1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 */ 36 37 #ifndef lint 38 #if 0 39 static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 40 #endif 41 static const char rcsid[] = 42 "$FreeBSD$"; 43 #endif /* not lint */ 44 45 #include <fcntl.h> 46 #include <signal.h> 47 #include <errno.h> 48 #include <unistd.h> 49 #include <stdlib.h> 50 #include <sys/param.h> 51 #ifdef BSD 52 #include <sys/wait.h> 53 #include <sys/time.h> 54 #include <sys/resource.h> 55 #include <paths.h> 56 #endif 57 #include <sys/ioctl.h> 58 59 #include "shell.h" 60 #if JOBS 61 #if OLD_TTY_DRIVER 62 #include "sgtty.h" 63 #else 64 #include <termios.h> 65 #endif 66 #undef CEOF /* syntax.h redefines this */ 67 #endif 68 #include "redir.h" 69 #include "show.h" 70 #include "main.h" 71 #include "parser.h" 72 #include "nodes.h" 73 #include "jobs.h" 74 #include "options.h" 75 #include "trap.h" 76 #include "syntax.h" 77 #include "input.h" 78 #include "output.h" 79 #include "memalloc.h" 80 #include "error.h" 81 #include "mystring.h" 82 83 84 struct job *jobtab; /* array of jobs */ 85 int njobs; /* size of array */ 86 MKINIT pid_t backgndpid = -1; /* pid of last background process */ 87 #if JOBS 88 int initialpgrp; /* pgrp of shell on invocation */ 89 int curjob; /* current job */ 90 #endif 91 int in_waitcmd = 0; /* are we in waitcmd()? */ 92 int in_dowait = 0; /* are we in dowait()? */ 93 volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 94 95 #if JOBS 96 STATIC void restartjob(struct job *); 97 #endif 98 STATIC void freejob(struct job *); 99 STATIC struct job *getjob(char *); 100 STATIC int dowait(int, struct job *); 101 #if SYSV 102 STATIC int onsigchild(void); 103 #endif 104 STATIC int waitproc(int, int *); 105 STATIC void cmdtxt(union node *); 106 STATIC void cmdputs(char *); 107 108 109 /* 110 * Turn job control on and off. 111 * 112 * Note: This code assumes that the third arg to ioctl is a character 113 * pointer, which is true on Berkeley systems but not System V. Since 114 * System V doesn't have job control yet, this isn't a problem now. 115 */ 116 117 MKINIT int jobctl; 118 119 #if JOBS 120 void 121 setjobctl(int on) 122 { 123 #ifdef OLD_TTY_DRIVER 124 int ldisc; 125 #endif 126 127 if (on == jobctl || rootshell == 0) 128 return; 129 if (on) { 130 do { /* while we are in the background */ 131 #ifdef OLD_TTY_DRIVER 132 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 133 #else 134 initialpgrp = tcgetpgrp(2); 135 if (initialpgrp < 0) { 136 #endif 137 out2str("sh: can't access tty; job control turned off\n"); 138 mflag = 0; 139 return; 140 } 141 if (initialpgrp == -1) 142 initialpgrp = getpgrp(); 143 else if (initialpgrp != getpgrp()) { 144 killpg(initialpgrp, SIGTTIN); 145 continue; 146 } 147 } while (0); 148 #ifdef OLD_TTY_DRIVER 149 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 150 out2str("sh: need new tty driver to run job control; job control turned off\n"); 151 mflag = 0; 152 return; 153 } 154 #endif 155 setsignal(SIGTSTP); 156 setsignal(SIGTTOU); 157 setsignal(SIGTTIN); 158 setpgid(0, rootpid); 159 #ifdef OLD_TTY_DRIVER 160 ioctl(2, TIOCSPGRP, (char *)&rootpid); 161 #else 162 tcsetpgrp(2, rootpid); 163 #endif 164 } else { /* turning job control off */ 165 setpgid(0, initialpgrp); 166 #ifdef OLD_TTY_DRIVER 167 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 168 #else 169 tcsetpgrp(2, initialpgrp); 170 #endif 171 setsignal(SIGTSTP); 172 setsignal(SIGTTOU); 173 setsignal(SIGTTIN); 174 } 175 jobctl = on; 176 } 177 #endif 178 179 180 #ifdef mkinit 181 INCLUDE <sys/types.h> 182 INCLUDE <stdlib.h> 183 184 SHELLPROC { 185 backgndpid = -1; 186 #if JOBS 187 