jobs.c revision 33138
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 1.17 1997/12/10 22:18:53 eivind Exp $ 37 */ 38 39#ifndef lint 40static 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/param.h> 49#ifdef BSD 50#include <sys/wait.h> 51#include <sys/time.h> 52#include <sys/resource.h> 53#endif 54#include <sys/ioctl.h> 55 56#include "shell.h" 57#if JOBS 58#if OLD_TTY_DRIVER 59#include "sgtty.h" 60#else 61#include <termios.h> 62#endif 63#undef CEOF /* syntax.h redefines this */ 64#endif 65#include "redir.h" 66#include "show.h" 67#include "main.h" 68#include "parser.h" 69#include "nodes.h" 70#include "jobs.h" 71#include "options.h" 72#include "trap.h" 73#include "syntax.h" 74#include "input.h" 75#include "output.h" 76#include "memalloc.h" 77#include "error.h" 78#include "mystring.h" 79 80 81struct job *jobtab; /* array of jobs */ 82int njobs; /* size of array */ 83MKINIT pid_t backgndpid = -1; /* pid of last background process */ 84#if JOBS 85int initialpgrp; /* pgrp of shell on invocation */ 86int curjob; /* current job */ 87#endif 88sig_t oldsigint; 89sig_t oldsigquit; 90int oldsigs_valid = 0; 91 92#if JOBS 93STATIC void restartjob __P((struct job *)); 94#endif 95STATIC void freejob __P((struct job *)); 96STATIC struct job *getjob __P((char *)); 97STATIC int dowait __P((int, struct job *)); 98#if SYSV 99STATIC int onsigchild __P((void)); 100#endif 101STATIC int waitproc __P((int, int *)); 102STATIC void cmdtxt __P((union node *)); 103STATIC void cmdputs __P((char *)); 104 105 106/* 107 * Turn job control on and off. 108 * 109 * Note: This code assumes that the third arg to ioctl is a character 110 * pointer, which is true on Berkeley systems but not System V. Since 111 * System V doesn't have job control yet, this isn't a problem now. 112 */ 113 114MKINIT int jobctl; 115 116#if JOBS 117void 118setjobctl(on) 119 int on; 120{ 121#ifdef OLD_TTY_DRIVER 122 int ldisc; 123#endif 124 125 if (on == jobctl || rootshell == 0) 126 return; 127 if (on) { 128 do { /* while we are in the background */ 129#ifdef OLD_TTY_DRIVER 130 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 131#else 132 initialpgrp = tcgetpgrp(2); 133 if (initialpgrp < 0) { 134#endif 135 out2str("sh: can't access tty; job control turned off\n"); 136 mflag = 0; 137 return; 138 } 139 if (initialpgrp == -1) 140 initialpgrp = getpgrp(); 141 else if (initialpgrp != getpgrp()) { 142 killpg(initialpgrp, SIGTTIN); 143 continue; 144 } 145 } while (0); 146#ifdef OLD_TTY_DRIVER 147 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 148 out2str("sh: need new tty driver to run job control; job control turned off\n"); 149 mflag = 0; 150 return; 151 } 152#endif 153 setsignal(SIGTSTP); 154 setsignal(SIGTTOU); 155 setsignal(SIGTTIN); 156 setpgid(0, rootpid); 157#ifdef OLD_TTY_DRIVER 158 ioctl(2, TIOCSPGRP, (char *)&rootpid); 159#else 160 tcsetpgrp(2, rootpid); 161#endif 162 } else { /* turning job control off */ 163 setpgid(0, initialpgrp); 164#ifdef OLD_TTY_DRIVER 165 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 166#else 167 tcsetpgrp(2, initialpgrp); 168#endif 169 setsignal(SIGTSTP); 170 setsignal(SIGTTOU); 171 setsignal(SIGTTIN); 172 } 173 jobctl = on; 174} 175#endif 176 177 178#ifdef mkinit 179INCLUDE <sys/types.h> 180INCLUDE <stdlib.h> 181 182SHELLPROC { 183 backgndpid = -1; 184#if JOBS 185 jobctl = 0; 186#endif 187} 188 189#endif 190 191 192 193#if JOBS 194int 195fgcmd(argc, argv) 196 int argc __unused; 197 char **argv; 198{ 199 struct job *jp; 200 int pgrp; 201 int status; 202 203 