jobs.c revision 1.12
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[] = "from: @(#)jobs.c 8.1 (Berkeley) 5/31/93";*/ 39 static char *rcsid = "$Id: jobs.c,v 1.12 1994/09/23 11:28:42 mycroft Exp $"; 40 #endif /* not lint */ 41 42 #include "shell.h" 43 #if JOBS 44 #include "sgtty.h" 45 #undef CEOF /* syntax.h redefines this */ 46 #endif 47 #include "main.h" 48 #include "parser.h" 49 #include "nodes.h" 50 #include "jobs.h" 51 #include "options.h" 52 #include "trap.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 #include <unistd.h> 63 #ifdef BSD 64 #include <sys/types.h> 65 #include <sys/wait.h> 66 #include <sys/time.h> 67 #include <sys/resource.h> 68 #endif 69 70 71 72 struct job *jobtab; /* array of jobs */ 73 int njobs; /* size of array */ 74 MKINIT short backgndpid = -1; /* pid of last background process */ 75 #if JOBS 76 int initialpgrp; /* pgrp of shell on invocation */ 77 short curjob; /* current job */ 78 #endif 79 80 #ifdef __STDC__ 81 STATIC void restartjob(struct job *); 82 STATIC struct job *getjob(char *); 83 STATIC void freejob(struct job *); 84 STATIC int procrunning(int); 85 STATIC int dowait(int, struct job *); 86 STATIC int waitproc(int, int *); 87 #else 88 STATIC void restartjob(); 89 STATIC struct job *getjob(); 90 STATIC void freejob(); 91 STATIC int procrunning(); 92 STATIC int dowait(); 93 STATIC int waitproc(); 94 #endif 95 96 97 98 /* 99 * Turn job control on and off. 100 * 101 * Note: This code assumes that the third arg to ioctl is a character 102 * pointer, which is true on Berkeley systems but not System V. Since 103 * System V doesn't have job control yet, this isn't a problem now. 104 */ 105 106 MKINIT int jobctl; 107 108 void 109 setjobctl(on) { 110 #ifdef OLD_TTY_DRIVER 111 int ldisc; 112 #endif 113 114 if (on == jobctl || rootshell == 0) 115 return; 116 if (on) { 117 do { /* while we are in the background */ 118 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 119 out2str("sh: can't access tty; job control turned off\n"); 120 mflag = 0; 121 return; 122 } 123 if (initialpgrp == -1) 124 initialpgrp = getpgrp(); 125 else if (initialpgrp != getpgrp()) { 126 killpg(initialpgrp, SIGTTIN); 127 continue; 128 } 129 } while (0); 130 #ifdef OLD_TTY_DRIVER 131 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 132 out2str("sh: need new tty driver to run job control; job control turned off\n"); 133 mflag = 0; 134 return; 135 } 136 #endif 137 setsignal(SIGTSTP); 138 setsignal(SIGTTOU); 139 setsignal(SIGTTIN); 140 setpgid(0, rootpid); 141 ioctl(2, TIOCSPGRP, (char *)&rootpid); 142 } else { /* turning job control off */ 143 setpgid(0, initialpgrp); 144 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 145 setsignal(SIGTSTP); 146 setsignal(SIGTTOU); 147 setsignal(SIGTTIN); 148 } 149 jobctl = on; 150 } 151 152 153 #ifdef mkinit 154 155 SHELLPROC { 156 backgndpid = -1; 157 #if JOBS 158 jobctl = 0; 159 #endif 160 } 161 162 #endif 163 164 165 166 #if JOBS 167 fgcmd(argc, argv) char **argv; { 168 struct job *jp; 169 int pgrp; 170 int status; 171 172 jp = getjob(argv[1]); 173 if (jp->jobctl == 0) 174 error("job not created under job control"); 175 pgrp = jp->ps[0].pid; 176 ioctl(2, TIOCSPGRP, (char *)&pgrp); 177 restartjob(jp); 178 INTOFF; 179 status = waitforjob(jp); 180 INTON; 181 return status; 182 } 183 184 185 bgcmd(argc, argv) char **argv; { 186 struct job *jp; 187 188 do { 189 jp = getjob(*++argv); 190 if (jp->jobctl == 0) 191 error("job not created under job control"); 192 restartjob(jp); 193 } while (--argc > 1); 194 return 0; 195 } 196 197 198 STATIC void 199 restartjob(jp) 200 struct job *jp; 201 { 202 struct procstat *ps; 203 int i; 204 205 if (jp->state == JOBDONE) 206 return; 207 INTOFF; 208 killpg(jp->ps[0].pid, SIGCONT); 209 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 210 if ((ps->status & 0377) == 0177) { 211 ps->status = -1; 212 jp->state = 0; 213 } 214 } 215 INTON; 216 } 217 #endif 218 219 220 int 221 jobscmd(argc, argv) char **argv; { 222 showjobs(0); 223 return 0; 224 } 225 226 227 /* 228 * Print a list of jobs. If "change" is nonzero, only print jobs whose 229 * statuses have changed since the last call to showjobs. 230 * 231 * If the shell is interrupted in the process of creating a job, the 232 * result may be a job structure containing zero processes. Such structures 233 * will be freed here. 234 */ 235 236 void 237 showjobs(change) { 238 int jobno; 239 int procno; 240 int i; 241 struct job *jp; 242 struct procstat *ps; 243 int col; 244 char s[64]; 245 246 TRACE(("showjobs(%d) called\n", change)); 247 while (dowait(0, (struct job *)NULL) > 0); 248 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 249 if (! jp->used) 250 continue; 251 if (jp->nprocs == 0) { 252 freejob(jp); 253 continue; 254 } 255 if (change && ! jp->changed) 256 continue; 257 procno = jp->nprocs; 258 for (ps = jp->ps ; ; ps++) { /* for each process */ 259 if (ps == jp->ps) 260 fmtstr(s, 64, "[%d] %d ", jobno, ps->pid); 261 else 262 fmtstr(s, 64, " %d ", ps->pid); 263 out1str(s); 264 col = strlen(s); 265 s[0] = '\0'; 266 if (ps->status == -1) { 267 /* don't print anything */ 268 } else if ((ps->status & 0xFF) == 0) { 269 fmtstr(s, 64, "Exit %d", ps->status >> 8); 270 } else { 271 i = ps->status; 272 #if JOBS 273 if ((i & 0xFF) == 0177) 274 i >>= 8; 275 #endif 276 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 277 scopy(sys_siglist[i & 0x7F], s); 278 else 279 fmtstr(s, 64, "Signal %d", i & 0x7F); 280 if (i & 0x80) 281 strcat(s, " (core dumped)"); 282 } 283 out1str(s); 284 col += strlen(s); 285 do { 286 out1c(' '); 287 col++; 288 } while (col < 30); 289 out1str(ps->cmd); 290 out1c('\n'); 291 if (--procno <= 0) 292 break; 293 } 294 jp->changed = 0; 295 if (jp->state == JOBDONE) { 296 freejob(jp); 297 } 298 } 299 } 300 301 302 /* 303 * Mark a job structure as unused. 304 */ 305 306 STATIC void 307 freejob(jp) 308 struct job *jp; 309 { 310 struct procstat *ps; 311 int i; 312 313 INTOFF; 314 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 315 if (ps->cmd != nullstr) 316 ckfree(ps->cmd); 317 } 318 if (jp->ps != &jp->ps0) 319 ckfree(jp->ps); 320 jp->used = 0; 321 #if JOBS 322 if (curjob == jp - jobtab + 1) 323 curjob = 0; 324 #endif 325 INTON; 326 } 327 328 329 330 int 331 waitcmd(argc, argv) char **argv; { 332 struct job *job; 333 int status; 334 struct job *jp; 335 336 if (argc > 1) { 337 job = getjob(argv[1]); 338 } else { 339 job = NULL; 340 } 341 for (;;) { /* loop until process terminated or stopped */ 342 if (job != NULL) { 343 if (job->state) { 344 status = job->ps[job->nprocs - 1].status; 345 if ((status & 0xFF) == 0) 346 status = status >> 8 & 0xFF; 347 #if JOBS 348 else if ((status & 