jobctl = 0; 188 #endif 189 } 190 191 #endif 192 193 194 195 #if JOBS 196 int 197 fgcmd(int argc __unused, 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, (int *)NULL); 215 INTON; 216 return status; 217 } 218 219 220 int 221 bgcmd(int argc, char **argv) 222 { 223 struct job *jp; 224 225 do { 226 jp = getjob(*++argv); 227 if (jp->jobctl == 0) 228 error("job not created under job control"); 229 restartjob(jp); 230 } while (--argc > 1); 231 return 0; 232 } 233 234 235 STATIC void 236 restartjob(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 (WIFSTOPPED(ps->status)) { 247 ps->status = -1; 248 jp->state = 0; 249 } 250 } 251 INTON; 252 } 253 #endif 254 255 256 int 257 jobscmd(int argc __unused, char **argv __unused) 258 { 259 showjobs(0); 260 return 0; 261 } 262 263 264 /* 265 * Print a list of jobs. If "change" is nonzero, only print jobs whose 266 * statuses have changed since the last call to showjobs. 267 * 268 * If the shell is interrupted in the process of creating a job, the 269 * result may be a job structure containing zero processes. Such structures 270 * will be freed here. 271 */ 272 273 void 274 showjobs(int change) 275 { 276 int jobno; 277 int procno; 278 int i; 279 struct job *jp; 280 struct procstat *ps; 281 int col; 282 char s[64]; 283 284 TRACE(("showjobs(%d) called\n", change)); 285 while (dowait(0, (struct job *)NULL) > 0); 286 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 287 if (! jp->used) 288 continue; 289 if (jp->nprocs == 0) { 290 freejob(jp); 291 continue; 292 } 293 if (change && ! jp->changed) 294 continue; 295 procno = jp->nprocs; 296 for (ps = jp->ps ; ; ps++) { /* for each process */ 297 if (ps == jp->ps) 298 fmtstr(s, 64, "[%d] %d ", jobno, ps->pid); 299 else 300 fmtstr(s, 64, " %d ", ps->pid); 301 out1str(s); 302 col = strlen(s); 303 s[0] = '\0'; 304 if (ps->status == -1) { 305 /* don't print anything */ 306 } else if (WIFEXITED(ps->status)) { 307 fmtstr(s, 64, "Exit %d", WEXITSTATUS(ps->status)); 308 } else { 309 #if JOBS 310 if (WIFSTOPPED(ps->status)) 311 i = WSTOPSIG(ps->status); 312 else 313 #endif 314 i = WTERMSIG(ps->status); 315 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 316 scopy(sys_siglist[i & 0x7F], s); 317 else 318 fmtstr(s, 64, "Signal %d", i & 0x7F); 319 if (WCOREDUMP(ps->status)) 320 strcat(s, " (core dumped)"); 321 } 322 out1str(s); 323 col += strlen(s); 324 do { 325 out1c(' '); 326 col++; 327 } while (col < 30); 328 out1str(ps->cmd); 329 out1c('\n'); 330 if (--procno <= 0) 331 break; 332 } 333 jp->changed = 0; 334 if (jp->state == JOBDONE) { 335 freejob(jp); 336 } 337 } 338 } 339 340 341 /* 342 * Mark a job structure as unused. 343 */ 344 345 STATIC void 346 freejob(struct job *jp) 347 { 348 struct procstat *ps; 349 int i; 350 351 INTOFF; 352 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 353 if (ps->cmd != nullstr) 354 ckfree(ps->cmd); 355 } 356 if (jp->ps != &jp->ps0) 357 ckfree(jp->ps); 358 jp->used = 0; 359 #if JOBS 360 if (curjob == jp - jobtab + 1) 361 curjob = 0; 362 #endif 363 INTON; 364 } 365 366 367 368 int 369 waitcmd(int argc, char **argv) 370 { 371 struct job *job; 372 int status, retval; 373 struct job *jp; 374 375 if (argc > 1) { 376 job = getjob(argv[1]); 377 } else { 378 job = NULL; 379 } 380 381 /* 382 * Loop until a process is terminated or stopped, or a SIGINT is 383 * received. 