jobs.c revision 97664
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 97664 2002-05-31 13:10:38Z 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 *); 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 __unused, char **argv __unused) 275{ 276 showjobs(0); 277 return 0; 278} 279 280STATIC void 281showjob(struct job *jp) 282{ 283 char s[64]; 284 struct procstat *ps; 285 int col, i, jobno, procno; 286 287 procno = jp->nprocs; 288 jobno = jp - jobtab + 1; 289 for (ps = jp->ps ; ; ps++) { /* for each process */ 290 if (ps == jp->ps) 291 fmtstr(s, 64, "[%d] %d ", jobno, ps->pid); 292 else 293 fmtstr(s, 64, " %d ", ps->pid); 294 out1str(s); 295 col = strlen(s); 296 s[0] = '\0'; 297 if (ps->status == -1) { 298 /* don't print anything */ 299 } else if (WIFEXITED(ps->status)) { 300 fmtstr(s, 64, "Exit %d", WEXITSTATUS(ps->status)); 301 } else { 302#if JOBS 303 if (WIFSTOPPED(ps->status)) 304 i = WSTOPSIG(ps->status); 305 else 306#endif 307 i = WTERMSIG(ps->status); 308 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 309 scopy(sys_siglist[i & 0x7F], s); 310 else 311 fmtstr(s, 64, "Signal %d", i & 0x7F); 312 if (WCOREDUMP(ps->status)) 313 strcat(s, " (core dumped)"); 314 } 315 out1str(s); 316 col += strlen(s); 317 do { 318 out1c(' '); 319 col++; 320 } while (col < 30); 321 out1str(ps->cmd); 322 out1c('\n'); 323 if (--procno <= 0) 324 break; 325 } 326} 327 328/* 329 * Print a list of jobs. If "change" is nonzero, only print jobs whose 330 * statuses have changed since the last call to showjobs. 331 * 332 * If the shell is interrupted in the process of creating a job, the 333 * result may be a job structure containing zero processes. Such structures 334 * will be freed here. 335 */ 336 337void 338showjobs(int change) 339{ 340 int jobno; 341 struct job *jp; 342 343 TRACE(("showjobs(%d) called\n", change)); 344 while (dowait(0, (struct job *)NULL) > 0); 345 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 346 if (! jp->used) 347 continue; 348 if (jp->nprocs == 0) { 349 freejob(jp); 350 continue; 351 } 352 if (change && ! jp->changed) 353 continue; 354 showjob(jp); 355 jp->changed = 0; 356 if (jp->state == JOBDONE) { 357 freejob(jp); 358 } 359 } 360} 361 362 363/* 364 * Mark a job structure as unused. 365 */ 366 367STATIC void 368freejob(struct job *jp) 369{ 370 struct procstat *ps; 371 int i; 372 373 INTOFF; 374 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 375 if (ps->cmd != nullstr) 376 ckfree(ps->cmd); 377 } 378 if (jp->ps != &jp->ps0) 379 ckfree(jp->ps); 380 jp->used = 0; 381#if JOBS 382 deljob(jp); 383#endif 384 INTON; 385} 386 387 388 389int 390waitcmd(int argc, char **argv) 391{ 392 struct job *job; 393 int status, retval; 394 struct job *jp; 395 396 if (argc > 1) { 397 job = getjob(argv[1]); 398 } else { 399 job = NULL; 400 } 401 402 /* 403 * Loop until a process is terminated or stopped, or a SIGINT is 404 * received. 405 */ 406 407 in_waitcmd++; 408 do { 409 if (job != NULL) { 410 if (job->state) { 411 status = job->ps[job->nprocs - 1].status; 412 if (WIFEXITED(status)) 413 retval = WEXITSTATUS(status); 414#if JOBS 415 else if (WIFSTOPPED(status)) 416 retval = WSTOPSIG(status) + 128; 417#endif 418 else 419 retval = WTERMSIG(status) + 128; 420 if (! iflag) 421 freejob(job); 422 in_waitcmd--; 423 return retval; 424 } 425 } else { 426 for (jp = jobtab ; ; jp++) { 427 if (jp >= jobtab + njobs) { /* no running procs */ 428 in_waitcmd--; 429 return 0; 430 } 431 if (jp->used && jp->state == 0) 432 break; 433 } 434 } 435 } while (dowait(1, (struct job *)NULL) != -1); 436 in_waitcmd--; 437 438 return 0; 439} 440 441 442 443int 444jobidcmd(int argc __unused, char **argv) 445{ 446 struct job *jp; 447 int i; 448 449 jp = getjob(argv[1]); 450 for (i = 0 ; i < jp->nprocs ; ) { 451 out1fmt("%d", jp->ps[i].pid); 452 out1c(++i < jp->nprocs? ' ' : '\n'); 453 } 454 return 0; 455} 456 457 458 459/* 460 * Convert a job name to a job structure. 