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 static char sccsid[] = "@(#)jobs.c 8.1 (Berkeley) 5/31/93"; 39 #endif /* not lint */ 40 41 #include "shell.h" 42 #if JOBS 43 #include "sgtty.h" 44 #undef CEOF /* syntax.h redefines this */ 45 #endif 46 #include "main.h" 47 #include "parser.h" 48 #include "nodes.h" 49 #include "jobs.h" 50 #include "options.h" 51 #include "trap.h" 52 #include "signames.h" 53 #include "syntax.h" 54 #include "input.h" 55 #include "output.h" 56 #include "memalloc.h" 57 #include "error.h" 58 #include "mystring.h" 59 #include <fcntl.h> 60 #include <signal.h> 61 #include <errno.h> 62 #ifdef BSD 63 #include <sys/types.h> 64 #include <sys/wait.h> 65 #include <sys/time.h> 66 #include <sys/resource.h> 67 #endif 68 69 70 71 struct job *jobtab; /* array of jobs */ 72 int njobs; /* size of array */ 73 MKINIT short backgndpid = -1; /* pid of last background process */ 74 #if JOBS 75 int initialpgrp; /* pgrp of shell on invocation */ 76 short curjob; /* current job */ 77 #endif 78 79 #ifdef __STDC__ 80 STATIC void restartjob(struct job *); 81 STATIC struct job *getjob(char *); 82 STATIC void freejob(struct job *); 83 STATIC int procrunning(int); 84 STATIC int dowait(int, struct job *); 85 STATIC int waitproc(int, int *); 86 #else 87 STATIC void restartjob(); 88 STATIC struct job *getjob(); 89 STATIC void freejob(); 90 STATIC int procrunning(); 91 STATIC int dowait(); 92 STATIC int waitproc(); 93 #endif 94 95 96 97 /* 98 * Turn job control on and off. 99 * 100 * Note: This code assumes that the third arg to ioctl is a character 101 * pointer, which is true on Berkeley systems but not System V. Since 102 * System V doesn't have job control yet, this isn't a problem now. 103 */ 104 105 MKINIT int jobctl; 106 107 void 108 setjobctl(on) { 109 #ifdef OLD_TTY_DRIVER 110 int ldisc; 111 #endif 112 113 if (on == jobctl || rootshell == 0) 114 return; 115 if (on) { 116 do { /* while we are in the background */ 117 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 118 out2str("sh: can't access tty; job control turned off\n"); 119 mflag = 0; 120 return; 121 } 122 if (initialpgrp == -1) 123 initialpgrp = getpgrp(0); 124 else if (initialpgrp != getpgrp(0)) { 125 killpg(initialpgrp, SIGTTIN); 126 continue; 127 } 128 } while (0); 129 #ifdef OLD_TTY_DRIVER 130 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 131 out2str("sh: need new tty driver to run job control; job control turned off\n"); 132 mflag = 0; 133 return; 134 } 135 #endif 136 setsignal(SIGTSTP); 137 setsignal(SIGTTOU); 138 setsignal(SIGTTIN); 139 setpgrp(0, rootpid); 140 ioctl(2, TIOCSPGRP, (char *)&rootpid); 141 } else { /* turning job control off */ 142 setpgrp(0, initialpgrp); 143 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 144 setsignal(SIGTSTP); 145 setsignal(SIGTTOU); 146 setsignal(SIGTTIN); 147 } 148 jobctl = on; 149 } 150 151 152 #ifdef mkinit 153 154 SHELLPROC { 155 backgndpid = -1; 156 #if JOBS 157 jobctl = 0; 158 #endif 159 } 160 161 #endif 162 163 164 165 #if JOBS 166 fgcmd(argc, argv) char **argv; { 167 struct job *jp; 168 int pgrp; 169 int status; 170 171 jp = getjob(argv[1]); 172 if (jp->jobctl == 0) 173 error("job not created under job control"); 174 pgrp = jp->ps[0].pid; 175 ioctl(2, TIOCSPGRP, (char *)&pgrp); 176 restartjob(jp); 177 INTOFF; 178 status = waitforjob(jp); 