jp = getjob(argv[1]); 204 if (jp->jobctl == 0) 205 error("job not created under job control"); 206 pgrp = jp->ps[0].pid; 207#ifdef OLD_TTY_DRIVER 208 ioctl(2, TIOCSPGRP, (char *)&pgrp); 209#else 210 tcsetpgrp(2, pgrp); 211#endif 212 restartjob(jp); 213 INTOFF; 214 status = waitforjob(jp); 215 INTON; 216 return status; 217} 218 219 220int 221bgcmd(argc, argv) 222 int argc; 223 char **argv; 224{ 225 struct job *jp; 226 227 do { 228 jp = getjob(*++argv); 229 if (jp->jobctl == 0) 230 error("job not created under job control"); 231 restartjob(jp); 232 } while (--argc > 1); 233 return 0; 234} 235 236 237STATIC void 238restartjob(jp) 239 struct job *jp; 240{ 241 struct procstat *ps; 242 int i; 243 244 if (jp->state == JOBDONE) 245 return; 246 INTOFF; 247 killpg(jp->ps[0].pid, SIGCONT); 248 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 249 if (WIFSTOPPED(ps->status)) { 250 ps->status = -1; 251 jp->state = 0; 252 } 253 } 254 INTON; 255} 256#endif 257 258 259int 260jobscmd(argc, argv) 261 int argc __unused; 262 char **argv __unused; 263{ 264 showjobs(0); 265 return 0; 266} 267 268 269/* 270 * Print a list of jobs. If "change" is nonzero, only print jobs whose 271 * statuses have changed since the last call to showjobs. 272 * 273 * If the shell is interrupted in the process of creating a job, the 274 * result may be a job structure containing zero processes. Such structures 275 * will be freed here. 276 */ 277 278void 279showjobs(change) 280 int change; 281{ 282 int jobno; 283 int procno; 284 int i; 285 struct job *jp; 286 struct procstat *ps; 287 int col; 288 char s[64]; 289 290 TRACE(("showjobs(%d) called\n", change)); 291 while (dowait(0, (struct job *)NULL) > 0); 292 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 293 if (! jp->used) 294 continue; 295 if (jp->nprocs == 0) { 296 freejob(jp); 297 continue; 298 } 299 if (change && ! jp->changed) 300 continue; 301 procno = jp->nprocs; 302 for (ps = jp->ps ; ; ps++) { /* for each process */ 303 if (ps == jp->ps) 304 fmtstr(s, 64, "[%d] %d ", jobno, ps->pid); 305 else 306 fmtstr(s, 64, " %d ", ps->pid); 307 out1str(s); 308 col = strlen(s); 309 s[0] = '\0'; 310 if (ps->status == -1) { 311 /* don't print anything */ 312 } else if (WIFEXITED(ps->status)) { 313 fmtstr(s, 64, "Exit %d", WEXITSTATUS(ps->status)); 314 } else { 315#if JOBS 316 if (WIFSTOPPED(ps->status)) 317 i = WSTOPSIG(ps->status); 318 else 319#endif 320 i = WTERMSIG(ps->status); 321 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 322 scopy(sys_siglist[i & 0x7F], s); 323 else 324 fmtstr(s, 64, "Signal %d", i & 0x7F); 325 if (WCOREDUMP(ps->status)) 326 strcat(s, " (core dumped)"); 327 } 328 out1str(s); 329 col += strlen(s); 330 do { 331 out1c(' '); 332 col++; 333 } while (col < 30); 334 out1str(ps->cmd); 335 out1c('\n'); 336 if (--procno <= 0) 337 break; 338 } 339 jp->changed = 0; 340 if (jp->state == JOBDONE) { 341 freejob(jp); 342 } 343 } 344} 345 346 347/* 348 * Mark a job structure as unused. 349 */ 350 351STATIC void 352freejob(jp) 353 struct job *jp; 354 { 355 struct procstat *ps; 356 int i; 357 358 INTOFF; 359 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 360 if (ps->cmd != nullstr) 361 ckfree(ps->cmd); 362 } 363 if (jp->ps != &jp->ps0) 364 ckfree(jp->ps); 365 jp->used = 0; 366#if JOBS 367 if (curjob == jp - jobtab + 1) 368 curjob = 0; 369#endif 370 INTON; 371} 372 373 374 375int 376waitcmd(argc, argv) 377 int argc; 378 char **argv; 379{ 380 struct job *job; 381 int status, retval; 382 struct job *jp; 383 384 if (argc > 1) { 