461 */ 462 463STATIC struct job * 464getjob(char *name) 465{ 466 int jobno; 467 struct job *jp; 468 int pid; 469 int i; 470 471 if (name == NULL) { 472#if JOBS 473currentjob: if ((jp = getcurjob(NULL)) == NULL) 474 error("No current job"); 475 return (jp); 476#else 477 error("No current job"); 478#endif 479 } else if (name[0] == '%') { 480 if (is_digit(name[1])) { 481 jobno = number(name + 1); 482 if (jobno > 0 && jobno <= njobs 483 && jobtab[jobno - 1].used != 0) 484 return &jobtab[jobno - 1]; 485#if JOBS 486 } else if (name[1] == '%' && name[2] == '\0') { 487 goto currentjob; 488#endif 489 } else { 490 struct job *found = NULL; 491 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 492 if (jp->used && jp->nprocs > 0 493 && prefix(name + 1, jp->ps[0].cmd)) { 494 if (found) 495 error("%s: ambiguous", name); 496 found = jp; 497 } 498 } 499 if (found) 500 return found; 501 } 502 } else if (is_number(name)) { 503 pid = number(name); 504 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 505 if (jp->used && jp->nprocs > 0 506 && jp->ps[jp->nprocs - 1].pid == pid) 507 return jp; 508 } 509 } 510 error("No such job: %s", name); 511 /*NOTREACHED*/ 512 return NULL; 513} 514 515 516 517/* 518 * Return a new job structure, 519 */ 520 521struct job * 522makejob(union node *node __unused, int nprocs) 523{ 524 int i; 525 struct job *jp; 526 527 for (i = njobs, jp = jobtab ; ; jp++) { 528 if (--i < 0) { 529 INTOFF; 530 if (njobs == 0) { 531 jobtab = ckmalloc(4 * sizeof jobtab[0]); 532#if JOBS 533 jobmru = NULL; 534#endif 535 } else { 536 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 537 memcpy(jp, jobtab, njobs * sizeof jp[0]); 538#if JOBS 539 /* Relocate `next' pointers and list head */ 540 jobmru = &jp[jobmru - jobtab]; 541 for (i = 0; i < njobs; i++) 542 if (jp[i].next != NULL) 543 jp[i].next = &jp[jp[i].next - 544 jobtab]; 545#endif 546 /* Relocate `ps' pointers */ 547 for (i = 0; i < njobs; i++) 548 if (jp[i].ps == &jobtab[i].ps0) 549 jp[i].ps = &jp[i].ps0; 550 ckfree(jobtab); 551 jobtab = jp; 552 } 553 jp = jobtab + njobs; 554 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 555 INTON; 556 break; 557 } 558 if (jp->used == 0) 559 break; 560 } 561 INTOFF; 562 jp->state = 0; 563 jp->used = 1; 564 jp->changed = 0; 565 jp->nprocs = 0; 566#if JOBS 567 jp->jobctl = jobctl; 568 jp->next = NULL; 569#endif 570 if (nprocs > 1) { 571 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 572 } else { 573 jp->ps = &jp->ps0; 574 } 575 INTON; 576 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 577 jp - jobtab + 1)); 578 return jp; 579} 580 581#if JOBS 582STATIC void 583setcurjob(struct job *cj) 584{ 585 struct job *jp, *prev; 586 587 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 588 if (jp == cj) { 589 if (prev != NULL) 590 prev->next = jp->next; 591 else 592 jobmru = jp->next; 593 jp->next = jobmru; 594 jobmru = cj; 595 return; 596 } 597 } 598 cj->next = jobmru; 599 jobmru = cj; 600} 601 602STATIC void 603deljob(struct job *j) 604{ 605 struct job *jp, *prev; 606 607 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 608 if (jp == j) { 609 if (prev != NULL) 610 prev->next = jp->next; 611 else 612 jobmru = jp->next; 613 return; 614 } 615 } 616} 617 618/* 619 * Return the most recently used job that isn't `nj', and preferably one 620 * that is stopped. 