jobs.c revision 97819
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 39static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 40#endif 41static const char rcsid[] = 42 "$FreeBSD: head/bin/sh/jobs.c 97819 2002-06-04 14:37:13Z tjr $"; 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 84struct job *jobtab; /* array of jobs */ 85int njobs; /* size of array */ 86MKINIT pid_t backgndpid = -1; /* pid of last background process */ 87#if JOBS 88struct job *jobmru; /* most recently used job list */ 89int initialpgrp; /* pgrp of shell on invocation */ 90#endif 91int in_waitcmd = 0; /* are we in waitcmd()? */ 92int in_dowait = 0; /* are we in dowait()? */ 93volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 94 95#if JOBS 96STATIC void restartjob(struct job *); 97#endif 98STATIC void freejob(struct job *); 99STATIC struct job *getjob(char *); 100STATIC int dowait(int, struct job *); 101#if SYSV 102STATIC int onsigchild(void); 103#endif 104STATIC int waitproc(int, int *); 105STATIC void cmdtxt(union node *); 106STATIC void cmdputs(char *); 107#if JOBS 108STATIC void setcurjob(struct job *); 109STATIC void deljob(struct job *); 110STATIC struct job *getcurjob(struct job *); 111#endif 112STATIC void showjob(struct job *, int, int); 113 114 115/* 116 * Turn job control on and off. 117 * 118 * Note: This code assumes that the third arg to ioctl is a character 119 * pointer, which is true on Berkeley systems but not System V. Since 120 * System V doesn't have job control yet, this isn't a problem now. 121 */ 122 123MKINIT int jobctl; 124 125#if JOBS 126void 127setjobctl(int on) 128{ 129#ifdef OLD_TTY_DRIVER 130 int ldisc; 131#endif 132 133 if (on == jobctl || rootshell == 0) 134 return; 135 if (on) { 136 do { /* while we are in the background */ 137#ifdef OLD_TTY_DRIVER 138 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 139#else 140 initialpgrp = tcgetpgrp(2); 141 if (initialpgrp < 0) { 142#endif 143 out2str("sh: can't access tty; job control turned off\n"); 144 mflag = 0; 145 return; 146 } 147 if (initialpgrp == -1) 148 initialpgrp = getpgrp(); 149 else if (initialpgrp != getpgrp()) { 150 killpg(initialpgrp, SIGTTIN); 151 continue; 152 } 153 } while (0); 154#ifdef OLD_TTY_DRIVER 155 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 156 out2str("sh: need new tty driver to run job control; job control turned off\n"); 157 mflag = 0; 158 return; 159 } 160#endif 161 setsignal(SIGTSTP); 162 setsignal(SIGTTOU); 163 setsignal(SIGTTIN); 164 setpgid(0, rootpid); 165#ifdef OLD_TTY_DRIVER 166 ioctl(2, TIOCSPGRP, (char *)&rootpid); 167#else 168 tcsetpgrp(2, rootpid); 169#endif 170 } else { /* turning job control off */ 171 setpgid(0, initialpgrp); 172#ifdef OLD_TTY_DRIVER 173 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 174#else 175 tcsetpgrp(2, initialpgrp); 176#endif 177 setsignal(SIGTSTP); 178 setsignal(SIGTTOU); 179 setsignal(SIGTTIN); 180 } 181 jobctl = on; 182} 183#endif 184 185 186#ifdef mkinit 187INCLUDE <sys/types.h> 188INCLUDE <stdlib.h> 189 190SHELLPROC { 191 backgndpid = -1; 192#if JOBS 193 jobctl = 0; 194#endif 195} 196 197#endif 198 199 200 201#if JOBS 202int 203fgcmd(int argc __unused, char **argv) 204{ 205 struct job *jp; 206 int pgrp; 207 int status; 208 209 jp = getjob(argv[1]); 210 if (jp->jobctl == 0) 211 error("job not created under job control"); 212 out1str(jp->ps[0].cmd); 213 out1c('\n'); 214 flushout(&output); 215 pgrp = jp->ps[0].pid; 216#ifdef OLD_TTY_DRIVER 217 ioctl(2, TIOCSPGRP, (char *)&pgrp); 218#else 219 tcsetpgrp(2, pgrp); 220#endif 221 restartjob(jp); 222 INTOFF; 223 status = waitforjob(jp, (int *)NULL); 224 INTON; 225 return status; 226} 227 228 229int 230bgcmd(int argc, char **argv) 231{ 232 char s[64]; 233 struct job *jp; 234 235 do { 236 jp = getjob(*++argv); 237 if (jp->jobctl == 0) 238 error("job not created under job control"); 239 if (jp->state == JOBDONE) 240 continue; 241 restartjob(jp); 242 fmtstr(s, 64, "[%d] ", jp - jobtab + 1); 243 out1str(s); 244 out1str(jp->ps[0].cmd); 245 out1c('\n'); 246 } while (--argc > 1); 247 return 0; 248} 249 250 251STATIC void 252restartjob(struct job *jp) 253{ 254 struct procstat *ps; 255 int i; 256 257 if (jp->state == JOBDONE) 258 return; 259 setcurjob(jp); 260 INTOFF; 261 killpg(jp->ps[0].pid, SIGCONT); 262 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 263 if (WIFSTOPPED(ps->status)) { 264 ps->status = -1; 265 jp->state = 0; 266 } 267 } 268 INTON; 269} 270#endif 271 272 273int 274jobscmd(int argc, char *argv[]) 275{ 276 struct job *jp; 277 char *id; 278 int ch, sformat, lformat; 279 280 optind = optreset = 1; 281 sformat = lformat = 0; 282 while ((ch = getopt(argc, argv, "ls")) != -1) { 283 switch (ch) { 284 case 'l': 285 lformat = 1; 286 break; 287 case 's': 288 sformat = 1; 289 break; 290 case '?': 291 default: 292 error("unknown option: -%c", optopt); 293 } 294 } 295 argc -= optind; 296 argv += optind; 297 298 if (argc == 0) 299 showjobs(0, sformat, lformat); 300 else 301 while ((id = *argv++) != NULL) 302 showjob(getjob(id), sformat, lformat); 303 304 return (0); 305} 306 307STATIC void 308showjob(struct job *jp, int sformat, int lformat) 309{ 310 char s[64]; 311 struct procstat *ps; 312 struct job *j; 313 int col, curr, i, jobno, prev, procno; 314 char c; 315 316 procno = jp->nprocs; 317 jobno = jp - jobtab + 1; 318 curr = prev = 0; 319#if JOBS 320 if ((j = getcurjob(NULL)) != NULL) { 321 curr = j - jobtab + 1; 322 if ((j = getcurjob(j)) != NULL) 323 prev = j - jobtab + 1; 324 } 325#endif 326 for (ps = jp->ps ; ; ps++) { /* for each process */ 327 if (sformat) { 328 out1fmt("%d\n", ps->pid); 329 goto skip; 330 } 331 if (!lformat && ps != jp->ps) 332 goto skip; 333 if (jobno == curr && ps == jp->ps) 334 c = '+'; 335 else if (jobno == prev && ps == jp->ps) 336 c = '-'; 337 else 338 c = ' '; 339 if (ps == jp->ps) 340 fmtstr(s, 64, "[%d] %c ", jobno, c); 341 else 342 fmtstr(s, 64, " %c ", c); 343 out1str(s); 344 col = strlen(s); 345 if (lformat) { 346 fmtstr(s, 64, "%d ", ps->pid); 347 out1str(s); 348 col += strlen(s); 349 } 350 s[0] = '\0'; 351 if (ps != jp->ps) { 352 *s = '\0'; 353 } else if (ps->status == -1) { 354 strcpy(s, "Running"); 355 } else if (WIFEXITED(ps->status)) { 356 fmtstr(s, 64, "Exit %d", WEXITSTATUS(ps->status)); 357 } else { 358#if JOBS 359 if (WIFSTOPPED(ps->status)) 360 i = WSTOPSIG(ps->status); 361 else 362#endif 363 i = WTERMSIG(ps->status); 364 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 365 scopy(sys_siglist[i & 0x7F], s); 366 else 367 fmtstr(s, 64, "Signal %d", i & 0x7F); 368 if (WCOREDUMP(ps->status)) 369 strcat(s, " (core dumped)"); 370 } 371 out1str(s); 372 col += strlen(s); 373 do { 374 out1c(' '); 375 col++; 376 } while (col < 30); 377 out1str(ps->cmd); 378 out1c('\n'); 379skip: if (--procno <= 0) 380 break; 381 } 382} 383 384/* 385 * Print a list of jobs. If "change" is nonzero, only print jobs whose 386 * statuses have changed since the last call to showjobs. 