384 */ 385 386 in_waitcmd++; 387 do { 388 if (job != NULL) { 389 if (job->state) { 390 status = job->ps[job->nprocs - 1].status; 391 if (WIFEXITED(status)) 392 retval = WEXITSTATUS(status); 393 #if JOBS 394 else if (WIFSTOPPED(status)) 395 retval = WSTOPSIG(status) + 128; 396 #endif 397 else 398 retval = WTERMSIG(status) + 128; 399 if (! iflag) 400 freejob(job); 401 in_waitcmd--; 402 return retval; 403 } 404 } else { 405 for (jp = jobtab ; ; jp++) { 406 if (jp >= jobtab + njobs) { /* no running procs */ 407 in_waitcmd--; 408 return 0; 409 } 410 if (jp->used && jp->state == 0) 411 break; 412 } 413 } 414 } while (dowait(1, (struct job *)NULL) != -1); 415 in_waitcmd--; 416 417 return 0; 418 } 419 420 421 422 int 423 jobidcmd(int argc __unused, 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 */ 441 442 STATIC struct job * 443 getjob(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(union node *node __unused, int nprocs) 503 { 504 int i; 505 struct job *jp; 506 507 for (i = njobs, jp = jobtab ; ; jp++) { 508 if (--i < 0) { 509 INTOFF; 510 if (njobs == 0) { 511 jobtab = ckmalloc(4 * sizeof jobtab[0]); 512 } else { 513 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 514 memcpy(jp, jobtab, njobs * sizeof jp[0]); 515 /* Relocate `ps' pointers */ 516 for (i = 0; i < njobs; i++) 517 if (jp[i].ps == &jobtab[i].ps0) 518 jp[i].ps = &jp[i].ps0; 519 ckfree(jobtab); 520 jobtab = jp; 521 } 522 jp = jobtab + njobs; 523 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 524 INTON; 525 break; 526 } 527 if (jp->used == 0) 528 break; 529 } 530 INTOFF; 531 jp->state = 0; 532 jp->used = 1; 533 jp->changed = 0; 534 jp->nprocs = 0; 535 #if JOBS 536 jp->jobctl = jobctl; 537 #endif 538 if (nprocs > 1) { 539 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 540 } else { 541 jp->ps = &jp->ps0; 542 } 543 INTON; 544 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 545 jp - jobtab + 1)); 546 return jp; 547 } 548 549 550 /* 551 * Fork of a subshell. If we are doing job control, give the subshell its 552 * own process group. Jp is a job structure that the job is to be added to. 553 * N is the command that will be evaluated by the child. Both jp and n may 554 * be NULL. The mode parameter can be one of the following: 555 * FORK_FG - Fork off a foreground process. 556 * FORK_BG - Fork off a background process. 557 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 558 * process group even if job control is on. 559 * 560 * When job control is turned off, background processes have their standard 561 * input redirected to /dev/null (except for the second and later processes 562 * in a pipeline). 563 */ 564 565 int 566 forkshell(struct job *jp, union node *n, int mode) 567 { 568 int pid; 569 int pgrp; 570 571 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 572 mode)); 573 INTOFF; 574 pid = fork(); 575 if (pid == -1) { 576 TRACE(("Fork failed, errno=%d\n", errno)); 577 INTON; 578 error("Cannot fork: %s", strerror(errno)); 579 } 580 if (pid == 0) { 581 struct job *p; 582 int wasroot; 583 int i; 584 585 TRACE(("Child shell %d\n", getpid())); 586 wasroot = rootshell; 587 rootshell = 0; 588 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 589 if (p->used) 590 freejob(p); 591 closescript(); 592 INTON; 593 clear_traps(); 594 #if JOBS 595 jobctl = 0; /* do job control only in root shell */ 596 if (wasroot && mode != FORK_NOJOB && mflag) { 597 if (jp == NULL || jp->nprocs == 0) 598 pgrp = getpid(); 599 else 600 pgrp = jp->ps[0].pid; 601 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 602 /*** this causes superfluous TIOCSPGRPS ***/ 603 #ifdef OLD_TTY_DRIVER 604 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 605 error("TIOCSPGRP failed, errno=%d", errno); 606 #else 607 if (tcsetpgrp(2, pgrp) < 0) 608 error("tcsetpgrp failed, errno=%d", errno); 609 #endif 610 } 611 setsignal(SIGTSTP); 612 setsignal(SIGTTOU); 613 } else if (mode == FORK_BG) { 614 ignoresig(SIGINT); 615 ignoresig(SIGQUIT); 616 if ((jp == NULL || jp->nprocs == 0) && 617 ! fd0_redirected_p ()) { 618 close(0); 619 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 620 error("Can't open %s: %s", 621 _PATH_DEVNULL, strerror(errno)); 622 } 623 } 624 #else 625 if (mode == FORK_BG) { 626 ignoresig(SIGINT); 627 ignoresig(SIGQUIT); 628 if ((jp == NULL || jp->nprocs == 0) && 629 ! fd0_redirected_p ()) { 630 close(0); 631 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 632 error("Can't open %s: %s", 633 _PATH_DEVNULL, strerror(errno)); 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 * foreground 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(struct job *jp, int *origstatus) 689 { 690 #if JOBS 691 int mypgrp = getpgrp(); 692 #endif 693 int status; 694 int st; 695 696 INTOFF; 697 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 698 while (jp->state == 0) 699 if (dowait(1, jp) == -1) 700 dotrap(); 701 #if JOBS 702 if (jp->jobctl) { 703 #ifdef OLD_TTY_DRIVER 704 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 705 error("TIOCSPGRP failed, errno=%d\n", errno); 706 #else 707 if (tcsetpgrp(2, mypgrp) < 0) 708 error("tcsetpgrp failed, errno=%d\n", errno); 709 #endif 710 } 711 if (jp->state == JOBSTOPPED) 712 curjob = jp - jobtab + 1; 713 #endif 714 status = jp->ps[jp->nprocs - 1].status; 715 if (origstatus != NULL) 716 *origstatus = status; 717 /* convert to 8 bits */ 718 if (WIFEXITED(status)) 719 st = WEXITSTATUS(status); 720 #if JOBS 721 else if (WIFSTOPPED(status)) 722 st = WSTOPSIG(status) + 128; 723 #endif 724 else 725 st = WTERMSIG(status) + 128; 726 if (! JOBS || jp->state == JOBDONE) 727 freejob(jp); 728 if (int_pending()) { 729 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 730 kill(getpid(), SIGINT); 731 else 732 CLEAR_PENDING_INT; 733 } 734 INTON; 735 return st; 736 } 737 738 739 740 /* 741 * Wait for a process to terminate. 742 */ 743 744 STATIC int 745 dowait(int block, struct job *job) 746 { 747 int pid; 748 int status; 749 struct procstat *sp; 750 struct job *jp; 751 struct job *thisjob; 752 int done; 753 int stopped; 754 int core; 755 int sig; 756 757 in_dowait++; 758 TRACE(("dowait(%d) called\n", block)); 759 do { 760 pid = waitproc(block, &status); 761 TRACE(("wait returns %d, status=%d\n", pid, status)); 762 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 763 (WIFSTOPPED(status) && !iflag)); 764 in_dowait--; 765 if (breakwaitcmd != 0) { 766 breakwaitcmd = 0; 767 return -1; 768 } 769 if (pid <= 0) 770 return pid; 771 INTOFF; 772 thisjob = NULL; 773 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 774 if (jp->used) { 775 done = 1; 776 stopped = 1; 777 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 778 if (sp->pid == -1) 779 continue; 780 if (sp->pid == pid) { 781 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 782 pid, sp->status, status)); 783 sp->status = status; 784 thisjob = jp; 785 } 786 if (sp->status == -1) 787 stopped = 0; 788 else if (WIFSTOPPED(sp->status)) 789 done = 0; 790 } 791 if (stopped) { /* stopped or done */ 792 int state = done? JOBDONE : JOBSTOPPED; 793 if (jp->state != state) { 794 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 795 jp->state = state; 796 #if JOBS 797 if (done && curjob == jp - jobtab + 1) 798 curjob = 0; /* no current job */ 799 #endif 800 } 801 } 802 } 803 } 804 INTON; 805 if (! rootshell || ! iflag || (job && thisjob == job)) { 806 core = WCOREDUMP(status); 807 #if JOBS 808 if (WIFSTOPPED(status)) 809 sig = WSTOPSIG(status); 810 else 811 #endif 812 if (WIFEXITED(status)) 813 sig = 0; 814 else 815 sig = WTERMSIG(status); 