179 INTON; 180 return status; 181 } 182 183 184 bgcmd(argc, argv) char **argv; { 185 struct job *jp; 186 187 do { 188 jp = getjob(*++argv); 189 if (jp->jobctl == 0) 190 error("job not created under job control"); 191 restartjob(jp); 192 } while (--argc > 1); 193 return 0; 194 } 195 196 197 STATIC void 198 restartjob(jp) 199 struct job *jp; 200 { 201 struct procstat *ps; 202 int i; 203 204 if (jp->state == JOBDONE) 205 return; 206 INTOFF; 207 killpg(jp->ps[0].pid, SIGCONT); 208 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 209 if ((ps->status & 0377) == 0177) { 210 ps->status = -1; 211 jp->state = 0; 212 } 213 } 214 INTON; 215 } 216 #endif 217 218 219 int 220 jobscmd(argc, argv) char **argv; { 221 showjobs(0); 222 return 0; 223 } 224 225 226 /* 227 * Print a list of jobs. If "change" is nonzero, only print jobs whose 228 * statuses have changed since the last call to showjobs. 229 * 230 * If the shell is interrupted in the process of creating a job, the 231 * result may be a job structure containing zero processes. Such structures 232 * will be freed here. 233 */ 234 235 void 236 showjobs(change) { 237 int jobno; 238 int procno; 239 int i; 240 struct job *jp; 241 struct procstat *ps; 242 int col; 243 char s[64]; 244 245 TRACE(("showjobs(%d) called\n", change)); 246 while (dowait(0, (struct job *)NULL) > 0); 247 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 248 if (! jp->used) 249 continue; 250 if (jp->nprocs == 0) { 251 freejob(jp); 252 continue; 253 } 254 if (change && ! jp->changed) 255 continue; 256 procno = jp->nprocs; 257 for (ps = jp->ps ; ; ps++) { /* for each process */ 258 if (ps == jp->ps) 259 fmtstr(s, 64, "[%d] %d ", jobno, ps->pid); 260 else 261 fmtstr(s, 64, " %d ", ps->pid); 262 out1str(s); 263 col = strlen(s); 264 s[0] = '\0'; 265 if (ps->status == -1) { 266 /* don't print anything */ 267 } else if ((ps->status & 0xFF) == 0) { 268 fmtstr(s, 64, "Exit %d", ps->status >> 8); 269 } else { 270 i = ps->status; 271 #if JOBS 272 if ((i & 0xFF) == 0177) 273 i >>= 8; 274 #endif 275 if ((i & 0x7F) <= MAXSIG && sigmesg[i & 0x7F]) 276 scopy(sigmesg[i & 0x7F], s); 277 else 278 fmtstr(s, 64, "Signal %d", i & 0x7F); 279 if (i & 0x80) 280 strcat(s, " (core dumped)"); 281 } 282 out1str(s); 283 col += strlen(s); 284 do { 285 out1c(' '); 286 col++; 287 } while (col < 30); 288 out1str(ps->cmd); 289 out1c('\n'); 290 if (--procno <= 0) 291 break; 292 } 293 jp->changed = 0; 294 if (jp->state == JOBDONE) { 295 freejob(jp); 296 } 297 } 298 } 299 300 301 /* 302 * Mark a job structure as unused. 303 */ 304 305 STATIC void 306 freejob(jp) 307 struct job *jp; 308 { 309 struct procstat *ps; 310 int i; 311 312 INTOFF; 313 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 314 if (ps->cmd != nullstr) 315 ckfree(ps->cmd); 316 } 317 if (jp->ps != &jp->ps0) 318 ckfree(jp->ps); 319 jp->used = 0; 320 #if JOBS 321 if (curjob == jp - jobtab + 1) 322 curjob = 0; 323 #endif 324 INTON; 325 } 326 327 328 329 int 330 waitcmd(argc, argv) char **argv; { 331 struct job *job; 332 int status; 333 struct job *jp; 334 335 if (argc > 1) { 336 job = getjob(argv[1]); 337 } else { 338 job = NULL; 339 } 340 for (;;) { /* loop until process terminated or stopped */ 341 if (job != NULL) { 342 if (job->state) { 343 status = job->ps[job->nprocs - 1].status; 344 if ((status & 0xFF) == 0) 345 status = status >> 8 & 0xFF; 346 #if JOBS 347 else if ((status & 0xFF) == 0177) 348 status = (status >> 8 & 0x7F) + 128; 349 #endif 350 else 351 status = (status & 0x7F) + 128; 352 if (! iflag) 353 freejob(job); 354 return status; 355 } 356 } else { 357 for (jp = jobtab ; ; jp++) { 358 if (jp >= jobtab + njobs) { /* no running procs */ 359 return 0; 360 } 361 if (jp->used && jp->state == 0) 362 break; 363 } 364 } 365 dowait(1, (struct job *)NULL); 366 } 367 } 368 369 370 371 jobidcmd(argc, argv) char **argv; { 372 struct job *jp; 373 int i; 374 375 jp = getjob(argv[1]); 376 for (i = 0 ; i < jp->nprocs ; ) { 377 out1fmt("%d", jp->ps[i].pid); 378 out1c(++i < jp->nprocs? ' ' : '\n'); 379 } 380 return 0; 381 } 382 383 384 385 /* 386 * Convert a job name to a job structure. 387 */ 388 389 STATIC struct job * 390 getjob(name) 391 char *name; 392 { 393 int jobno; 394 register struct job *jp; 395 int pid; 396 int i; 397 398 if (name == NULL) { 399 #if JOBS 400 currentjob: 401 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 402 error("No current job"); 403 return &jobtab[jobno - 1]; 404 #else 405 error("No current job"); 406 #endif 407 } else if (name[0] == '%') { 408 if (is_digit(name[1])) { 409 jobno = number(name + 1); 410 if (jobno > 0 && jobno <= njobs 411 && jobtab[jobno - 1].used != 0) 412 return &jobtab[jobno - 1]; 413 #if JOBS 414 } else if (name[1] == '%' && name[2] == '\0') { 415 goto currentjob; 416 #endif 417 } else { 418 register struct job *found = NULL; 419 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 420 if (jp->used && jp->nprocs > 0 421 && prefix(name + 1, jp->ps[0].cmd)) { 422 if (found) 423 error("%s: ambiguous", name); 424 found = jp; 425 } 426 } 427 if (found) 428 return found; 429 } 430 } else if (is_number(name)) { 431 pid = number(name); 432 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 433 if (jp->used && jp->nprocs > 0 434 && jp->ps[jp->nprocs - 1].pid == pid) 435 return jp; 436 } 437 } 438 error("No such job: %s", name); 439 } 440 441 442 443 /* 444 * Return a new job structure, 445 */ 446 447 struct job * 448 makejob(node, nprocs) 449 union node *node; 450 { 451 int i; 452 struct job *jp; 453 454 for (i = njobs, jp = jobtab ; ; jp++) { 455 if (--i < 0) { 456 INTOFF; 457 if (njobs == 0) { 458 jobtab = ckmalloc(4 * sizeof jobtab[0]); 459 } else { 460 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 461 bcopy(jobtab, jp, njobs * sizeof jp[0]); 462 ckfree(jobtab); 463 jobtab = jp; 464 } 465 jp = jobtab + njobs; 466 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 467 INTON; 468 break; 469 } 470 if (jp->used == 0) 471 break; 472 } 473 INTOFF; 474 jp->state = 0; 475 jp->used = 1; 476 jp->changed = 0; 477 jp->nprocs = 0; 478 #if JOBS 479 jp->jobctl = jobctl; 480 #endif 481 if (nprocs > 1) { 482 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 483 } else { 484 jp->ps = &jp->ps0; 485 } 486 INTON; 487 TRACE(("makejob(0x%x, %d) returns %%%d\n", (int)node, nprocs, jp - jobtab + 1)); 488 return jp; 489 } 490 491 492 /* 493 * Fork of a subshell. If we are doing job control, give the subshell its 494 * own process group. Jp is a job structure that the job is to be added to. 495 * N is the command that will be evaluated by the child. Both jp and n may 496 * be NULL. The mode parameter can be one of the following: 497 * FORK_FG - Fork off a foreground process. 