387 * 388 * If the shell is interrupted in the process of creating a job, the 389 * result may be a job structure containing zero processes. Such structures 390 * will be freed here. 391 */ 392 393void 394showjobs(int change, int sformat, int lformat) 395{ 396 int jobno; 397 struct job *jp; 398 399 TRACE(("showjobs(%d) called\n", change)); 400 while (dowait(0, (struct job *)NULL) > 0); 401 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 402 if (! jp->used) 403 continue; 404 if (jp->nprocs == 0) { 405 freejob(jp); 406 continue; 407 } 408 if (change && ! jp->changed) 409 continue; 410 showjob(jp, sformat, lformat); 411 jp->changed = 0; 412 if (jp->state == JOBDONE) { 413 freejob(jp); 414 } 415 } 416} 417 418 419/* 420 * Mark a job structure as unused. 421 */ 422 423STATIC void 424freejob(struct job *jp) 425{ 426 struct procstat *ps; 427 int i; 428 429 INTOFF; 430 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 431 if (ps->cmd != nullstr) 432 ckfree(ps->cmd); 433 } 434 if (jp->ps != &jp->ps0) 435 ckfree(jp->ps); 436 jp->used = 0; 437#if JOBS 438 deljob(jp); 439#endif 440 INTON; 441} 442 443 444 445int 446waitcmd(int argc, char **argv) 447{ 448 struct job *job; 449 int status, retval; 450 struct job *jp; 451 452 if (argc > 1) { 453 job = getjob(argv[1]); 454 } else { 455 job = NULL; 456 } 457 458 /* 459 * Loop until a process is terminated or stopped, or a SIGINT is 460 * received. 461 */ 462 463 in_waitcmd++; 464 do { 465 if (job != NULL) { 466 if (job->state) { 467 status = job->ps[job->nprocs - 1].status; 468 if (WIFEXITED(status)) 469 retval = WEXITSTATUS(status); 470#if JOBS 471 else if (WIFSTOPPED(status)) 472 retval = WSTOPSIG(status) + 128; 473#endif 474 else 475 retval = WTERMSIG(status) + 128; 476 if (! iflag) 477 freejob(job); 478 in_waitcmd--; 479 return retval; 480 } 481 } else { 482 for (jp = jobtab ; ; jp++) { 483 if (jp >= jobtab + njobs) { /* no running procs */ 484 in_waitcmd--; 485 return 0; 486 } 487 if (jp->used && jp->state == 0) 488 break; 489 } 490 } 491 } while (dowait(1, (struct job *)NULL) != -1); 492 in_waitcmd--; 493 494 return 0; 495} 496 497 498 499int 500jobidcmd(int argc __unused, char **argv) 501{ 502 struct job *jp; 503 int i; 504 505 jp = getjob(argv[1]); 506 for (i = 0 ; i < jp->nprocs ; ) { 507 out1fmt("%d", jp->ps[i].pid); 508 out1c(++i < jp->nprocs? ' ' : '\n'); 509 } 510 return 0; 511} 512 513 514 515/* 516 * Convert a job name to a job structure. 517 */ 518 519STATIC struct job * 520getjob(char *name) 521{ 522 int jobno; 523 struct job *found, *jp; 524 int pid; 525 int i; 526 527 if (name == NULL) { 528#if JOBS 529currentjob: if ((jp = getcurjob(NULL)) == NULL) 530 error("No current job"); 531 return (jp); 532#else 533 error("No current job"); 534#endif 535 } else if (name[0] == '%') { 536 if (is_digit(name[1])) { 537 jobno = number(name + 1); 538 if (jobno > 0 && jobno <= njobs 539 && jobtab[jobno - 1].used != 0) 540 return &jobtab[jobno - 1]; 541#if JOBS 542 } else if (name[1] == '%' && name[2] == '\0') { 543 goto currentjob; 544 } else if (name[1] == '+' && name[2] == '\0') { 545 goto currentjob; 546 } else if (name[1] == '-' && name[2] == '\0') { 547 if ((jp = getcurjob(NULL)) == NULL || 548 (jp = getcurjob(jp)) == NULL) 549 error("No previous job"); 550 return (jp); 551#endif 552 } else if (name[1] == '?') { 553 found = NULL; 554 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 555 if (jp->used && jp->nprocs > 0 556 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 557 if (found) 558 error("%s: ambiguous", name); 559 found = jp; 560 } 561 } 562 if (found != NULL) 563 return (found); 564 } else { 565 found = NULL; 566 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 567 if (jp->used && jp->nprocs > 0 568 && prefix(name + 1, jp->ps[0].cmd)) { 569 if (found) 570 error("%s: ambiguous", name); 571 found = jp; 572 } 573 } 574 if (found) 575 return found; 576 } 577 } else if (is_number(name)) { 578 pid = number(name); 579 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 580 if (jp->used && jp->nprocs > 0 581 && jp->ps[jp->nprocs - 1].pid == pid) 582 return jp; 583 } 584 } 585 error("No such job: %s", name); 586 /*NOTREACHED*/ 587 return NULL; 588} 589 590 591 592/* 593 * Return a new job structure, 594 */ 595 596struct job * 597makejob(union node *node __unused, int nprocs) 598{ 599 int i; 600 struct job *jp; 601 602 for (i = njobs, jp = jobtab ; ; jp++) { 603 if (--i < 0) { 604 INTOFF; 605 if (njobs == 0) { 606 jobtab = ckmalloc(4 * sizeof jobtab[0]); 607#if JOBS 608 jobmru = NULL; 609#endif 610 } else { 611 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 612 memcpy(jp, jobtab, njobs * sizeof jp[0]); 613#if JOBS 614 /* Relocate `next' pointers and list head */ 615 jobmru = &jp[jobmru - jobtab]; 616 for (i = 0; i < njobs; i++) 617 if (jp[i].next != NULL) 618 jp[i].next = &jp[jp[i].next - 619 jobtab]; 620#endif 621 /* Relocate `ps' pointers */ 622 for (i = 0; i < njobs; i++) 623 if (jp[i].ps == &jobtab[i].ps0) 624 jp[i].ps = &jp[i].ps0; 625 ckfree(jobtab); 626 jobtab = jp; 627 } 628 jp = jobtab + njobs; 629 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 630 INTON; 631 break; 632 } 633 if (jp->used == 0) 634 break; 635 } 636 INTOFF; 637 jp->state = 0; 638 jp->used = 1; 639 jp->changed = 0; 640 jp->nprocs = 0; 641#if JOBS 642 jp->jobctl = jobctl; 643 jp->next = NULL; 644#endif 645 if (nprocs > 1) { 646 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 647 } else { 648 jp->ps = &jp->ps0; 649 } 650 INTON; 651 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 652 jp - jobtab + 1)); 653 return jp; 654} 655 656#if JOBS 657STATIC void 658setcurjob(struct job *cj) 659{ 660 struct job *jp, *prev; 661 662 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 663 if (jp == cj) { 664 if (prev != NULL) 665 prev->next = jp->next; 666 else 667 jobmru = jp->next; 668 jp->next = jobmru; 669 jobmru = cj; 670 return; 671 } 672 } 673 cj->next = jobmru; 674 jobmru = cj; 675} 676 677STATIC void 678deljob(struct job *j) 679{ 680 struct job *jp, *prev; 681 682 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 683 if (jp == j) { 684 if (prev != NULL) 685 prev->next = jp->next; 686 else 687 jobmru = jp->next; 688 return; 689 } 690 } 691} 692 693/* 694 * Return the most recently used job that isn't `nj', and preferably one 695 * that is stopped. 696 */ 697STATIC struct job * 698getcurjob(struct job *nj) 699{ 700 struct job *jp; 701 702 /* Try to find a stopped one.. */ 703 for (jp = jobmru; jp != NULL; jp = jp->next) 704 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 705 return (jp); 706 /* Otherwise the most recently used job that isn't `nj' */ 707 for (jp = jobmru; jp != NULL; jp = jp->next) 708 if (jp->used && jp != nj) 709 return (jp); 710 711 return (NULL); 712} 713 714#endif 715 716/* 717 * Fork of a subshell. If we are doing job control, give the subshell its 718 * own process group. Jp is a job structure that the job is to be added to. 719 * N is the command that will be evaluated by the child. Both jp and n may 720 * be NULL. The mode parameter can be one of the following: 721 * FORK_FG - Fork off a foreground process. 