621 */ 622STATIC struct job * 623getcurjob(struct job *nj) 624{ 625 struct job *jp; 626 627 /* Try to find a stopped one.. */ 628 for (jp = jobmru; jp != NULL; jp = jp->next) 629 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 630 return (jp); 631 /* Otherwise the most recently used job that isn't `nj' */ 632 for (jp = jobmru; jp != NULL; jp = jp->next) 633 if (jp->used && jp != nj) 634 return (jp); 635 636 return (NULL); 637} 638 639#endif 640 641/* 642 * Fork of a subshell. If we are doing job control, give the subshell its 643 * own process group. Jp is a job structure that the job is to be added to. 644 * N is the command that will be evaluated by the child. Both jp and n may 645 * be NULL. The mode parameter can be one of the following: 646 * FORK_FG - Fork off a foreground process. 647 * FORK_BG - Fork off a background process. 648 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 649 * process group even if job control is on. 650 * 651 * When job control is turned off, background processes have their standard 652 * input redirected to /dev/null (except for the second and later processes 653 * in a pipeline). 654 */ 655 656int 657forkshell(struct job *jp, union node *n, int mode) 658{ 659 int pid; 660 int pgrp; 661 662 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 663 mode)); 664 INTOFF; 665 pid = fork(); 666 if (pid == -1) { 667 TRACE(("Fork failed, errno=%d\n", errno)); 668 INTON; 669 error("Cannot fork: %s", strerror(errno)); 670 } 671 if (pid == 0) { 672 struct job *p; 673 int wasroot; 674 int i; 675 676 TRACE(("Child shell %d\n", getpid())); 677 wasroot = rootshell; 678 rootshell = 0; 679 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 680 if (p->used) 681 freejob(p); 682 closescript(); 683 INTON; 684 clear_traps(); 685#if JOBS 686 jobctl = 0; /* do job control only in root shell */ 687 if (wasroot && mode != FORK_NOJOB && mflag) { 688 if (jp == NULL || jp->nprocs == 0) 689 pgrp = getpid(); 690 else 691 pgrp = jp->ps[0].pid; 692 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 693 /*** this causes superfluous TIOCSPGRPS ***/ 694#ifdef OLD_TTY_DRIVER 695 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 696 error("TIOCSPGRP failed, errno=%d", errno); 697#else 698 if (tcsetpgrp(2, pgrp) < 0) 699 error("tcsetpgrp failed, errno=%d", errno); 700#endif 701 } 702 setsignal(SIGTSTP); 703 setsignal(SIGTTOU); 704 } else if (mode == FORK_BG) { 705 ignoresig(SIGINT); 706 ignoresig(SIGQUIT); 707 if ((jp == NULL || jp->nprocs == 0) && 708 ! fd0_redirected_p ()) { 709 close(0); 710 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 711 error("Can't open %s: %s", 712 _PATH_DEVNULL, strerror(errno)); 713 } 714 } 715#else 716 if (mode == FORK_BG) { 717 ignoresig(SIGINT); 718 ignoresig(SIGQUIT); 719 if ((jp == NULL || jp->nprocs == 0) && 720 ! fd0_redirected_p ()) { 721 close(0); 722 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 723 error("Can't open %s: %s", 724 _PATH_DEVNULL, strerror(errno)); 725 } 726 } 727#endif 728 if (wasroot && iflag) { 729 setsignal(SIGINT); 730 setsignal(SIGQUIT); 731 setsignal(SIGTERM); 732 } 733 return pid; 734 } 735 if (rootshell && mode != FORK_NOJOB && mflag) { 736 if (jp == NULL || jp->nprocs == 0) 737 pgrp = pid; 738 else 739 pgrp = jp->ps[0].pid; 740 setpgid(pid, pgrp); 741 } 742 if (mode == FORK_BG) 743 backgndpid = pid; /* set $! */ 744 if (jp) { 745 struct procstat *ps = &jp->ps[jp->nprocs++]; 746 ps->pid = pid; 747 ps->status = -1; 748 ps->cmd = nullstr; 749 if (iflag && rootshell && n) 750 ps->cmd = commandtext(n); 751#if JOBS 752 setcurjob(jp); 753#endif 754 } 755 INTON; 756 TRACE(("In parent shell: child = %d\n", pid)); 757 return pid; 758} 759 760 761 762/* 763 * Wait for job to finish. 