498 * FORK_BG - Fork off a background process. 499 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 500 * process group even if job control is on. 501 * 502 * When job control is turned off, background processes have their standard 503 * input redirected to /dev/null (except for the second and later processes 504 * in a pipeline). 505 */ 506 507 int 508 forkshell(jp, n, mode) 509 union node *n; 510 struct job *jp; 511 { 512 int pid; 513 int pgrp; 514 515 TRACE(("forkshell(%%%d, 0x%x, %d) called\n", jp - jobtab, (int)n, mode)); 516 INTOFF; 517 pid = fork(); 518 if (pid == -1) { 519 TRACE(("Fork failed, errno=%d\n", errno)); 520 INTON; 521 error("Cannot fork"); 522 } 523 if (pid == 0) { 524 struct job *p; 525 int wasroot; 526 int i; 527 528 TRACE(("Child shell %d\n", getpid())); 529 wasroot = rootshell; 530 rootshell = 0; 531 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 532 if (p->used) 533 freejob(p); 534 closescript(); 535 INTON; 536 clear_traps(); 537 #if JOBS 538 jobctl = 0; /* do job control only in root shell */ 539 if (wasroot && mode != FORK_NOJOB && mflag) { 540 if (jp == NULL || jp->nprocs == 0) 541 pgrp = getpid(); 542 else 543 pgrp = jp->ps[0].pid; 544 setpgrp(0, pgrp); 545 if (mode == FORK_FG) { 546 /*** this causes superfluous TIOCSPGRPS ***/ 547 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 548 error("TIOCSPGRP failed, errno=%d\n", errno); 549 } 550 setsignal(SIGTSTP); 551 setsignal(SIGTTOU); 552 } else if (mode == FORK_BG) { 553 ignoresig(SIGINT); 554 ignoresig(SIGQUIT); 555 if ((jp == NULL || jp->nprocs == 0) && 556 ! fd0_redirected_p ()) { 557 close(0); 558 if (open("/dev/null", O_RDONLY) != 0) 559 error("Can't open /dev/null"); 560 } 561 } 562 #else 563 if (mode == FORK_BG) { 564 ignoresig(SIGINT); 565 ignoresig(SIGQUIT); 566 if ((jp == NULL || jp->nprocs == 0) && 567 ! fd0_redirected_p ()) { 568 close(0); 569 if (open("/dev/null", O_RDONLY) != 0) 570 error("Can't open /dev/null"); 571 } 572 } 573 #endif 574 if (wasroot && iflag) { 575 setsignal(SIGINT); 576 setsignal(SIGQUIT); 577 setsignal(SIGTERM); 578 } 579 return pid; 580 } 581 if (rootshell && mode != FORK_NOJOB && mflag) { 582 if (jp == NULL || jp->nprocs == 0) 583 pgrp = pid; 584 else 585 pgrp = jp->ps[0].pid; 586 setpgrp(pid, pgrp); 587 } 588 if (mode == FORK_BG) 589 backgndpid = pid; /* set $! */ 590 if (jp) { 591 struct procstat *ps = &jp->ps[jp->nprocs++]; 592 ps->pid = pid; 593 ps->status = -1; 594 ps->cmd = nullstr; 595 if (iflag && rootshell && n) 596 ps->cmd = commandtext(n); 597 } 598 INTON; 599 TRACE(("In parent shell: child = %d\n", pid)); 600 return pid; 601 } 602 603 604 605 /* 606 * Wait for job to finish. 607 * 608 * Under job control we have the problem that while a child process is 609 * running interrupts generated by the user are sent to the child but not 610 * to the shell. This means that an infinite loop started by an inter- 611 * active user may be hard to kill. With job control turned off, an 612 * interactive user may place an interactive program inside a loop. If 613 * the interactive program catches interrupts, the user doesn't want 614 * these interrupts to also abort the loop. The approach we take here 615 * is to have the shell ignore interrupt signals while waiting for a 616 * forground process to terminate, and then send itself an interrupt 617 * signal if the child process was terminated by an interrupt signal. 