722 * FORK_BG - Fork off a background process. 723 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 724 * process group even if job control is on. 725 * 726 * When job control is turned off, background processes have their standard 727 * input redirected to /dev/null (except for the second and later processes 728 * in a pipeline). 729 */ 730 731int 732forkshell(struct job *jp, union node *n, int mode) 733{ 734 int pid; 735 int pgrp; 736 737 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 738 mode)); 739 INTOFF; 740 pid = fork(); 741 if (pid == -1) { 742 TRACE(("Fork failed, errno=%d\n", errno)); 743 INTON; 744 error("Cannot fork: %s", strerror(errno)); 745 } 746 if (pid == 0) { 747 struct job *p; 748 int wasroot; 749 int i; 750 751 TRACE(("Child shell %d\n", getpid())); 752 wasroot = rootshell; 753 rootshell = 0; 754 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 755 if (p->used) 756 freejob(p); 757 closescript(); 758 INTON; 759 clear_traps(); 760#if JOBS 761 jobctl = 0; /* do job control only in root shell */ 762 if (wasroot && mode != FORK_NOJOB && mflag) { 763 if (jp == NULL || jp->nprocs == 0) 764 pgrp = getpid(); 765 else 766 pgrp = jp->ps[0].pid; 767 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 768 /*** this causes superfluous TIOCSPGRPS ***/ 769#ifdef OLD_TTY_DRIVER 770 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 771 error("TIOCSPGRP failed, errno=%d", errno); 772#else 773 if (tcsetpgrp(2, pgrp) < 0) 774 error("tcsetpgrp failed, errno=%d", errno); 775#endif 776 } 777 setsignal(SIGTSTP); 778 setsignal(SIGTTOU); 779 } else if (mode == FORK_BG) { 780 ignoresig(SIGINT); 781 ignoresig(SIGQUIT); 782 if ((jp == NULL || jp->nprocs == 0) && 783 ! fd0_redirected_p ()) { 784 close(0); 785 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 786 error("Can't open %s: %s", 787 _PATH_DEVNULL, strerror(errno)); 788 } 789 } 790#else 791 if (mode == FORK_BG) { 792 ignoresig(SIGINT); 793 ignoresig(SIGQUIT); 794 if ((jp == NULL || jp->nprocs == 0) && 795 ! fd0_redirected_p ()) { 796 close(0); 797 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 798 error("Can't open %s: %s", 799 _PATH_DEVNULL, strerror(errno)); 800 } 801 } 802#endif 803 if (wasroot && iflag) { 804 setsignal(SIGINT); 805 setsignal(SIGQUIT); 806 setsignal(SIGTERM); 807 } 808 return pid; 809 } 810 if (rootshell && mode != FORK_NOJOB && mflag) { 811 if (jp == NULL || jp->nprocs == 0) 812 pgrp = pid; 813 else 814 pgrp = jp->ps[0].pid; 815 setpgid(pid, pgrp); 816 } 817 if (mode == FORK_BG) 818 backgndpid = pid; /* set $! */ 819 if (jp) { 820 struct procstat *ps = &jp->ps[jp->nprocs++]; 821 ps->pid = pid; 822 ps->status = -1; 823 ps->cmd = nullstr; 824 if (iflag && rootshell && n) 825 ps->cmd = commandtext(n); 826#if JOBS 827 setcurjob(jp); 828#endif 829 } 830 INTON; 831 TRACE(("In parent shell: child = %d\n", pid)); 832 return pid; 833} 834 835 836 837/* 838 * Wait for job to finish. 839 * 840 * Under job control we have the problem that while a child process is 841 * running interrupts generated by the user are sent to the child but not 842 * to the shell. This means that an infinite loop started by an inter- 843 * active user may be hard to kill. With job control turned off, an 844 * interactive user may place an interactive program inside a loop. If 845 * the interactive program catches interrupts, the user doesn't want 846 * these interrupts to also abort the loop. The approach we take here 847 * is to have the shell ignore interrupt signals while waiting for a 848 * foreground process to terminate, and then send itself an interrupt 849 * signal if the child process was terminated by an interrupt signal. 