764 * 765 * Under job control we have the problem that while a child process is 766 * running interrupts generated by the user are sent to the child but not 767 * to the shell. This means that an infinite loop started by an inter- 768 * active user may be hard to kill. With job control turned off, an 769 * interactive user may place an interactive program inside a loop. If 770 * the interactive program catches interrupts, the user doesn't want 771 * these interrupts to also abort the loop. The approach we take here 772 * is to have the shell ignore interrupt signals while waiting for a 773 * foreground process to terminate, and then send itself an interrupt 774 * signal if the child process was terminated by an interrupt signal. 775 * Unfortunately, some programs want to do a bit of cleanup and then 776 * exit on interrupt; unless these processes terminate themselves by 777 * sending a signal to themselves (instead of calling exit) they will 778 * confuse this approach. 779 */ 780 781int 782waitforjob(struct job *jp, int *origstatus) 783{ 784#if JOBS 785 int mypgrp = getpgrp(); 786#endif 787 int status; 788 int st; 789 790 INTOFF; 791 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 792 while (jp->state == 0) 793 if (dowait(1, jp) == -1) 794 dotrap(); 795#if JOBS 796 if (jp->jobctl) { 797#ifdef OLD_TTY_DRIVER 798 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 799 error("TIOCSPGRP failed, errno=%d\n", errno); 800#else 801 if (tcsetpgrp(2, mypgrp) < 0) 802 error("tcsetpgrp failed, errno=%d\n", errno); 803#endif 804 } 805 if (jp->state == JOBSTOPPED) 806 setcurjob(jp); 807#endif 808 status = jp->ps[jp->nprocs - 1].status; 809 if (origstatus != NULL) 810 *origstatus = status; 811 /* convert to 8 bits */ 812 if (WIFEXITED(status)) 813 st = WEXITSTATUS(status); 814#if JOBS 815 else if (WIFSTOPPED(status)) 816 st = WSTOPSIG(status) + 128; 817#endif 818 else 819 st = WTERMSIG(status) + 128; 820 if (! JOBS || jp->state == JOBDONE) 821 freejob(jp); 822 if (int_pending()) { 823 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 824 kill(getpid(), SIGINT); 825 else 826 CLEAR_PENDING_INT; 827 } 828 INTON; 829 return st; 830} 831 832 833 834/* 835 * Wait for a process to terminate. 836 */ 837 838STATIC int 839dowait(int block, struct job *job) 840{ 841 int pid; 842 int status; 843 struct procstat *sp; 844 struct job *jp; 845 struct job *thisjob; 846 int done; 847 int stopped; 848 int core; 849 int sig; 850 851 in_dowait++; 852 TRACE(("dowait(%d) called\n", block)); 853 do { 854 pid = waitproc(block, &status); 855 TRACE(("wait returns %d, status=%d\n", pid, status)); 856 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 857 (WIFSTOPPED(status) && !iflag)); 858 in_dowait--; 859 if (breakwaitcmd != 0) { 860 breakwaitcmd = 0; 861 return -1; 862 } 863 if (pid <= 0) 864 return pid; 865 INTOFF; 866 thisjob = NULL; 867 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 868 if (jp->used) { 869 done = 1; 870 stopped = 1; 871 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 872 if (sp->pid == -1) 873 continue; 874 if (sp->pid == pid) { 875 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 876 pid, sp->status, status)); 877 sp->status = status; 878 thisjob = jp; 879 } 880 if (sp->status == -1) 881 stopped = 0; 882 else if (WIFSTOPPED(sp->status)) 883 done = 0; 884 } 885 if (stopped) { /* stopped or done */ 886 int state = done? JOBDONE : JOBSTOPPED; 887 if (jp->state != state) { 888 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 