385 job = getjob(argv[1]); 386 } else { 387 job = NULL; 388 } 389 for (;;) { /* loop until process terminated or stopped */ 390 if (job != NULL) { 391 if (job->state) { 392 status = job->ps[job->nprocs - 1].status; 393 if (WIFEXITED(status)) 394 retval = WEXITSTATUS(status); 395#if JOBS 396 else if (WIFSTOPPED(status)) 397 retval = WSTOPSIG(status) + 128; 398#endif 399 else 400 retval = WTERMSIG(status) + 128; 401 if (! iflag) 402 freejob(job); 403 return retval; 404 } 405 } else { 406 for (jp = jobtab ; ; jp++) { 407 if (jp >= jobtab + njobs) { /* no running procs */ 408 return 0; 409 } 410 if (jp->used && jp->state == 0) 411 break; 412 } 413 } 414 dowait(1, (struct job *)NULL); 415 } 416} 417 418 419 420int 421jobidcmd(argc, argv) 422 int argc __unused; 423 char **argv; 424{ 425 struct job *jp; 426 int i; 427 428 jp = getjob(argv[1]); 429 for (i = 0 ; i < jp->nprocs ; ) { 430 out1fmt("%d", jp->ps[i].pid); 431 out1c(++i < jp->nprocs? ' ' : '\n'); 432 } 433 return 0; 434} 435 436 437 438/* 439 * Convert a job name to a job structure. 440 */ 441 442STATIC struct job * 443getjob(name) 444 char *name; 445 { 446 int jobno; 447 struct job *jp; 448 int pid; 449 int i; 450 451 if (name == NULL) { 452#if JOBS 453currentjob: 454 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 455 error("No current job"); 456 return &jobtab[jobno - 1]; 457#else 458 error("No current job"); 459#endif 460 } else if (name[0] == '%') { 461 if (is_digit(name[1])) { 462 jobno = number(name + 1); 463 if (jobno > 0 && jobno <= njobs 464 && jobtab[jobno - 1].used != 0) 465 return &jobtab[jobno - 1]; 466#if JOBS 467 } else if (name[1] == '%' && name[2] == '\0') { 468 goto currentjob; 469#endif 470 } else { 471 struct job *found = NULL; 472 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 473 if (jp->used && jp->nprocs > 0 474 && prefix(name + 1, jp->ps[0].cmd)) { 475 if (found) 476 error("%s: ambiguous", name); 477 found = jp; 478 } 479 } 480 if (found) 481 return found; 482 } 483 } else if (is_number(name)) { 484 pid = number(name); 485 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 486 if (jp->used && jp->nprocs > 0 487 && jp->ps[jp->nprocs - 1].pid == pid) 488 return jp; 489 } 490 } 491 error("No such job: %s", name); 492 /*NOTREACHED*/ 493 return NULL; 494} 495 496 497 498/* 499 * Return a new job structure, 500 */ 501 502struct job * 503makejob(node, nprocs) 504 union node *node __unused; 505 int nprocs; 506{ 507 int i; 508 struct job *jp; 509 510 for (i = njobs, jp = jobtab ; ; jp++) { 511 if (--i < 0) { 512 INTOFF; 513 if (njobs == 0) { 514 jobtab = ckmalloc(4 * sizeof jobtab[0]); 515 } else { 516 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 517 memcpy(jp, jobtab, njobs * sizeof jp[0]); 518 /* Relocate `ps' pointers */ 519 for (i = 0; i < njobs; i++) 520 if (jp[i].ps == &jobtab[i].ps0) 521 jp[i].ps = &jp[i].ps0; 522 ckfree(jobtab); 523 jobtab = jp; 524 } 525 jp = jobtab + njobs; 526 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 527 INTON; 528 break; 529 } 530 if (jp->used == 0) 531 break; 532 } 533 INTOFF; 534 jp->state = 0; 535 jp->used = 1; 536 jp->changed = 0; 537 jp->nprocs = 0; 538#if JOBS 539 jp->jobctl = jobctl; 540#endif 541 if (nprocs > 1) { 542 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 543 } else { 544 jp->ps = &jp->ps0; 545 } 546 INTON; 547 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 548 jp - jobtab + 1)); 549 return jp; 550} 551 552 553/* 554 * Fork of a subshell. If we are doing job control, give the subshell its 555 * own process group. Jp is a job structure that the job is to be added to. 556 * N is the command that will be evaluated by the child. Both jp and n may 557 * be NULL. The mode parameter can be one of the following: 558 * FORK_FG - Fork off a foreground process. 