850 * Unfortunately, some programs want to do a bit of cleanup and then 851 * exit on interrupt; unless these processes terminate themselves by 852 * sending a signal to themselves (instead of calling exit) they will 853 * confuse this approach. 854 */ 855 856int 857waitforjob(struct job *jp, int *origstatus) 858{ 859#if JOBS 860 int mypgrp = getpgrp(); 861#endif 862 int status; 863 int st; 864 865 INTOFF; 866 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 867 while (jp->state == 0) 868 if (dowait(1, jp) == -1) 869 dotrap(); 870#if JOBS 871 if (jp->jobctl) { 872#ifdef OLD_TTY_DRIVER 873 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 874 error("TIOCSPGRP failed, errno=%d\n", errno); 875#else 876 if (tcsetpgrp(2, mypgrp) < 0) 877 error("tcsetpgrp failed, errno=%d\n", errno); 878#endif 879 } 880 if (jp->state == JOBSTOPPED) 881 setcurjob(jp); 882#endif 883 status = jp->ps[jp->nprocs - 1].status; 884 if (origstatus != NULL) 885 *origstatus = status; 886 /* convert to 8 bits */ 887 if (WIFEXITED(status)) 888 st = WEXITSTATUS(status); 889#if JOBS 890 else if (WIFSTOPPED(status)) 891 st = WSTOPSIG(status) + 128; 892#endif 893 else 894 st = WTERMSIG(status) + 128; 895 if (! JOBS || jp->state == JOBDONE) 896 freejob(jp); 897 if (int_pending()) { 898 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 899 kill(getpid(), SIGINT); 900 else 901 CLEAR_PENDING_INT; 902 } 903 INTON; 904 return st; 905} 906 907 908 909/* 910 * Wait for a process to terminate. 911 */ 912 913STATIC int 914dowait(int block, struct job *job) 915{ 916 int pid; 917 int status; 918 struct procstat *sp; 919 struct job *jp; 920 struct job *thisjob; 921 int done; 922 int stopped; 923 int core; 924 int sig; 925 926 in_dowait++; 927 TRACE(("dowait(%d) called\n", block)); 928 do { 929 pid = waitproc(block, &status); 930 TRACE(("wait returns %d, status=%d\n", pid, status)); 931 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 932 (WIFSTOPPED(status) && !iflag)); 933 in_dowait--; 934 if (breakwaitcmd != 0) { 935 breakwaitcmd = 0; 936 return -1; 937 } 938 if (pid <= 0) 939 return pid; 940 INTOFF; 941 thisjob = NULL; 942 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 943 if (jp->used) { 944 done = 1; 945 stopped = 1; 946 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 947 if (sp->pid == -1) 948 continue; 949 if (sp->pid == pid) { 950 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 951 pid, sp->status, status)); 952 sp->status = status; 953 thisjob = jp; 954 } 955 if (sp->status == -1) 956 stopped = 0; 957 else if (WIFSTOPPED(sp->status)) 958 done = 0; 959 } 960 if (stopped) { /* stopped or done */ 961 int state = done? JOBDONE : JOBSTOPPED; 962 if (jp->state != state) { 963 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 964 jp->state = state; 965#if JOBS 966 if (done) 967 deljob(jp); 968#endif 969 } 970 } 971 } 972 } 973 INTON; 974 if (! rootshell || ! iflag || (job && thisjob == job)) { 975#if JOBS 976 if (WIFSTOPPED(status)) 977 sig = WSTOPSIG(status); 978 else 979#endif 980 { 981 if (WIFEXITED(status)) 982 sig = 0; 983 else 984 sig = WTERMSIG(status); 985 } 986 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) 987 showjob(thisjob, 0, 0); 988 } else { 989 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 990 if (thisjob) 991 thisjob->changed = 1; 992 } 993 return pid; 994} 995 996 997 998/* 999 * Do a wait system call. If job control is compiled in, we accept 1000 * stopped processes. If block is zero, we return a value of zero 1001 * rather than blocking. 