 curjob = 0; 366 #endif 367 INTON; 368 } 369 370 371 372 int 373 waitcmd(argc, argv) 374 int argc; 375 char **argv; 376 { 377 struct job *job; 378 int status, retval; 379 struct job *jp; 380 381 if (argc > 1) { 382 job = getjob(argv[1]); 383 } else { 384 job = NULL; 385 } 386 for (;;) { /* loop until process terminated or stopped */ 387 if (job != NULL) { 388 if (job->state) { 389 status = job->ps[job->nprocs - 1].status; 390 if (WIFEXITED(status)) 391 retval = WEXITSTATUS(status); 392 #if JOBS 393 else if (WIFSTOPPED(status)) 394 retval = WSTOPSIG(status) + 128; 395 #endif 396 else { 397 /* XXX: limits number of signals */ 398 retval = WTERMSIG(status) + 128; 399 } 400 if (! iflag) 401 freejob(job); 402 return retval; 403 } 404 } else { 405 for (jp = jobtab ; ; jp++) { 406 if (jp >= jobtab + njobs) { /* no running procs */ 407 return 0; 408 } 409 if (jp->used && jp->state == 0) 410 break; 411 } 412 } 413 dowait(1, (struct job *)NULL); 414 } 415 } 416 417 418 419 int 420 jobidcmd(argc, argv) 421 int argc; 422 char **argv; 423 { 424 struct job *jp; 425 int i; 426 427 jp = getjob(argv[1]); 428 for (i = 0 ; i < jp->nprocs ; ) { 429 out1fmt("%d", jp->ps[i].pid); 430 out1c(++i < jp->nprocs? ' ' : '\n'); 431 } 432 return 0; 433 } 434 435 436 437 /* 438 * Convert a job name to a job structure. 439 */ 440 441 STATIC struct job * 442 getjob(name) 443 char *name; 444 { 445 int jobno; 446 struct job *jp; 447 int pid; 448 int i; 449 450 if (name == NULL) { 451 #if JOBS 452 currentjob: 453 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 454 error("No current job"); 455 return &jobtab[jobno - 1]; 456 #else 457 error("No current job"); 458 #endif 459 } else if (name[0] == '%') { 460 if (is_digit(name[1])) { 461 jobno = number(name + 1); 462 if (jobno > 0 && jobno <= njobs 463 && jobtab[jobno - 1].used != 0) 464 return &jobtab[jobno - 1]; 465 #if JOBS 466 } else if (name[1] == '%' && name[2] == '\0') { 467 goto currentjob; 468 #endif 469 } else { 470 struct job *found = NULL; 471 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 472 if (jp->used && jp->nprocs > 0 473 && prefix(name + 1, jp->ps[0].cmd)) { 474 if (found) 475 error("%s: ambiguous", name); 476 found = jp; 477 } 478 } 479 if (found) 480 return found; 481 } 482 } else if (is_number(name)) { 483 pid = number(name); 484 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 485 if (jp->used && jp->nprocs > 0 486 && jp->ps[jp->nprocs - 1].pid == pid) 487 return jp; 488 } 489 } 490 error("No such job: %s", name); 491 /*NOTREACHED*/ 492 return NULL; 493 } 494 495 496 497 /* 498 * Return a new job structure, 499 */ 500 501 struct job * 502 makejob(node, nprocs) 503 union node *node; 504 int nprocs; 505 { 506 int i; 507 struct job *jp; 508 509 for (i = njobs, jp = jobtab ; ; jp++) { 510 if (--i < 0) { 511 INTOFF; 512 if (njobs == 0) { 513 jobtab = ckmalloc(4 * sizeof jobtab[0]); 514 } else { 515 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 516 memcpy(jp, jobtab, njobs * sizeof jp[0]); 517 /* Relocate `ps' pointers */ 518 for (i = 0; i < njobs; i++) 519 if (jp[i].ps == &jobtab[i].ps0) 520 jp[i].ps = &jp[i].ps0; 521 ckfree(jobtab); 522 jobtab = jp; 523 } 524 jp = jobtab + njobs; 525 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 526 INTON; 527 break; 528 } 529 if (jp->used == 0) 530 break; 531 } 532 INTOFF; 533 jp->state = 0; 534 jp->used = 1; 535 jp->changed = 0; 536 jp->nprocs = 0; 537 #if JOBS 538 jp->jobctl = jobctl; 539 #endif 540 if (nprocs > 1) { 541 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 542 } else { 543 jp->ps = &jp->ps0; 544 } 545 INTON; 546 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 547 jp - jobtab + 1)); 548 return jp; 549 } 550 551 552 /* 553 * Fork of a subshell. If we are doing job control, give the subshell its 554 * own process group. Jp is a job structure that the job is to be added to. 555 * N is the command that will be evaluated by the child. Both jp and n may 556 * be NULL. The mode parameter can be one of the following: 557 * FORK_FG - Fork off a foreground process. 