0xFF) == 0177) 349 status = (status >> 8 & 0x7F) + 128; 350 #endif 351 else 352 status = (status & 0x7F) + 128; 353 if (! iflag) 354 freejob(job); 355 return status; 356 } 357 } else { 358 for (jp = jobtab ; ; jp++) { 359 if (jp >= jobtab + njobs) { /* no running procs */ 360 return 0; 361 } 362 if (jp->used && jp->state == 0) 363 break; 364 } 365 } 366 dowait(1, (struct job *)NULL); 367 } 368 } 369 370 371 372 jobidcmd(argc, argv) char **argv; { 373 struct job *jp; 374 int i; 375 376 jp = getjob(argv[1]); 377 for (i = 0 ; i < jp->nprocs ; ) { 378 out1fmt("%d", jp->ps[i].pid); 379 out1c(++i < jp->nprocs? ' ' : '\n'); 380 } 381 return 0; 382 } 383 384 385 386 /* 387 * Convert a job name to a job structure. 388 */ 389 390 STATIC struct job * 391 getjob(name) 392 char *name; 393 { 394 int jobno; 395 register struct job *jp; 396 int pid; 397 int i; 398 399 if (name == NULL) { 400 #if JOBS 401 currentjob: 402 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 403 error("No current job"); 404 return &jobtab[jobno - 1]; 405 #else 406 error("No current job"); 407 #endif 408 } else if (name[0] == '%') { 409 if (is_digit(name[1])) { 410 jobno = number(name + 1); 411 if (jobno > 0 && jobno <= njobs 412 && jobtab[jobno - 1].used != 0) 413 return &jobtab[jobno - 1]; 414 #if JOBS 415 } else if (name[1] == '%' && name[2] == '\0') { 416 goto currentjob; 417 #endif 418 } else { 419 register struct job *found = NULL; 420 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 421 if (jp->used && jp->nprocs > 0 422 && prefix(name + 1, jp->ps[0].cmd)) { 423 if (found) 424 error("%s: ambiguous", name); 425 found = jp; 426 } 427 } 428 if (found) 429 return found; 430 } 431 } else if (is_number(name)) { 432 pid = number(name); 433 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 434 if (jp->used && jp->nprocs > 0 435 && jp->ps[jp->nprocs - 1].pid == pid) 436 return jp; 437 } 438 } 439 error("No such job: %s", name); 440 } 441 442 443 444 /* 445 * Return a new job structure, 446 */ 447 448 struct job * 449 makejob(node, nprocs) 450 union node *node; 451 { 452 int i; 453 struct job *jp; 454 455 for (i = njobs, jp = jobtab ; ; jp++) { 456 if (--i < 0) { 457 INTOFF; 458 if (njobs == 0) { 459 jobtab = ckmalloc(4 * sizeof jobtab[0]); 460 } else { 461 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 462 memcpy(jp, jobtab, njobs * sizeof jp[0]); 463 ckfree(jobtab); 464 jobtab = jp; 465 } 466 jp = jobtab + njobs; 467 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 468 INTON; 469 break; 470 } 471 if (jp->used == 0) 472 break; 473 } 474 INTOFF; 475 jp->state = 0; 476 jp->used = 1; 477 jp->changed = 0; 478 jp->nprocs = 0; 479 #if JOBS 480 jp->jobctl = jobctl; 481 #endif 482 if (nprocs > 1) { 483 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 484 } else { 485 jp->ps = &jp->ps0; 486 } 487 INTON; 488 TRACE(("makejob(0x%x, %d) returns %%%d\n", (int)node, nprocs, jp - jobtab + 1)); 489 return jp; 490 } 491 492 493 /* 494 * Fork of a subshell. If we are doing job control, give the subshell its 495 * own process group. Jp is a job structure that the job is to be added to. 496 * N is the command that will be evaluated by the child. Both jp and n may 497 * be NULL. The mode parameter can be one of the following: 498 * FORK_FG - Fork off a foreground process. 499 * FORK_BG - Fork off a background process. 