1002 * 1003 * System V doesn't have a non-blocking wait system call. It does 1004 * have a SIGCLD signal that is sent to a process when one of it's 1005 * children dies. The obvious way to use SIGCLD would be to install 1006 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 1007 * was received, and have waitproc bump another counter when it got 1008 * the status of a process. Waitproc would then know that a wait 1009 * system call would not block if the two counters were different. 1010 * This approach doesn't work because if a process has children that 1011 * have not been waited for, System V will send it a SIGCLD when it 1012 * installs a signal handler for SIGCLD. What this means is that when 1013 * a child exits, the shell will be sent SIGCLD signals continuously 1014 * until is runs out of stack space, unless it does a wait call before 1015 * restoring the signal handler. The code below takes advantage of 1016 * this (mis)feature by installing a signal handler for SIGCLD and 1017 * then checking to see whether it was called. If there are any 1018 * children to be waited for, it will be. 1019 * 1020 * If neither SYSV nor BSD is defined, we don't implement nonblocking 1021 * waits at all. In this case, the user will not be informed when 1022 * a background process until the next time she runs a real program 1023 * (as opposed to running a builtin command or just typing return), 1024 * and the jobs command may give out of date information. 1025 */ 1026 1027#ifdef SYSV 1028STATIC sig_atomic_t gotsigchild; 1029 1030STATIC int onsigchild() { 1031 gotsigchild = 1; 1032} 1033#endif 1034 1035 1036STATIC int 1037waitproc(int block, int *status) 1038{ 1039#ifdef BSD 1040 int flags; 1041 1042#if JOBS 1043 flags = WUNTRACED; 1044#else 1045 flags = 0; 1046#endif 1047 if (block == 0) 1048 flags |= WNOHANG; 1049 return wait3(status, flags, (struct rusage *)NULL); 1050#else 1051#ifdef SYSV 1052 int (*save)(); 1053 1054 if (block == 0) { 1055 gotsigchild = 0; 1056 save = signal(SIGCLD, onsigchild); 1057 signal(SIGCLD, save); 1058 if (gotsigchild == 0) 1059 return 0; 1060 } 1061 return wait(status); 1062#else 1063 if (block == 0) 1064 return 0; 1065 return wait(status); 1066#endif 1067#endif 1068} 1069 1070/* 1071 * return 1 if there are stopped jobs, otherwise 0 1072 */ 1073int job_warning = 0; 1074int 1075stoppedjobs(void) 1076{ 1077 int jobno; 1078 struct job *jp; 1079 1080 if (job_warning) 1081 return (0); 1082 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1083 if (jp->used == 0) 1084 continue; 1085 if (jp->state == JOBSTOPPED) { 1086 out2str("You have stopped jobs.\n"); 1087 job_warning = 2; 1088 return (1); 1089 } 1090 } 1091 1092 return (0); 1093} 1094 1095/* 1096 * Return a string identifying a command (to be printed by the 1097 * jobs command. 