889 jp->state = state; 890#if JOBS 891 if (done) 892 deljob(jp); 893#endif 894 } 895 } 896 } 897 } 898 INTON; 899 if (! rootshell || ! iflag || (job && thisjob == job)) { 900#if JOBS 901 if (WIFSTOPPED(status)) 902 sig = WSTOPSIG(status); 903 else 904#endif 905 { 906 if (WIFEXITED(status)) 907 sig = 0; 908 else 909 sig = WTERMSIG(status); 910 } 911 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) 912 showjob(thisjob); 913 } else { 914 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 915 if (thisjob) 916 thisjob->changed = 1; 917 } 918 return pid; 919} 920 921 922 923/* 924 * Do a wait system call. If job control is compiled in, we accept 925 * stopped processes. If block is zero, we return a value of zero 926 * rather than blocking. 927 * 928 * System V doesn't have a non-blocking wait system call. It does 929 * have a SIGCLD signal that is sent to a process when one of it's 930 * children dies. The obvious way to use SIGCLD would be to install 931 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 932 * was received, and have waitproc bump another counter when it got 933 * the status of a process. Waitproc would then know that a wait 934 * system call would not block if the two counters were different. 935 * This approach doesn't work because if a process has children that 936 * have not been waited for, System V will send it a SIGCLD when it 937 * installs a signal handler for SIGCLD. What this means is that when 938 * a child exits, the shell will be sent SIGCLD signals continuously 939 * until is runs out of stack space, unless it does a wait call before 940 * restoring the signal handler. The code below takes advantage of 941 * this (mis)feature by installing a signal handler for SIGCLD and 942 * then checking to see whether it was called. If there are any 943 * children to be waited for, it will be. 944 * 945 * If neither SYSV nor BSD is defined, we don't implement nonblocking 946 * waits at all. In this case, the user will not be informed when 947 * a background process until the next time she runs a real program 948 * (as opposed to running a builtin command or just typing return), 949 * and the jobs command may give out of date information. 950 */ 951 952#ifdef SYSV 953STATIC sig_atomic_t gotsigchild; 954 955STATIC int onsigchild() { 956 gotsigchild = 1; 957} 958#endif 959 960 961STATIC int 962waitproc(int block, int *status) 963{ 964#ifdef BSD 965 int flags; 966 967#if JOBS 968 flags = WUNTRACED; 969#else 970 flags = 0; 971#endif 972 if (block == 0) 973 flags |= WNOHANG; 974 return wait3(status, flags, (struct rusage *)NULL); 975#else 976#ifdef SYSV 977 int (*save)(); 978 979 if (block == 0) { 980 gotsigchild = 0; 981 save = signal(SIGCLD, onsigchild); 982 signal(SIGCLD, save); 983 if (gotsigchild == 0) 984 return 0; 985 } 986 return wait(status); 987#else 988 if (block == 0) 989 return 0; 990 return wait(status); 991#endif 992#endif 993} 994 995/* 996 * return 1 if there are stopped jobs, otherwise 0 997 */ 998int job_warning = 0; 999int 1000stoppedjobs(void) 1001{ 1002 int jobno; 1003 struct job *jp; 1004 1005 if (job_warning) 1006 return (0); 1007 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1008 if (jp->used == 0) 1009 continue; 1010 if (jp->state == JOBSTOPPED) { 1011 out2str("You have stopped jobs.\n"); 1012 job_warning = 2; 1013 return (1); 1014 } 1015 } 1016 1017 return (0); 1018} 1019 1020/* 1021 * Return a string identifying a command (to be printed by the 1022 * jobs command. 