1 /*- 2 * Copyright (c) 1991 The Regents of the University of California. 3 * 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 5.7 (Berkeley) 10/17/92"; 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 close(0); 557 if (open("/dev/null", O_RDONLY) != 0) 558 error("Can't open /dev/null"); 559 } 560 } 561 #else 562 if (mode == FORK_BG) { 563 ignoresig(SIGINT); 564 ignoresig(SIGQUIT); 565 if (jp == NULL || jp->nprocs == 0) { 566 close(0); 567 if (open("/dev/null", O_RDONLY) != 0) 568 error("Can't open /dev/null"); 569 } 570 } 571 #endif 572 if (wasroot && iflag) { 573 setsignal(SIGINT); 574 setsignal(SIGQUIT); 575 setsignal(SIGTERM); 576 } 577 return pid; 578 } 579 if (rootshell && mode != FORK_NOJOB && mflag) { 580 if (jp == NULL || jp->nprocs == 0) 581 pgrp = pid; 582 else 583 pgrp = jp->ps[0].pid; 584 setpgrp(pid, pgrp); 585 } 586 if (mode == FORK_BG) 587 backgndpid = pid; /* set $! */ 588 if (jp) { 589 struct procstat *ps = &jp->ps[jp->nprocs++]; 590 ps->pid = pid; 591 ps->status = -1; 592 ps->cmd = nullstr; 593 if (iflag && rootshell && n) 594 ps->cmd = commandtext(n); 595 } 596 INTON; 597 TRACE(("In parent shell: child = %d\n", pid)); 598 return pid; 599 } 600 601 602 603 /* 604 * Wait for job to finish. 605 * 606 * Under job control we have the problem that while a child process is 607 * running interrupts generated by the user are sent to the child but not 608 * to the shell. This means that an infinite loop started by an inter- 609 * active user may be hard to kill. With job control turned off, an 610 * interactive user may place an interactive program inside a loop. If 611 * the interactive program catches interrupts, the user doesn't want 612 * these interrupts to also abort the loop. The approach we take here 613 * is to have the shell ignore interrupt signals while waiting for a 614 * forground process to terminate, and then send itself an interrupt 615 * signal if the child process was terminated by an interrupt signal. 616 * Unfortunately, some programs want to do a bit of cleanup and then 617 * exit on interrupt; unless these processes terminate themselves by 618 * sending a signal to themselves (instead of calling exit) they will 619 * confuse this approach. 620 */ 621 622 int 623 waitforjob(jp) 624 register struct job *jp; 625 { 626 #if JOBS 627 int mypgrp = getpgrp(0); 628 #endif 629 int status; 630 int st; 631 632 INTOFF; 633 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 634 while (jp->state == 0) { 635 dowait(1, jp); 636 } 637 #if JOBS 638 if (jp->jobctl) { 639 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 640 error("TIOCSPGRP failed, errno=%d\n", errno); 641 } 642 if (jp->state == JOBSTOPPED) 643 curjob = jp - jobtab + 1; 644 #endif 645 status = jp->ps[jp->nprocs - 1].status; 646 /* convert to 8 bits */ 647 if ((status & 0xFF) == 0) 648 st = status >> 8 & 0xFF; 649 #if JOBS 650 else if ((status & 0xFF) == 0177) 651 st = (status >> 8 & 0x7F) + 128; 652 #endif 653 else 654 st = (status & 0x7F) + 128; 655 if (! JOBS || jp->state == JOBDONE) 656 freejob(jp); 657 CLEAR_PENDING_INT; 658 if ((status & 0x7F) == SIGINT) 659 kill(getpid(), SIGINT); 660 INTON; 661 return st; 662 } 663 664 665 666 /* 667 * Wait for a process to terminate. 668 */ 669 670 STATIC int 671 dowait(block, job) 672 struct job *job; 673 { 674 int pid; 675 int status; 676 struct procstat *sp; 677 struct job *jp; 678 struct job *thisjob; 679 int done; 680 int stopped; 681 int core; 682 683 TRACE(("dowait(%d) called\n", block)); 684 do { 685 pid = waitproc(block, &status); 686 TRACE(("wait returns %d, status=%d\n", pid, status)); 687 } while (pid == -1 && errno == EINTR); 688 if (pid <= 0) 689 return pid; 690 INTOFF; 691 thisjob = NULL; 692 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 693 if (jp->used) { 694 done = 1; 695 stopped = 1; 696 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 697 if (sp->pid == -1) 698 continue; 699 if (sp->pid == pid) { 700 TRACE(("Changin