559 * FORK_BG - Fork off a background process. 560 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 561 * process group even if job control is on. 562 * 563 * When job control is turned off, background processes have their standard 564 * input redirected to /dev/null (except for the second and later processes 565 * in a pipeline). 566 */ 567 568int 569forkshell(jp, n, mode) 570 union node *n; 571 struct job *jp; 572 int mode; 573{ 574 int pid; 575 int pgrp; 576 577 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 578 mode)); 579 INTOFF; 580 if (mode == FORK_FG) { 581 oldsigquit = signal(SIGQUIT,SIG_IGN); 582 oldsigint = signal(SIGINT,SIG_IGN); 583 oldsigs_valid = 1; 584 } 585 pid = fork(); 586 if (pid == -1) { 587 TRACE(("Fork failed, errno=%d\n", errno)); 588 INTON; 589 error("Cannot fork"); 590 } 591 if (pid == 0) { 592 struct job *p; 593 int wasroot; 594 int i; 595 596 TRACE(("Child shell %d\n", getpid())); 597 signal(SIGQUIT,SIG_DFL); 598 signal(SIGINT,SIG_DFL); 599 wasroot = rootshell; 600 rootshell = 0; 601 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 602 if (p->used) 603 freejob(p); 604 closescript(); 605 INTON; 606 clear_traps(); 607#if JOBS 608 jobctl = 0; /* do job control only in root shell */ 609 if (wasroot && mode != FORK_NOJOB && mflag) { 610 if (jp == NULL || jp->nprocs == 0) 611 pgrp = getpid(); 612 else 613 pgrp = jp->ps[0].pid; 614 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 615 /*** this causes superfluous TIOCSPGRPS ***/ 616#ifdef OLD_TTY_DRIVER 617 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 618 error("TIOCSPGRP failed, errno=%d", errno); 619#else 620 if (tcsetpgrp(2, pgrp) < 0) 621 error("tcsetpgrp failed, errno=%d", errno); 622#endif 623 } 624 setsignal(SIGTSTP); 625 setsignal(SIGTTOU); 626 } else 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#else 637 if (mode == FORK_BG) { 638 ignoresig(SIGINT); 639 ignoresig(SIGQUIT); 640 if ((jp == NULL || jp->nprocs == 0) && 641 ! fd0_redirected_p ()) { 642 close(0); 643 if (open("/dev/null", O_RDONLY) != 0) 644 error("Can't open /dev/null"); 645 } 646 } 647#endif 648 if (wasroot && iflag) { 649 setsignal(SIGINT); 650 setsignal(SIGQUIT); 651 setsignal(SIGTERM); 652 } 653 return pid; 654 } 655 if (rootshell && mode != FORK_NOJOB && mflag) { 656 if (jp == NULL || jp->nprocs == 0) 657 pgrp = pid; 658 else 659 pgrp = jp->ps[0].pid; 660 setpgid(pid, pgrp); 661 } 662 if (mode == FORK_BG) 663 backgndpid = pid; /* set $! */ 664 if (jp) { 665 struct procstat *ps = &jp->ps[jp->nprocs++]; 666 ps->pid = pid; 667 ps->status = -1; 668 ps->cmd = nullstr; 669 if (iflag && rootshell && n) 670 ps->cmd = commandtext(n); 671 } 672 INTON; 673 TRACE(("In parent shell: child = %d\n", pid)); 674 return pid; 675} 676 677 678 679/* 680 * Wait for job to finish. 681 * 682 * Under job control we have the problem that while a child process is 683 * running interrupts generated by the user are sent to the child but not 684 * to the shell. This means that an infinite loop started by an inter- 685 * active user may be hard to kill. With job control turned off, an 686 * interactive user may place an interactive program inside a loop. If 687 * the interactive program catches interrupts, the user doesn't want 688 * these interrupts to also abort the loop. The approach we take here 689 * is to have the shell ignore interrupt signals while waiting for a 690 * forground process to terminate, and then send itself an interrupt 691 * signal if the child process was terminated by an interrupt signal. 