618 * Unfortunately, some programs want to do a bit of cleanup and then 619 * exit on interrupt; unless these processes terminate themselves by 620 * sending a signal to themselves (instead of calling exit) they will 621 * confuse this approach. 622 */ 623 624 int 625 waitforjob(jp) 626 register struct job *jp; 627 { 628 #if JOBS 629 int mypgrp = getpgrp(0); 630 #endif 631 int status; 632 int st; 633 634 INTOFF; 635 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 636 while (jp->state == 0) { 637 dowait(1, jp); 638 } 639 #if JOBS 640 if (jp->jobctl) { 641 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 642 error("TIOCSPGRP failed, errno=%d\n", errno); 643 } 644 if (jp->state == JOBSTOPPED) 645 curjob = jp - jobtab + 1; 646 #endif 647 status = jp->ps[jp->nprocs - 1].status; 648 /* convert to 8 bits */ 649 if ((status & 0xFF) == 0) 650 st = status >> 8 & 0xFF; 651 #if JOBS 652 else if ((status & 0xFF) == 0177) 653 st = (status >> 8 & 0x7F) + 128; 654 #endif 655 else 656 st = (status & 0x7F) + 128; 657 if (! JOBS || jp->state == JOBDONE) 658 freejob(jp); 659 CLEAR_PENDING_INT; 660 if ((status & 0x7F) == SIGINT) 661 kill(getpid(), SIGINT); 662 INTON; 663 return st; 664 } 665 666 667 668 /* 669 * Wait for a process to terminate. 670 */ 671 672 STATIC int 673 dowait(block, job) 674 struct job *job; 675 { 676 int pid; 677 int status; 678 struct procstat *sp; 679 struct job *jp; 680 struct job *thisjob; 681 int done; 682 int stopped; 683 int core; 684 685 TRACE(("dowait(%d) called\n", block)); 686 do { 687 pid = waitproc(block, &status); 688 TRACE(("wait returns %d, status=%d\n", pid, status)); 689 } while (pid == -1 && errno == EINTR); 690 if (pid <= 0) 691 return pid; 692 INTOFF; 693 thisjob = NULL; 694 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 695 if (jp->used) { 696 done = 1; 697 stopped = 1; 698 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 699 if (sp->pid == -1) 700 continue; 701 if (sp->pid == pid) { 702 TRACE(("Changin status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 703 sp->status = status; 704 thisjob = jp; 705 } 706 if (sp->status == -1) 707 stopped = 0; 708 else if ((sp->status & 0377) == 0177) 709 done = 0; 710 } 711 if (stopped) { /* stopped or done */ 712 int state = done? JOBDONE : JOBSTOPPED; 713 if (jp->state != state) { 714 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 715 jp->state = state; 716 #if JOBS 717 if (done && curjob == jp - jobtab + 1) 718 curjob = 0; /* no current job */ 719 #endif 720 } 721 } 722 } 723 } 724 INTON; 725 if (! rootshell || ! iflag || (job && thisjob == job)) { 726 #if JOBS 727 if ((status & 0xFF) == 0177) 728 status >>= 8; 729 #endif 730 core = status & 0x80; 731 status &= 0x7F; 732 if (status != 0 && status != SIGINT && status != SIGPIPE) { 733 if (thisjob != job) 734 outfmt(out2, "%d: ", pid); 735 #if JOBS 736 if (status == SIGTSTP && rootshell && iflag) 737 outfmt(out2, "%%%d ", job - jobtab + 1); 738 #endif 739 if (status <= MAXSIG && sigmesg[status]) 740 out2str(sigmesg[status]); 741 else 742 outfmt(out2, "Signal %d", status); 743 if (core) 744 out2str(" - core dumped"); 745 out2c('\n'); 746 flushout(&errout); 747 } else { 748 TRACE(("Not printing status: status=%d\n", status)); 749 } 750 } else { 751 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 752 if (thisjob) 753 thisjob->changed = 1; 754 } 755 return pid; 756 } 757 758 759 760 /* 761 * Do a wait system call. If job control is compiled in, we accept 762 * stopped processes. If block is zero, we return a value of zero 763 * rather than blocking. 