1023 */ 1024 1025STATIC char *cmdnextc; 1026STATIC int cmdnleft; 1027#define MAXCMDTEXT 200 1028 1029char * 1030commandtext(union node *n) 1031{ 1032 char *name; 1033 1034 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1035 cmdnleft = MAXCMDTEXT - 4; 1036 cmdtxt(n); 1037 *cmdnextc = '\0'; 1038 return name; 1039} 1040 1041 1042STATIC void 1043cmdtxt(union node *n) 1044{ 1045 union node *np; 1046 struct nodelist *lp; 1047 char *p; 1048 int i; 1049 char s[2]; 1050 1051 if (n == NULL) 1052 return; 1053 switch (n->type) { 1054 case NSEMI: 1055 cmdtxt(n->nbinary.ch1); 1056 cmdputs("; "); 1057 cmdtxt(n->nbinary.ch2); 1058 break; 1059 case NAND: 1060 cmdtxt(n->nbinary.ch1); 1061 cmdputs(" && "); 1062 cmdtxt(n->nbinary.ch2); 1063 break; 1064 case NOR: 1065 cmdtxt(n->nbinary.ch1); 1066 cmdputs(" || "); 1067 cmdtxt(n->nbinary.ch2); 1068 break; 1069 case NPIPE: 1070 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1071 cmdtxt(lp->n); 1072 if (lp->next) 1073 cmdputs(" | "); 1074 } 1075 break; 1076 case NSUBSHELL: 1077 cmdputs("("); 1078 cmdtxt(n->nredir.n); 1079 cmdputs(")"); 1080 break; 1081 case NREDIR: 1082 case NBACKGND: 1083 cmdtxt(n->nredir.n); 1084 break; 1085 case NIF: 1086 cmdputs("if "); 1087 cmdtxt(n->nif.test); 1088 cmdputs("; then "); 1089 cmdtxt(n->nif.ifpart); 1090 cmdputs("..."); 1091 break; 1092 case NWHILE: 1093 cmdputs("while "); 1094 goto until; 1095 case NUNTIL: 1096 cmdputs("until "); 1097until: 1098 cmdtxt(n->nbinary.ch1); 1099 cmdputs("; do "); 1100 cmdtxt(n->nbinary.ch2); 1101 cmdputs("; done"); 1102 break; 1103 case NFOR: 1104 cmdputs("for "); 1105 cmdputs(n->nfor.var); 1106 cmdputs(" in ..."); 1107 break; 1108 case NCASE: 1109 cmdputs("case "); 1110 cmdputs(n->ncase.expr->narg.text); 1111 cmdputs(" in ..."); 1112 break; 1113 case NDEFUN: 1114 cmdputs(n->narg.text); 1115 cmdputs("() ..."); 1116 break; 1117 case NCMD: 1118 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1119 cmdtxt(np); 1120 if (np->narg.next) 1121 cmdputs(" "); 1122 } 1123 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1124 cmdputs(" "); 1125 cmdtxt(np); 1126 } 1127 break; 1128 case NARG: 1129 cmdputs(n->narg.text); 1130 break; 1131 case NTO: 1132 p = ">"; i = 1; goto redir; 1133 case NAPPEND: 1134 p = ">>"; i = 1; goto redir; 1135 case NTOFD: 1136 p = ">&"; i = 1; goto redir; 1137 case NCLOBBER: 1138 p = ">|"; i = 1; goto redir; 1139 case NFROM: 1140 p = "<"; i = 0; goto redir; 1141 case NFROMTO: 1142 p = "<>"; i = 0; goto redir; 1143 case NFROMFD: 1144 p = "<&"; i = 0; goto redir; 1145redir: 1146 if (n->nfile.fd != i) { 1147 s[0] = n->nfile.fd + '0'; 1148 s[1] = '\0'; 1149 cmdputs(s); 1150 } 1151 cmdputs(p); 1152 if (n->type == NTOFD || n->type == NFROMFD) { 1153 s[0] = n->ndup.dupfd + '0'; 1154 s[1] = '\0'; 1155 cmdputs(s); 1156 } else { 1157 cmdtxt(n->nfile.fname); 1158 } 1159 break; 1160 case NHERE: 1161 case NXHERE: 1162 cmdputs("<<..."); 1163 break; 1164 default: 1165 cmdputs("???"); 1166 break; 1167 } 1168} 1169 1170 1171 1172STATIC void 1173cmdputs(char *s) 1174{ 1175 char *p, *q; 1176 char c; 1177 int subtype = 0; 1178 1179 if (cmdnleft <= 0) 1180 return; 1181 p = s; 1182 q = cmdnextc; 1183 while ((c = *p++) != '\0') { 1184 if (c == CTLESC) 1185 *q++ = *p++; 1186 else if (c == CTLVAR) { 1187 *q++ = '$'; 1188 if (--cmdnleft > 0) 1189 *q++ = '{'; 1190 subtype = *p++; 1191 } else if (c == '=' && subtype != 0) { 1192 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1193 subtype = 0; 1194 } else if (c == CTLENDVAR) { 1195 *q++ = '}'; 1196 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1197 cmdnleft++; /* ignore it */ 1198 else 1199 *q++ = c; 1200 if (--cmdnleft <= 0) { 1201 *q++ = '.'; 1202 *q++ = '.'; 1203 *q++ = '.'; 1204 break; 1205 } 1206 } 1207 cmdnextc = q; 1208} 1209