816 817 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 818 if (thisjob != job) 819 outfmt(out2, "%d: ", pid); 820 #if JOBS 821 if (sig == SIGTSTP && rootshell && iflag) 822 outfmt(out2, "%%%d ", job - jobtab + 1); 823 #endif 824 if (sig < NSIG && sys_siglist[sig]) 825 out2str(sys_siglist[sig]); 826 else 827 outfmt(out2, "Signal %d", sig); 828 if (core) 829 out2str(" - core dumped"); 830 out2c('\n'); 831 flushout(&errout); 832 } else { 833 TRACE(("Not printing status: status=%d, sig=%d\n", 834 status, sig)); 835 } 836 } else { 837 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 838 if (thisjob) 839 thisjob->changed = 1; 840 } 841 return pid; 842 } 843 844 845 846 /* 847 * Do a wait system call. If job control is compiled in, we accept 848 * stopped processes. If block is zero, we return a value of zero 849 * rather than blocking. 850 * 851 * System V doesn't have a non-blocking wait system call. It does 852 * have a SIGCLD signal that is sent to a process when one of it's 853 * children dies. The obvious way to use SIGCLD would be to install 854 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 855 * was received, and have waitproc bump another counter when it got 856 * the status of a process. Waitproc would then know that a wait 857 * system call would not block if the two counters were different. 858 * This approach doesn't work because if a process has children that 859 * have not been waited for, System V will send it a SIGCLD when it 860 * installs a signal handler for SIGCLD. What this means is that when 861 * a child exits, the shell will be sent SIGCLD signals continuously 862 * until is runs out of stack space, unless it does a wait call before 863 * restoring the signal handler. The code below takes advantage of 864 * this (mis)feature by installing a signal handler for SIGCLD and 865 * then checking to see whether it was called. If there are any 866 * children to be waited for, it will be. 867 * 868 * If neither SYSV nor BSD is defined, we don't implement nonblocking 869 * waits at all. In this case, the user will not be informed when 870 * a background process until the next time she runs a real program 871 * (as opposed to running a builtin command or just typing return), 872 * and the jobs command may give out of date information. 873 */ 874 875 #ifdef SYSV 876 STATIC sig_atomic_t gotsigchild; 877 878 STATIC int onsigchild() { 879 gotsigchild = 1; 880 } 881 #endif 882 883 884 STATIC int 885 waitproc(int block, int *status) 886 { 887 #ifdef BSD 888 int flags; 889 890 #if JOBS 891 flags = WUNTRACED; 892 #else 893 flags = 0; 894 #endif 895 if (block == 0) 896 flags |= WNOHANG; 897 return wait3(status, flags, (struct rusage *)NULL); 898 #else 899 #ifdef SYSV 900 int (*save)(); 901 902 if (block == 0) { 903 gotsigchild = 0; 904 save = signal(SIGCLD, onsigchild); 905 signal(SIGCLD, save); 906 if (gotsigchild == 0) 907 return 0; 908 } 909 return wait(status); 910 #else 911 if (block == 0) 912 return 0; 913 return wait(status); 914 #endif 915 #endif 916 } 917 918 /* 919 * return 1 if there are stopped jobs, otherwise 0 920 */ 921 int job_warning = 0; 922 int 923 stoppedjobs(void) 924 { 925 int jobno; 926 struct job *jp; 927 928 if (job_warning) 929 return (0); 930 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 931 if (jp->used == 0) 932 continue; 933 if (jp->state == JOBSTOPPED) { 934 out2str("You have stopped jobs.\n"); 935 job_warning = 2; 936 return (1); 937 } 938 } 939 940 return (0); 941 } 942 943 /* 944 * Return a string identifying a command (to be printed by the 945 * jobs command. 