692 * Unfortunately, some programs want to do a bit of cleanup and then 693 * exit on interrupt; unless these processes terminate themselves by 694 * sending a signal to themselves (instead of calling exit) they will 695 * confuse this approach. 696 */ 697 698int 699waitforjob(jp) 700 struct job *jp; 701 { 702#if JOBS 703 int mypgrp = getpgrp(); 704#endif 705 int status; 706 int st; 707 708 INTOFF; 709 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 710 while (jp->state == 0) { 711 dowait(1, jp); 712 } 713 if (oldsigs_valid) { 714 signal(SIGQUIT,oldsigquit); 715 signal(SIGINT,oldsigint); 716 oldsigs_valid = 0; 717 } 718 719#if JOBS 720 if (jp->jobctl) { 721#ifdef OLD_TTY_DRIVER 722 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 723 error("TIOCSPGRP failed, errno=%d\n", errno); 724#else 725 if (tcsetpgrp(2, mypgrp) < 0) 726 error("tcsetpgrp failed, errno=%d\n", errno); 727#endif 728 } 729 if (jp->state == JOBSTOPPED) 730 curjob = jp - jobtab + 1; 731#endif 732 status = jp->ps[jp->nprocs - 1].status; 733 /* convert to 8 bits */ 734 if (WIFEXITED(status)) 735 st = WEXITSTATUS(status); 736#if JOBS 737 else if (WIFSTOPPED(status)) 738 st = WSTOPSIG(status) + 128; 739#endif 740 else 741 st = WTERMSIG(status) + 128; 742 if (! JOBS || jp->state == JOBDONE) 743 freejob(jp); 744 CLEAR_PENDING_INT; 745 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 746 kill(getpid(), SIGINT); 747 INTON; 748 return st; 749} 750 751 752 753/* 754 * Wait for a process to terminate. 755 */ 756 757STATIC int 758dowait(block, job) 759 int block; 760 struct job *job; 761{ 762 int pid; 763 int status; 764 struct procstat *sp; 765 struct job *jp; 766 struct job *thisjob; 767 int done; 768 int stopped; 769 int core; 770 int sig; 771 772 TRACE(("dowait(%d) called\n", block)); 773 do { 774 pid = waitproc(block, &status); 775 TRACE(("wait returns %d, status=%d\n", pid, status)); 776 } while (pid == -1 && errno == EINTR); 777 if (pid <= 0) 778 return pid; 779 INTOFF; 780 thisjob = NULL; 781 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 782 if (jp->used) { 783 done = 1; 784 stopped = 1; 785 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 786 if (sp->pid == -1) 787 continue; 788 if (sp->pid == pid) { 789 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 790 pid, sp->status, status)); 791 sp->status = status; 792 thisjob = jp; 793 } 794 if (sp->status == -1) 795 stopped = 0; 796 else if (WIFSTOPPED(sp->status)) 797 done = 0; 798 } 799 if (stopped) { /* stopped or done */ 800 int state = done? JOBDONE : JOBSTOPPED; 801 if (jp->state != state) { 802 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 803 jp->state = state; 804#if JOBS 805 if (done && curjob == jp - jobtab + 1) 806 curjob = 0; /* no current job */ 807#endif 808 } 809 } 810 } 811 } 812 INTON; 813 if (! rootshell || ! iflag || (job && thisjob == job)) { 814 core = WCOREDUMP(status); 815#if JOBS 816 if (WIFSTOPPED(status)) 817 sig = WSTOPSIG(status); 818 else 819#endif 820 if (WIFEXITED(status)) 821 sig = 0; 822 else 823 sig = WTERMSIG(status); 824 825 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 826 if (thisjob != job) 827 outfmt(out2, "%d: ", pid); 828#if JOBS 829 if (sig == SIGTSTP && rootshell && iflag) 830 