764 * 765 * System V doesn't have a non-blocking wait system call. It does 766 * have a SIGCLD signal that is sent to a process when one of it's 767 * children dies. The obvious way to use SIGCLD would be to install 768 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 769 * was received, and have waitproc bump another counter when it got 770 * the status of a process. Waitproc would then know that a wait 771 * system call would not block if the two counters were different. 772 * This approach doesn't work because if a process has children that 773 * have not been waited for, System V will send it a SIGCLD when it 774 * installs a signal handler for SIGCLD. What this means is that when 775 * a child exits, the shell will be sent SIGCLD signals continuously 776 * until is runs out of stack space, unless it does a wait call before 777 * restoring the signal handler. The code below takes advantage of 778 * this (mis)feature by installing a signal handler for SIGCLD and 779 * then checking to see whether it was called. If there are any 780 * children to be waited for, it will be. 781 * 782 * If neither SYSV nor BSD is defined, we don't implement nonblocking 783 * waits at all. In this case, the user will not be informed when 784 * a background process until the next time she runs a real program 785 * (as opposed to running a builtin command or just typing return), 786 * and the jobs command may give out of date information. 787 */ 788 789 #ifdef SYSV 790 STATIC int gotsigchild; 791 792 STATIC int onsigchild() { 793 gotsigchild = 1; 794 } 795 #endif 796 797 798 STATIC int 799 waitproc(block, status) 800 int *status; 801 { 802 #ifdef BSD 803 int flags; 804 805 #if JOBS 806 flags = WUNTRACED; 807 #else 808 flags = 0; 809 #endif 810 if (block == 0) 811 flags |= WNOHANG; 812 return wait3(status, flags, (struct rusage *)NULL); 813 #else 814 #ifdef SYSV 815 int (*save)(); 816 817 if (block == 0) { 818 gotsigchild = 0; 819 save = signal(SIGCLD, onsigchild); 820 signal(SIGCLD, save); 821 if (gotsigchild == 0) 822 return 0; 823 } 824 return wait(status); 825 #else 826 if (block == 0) 827 return 0; 828 return wait(status); 829 #endif 830 #endif 831 } 832 833 /* 834 * return 1 if there are stopped jobs, otherwise 0 835 */ 836 int job_warning = 0; 837 int 838 stoppedjobs() 839 { 840 register int jobno; 841 register struct job *jp; 842 843 if (job_warning) 844 return (0); 845 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 846 if (jp->used == 0) 847 continue; 848 if (jp->state == JOBSTOPPED) { 849 out2str("You have stopped jobs.\n"); 850 job_warning = 2; 851 return (1); 852 } 853 } 854 855 return (0); 856 } 857 858 /* 859 * Return a string identifying a command (to be printed by the 860 * jobs command. 