558 * FORK_BG - Fork off a background process. 559 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 560 * process group even if job control is on. 561 * 562 * When job control is turned off, background processes have their standard 563 * input redirected to /dev/null (except for the second and later processes 564 * in a pipeline). 565 */ 566 567 int 568 forkshell(jp, n, mode) 569 union node *n; 570 struct job *jp; 571 int mode; 572 { 573 int pid; 574 int pgrp; 575 576 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 577 mode)); 578 INTOFF; 579 pid = fork(); 580 if (pid == -1) { 581 TRACE(("Fork failed, errno=%d\n", errno)); 582 INTON; 583 error("Cannot fork"); 584 } 585 if (pid == 0) { 586 struct job *p; 587 int wasroot; 588 int i; 589 590 TRACE(("Child shell %d\n", getpid())); 591 wasroot = rootshell; 592 rootshell = 0; 593 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 594 if (p->used) 595 freejob(p); 596 closescript(); 597 INTON; 598 clear_traps(); 599 #if JOBS 600 jobctl = 0; /* do job control only in root shell */ 601 if (wasroot && mode != FORK_NOJOB && mflag) { 602 if (jp == NULL || jp->nprocs == 0) 603 pgrp = getpid(); 604 else 605 pgrp = jp->ps[0].pid; 606 setpgid(0, pgrp); 607 if (mode == FORK_FG) { 608 /*** this causes superfluous TIOCSPGRPS ***/ 609 #ifdef OLD_TTY_DRIVER 610 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 611 error("TIOCSPGRP failed, errno=%d", errno); 612 #else 613 if (tcsetpgrp(2, pgrp) < 0) 614 error("tcsetpgrp failed, errno=%d", errno); 615 #endif 616 } 617 setsignal(SIGTSTP); 618 setsignal(SIGTTOU); 619 } else if (mode == FORK_BG) { 620 ignoresig(SIGINT); 621 ignoresig(SIGQUIT); 622 if ((jp == NULL || jp->nprocs == 0) && 623 ! fd0_redirected_p ()) { 624 close(0); 625 if (open("/dev/null", O_RDONLY) != 0) 626 error("Can't open /dev/null"); 627 } 628 } 629 #else 630 if (mode == FORK_BG) { 631 ignoresig(SIGINT); 632 ignoresig(SIGQUIT); 633 if ((jp == NULL || jp->nprocs == 0) && 634 ! fd0_redirected_p ()) { 635 close(0); 636 if (open("/dev/null", O_RDONLY) != 0) 637 error("Can't open /dev/null"); 638 } 639 } 640 #endif 641 if (wasroot && iflag) { 642 setsignal(SIGINT); 643 setsignal(SIGQUIT); 644 setsignal(SIGTERM); 645 } 646 return pid; 647 } 648 if (rootshell && mode != FORK_NOJOB && mflag) { 649 if (jp == NULL || jp->nprocs == 0) 650 pgrp = pid; 651 else 652 pgrp = jp->ps[0].pid; 653 setpgid(pid, pgrp); 654 } 655 if (mode == FORK_BG) 656 backgndpid = pid; /* set $! */ 657 if (jp) { 658 struct procstat *ps = &jp->ps[jp->nprocs++]; 659 ps->pid = pid; 660 ps->status = -1; 661 ps->cmd = nullstr; 662 if (iflag && rootshell && n) 663 ps->cmd = commandtext(n); 664 } 665 INTON; 666 TRACE(("In parent shell: child = %d\n", pid)); 667 return pid; 668 } 669 670 671 672 /* 673 * Wait for job to finish. 