outfmt(out2, "%%%d ", job - jobtab + 1); 831#endif 832 if (sig < NSIG && sys_siglist[sig]) 833 out2str(sys_siglist[sig]); 834 else 835 outfmt(out2, "Signal %d", sig); 836 if (core) 837 out2str(" - core dumped"); 838 out2c('\n'); 839 flushout(&errout); 840 } else { 841 TRACE(("Not printing status: status=%d, sig=%d\n", 842 status, sig)); 843 } 844 } else { 845 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 846 if (thisjob) 847 thisjob->changed = 1; 848 } 849 return pid; 850} 851 852 853 854/* 855 * Do a wait system call. If job control is compiled in, we accept 856 * stopped processes. If block is zero, we return a value of zero 857 * rather than blocking. 858 * 859 * System V doesn't have a non-blocking wait system call. It does 860 * have a SIGCLD signal that is sent to a process when one of it's 861 * children dies. The obvious way to use SIGCLD would be to install 862 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 863 * was received, and have waitproc bump another counter when it got 864 * the status of a process. Waitproc would then know that a wait 865 * system call would not block if the two counters were different. 866 * This approach doesn't work because if a process has children that 867 * have not been waited for, System V will send it a SIGCLD when it 868 * installs a signal handler for SIGCLD. What this means is that when 869 * a child exits, the shell will be sent SIGCLD signals continuously 870 * until is runs out of stack space, unless it does a wait call before 871 * restoring the signal handler. The code below takes advantage of 872 * this (mis)feature by installing a signal handler for SIGCLD and 873 * then checking to see whether it was called. If there are any 874 * children to be waited for, it will be. 875 * 876 * If neither SYSV nor BSD is defined, we don't implement nonblocking 877 * waits at all. In this case, the user will not be informed when 878 * a background process until the next time she runs a real program 879 * (as opposed to running a builtin command or just typing return), 880 * and the jobs command may give out of date information. 881 */ 882 883#ifdef SYSV 884STATIC int gotsigchild; 885 886STATIC int onsigchild() { 887 gotsigchild = 1; 888} 889#endif 890 891 892STATIC int 893waitproc(block, status) 894 int block; 895 int *status; 896{ 897#ifdef BSD 898 int flags; 899 900#if JOBS 901 flags = WUNTRACED; 902#else 903 flags = 0; 904#endif 905 if (block == 0) 906 flags |= WNOHANG; 907 return wait3(status, flags, (struct rusage *)NULL); 908#else 909#ifdef SYSV 910 int (*save)(); 911 912 if (block == 0) { 913 gotsigchild = 0; 914 save = signal(SIGCLD, onsigchild); 915 signal(SIGCLD, save); 916 if (gotsigchild == 0) 917 return 0; 918 } 919 return wait(status); 920#else 921 if (block == 0) 922 return 0; 923 return wait(status); 924#endif 925#endif 926} 927 928/* 929 * return 1 if there are stopped jobs, otherwise 0 930 */ 931int job_warning = 0; 932int 933stoppedjobs() 934{ 935 int jobno; 936 struct job *jp; 937 938 if (job_warning) 939 return (0); 940 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 941 if (jp->used == 0) 942 continue; 943 if (jp->state == JOBSTOPPED) { 944 out2str("You have stopped jobs.\n"); 945 job_warning = 2; 946 return (1); 947 } 948 } 949 950 return (0); 951} 952 953/* 954 * Return a string identifying a command (to be printed by the 955 * jobs command. 