500 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 501 * process group even if job control is on. 502 * 503 * When job control is turned off, background processes have their standard 504 * input redirected to /dev/null (except for the second and later processes 505 * in a pipeline). 506 */ 507 508 int 509 forkshell(jp, n, mode) 510 union node *n; 511 struct job *jp; 512 { 513 int pid; 514 int pgrp; 515 516 TRACE(("forkshell(%%%d, 0x%x, %d) called\n", jp - jobtab, (int)n, mode)); 517 INTOFF; 518 pid = fork(); 519 if (pid == -1) { 520 TRACE(("Fork failed, errno=%d\n", errno)); 521 INTON; 522 error("Cannot fork"); 523 } 524 if (pid == 0) { 525 struct job *p; 526 int wasroot; 527 int i; 528 529 TRACE(("Child shell %d\n", getpid())); 530 wasroot = rootshell; 531 rootshell = 0; 532 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 533 if (p->used) 534 freejob(p); 535 closescript(); 536 INTON; 537 clear_traps(); 538 #if JOBS 539 jobctl = 0; /* do job control only in root shell */ 540 if (wasroot && mode != FORK_NOJOB && mflag) { 541 if (jp == NULL || jp->nprocs == 0) 542 pgrp = getpid(); 543 else 544 pgrp = jp->ps[0].pid; 545 setpgid(0, pgrp); 546 if (mode == FORK_FG) { 547 /*** this causes superfluous TIOCSPGRPS ***/ 548 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 549 error("TIOCSPGRP failed, errno=%d\n", errno); 550 } 551 setsignal(SIGTSTP); 552 setsignal(SIGTTOU); 553 } else if (mode == FORK_BG) { 554 ignoresig(SIGINT); 555 ignoresig(SIGQUIT); 556 if ((jp == NULL || jp->nprocs == 0) && 557 ! fd0_redirected_p ()) { 558 close(0); 559 if (open("/dev/null", O_RDONLY) != 0) 560 error("Can't open /dev/null"); 561 } 562 } 563 #else 564 if (mode == FORK_BG) { 565 ignoresig(SIGINT); 566 ignoresig(SIGQUIT); 567 if ((jp == NULL || jp->nprocs == 0) && 568 ! fd0_redirected_p ()) { 569 close(0); 570 if (open("/dev/null", O_RDONLY) != 0) 571 error("Can't open /dev/null"); 572 } 573 } 574 #endif 575 if (wasroot && iflag) { 576 setsignal(SIGINT); 577 setsignal(SIGQUIT); 578 setsignal(SIGTERM); 579 } 580 return pid; 581 } 582 if (rootshell && mode != FORK_NOJOB && mflag) { 583 if (jp == NULL || jp->nprocs == 0) 584 pgrp = pid; 585 else 586 pgrp = jp->ps[0].pid; 587 setpgid(pid, pgrp); 588 } 589 if (mode == FORK_BG) 590 backgndpid = pid; /* set $! */ 591 if (jp) { 592 struct procstat *ps = &jp->ps[jp->nprocs++]; 593 ps->pid = pid; 594 ps->status = -1; 595 ps->cmd = nullstr; 596 if (iflag && rootshell && n) 597 ps->cmd = commandtext(n); 598 } 599 INTON; 600 TRACE(("In parent shell: child = %d\n", pid)); 601 return pid; 602 } 603 604 605 606 /* 607 * Wait for job to finish. 608 * 609 * Under job control we have the problem that while a child process is 610 * running interrupts generated by the user are sent to the child but not 611 * to the shell. This means that an infinite loop started by an inter- 612 * active user may be hard to kill. With job control turned off, an 613 * interactive user may place an interactive program inside a loop. If 614 * the interactive program catches interrupts, the user doesn't want 615 * these interrupts to also abort the loop. The approach we take here 616 * is to have the shell ignore interrupt signals while waiting for a 617 * forground process to terminate, and then send itself an interrupt 618 * signal if the child process was terminated by an interrupt signal. 