946 */ 947 948 STATIC char *cmdnextc; 949 STATIC int cmdnleft; 950 #define MAXCMDTEXT 200 951 952 char * 953 commandtext(union node *n) 954 { 955 char *name; 956 957 cmdnextc = name = ckmalloc(MAXCMDTEXT); 958 cmdnleft = MAXCMDTEXT - 4; 959 cmdtxt(n); 960 *cmdnextc = '\0'; 961 return name; 962 } 963 964 965 STATIC void 966 cmdtxt(union node *n) 967 { 968 union node *np; 969 struct nodelist *lp; 970 char *p; 971 int i; 972 char s[2]; 973 974 if (n == NULL) 975 return; 976 switch (n->type) { 977 case NSEMI: 978 cmdtxt(n->nbinary.ch1); 979 cmdputs("; "); 980 cmdtxt(n->nbinary.ch2); 981 break; 982 case NAND: 983 cmdtxt(n->nbinary.ch1); 984 cmdputs(" && "); 985 cmdtxt(n->nbinary.ch2); 986 break; 987 case NOR: 988 cmdtxt(n->nbinary.ch1); 989 cmdputs(" || "); 990 cmdtxt(n->nbinary.ch2); 991 break; 992 case NPIPE: 993 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 994 cmdtxt(lp->n); 995 if (lp->next) 996 cmdputs(" | "); 997 } 998 break; 999 case NSUBSHELL: 1000 cmdputs("("); 1001 cmdtxt(n->nredir.n); 1002 cmdputs(")"); 1003 break; 1004 case NREDIR: 1005 case NBACKGND: 1006 cmdtxt(n->nredir.n); 1007 break; 1008 case NIF: 1009 cmdputs("if "); 1010 cmdtxt(n->nif.test); 1011 cmdputs("; then "); 1012 cmdtxt(n->nif.ifpart); 1013 cmdputs("..."); 1014 break; 1015 case NWHILE: 1016 cmdputs("while "); 1017 goto until; 1018 case NUNTIL: 1019 cmdputs("until "); 1020 until: 1021 cmdtxt(n->nbinary.ch1); 1022 cmdputs("; do "); 1023 cmdtxt(n->nbinary.ch2); 1024 cmdputs("; done"); 1025 break; 1026 case NFOR: 1027 cmdputs("for "); 1028 cmdputs(n->nfor.var); 1029 cmdputs(" in ..."); 1030 break; 1031 case NCASE: 1032 cmdputs("case "); 1033 cmdputs(n->ncase.expr->narg.text); 1034 cmdputs(" in ..."); 1035 break; 1036 case NDEFUN: 1037 cmdputs(n->narg.text); 1038 cmdputs("() ..."); 1039 break; 1040 case NCMD: 1041 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1042 cmdtxt(np); 1043 if (np->narg.next) 1044 cmdputs(" "); 1045 } 1046 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1047 cmdputs(" "); 1048 cmdtxt(np); 1049 } 1050 break; 1051 case NARG: 1052 cmdputs(n->narg.text); 1053 break; 1054 case NTO: 1055 p = ">"; i = 1; goto redir; 1056 case NAPPEND: 1057 p = ">>"; i = 1; goto redir; 1058 case NTOFD: 1059 p = ">&"; i = 1; goto redir; 1060 case NFROM: 1061 p = "<"; i = 0; goto redir; 1062 case NFROMTO: 1063 p = "<>"; i = 0; goto redir; 1064 case NFROMFD: 1065 p = "<&"; i = 0; goto redir; 1066 redir: 1067 if (n->nfile.fd != i) { 1068 s[0] = n->nfile.fd + '0'; 1069 s[1] = '\0'; 1070 cmdputs(s); 1071 } 1072 cmdputs(p); 1073 if (n->type == NTOFD || n->type == NFROMFD) { 1074 s[0] = n->ndup.dupfd + '0'; 1075 s[1] = '\0'; 1076 cmdputs(s); 1077 } else { 1078 cmdtxt(n->nfile.fname); 1079 } 1080 break; 1081 case NHERE: 1082 case NXHERE: 1083 cmdputs("<<..."); 1084 break; 1085 default: 1086 cmdputs("???"); 1087 break; 1088 } 1089 } 1090 1091 1092 1093 STATIC void 1094 cmdputs(char *s) 1095 { 1096 char *p, *q; 1097 char c; 1098 int subtype = 0; 1099 1100 if (cmdnleft <= 0) 1101 return; 1102 p = s; 1103 q = cmdnextc; 1104 while ((c = *p++) != '\0') { 1105 if (c == CTLESC) 1106 *q++ = *p++; 1107 else if (c == CTLVAR) { 1108 *q++ = '$'; 1109 if (--cmdnleft > 0) 1110 *q++ = '{'; 1111 subtype = *p++; 1112 } else if (c == '=' && subtype != 0) { 1113 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1114 subtype = 0; 1115 } else if (c == CTLENDVAR) { 1116 *q++ = '}'; 1117 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1118 cmdnleft++; /* ignore it */ 1119 else 1120 *q++ = c; 1121 if (--cmdnleft <= 0) { 1122 *q++ = '.'; 1123 *q++ = '.'; 1124 *q++ = '.'; 1125 break; 1126 } 1127 } 1128 cmdnextc = q; 1129 } 1130