956 */ 957 958STATIC char *cmdnextc; 959STATIC int cmdnleft; 960STATIC void cmdtxt(), cmdputs(); 961#define MAXCMDTEXT 200 962 963char * 964commandtext(n) 965 union node *n; 966 { 967 char *name; 968 969 cmdnextc = name = ckmalloc(MAXCMDTEXT); 970 cmdnleft = MAXCMDTEXT - 4; 971 cmdtxt(n); 972 *cmdnextc = '\0'; 973 return name; 974} 975 976 977STATIC void 978cmdtxt(n) 979 union node *n; 980 { 981 union node *np; 982 struct nodelist *lp; 983 char *p; 984 int i; 985 char s[2]; 986 987 if (n == NULL) 988 return; 989 switch (n->type) { 990 case NSEMI: 991 cmdtxt(n->nbinary.ch1); 992 cmdputs("; "); 993 cmdtxt(n->nbinary.ch2); 994 break; 995 case NAND: 996 cmdtxt(n->nbinary.ch1); 997 cmdputs(" && "); 998 cmdtxt(n->nbinary.ch2); 999 break; 1000 case NOR: 1001 cmdtxt(n->nbinary.ch1); 1002 cmdputs(" || "); 1003 cmdtxt(n->nbinary.ch2); 1004 break; 1005 case NPIPE: 1006 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1007 cmdtxt(lp->n); 1008 if (lp->next) 1009 cmdputs(" | "); 1010 } 1011 break; 1012 case NSUBSHELL: 1013 cmdputs("("); 1014 cmdtxt(n->nredir.n); 1015 cmdputs(")"); 1016 break; 1017 case NREDIR: 1018 case NBACKGND: 1019 cmdtxt(n->nredir.n); 1020 break; 1021 case NIF: 1022 cmdputs("if "); 1023 cmdtxt(n->nif.test); 1024 cmdputs("; then "); 1025 cmdtxt(n->nif.ifpart); 1026 cmdputs("..."); 1027 break; 1028 case NWHILE: 1029 cmdputs("while "); 1030 goto until; 1031 case NUNTIL: 1032 cmdputs("until "); 1033until: 1034 cmdtxt(n->nbinary.ch1); 1035 cmdputs("; do "); 1036 cmdtxt(n->nbinary.ch2); 1037 cmdputs("; done"); 1038 break; 1039 case NFOR: 1040 cmdputs("for "); 1041 cmdputs(n->nfor.var); 1042 cmdputs(" in ..."); 1043 break; 1044 case NCASE: 1045 cmdputs("case "); 1046 cmdputs(n->ncase.expr->narg.text); 1047 cmdputs(" in ..."); 1048 break; 1049 case NDEFUN: 1050 cmdputs(n->narg.text); 1051 cmdputs("() ..."); 1052 break; 1053 case NCMD: 1054 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1055 cmdtxt(np); 1056 if (np->narg.next) 1057 cmdputs(" "); 1058 } 1059 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1060 cmdputs(" "); 1061 cmdtxt(np); 1062 } 1063 break; 1064 case NARG: 1065 cmdputs(n->narg.text); 1066 break; 1067 case NTO: 1068 p = ">"; i = 1; goto redir; 1069 case NAPPEND: 1070 p = ">>"; i = 1; goto redir; 1071 case NTOFD: 1072 p = ">&"; i = 1; goto redir; 1073 case NFROM: 1074 p = "<"; i = 0; goto redir; 1075 case NFROMFD: 1076 p = "<&"; i = 0; goto redir; 1077redir: 1078 if (n->nfile.fd != i) { 1079 s[0] = n->nfile.fd + '0'; 1080 s[1] = '\0'; 1081 cmdputs(s); 1082 } 1083 cmdputs(p); 1084 if (n->type == NTOFD || n->type == NFROMFD) { 1085 s[0] = n->ndup.dupfd + '0'; 1086 s[1] = '\0'; 1087 cmdputs(s); 1088 } else { 1089 cmdtxt(n->nfile.fname); 1090 } 1091 break; 1092 case NHERE: 1093 case NXHERE: 1094 cmdputs("<<..."); 1095 break; 1096 default: 1097 cmdputs("???"); 1098 break; 1099 } 1100} 1101 1102 1103 1104STATIC void 1105cmdputs(s) 1106 char *s; 1107 { 1108 char *p, *q; 1109 char c; 1110 int subtype = 0; 1111 1112 if (cmdnleft <= 0) 1113 return; 1114 p = s; 1115 q = cmdnextc; 1116 while ((c = *p++) != '\0') { 1117 if (c == CTLESC) 1118 *q++ = *p++; 1119 else if (c == CTLVAR) { 1120 *q++ = '$'; 1121 if (--cmdnleft > 0) 1122 *q++ = '{'; 1123 subtype = *p++; 1124 } else if (c == '=' && subtype != 0) { 1125 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1126 subtype = 0; 1127 } else if (c == CTLENDVAR) { 1128 *q++ = '}'; 1129 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1130 cmdnleft++; /* ignore it */ 1131 else 1132 *q++ = c; 1133 if (--cmdnleft <= 0) { 1134 *q++ = '.'; 1135 *q++ = '.'; 1136 *q++ = '.'; 1137 break; 1138 } 1139 } 1140 cmdnextc = q; 1141} 1142