619 * Unfortunately, some programs want to do a bit of cleanup and then 620 * exit on interrupt; unless these processes terminate themselves by 621 * sending a signal to themselves (instead of calling exit) they will 622 * confuse this approach. 623 */ 624 625 int 626 waitforjob(jp) 627 register struct job *jp; 628 { 629 #if JOBS 630 int mypgrp = getpgrp(); 631 #endif 632 int status; 633 int st; 634 635 INTOFF; 636 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 637 while (jp->state == 0) { 638 dowait(1, jp); 639 } 640 #if JOBS 641 if (jp->jobctl) { 642 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 643 error("TIOCSPGRP failed, errno=%d\n", errno); 644 } 645 if (jp->state == JOBSTOPPED) 646 curjob = jp - jobtab + 1; 647 #endif 648 status = jp->ps[jp->nprocs - 1].status; 649 /* convert to 8 bits */ 650 if ((status & 0xFF) == 0) 651 st = status >> 8 & 0xFF; 652 #if JOBS 653 else if ((status & 0xFF) == 0177) 654 st = (status >> 8 & 0x7F) + 128; 655 #endif 656 else 657 st = (status & 0x7F) + 128; 658 if (! JOBS || jp->state == JOBDONE) 659 freejob(jp); 660 CLEAR_PENDING_INT; 661 if ((status & 0x7F) == SIGINT) 662 kill(getpid(), SIGINT); 663 INTON; 664 return st; 665 } 666 667 668 669 /* 670 * Wait for a process to terminate. 671 */ 672 673 STATIC int 674 dowait(block, job) 675 struct job *job; 676 { 677 int pid; 678 int status; 679 struct procstat *sp; 680 struct job *jp; 681 struct job *thisjob; 682 int done; 683 int stopped; 684 int core; 685 686 TRACE(("dowait(%d) called\n", block)); 687 do { 688 pid = waitproc(block, &status); 689 TRACE(("wait returns %d, status=%d\n", pid, status)); 690 } while (pid == -1 && errno == EINTR); 691 if (pid <= 0) 692 return pid; 693 INTOFF; 694 thisjob = NULL; 695 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 696 if (jp->used) { 697 done = 1; 698 stopped = 1; 699 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 700 if (sp->pid == -1) 701 continue; 702 if (sp->pid == pid) { 703 TRACE(("Changin status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); 704 sp->status = status; 705 thisjob = jp; 706 } 707 if (sp->status == -1) 708 stopped = 0; 709 else if ((sp->status & 0377) == 0177) 710 done = 0; 711 } 712 if (stopped) { /* stopped or done */ 713 int state = done? JOBDONE : JOBSTOPPED; 714 if (jp->state != state) { 715 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 716 jp->state = state; 717 #if JOBS 718 if (done && curjob == jp - jobtab + 1) 719 curjob = 0; /* no current job */ 720 #endif 721 } 722 } 723 } 724 } 725 INTON; 726 if (! rootshell || ! iflag || (job && thisjob == job)) { 727 #if JOBS 728 if ((status & 0xFF) == 0177) 729 status >>= 8; 730 #endif 731 core = status & 0x80; 732 status &= 0x7F; 733 if (status != 0 && status != SIGINT && status != SIGPIPE) { 734 if (thisjob != job) 735 outfmt(out2, "%d: ", pid); 736 #if JOBS 737 if (status == SIGTSTP && rootshell && iflag) 738 outfmt(out2, "%%%d ", job - jobtab + 1); 739 #endif 740 if (status < NSIG && sys_siglist[status]) 741 out2str(sys_siglist[status]); 742 else 743 outfmt(out2, "Signal %d", status); 744 if (core) 745 out2str(" - core dumped"); 746 out2c('\n'); 747 flushout(&errout); 748 } else { 749 TRACE(("Not printing status: status=%d\n", status)); 750 } 751 } else { 752 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 753 if (thisjob) 754 thisjob->changed = 1; 755 } 756 return pid; 757 } 758 759 760 761 /* 762 * Do a wait system call. If job control is compiled in, we accept 763 * stopped processes. If block is zero, we return a value of zero 764 * rather than blocking. 