861 */ 862 863 STATIC char *cmdnextc; 864 STATIC int cmdnleft; 865 STATIC void cmdtxt(), cmdputs(); 866 #define MAXCMDTEXT 200 867 868 char * 869 commandtext(n) 870 union node *n; 871 { 872 char *name; 873 874 cmdnextc = name = ckmalloc(MAXCMDTEXT); 875 cmdnleft = MAXCMDTEXT - 4; 876 cmdtxt(n); 877 *cmdnextc = '\0'; 878 return name; 879 } 880 881 882 STATIC void 883 cmdtxt(n) 884 union node *n; 885 { 886 union node *np; 887 struct nodelist *lp; 888 char *p; 889 int i; 890 char s[2]; 891 892 if (n == NULL) 893 return; 894 switch (n->type) { 895 case NSEMI: 896 cmdtxt(n->nbinary.ch1); 897 cmdputs("; "); 898 cmdtxt(n->nbinary.ch2); 899 break; 900 case NAND: 901 cmdtxt(n->nbinary.ch1); 902 cmdputs(" && "); 903 cmdtxt(n->nbinary.ch2); 904 break; 905 case NOR: 906 cmdtxt(n->nbinary.ch1); 907 cmdputs(" || "); 908 cmdtxt(n->nbinary.ch2); 909 break; 910 case NPIPE: 911 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 912 cmdtxt(lp->n); 913 if (lp->next) 914 cmdputs(" | "); 915 } 916 break; 917 case NSUBSHELL: 918 cmdputs("("); 919 cmdtxt(n->nredir.n); 920 cmdputs(")"); 921 break; 922 case NREDIR: 923 case NBACKGND: 924 cmdtxt(n->nredir.n); 925 break; 926 case NIF: 927 cmdputs("if "); 928 cmdtxt(n->nif.test); 929 cmdputs("; then "); 930 cmdtxt(n->nif.ifpart); 931 cmdputs("..."); 932 break; 933 case NWHILE: 934 cmdputs("while "); 935 goto until; 936 case NUNTIL: 937 cmdputs("until "); 938 until: 939 cmdtxt(n->nbinary.ch1); 940 cmdputs("; do "); 941 cmdtxt(n->nbinary.ch2); 942 cmdputs("; done"); 943 break; 944 case NFOR: 945 cmdputs("for "); 946 cmdputs(n->nfor.var); 947 cmdputs(" in ..."); 948 break; 949 case NCASE: 950 cmdputs("case "); 951 cmdputs(n->ncase.expr->narg.text); 952 cmdputs(" in ..."); 953 break; 954 case NDEFUN: 955 cmdputs(n->narg.text); 956 cmdputs("() ..."); 957 break; 958 case NCMD: 959 for (np = n->ncmd.args ; np ; np = np->narg.next) { 960 cmdtxt(np); 961 if (np->narg.next) 962 cmdputs(" "); 963 } 964 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 965 cmdputs(" "); 966 cmdtxt(np); 967 } 968 break; 969 case NARG: 970 cmdputs(n->narg.text); 971 break; 972 case NTO: 973 p = ">"; i = 1; goto redir; 974 case NAPPEND: 975 p = ">>"; i = 1; goto redir; 976 case NTOFD: 977 p = ">&"; i = 1; goto redir; 978 case NFROM: 979 p = "<"; i = 0; goto redir; 980 case NFROMFD: 981 p = "<&"; i = 0; goto redir; 982 redir: 983 if (n->nfile.fd != i) { 984 s[0] = n->nfile.fd + '0'; 985 s[1] = '\0'; 986 cmdputs(s); 987 } 988 cmdputs(p); 989 if (n->type == NTOFD || n->type == NFROMFD) { 990 s[0] = n->ndup.dupfd + '0'; 991 s[1] = '\0'; 992 cmdputs(s); 993 } else { 994 cmdtxt(n->nfile.fname); 995 } 996 break; 997 case NHERE: 998 case NXHERE: 999 cmdputs("<<..."); 1000 break; 1001 default: 1002 cmdputs("???"); 1003 break; 1004 } 1005 } 1006 1007 1008 1009 STATIC void 1010 cmdputs(s) 1011 char *s; 1012 { 1013 register char *p, *q; 1014 register char c; 1015 int subtype = 0; 1016 1017 if (cmdnleft <= 0) 1018 return; 1019 p = s; 1020 q = cmdnextc; 1021 while ((c = *p++) != '\0') { 1022 if (c == CTLESC) 1023 *q++ = *p++; 1024 else if (c == CTLVAR) { 1025 *q++ = '$'; 1026 if (--cmdnleft > 0) 1027 *q++ = '{'; 1028 subtype = *p++; 1029 } else if (c == '=' && subtype != 0) { 1030 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1031 subtype = 0; 1032 } else if (c == CTLENDVAR) { 1033 *q++ = '}'; 1034 } else if (c == CTLBACKQ | c == CTLBACKQ+CTLQUOTE) 1035 cmdnleft++; /* ignore it */ 1036 else 1037 *q++ = c; 1038 if (--cmdnleft <= 0) { 1039 *q++ = '.'; 1040 *q++ = '.'; 1041 *q++ = '.'; 1042 break; 1043 } 1044 } 1045 cmdnextc = q; 1046 } 1047