674 * 675 * Under job control we have the problem that while a child process is 676 * running interrupts generated by the user are sent to the child but not 677 * to the shell. This means that an infinite loop started by an inter- 678 * active user may be hard to kill. With job control turned off, an 679 * interactive user may place an interactive program inside a loop. If 680 * the interactive program catches interrupts, the user doesn't want 681 * these interrupts to also abort the loop. The approach we take here 682 * is to have the shell ignore interrupt signals while waiting for a 683 * forground process to terminate, and then send itself an interrupt 684 * signal if the child process was terminated by an interrupt signal. 685 * Unfortunately, some programs want to do a bit of cleanup and then 686 * exit on interrupt; unless these processes terminate themselves by 687 * sending a signal to themselves (instead of calling exit) they will 688 * confuse this approach. 689 */ 690 691 int 692 waitforjob(jp) 693 struct job *jp; 694 { 695 #if JOBS 696 int mypgrp = getpgrp(); 697 #endif 698 int status; 699 int st; 700 701 INTOFF; 702 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 703 while (jp->state == 0) { 704 dowait(1, jp); 705 } 706 #if JOBS 707 if (jp->jobctl) { 708 #ifdef OLD_TTY_DRIVER 709 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 710 error("TIOCSPGRP failed, errno=%d\n", errno); 711 #else 712 if (tcsetpgrp(2, mypgrp) < 0) 713 error("tcsetpgrp failed, errno=%d\n", errno); 714 #endif 715 } 716 if (jp->state == JOBSTOPPED) 717 curjob = jp - jobtab + 1; 718 #endif 719 status = jp->ps[jp->nprocs - 1].status; 720 /* convert to 8 bits */ 721 if (WIFEXITED(status)) 722 st = WEXITSTATUS(status); 723 #if JOBS 724 else if (WIFSTOPPED(status)) 725 st = WSTOPSIG(status) + 128; 726 #endif 727 else 728 st = WTERMSIG(status) + 128; 729 if (! JOBS || jp->state == JOBDONE) 730 freejob(jp); 731 CLEAR_PENDING_INT; 732 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 733 kill(getpid(), SIGINT); 734 INTON; 735 return st; 736 } 737 738 739 740 /* 741 * Wait for a process to terminate. 742 */ 743 744 STATIC int 745 dowait(block, job) 746 int block; 747 struct job *job; 748 { 749 int pid; 750 int status; 751 struct procstat *sp; 752 struct job *jp; 753 struct job *thisjob; 754 int done; 755 int stopped; 756 int core; 757 int sig; 758 759 TRACE(("dowait(%d) called\n", block)); 760 do { 761 pid = waitproc(block, &status); 762 TRACE(("wait returns %d, status=%d\n", pid, status)); 763 } while (pid == -1 && errno == EINTR); 764 if (pid <= 0) 765 return pid; 766 INTOFF; 767 thisjob = NULL; 768 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 769 if (jp->used) { 770 done = 1; 771 stopped = 1; 772 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 773 if (sp->pid == -1) 774 continue; 775 if (sp->pid == pid) { 776 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 777 sp->status = status; 778 thisjob = jp; 779 } 780 if (sp->status == -1) 781 stopped = 0; 782 else if (WIFSTOPPED(sp->status)) 783 done = 0; 784 } 785 if (stopped) { /* stopped or done */ 786 int state = done? JOBDONE : JOBSTOPPED; 787 if (jp->state != state) { 788 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 789 jp->state = state; 790 #if JOBS 791 if (done && curjob == jp - jobtab + 1) 792 curjob = 0; /* no current job */ 793 #endif 794 } 795 } 796 } 797 } 798 INTON; 799 if (! rootshell || ! iflag || (job && thisjob == job)) { 800 core = WCOREDUMP(status); 801 #if JOBS 802 if (WIFSTOPPED(status)) sig = WSTOPSIG(status); 803 else 804 #endif 805 if (WIFEXITED(status)) sig = 0; 806 else sig = WTERMSIG(status); 807 808 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 809 if (thisjob != job) 810 outfmt(out2, "%d: ", pid); 811 #if JOBS 812 if (sig == SIGTSTP && rootshell && iflag) 813 outfmt(out2, "%%%ld ", 814 (long)(job - jobtab + 1)); 815 #endif 816 if (sig < NSIG && sys_siglist[sig]) 817 out2str(sys_siglist[sig]); 818 else 819 outfmt(out2, "Signal %d", sig); 820 if (core) 821 out2str(" - core dumped"); 822 out2c('\n'); 823 flushout(&errout); 824 } else { 825 TRACE(("Not printing status: status=%d, sig=%d\n", 826 status, sig)); 827 } 828 } else { 829 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 830 if (thisjob) 831 thisjob->changed = 1; 832 } 833 return pid; 834 } 835 836 837 838 /* 839 * Do a wait system call. If job control is compiled in, we accept 840 * stopped processes. If block is zero, we return a value of zero 841 * rather than blocking. 842 * 843 * System V doesn't have a non-blocking wait system call. It does 844 * have a SIGCLD signal that is sent to a process when one of it's 845 * children dies. The obvious way to use SIGCLD would be to install 846 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 847 * was received, and have waitproc bump another counter when it got 848 * the status of a process. Waitproc would then know that a wait 849 * system call would not block if the two counters were different. 850 * This approach doesn't work because if a process has children that 851 * have not been waited for, System V will send it a SIGCLD when it 852 * installs a signal handler for SIGCLD. What this means is that when 853 * a child exits, the shell will be sent SIGCLD signals continuously 854 * until is runs out of stack space, unless it does a wait call before 855 * restoring the signal handler. The code below takes advantage of 856 * this (mis)feature by installing a signal handler for SIGCLD and 857 * then checking to see whether it was called. If there are any 858 * children to be waited for, it will be. 859 * 860 * If neither SYSV nor BSD is defined, we don't implement nonblocking 861 * waits at all. In this case, the user will not be informed when 862 * a background process until the next time she runs a real program 863 * (as opposed to running a builtin command or just typing return), 864 * and the jobs command may give out of date information. 865 */ 866 867 #ifdef SYSV 868 STATIC int gotsigchild; 869 870 STATIC int onsigchild() { 871 gotsigchild = 1; 872 } 873 #endif 874 875 876 STATIC int 877 waitproc(block, status) 878 int block; 879 int *status; 880 { 881 #ifdef BSD 882 int flags; 883 884 #if JOBS 885 flags = WUNTRACED; 886 #else 887 flags = 0; 888 #endif 889 if (block == 0) 890 flags |= WNOHANG; 891 return wait3(status, flags, (struct rusage *)NULL); 892 #else 893 #ifdef SYSV 894 int (*save)(); 895 896 if (block == 0) { 897 gotsigchild = 0; 898 save = signal(SIGCLD, onsigchild); 899 signal(SIGCLD, save); 900 if (gotsigchild == 0) 901 return 0; 902 } 903 return wait(status); 904 #else 905 if (block == 0) 906 return 0; 907 return wait(status); 908 #endif 909 #endif 910 } 911 912 /* 913 * return 1 if there are stopped jobs, otherwise 0 914 */ 915 int job_warning = 0; 916 int 917 stoppedjobs() 918 { 919 int jobno; 920 struct job *jp; 921 922 if (job_warning) 923 return (0); 924 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 925 if (jp->used == 0) 926 continue; 927 if (jp->state == JOBSTOPPED) { 928 out2str("You have stopped jobs.\n"); 929 job_warning = 2; 930 return (1); 931 } 932 } 933 934 return (0); 935 } 936 937 /* 938 * Return a string identifying a command (to be printed by the 939 * jobs command. 