status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 701 sp->status = status; 702 thisjob = jp; 703 } 704 if (sp->status == -1) 705 stopped = 0; 706 else if ((sp->status & 0377) == 0177) 707 done = 0; 708 } 709 if (stopped) { /* stopped or done */ 710 int state = done? JOBDONE : JOBSTOPPED; 711 if (jp->state != state) { 712 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 713 jp->state = state; 714 #if JOBS 715 if (done && curjob == jp - jobtab + 1) 716 curjob = 0; /* no current job */ 717 #endif 718 } 719 } 720 } 721 } 722 INTON; 723 if (! rootshell || ! iflag || (job && thisjob == job)) { 724 #if JOBS 725 if ((status & 0xFF) == 0177) 726 status >>= 8; 727 #endif 728 core = status & 0x80; 729 status &= 0x7F; 730 if (status != 0 && status != SIGINT && status != SIGPIPE) { 731 if (thisjob != job) 732 outfmt(out2, "%d: ", pid); 733 #if JOBS 734 if (status == SIGTSTP && rootshell && iflag) 735 outfmt(out2, "%%%d ", job - jobtab + 1); 736 #endif 737 if (status <= MAXSIG && sigmesg[status]) 738 out2str(sigmesg[status]); 739 else 740 outfmt(out2, "Signal %d", status); 741 if (core) 742 out2str(" - core dumped"); 743 out2c('\n'); 744 flushout(&errout); 745 } else { 746 TRACE(("Not printing status: status=%d\n", status)); 747 } 748 } else { 749 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 750 if (thisjob) 751 thisjob->changed = 1; 752 } 753 return pid; 754 } 755 756 757 758 /* 759 * Do a wait system call. If job control is compiled in, we accept 760 * stopped processes. If block is zero, we return a value of zero 761 * rather than blocking. 762 * 763 * System V doesn't have a non-blocking wait system call. It does 764 * have a SIGCLD signal that is sent to a process when one of it's 765 * children dies. The obvious way to use SIGCLD would be to install 766 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 767 * was received, and have waitproc bump another counter when it got 768 * the status of a process. Waitproc would then know that a wait 769 * system call would not block if the two counters were different. 770 * This approach doesn't work because if a process has children that 771 * have not been waited for, System V will send it a SIGCLD when it 772 * installs a signal handler for SIGCLD. What this means is that when 773 * a child exits, the shell will be sent SIGCLD signals continuously 774 * until is runs out of stack space, unless it does a wait call before 775 * restoring the signal handler. The code below takes advantage of 776 * this (mis)feature by installing a signal handler for SIGCLD and 777 * then checking to see whether it was called. If there are any 778 * children to be waited for, it will be. 779 * 780 * If neither SYSV nor BSD is defined, we don't implement nonblocking 781 * waits at all. In this case, the user will not be informed when 782 * a background process until the next time she runs a real program 783 * (as opposed to running a builtin command or just typing return), 784 * and the jobs command may give out of date information. 785 */ 786 787 #ifdef SYSV 788 STATIC int gotsigchild; 789 790 STATIC int onsigchild() { 791 gotsigchild = 1; 792 } 793 #endif 794 795 796 STATIC int 797 waitproc(block, status) 798 int *status; 799 { 800 #ifdef BSD 801 int flags; 802 803 #if JOBS 804 flags = WUNTRACED; 805 #else 806 flags = 0; 807 #endif 808 if (block == 0) 809 flags |= WNOHANG; 810 return wait3(status, flags, (struct rusage *)NULL); 811 #else 812 #ifdef SYSV 813 int (*save)(); 814 815 if (block == 0) { 816 gotsigchild = 0; 817 save = signal(SIGCLD, onsigchild); 818 signal(SIGCLD, save); 819 if (gotsigchild == 0) 820 return 0; 821 } 822 return wait(status); 823 #else 824 if (block == 0) 825 return 0; 826 return wait(status); 827 #endif 828 #endif 829 } 830 831 /* 832 * return 1 if there are stopped jobs, otherwise 0 833 */ 834 int job_warning = 0; 835 int 836 stoppedjobs() 837 { 838 register int jobno; 839 register struct job *jp; 840 841 if (job_warning) 842 return (0); 843 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 844 if (jp->used == 0) 845 continue; 846 if (jp->state == JOBSTOPPED) { 847 out2str("You have stopped jobs.