765 * 766 * System V doesn't have a non-blocking wait system call. It does 767 * have a SIGCLD signal that is sent to a process when one of it's 768 * children dies. The obvious way to use SIGCLD would be to install 769 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 770 * was received, and have waitproc bump another counter when it got 771 * the status of a process. Waitproc would then know that a wait 772 * system call would not block if the two counters were different. 773 * This approach doesn't work because if a process has children that 774 * have not been waited for, System V will send it a SIGCLD when it 775 * installs a signal handler for SIGCLD. What this means is that when 776 * a child exits, the shell will be sent SIGCLD signals continuously 777 * until is runs out of stack space, unless it does a wait call before 778 * restoring the signal handler. The code below takes advantage of 779 * this (mis)feature by installing a signal handler for SIGCLD and 780 * then checking to see whether it was called. If there are any 781 * children to be waited for, it will be. 782 * 783 * If neither SYSV nor BSD is defined, we don't implement nonblocking 784 * waits at all. In this case, the user will not be informed when 785 * a background process until the next time she runs a real program 786 * (as opposed to running a builtin command or just typing return), 787 * and the jobs command may give out of date information. 788 */ 789 790 #ifdef SYSV 791 STATIC int gotsigchild; 792 793 STATIC int onsigchild() { 794 gotsigchild = 1; 795 } 796 #endif 797 798 799 STATIC int 800 waitproc(block, status) 801 int *status; 802 { 803 #ifdef BSD 804 int flags; 805 806 #if JOBS 807 flags = WUNTRACED; 808 #else 809 flags = 0; 810 #endif 811 if (block == 0) 812 flags |= WNOHANG; 813 return wait3(status, flags, (struct rusage *)NULL); 814 #else 815 #ifdef SYSV 816 int (*save)(); 817 818 if (block == 0) { 819 gotsigchild = 0; 820 save = signal(SIGCLD, onsigchild); 821 signal(SIGCLD, save); 822 if (gotsigchild == 0) 823 return 0; 824 } 825 return wait(status); 826 #else 827 if (block == 0) 828 return 0; 829 return wait(status); 830 #endif 831 #endif 832 } 833 834 /* 835 * return 1 if there are stopped jobs, otherwise 0 836 */ 837 int job_warning = 0; 838 int 839 stoppedjobs() 840 { 841 register int jobno; 842 register struct job *jp; 843 844 if (job_warning) 845 return (0); 846 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 847 if (jp->used == 0) 848 continue; 849 if (jp->state == JOBSTOPPED) { 850 out2str("You have stopped jobs.\n"); 851 job_warning = 2; 852 return (1); 853 } 854 } 855 856 return (0); 857 } 858 859 /* 860 * Return a string identifying a command (to be printed by the 861 * jobs command. 