940 */ 941 942 STATIC char *cmdnextc; 943 STATIC int cmdnleft; 944 #define MAXCMDTEXT 200 945 946 char * 947 commandtext(n) 948 union node *n; 949 { 950 char *name; 951 952 cmdnextc = name = ckmalloc(MAXCMDTEXT); 953 cmdnleft = MAXCMDTEXT - 4; 954 cmdtxt(n); 955 *cmdnextc = '\0'; 956 return name; 957 } 958 959 960 STATIC void 961 cmdtxt(n) 962 union node *n; 963 { 964 union node *np; 965 struct nodelist *lp; 966 char *p; 967 int i; 968 char s[2]; 969 970 if (n == NULL) 971 return; 972 switch (n->type) { 973 case NSEMI: 974 cmdtxt(n->nbinary.ch1); 975 cmdputs("; "); 976 cmdtxt(n->nbinary.ch2); 977 break; 978 case NAND: 979 cmdtxt(n->nbinary.ch1); 980 cmdputs(" && "); 981 cmdtxt(n->nbinary.ch2); 982 break; 983 case NOR: 984 cmdtxt(n->nbinary.ch1); 985 cmdputs(" || "); 986 cmdtxt(n->nbinary.ch2); 987 break; 988 case NPIPE: 989 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 990 cmdtxt(lp->n); 991 if (lp->next) 992 cmdputs(" | "); 993 } 994 break; 995 case NSUBSHELL: 996 cmdputs("("); 997 cmdtxt(n->nredir.n); 998 cmdputs(")"); 999 break; 1000 case NREDIR: 1001 case NBACKGND: 1002 cmdtxt(n->nredir.n); 1003 break; 1004 case NIF: 1005 cmdputs("if "); 1006 cmdtxt(n->nif.test); 1007 cmdputs("; then "); 1008 cmdtxt(n->nif.ifpart); 1009 cmdputs("..."); 1010 break; 1011 case NWHILE: 1012 cmdputs("while "); 1013 goto until; 1014 case NUNTIL: 1015 cmdputs("until "); 1016 until: 1017 cmdtxt(n->nbinary.ch1); 1018 cmdputs("; do "); 1019 cmdtxt(n->nbinary.ch2); 1020 cmdputs("; done"); 1021 break; 1022 case NFOR: 1023 cmdputs("for "); 1024 cmdputs(n->nfor.var); 1025 cmdputs(" in ..."); 1026 break; 1027 case NCASE: 1028 cmdputs("case "); 1029 cmdputs(n->ncase.expr->narg.text); 1030 cmdputs(" in ..."); 1031 break; 1032 case NDEFUN: 1033 cmdputs(n->narg.text); 1034 cmdputs("() ..."); 1035 break; 1036 case NCMD: 1037 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1038 cmdtxt(np); 1039 if (np->narg.next) 1040 cmdputs(" "); 1041 } 1042 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1043 cmdputs(" "); 1044 cmdtxt(np); 1045 } 1046 break; 1047 case NARG: 1048 cmdputs(n->narg.text); 1049 break; 1050 case NTO: 1051 p = ">"; i = 1; goto redir; 1052 case NAPPEND: 1053 p = ">>"; i = 1; goto redir; 1054 case NTOFD: 1055 p = ">&"; i = 1; goto redir; 1056 case NFROM: 1057 p = "<"; i = 0; goto redir; 1058 case NFROMFD: 1059 p = "<&"; i = 0; goto redir; 1060 redir: 1061 if (n->nfile.fd != i) { 1062 s[0] = n->nfile.fd + '0'; 1063 s[1] = '\0'; 1064 cmdputs(s); 1065 } 1066 cmdputs(p); 1067 if (n->type == NTOFD || n->type == NFROMFD) { 1068 s[0] = n->ndup.dupfd + '0'; 1069 s[1] = '\0'; 1070 cmdputs(s); 1071 } else { 1072 cmdtxt(n->nfile.fname); 1073 } 1074 break; 1075 case NHERE: 1076 case NXHERE: 1077 cmdputs("<<..."); 1078 break; 1079 default: 1080 cmdputs("???"); 1081 break; 1082 } 1083 } 1084 1085 1086 1087 STATIC void 1088 cmdputs(s) 1089 char *s; 1090 { 1091 char *p, *q; 1092 char c; 1093 int subtype = 0; 1094 1095 if (cmdnleft <= 0) 1096 return; 1097 p = s; 1098 q = cmdnextc; 1099 while ((c = *p++) != '\0') { 1100 if (c == CTLESC) 1101 *q++ = *p++; 1102 else if (c == CTLVAR) { 1103 *q++ = '$'; 1104 if (--cmdnleft > 0) 1105 *q++ = '{'; 1106 subtype = *p++; 1107 } else if (c == '=' && subtype != 0) { 1108 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1109 subtype = 0; 1110 } else if (c == CTLENDVAR) { 1111 *q++ = '}'; 1112 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1113 cmdnleft++; /* ignore it */ 1114 else 1115 *q++ = c; 1116 if (--cmdnleft <= 0) { 1117 *q++ = '.'; 1118 *q++ = '.'; 1119 *q++ = '.'; 1120 break; 1121 } 1122 } 1123 cmdnextc = q; 1124 } 1125
Indexes created Thu Oct 02 14:10:14 GMT 2025