\n"); 848 job_warning = 2; 849 return (1); 850 } 851 } 852 853 return (0); 854 } 855 856 /* 857 * Return a string identifying a command (to be printed by the 858 * jobs command. 859 */ 860 861 STATIC char *cmdnextc; 862 STATIC int cmdnleft; 863 STATIC void cmdtxt(), cmdputs(); 864 #define MAXCMDTEXT 200 865 866 char * 867 commandtext(n) 868 union node *n; 869 { 870 char *name; 871 872 cmdnextc = name = ckmalloc(MAXCMDTEXT); 873 cmdnleft = MAXCMDTEXT - 4; 874 cmdtxt(n); 875 *cmdnextc = '\0'; 876 return name; 877 } 878 879 880 STATIC void 881 cmdtxt(n) 882 union node *n; 883 { 884 union node *np; 885 struct nodelist *lp; 886 char *p; 887 int i; 888 char s[2]; 889 890 if (n == NULL) 891 return; 892 switch (n->type) { 893 case NSEMI: 894 cmdtxt(n->nbinary.ch1); 895 cmdputs("; "); 896 cmdtxt(n->nbinary.ch2); 897 break; 898 case NAND: 899 cmdtxt(n->nbinary.ch1); 900 cmdputs(" && "); 901 cmdtxt(n->nbinary.ch2); 902 break; 903 case NOR: 904 cmdtxt(n->nbinary.ch1); 905 cmdputs(" || "); 906 cmdtxt(n->nbinary.ch2); 907 break; 908 case NPIPE: 909 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 910 cmdtxt(lp->n); 911 if (lp->next) 912 cmdputs(" | "); 913 } 914 break; 915 case NSUBSHELL: 916 cmdputs("("); 917 cmdtxt(n->nredir.n); 918 cmdputs(")"); 919 break; 920 case NREDIR: 921 case NBACKGND: 922 cmdtxt(n->nredir.n); 923 break; 924 case NIF: 925 cmdputs("if "); 926 cmdtxt(n->nif.test); 927 cmdputs("; then "); 928 cmdtxt(n->nif.ifpart); 929 cmdputs("..."); 930 break; 931 case NWHILE: 932 cmdputs("while "); 933 goto until; 934 case NUNTIL: 935 cmdputs("until "); 936 until: 937 cmdtxt(n->nbinary.ch1); 938 cmdputs("; do "); 939 cmdtxt(n->nbinary.ch2); 940 cmdputs("; done"); 941 break; 942 case NFOR: 943 cmdputs("for "); 944 cmdputs(n->nfor.var); 945 cmdputs(" in ..."); 946 break; 947 case NCASE: 948 cmdputs("case "); 949 cmdputs(n->ncase.expr->narg.text); 950 cmdputs(" in ..."); 951 break; 952 case NDEFUN: 953 cmdputs(n->narg.text); 954 cmdputs("() ..."); 955 break; 956 case NCMD: 957 for (np = n->ncmd.args ; np ; np = np->narg.next) { 958 cmdtxt(np); 959 if (np->narg.next) 960 cmdputs(" "); 961 } 962 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 963 cmdputs(" "); 964 cmdtxt(np); 965 } 966 break; 967 case NARG: 968 cmdputs(n->narg.text); 969 break; 970 case NTO: 971 p = ">"; i = 1; goto redir; 972 case NAPPEND: 973 p = ">>"; i = 1; goto redir; 974 case NTOFD: 975 p = ">&"; i = 1; goto redir; 976 case NFROM: 977 p = "<"; i = 0; goto redir; 978 case NFROMFD: 979 p = "<&"; i = 0; goto redir; 980 redir: 981 if (n->nfile.fd != i) { 982 s[0] = n->nfile.fd + '0'; 983 s[1] = '\0'; 984 cmdputs(s); 985 } 986 cmdputs(p); 987 if (n->type == NTOFD || n->type == NFROMFD) { 988 s[0] = n->ndup.dupfd + '0'; 989 s[1] = '\0'; 990 cmdputs(s); 991 } else { 992 cmdtxt(n->nfile.fname); 993 } 994 break; 995 case NHERE: 996 case NXHERE: 997 cmdputs("<<..."); 998 break; 999 default: 1000 cmdputs("???"); 1001 break; 1002 } 1003 } 1004 1005 1006 1007 STATIC void 1008 cmdputs(s) 1009 char *s; 1010 { 1011 register char *p, *q; 1012 register char c; 1013 int subtype = 0; 1014 1015 if (cmdnleft <= 0) 1016 return; 1017 p = s; 1018 q = cmdnextc; 1019 while ((c = *p++) != '\0') { 1020 if (c == CTLESC) 1021 *q++ = *p++; 1022 else if (c == CTLVAR) { 1023 *q++ = '$'; 1024 if (--cmdnleft > 0) 1025 *q++ = '{'; 1026 subtype = *p++; 1027 } else if (c == '=' && subtype != 0) { 1028 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1029 subtype = 0; 1030 } else if (c == CTLENDVAR) { 1031 *q++ = '}'; 1032 } else if (c == CTLBACKQ | c == CTLBACKQ+CTLQUOTE) 1033 cmdnleft++; /* ignore it */ 1034 else 1035 *q++ = c; 1036 if (--cmdnleft <= 0) { 1037 *q++ = '.'; 1038 *q++ = '.'; 1039 *q++ = '.'; 1040 break; 1041 } 1042 } 1043 cmdnextc = q; 1044 } 1045