1098 */ 1099 1100STATIC char *cmdnextc; 1101STATIC int cmdnleft; 1102#define MAXCMDTEXT 200 1103 1104char * 1105commandtext(union node *n) 1106{ 1107 char *name; 1108 1109 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1110 cmdnleft = MAXCMDTEXT - 4; 1111 cmdtxt(n); 1112 *cmdnextc = '\0'; 1113 return name; 1114} 1115 1116 1117STATIC void 1118cmdtxt(union node *n) 1119{ 1120 union node *np; 1121 struct nodelist *lp; 1122 char *p; 1123 int i; 1124 char s[2]; 1125 1126 if (n == NULL) 1127 return; 1128 switch (n->type) { 1129 case NSEMI: 1130 cmdtxt(n->nbinary.ch1); 1131 cmdputs("; "); 1132 cmdtxt(n->nbinary.ch2); 1133 break; 1134 case NAND: 1135 cmdtxt(n->nbinary.ch1); 1136 cmdputs(" && "); 1137 cmdtxt(n->nbinary.ch2); 1138 break; 1139 case NOR: 1140 cmdtxt(n->nbinary.ch1); 1141 cmdputs(" || "); 1142 cmdtxt(n->nbinary.ch2); 1143 break; 1144 case NPIPE: 1145 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1146 cmdtxt(lp->n); 1147 if (lp->next) 1148 cmdputs(" | "); 1149 } 1150 break; 1151 case NSUBSHELL: 1152 cmdputs("("); 1153 cmdtxt(n->nredir.n); 1154 cmdputs(")"); 1155 break; 1156 case NREDIR: 1157 case NBACKGND: 1158 cmdtxt(n->nredir.n); 1159 break; 1160 case NIF: 1161 cmdputs("if "); 1162 cmdtxt(n->nif.test); 1163 cmdputs("; then "); 1164 cmdtxt(n->nif.ifpart); 1165 cmdputs("..."); 1166 break; 1167 case NWHILE: 1168 cmdputs("while "); 1169 goto until; 1170 case NUNTIL: 1171 cmdputs("until "); 1172until: 1173 cmdtxt(n->nbinary.ch1); 1174 cmdputs("; do "); 1175 cmdtxt(n->nbinary.ch2); 1176 cmdputs("; done"); 1177 break; 1178 case NFOR: 1179 cmdputs("for "); 1180 cmdputs(n->nfor.var); 1181 cmdputs(" in ..."); 1182 break; 1183 case NCASE: 1184 cmdputs("case "); 1185 cmdputs(n->ncase.expr->narg.text); 1186 cmdputs(" in ..."); 1187 break; 1188 case NDEFUN: 1189 cmdputs(n->narg.text); 1190 cmdputs("() ..."); 1191 break; 1192 case NCMD: 1193 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1194 cmdtxt(np); 1195 if (np->narg.next) 1196 cmdputs(" "); 1197 } 1198 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1199 cmdputs(" "); 1200 cmdtxt(np); 1201 } 1202 break; 1203 case NARG: 1204 cmdputs(n->narg.text); 1205 break; 1206 case NTO: 1207 p = ">"; i = 1; goto redir; 1208 case NAPPEND: 1209 p = ">>"; i = 1; goto redir; 1210 case NTOFD: 1211 p = ">&"; i = 1; goto redir; 1212 case NCLOBBER: 1213 p = ">|"; i = 1; goto redir; 1214 case NFROM: 1215 p = "<"; i = 0; goto redir; 1216 case NFROMTO: 1217 p = "<>"; i = 0; goto redir; 1218 case NFROMFD: 1219 p = "<&"; i = 0; goto redir; 1220redir: 1221 if (n->nfile.fd != i) { 1222 s[0] = n->nfile.fd + '0'; 1223 s[1] = '\0'; 1224 cmdputs(s); 1225 } 1226 cmdputs(p); 1227 if (n->type == NTOFD || n->type == NFROMFD) { 1228 s[0] = n->ndup.dupfd + '0'; 1229 s[1] = '\0'; 1230 cmdputs(s); 1231 } else { 1232 cmdtxt(n->nfile.fname); 1233 } 1234 break; 1235 case NHERE: 1236 case NXHERE: 1237 cmdputs("<<..."); 1238 break; 1239 default: 1240 cmdputs("???"); 1241 break; 1242 } 1243} 1244 1245 1246 1247STATIC void 1248cmdputs(char *s) 1249{ 1250 char *p, *q; 1251 char c; 1252 int subtype = 0; 1253 1254 if (cmdnleft <= 0) 1255 return; 1256 p = s; 1257 q = cmdnextc; 1258 while ((c = *p++) != '\0') { 1259 if (c == CTLESC) 1260 *q++ = *p++; 1261 else if (c == CTLVAR) { 1262 *q++ = '$'; 1263 if (--cmdnleft > 0) 1264 *q++ = '{'; 1265 subtype = *p++; 1266 } else if (c == '=' && subtype != 0) { 1267 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1268 subtype = 0; 1269 } else if (c == CTLENDVAR) { 1270 *q++ = '}'; 1271 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1272 cmdnleft++; /* ignore it */ 1273 else 1274 *q++ = c; 1275 if (--cmdnleft <= 0) { 1276 *q++ = '.'; 1277 *q++ = '.'; 1278 *q++ = '.'; 1279 break; 1280 } 1281 } 1282 cmdnextc = q; 1283} 1284