862 */ 863 864 STATIC char *cmdnextc; 865 STATIC int cmdnleft; 866 STATIC void cmdtxt(), cmdputs(); 867 #define MAXCMDTEXT 200 868 869 char * 870 commandtext(n) 871 union node *n; 872 { 873 char *name; 874 875 cmdnextc = name = ckmalloc(MAXCMDTEXT); 876 cmdnleft = MAXCMDTEXT - 4; 877 cmdtxt(n); 878 *cmdnextc = '\0'; 879 return name; 880 } 881 882 883 STATIC void 884 cmdtxt(n) 885 union node *n; 886 { 887 union node *np; 888 struct nodelist *lp; 889 char *p; 890 int i; 891 char s[2]; 892 893 if (n == NULL) 894 return; 895 switch (n->type) { 896 case NSEMI: 897 cmdtxt(n->nbinary.ch1); 898 cmdputs("; "); 899 cmdtxt(n->nbinary.ch2); 900 break; 901 case NAND: 902 cmdtxt(n->nbinary.ch1); 903 cmdputs(" && "); 904 cmdtxt(n->nbinary.ch2); 905 break; 906 case NOR: 907 cmdtxt(n->nbinary.ch1); 908 cmdputs(" || "); 909 cmdtxt(n->nbinary.ch2); 910 break; 911 case NPIPE: 912 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 913 cmdtxt(lp->n); 914 if (lp->next) 915 cmdputs(" | "); 916 } 917 break; 918 case NSUBSHELL: 919 cmdputs("("); 920 cmdtxt(n->nredir.n); 921 cmdputs(")"); 922 break; 923 case NREDIR: 924 case NBACKGND: 925 cmdtxt(n->nredir.n); 926 break; 927 case NIF: 928 cmdputs("if "); 929 cmdtxt(n->nif.test); 930 cmdputs("; then "); 931 cmdtxt(n->nif.ifpart); 932 cmdputs("..."); 933 break; 934 case NWHILE: 935 cmdputs("while "); 936 goto until; 937 case NUNTIL: 938 cmdputs("until "); 939 until: 940 cmdtxt(n->nbinary.ch1); 941 cmdputs("; do "); 942 cmdtxt(n->nbinary.ch2); 943 cmdputs("; done"); 944 break; 945 case NFOR: 946 cmdputs("for "); 947 cmdputs(n->nfor.var); 948 cmdputs(" in ..."); 949 break; 950 case NCASE: 951 cmdputs("case "); 952 cmdputs(n->ncase.expr->narg.text); 953 cmdputs(" in ..."); 954 break; 955 case NDEFUN: 956 cmdputs(n->narg.text); 957 cmdputs("() ..."); 958 break; 959 case NCMD: 960 for (np = n->ncmd.args ; np ; np = np->narg.next) { 961 cmdtxt(np); 962 if (np->narg.next) 963 cmdputs(" "); 964 } 965 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 966 cmdputs(" "); 967 cmdtxt(np); 968 } 969 break; 970 case NARG: 971 cmdputs(n->narg.text); 972 break; 973 case NTO: 974 p = ">"; i = 1; goto redir; 975 case NAPPEND: 976 p = ">>"; i = 1; goto redir; 977 case NTOFD: 978 p = ">&"; i = 1; goto redir; 979 case NFROM: 980 p = "<"; i = 0; goto redir; 981 case NFROMFD: 982 p = "<&"; i = 0; goto redir; 983 redir: 984 if (n->nfile.fd != i) { 985 s[0] = n->nfile.fd + '0'; 986 s[1] = '\0'; 987 cmdputs(s); 988 } 989 cmdputs(p); 990 if (n->type == NTOFD || n->type == NFROMFD) { 991 s[0] = n->ndup.dupfd + '0'; 992 s[1] = '\0'; 993 cmdputs(s); 994 } else { 995 cmdtxt(n->nfile.fname); 996 } 997 break; 998 case NHERE: 999 case NXHERE: 1000 cmdputs("<<..."); 1001 break; 1002 default: 1003 cmdputs("???"); 1004 break; 1005 } 1006 } 1007 1008 1009 1010 STATIC void 1011 cmdputs(s) 1012 char *s; 1013 { 1014 register char *p, *q; 1015 register char c; 1016 int subtype = 0; 1017 1018 if (cmdnleft <= 0) 1019 return; 1020 p = s; 1021 q = cmdnextc; 1022 while ((c = *p++) != '\0') { 1023 if (c == CTLESC) 1024 *q++ = *p++; 1025 else if (c == CTLVAR) { 1026 *q++ = '$'; 1027 if (--cmdnleft > 0) 1028 *q++ = '{'; 1029 subtype = *p++; 1030 } else if (c == '=' && subtype != 0) { 1031 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1032 subtype = 0; 1033 } else if (c == CTLENDVAR) { 1034 *q++ = '}'; 1035 } else if (c == CTLBACKQ | c == CTLBACKQ+CTLQUOTE) 1036 cmdnleft++; /* ignore it */ 1037 else 1038 *q++ = c; 1039 if (--cmdnleft <= 0) { 1040 *q++ = '.'; 1041 *q++ = '.'; 1042 *q++ = '.'; 1043 break; 1044 } 1045 } 1046 cmdnextc = q; 1047 } 1048
Indexes created Thu Oct 02 07:10:07 GMT 2025