jobs.c revision 97663
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 97663 2002-05-31 13:07:05Z 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 jobmru = NULL; 533 } else { 534 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 535 memcpy(jp, jobtab, njobs * sizeof jp[0]); 536#if JOBS 537 /* Relocate `next' pointers and list head */ 538 jobmru = &jp[jobmru - jobtab]; 539 for (i = 0; i < njobs; i++) 540 if (jp[i].next != NULL) 541 jp[i].next = &jp[jp[i].next - 542 jobtab]; 543#endif 544 /* Relocate `ps' pointers */ 545 for (i = 0; i < njobs; i++) 546 if (jp[i].ps == &jobtab[i].ps0) 547 jp[i].ps = &jp[i].ps0; 548 ckfree(jobtab); 549 jobtab = jp; 550 } 551 jp = jobtab + njobs; 552 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 553 INTON; 554 break; 555 } 556 if (jp->used == 0) 557 break; 558 } 559 INTOFF; 560 jp->state = 0; 561 jp->used = 1; 562 jp->changed = 0; 563 jp->nprocs = 0; 564#if JOBS 565 jp->jobctl = jobctl; 566 jp->next = NULL; 567#endif 568 if (nprocs > 1) { 569 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 570 } else { 571 jp->ps = &jp->ps0; 572 } 573 INTON; 574 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 575 jp - jobtab + 1)); 576 return jp; 577} 578 579#if JOBS 580STATIC void 581setcurjob(struct job *cj) 582{ 583 struct job *jp, *prev; 584 585 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 586 if (jp == cj) { 587 if (prev != NULL) 588 prev->next = jp->next; 589 else 590 jobmru = jp->next; 591 jp->next = jobmru; 592 jobmru = cj; 593 return; 594 } 595 } 596 cj->next = jobmru; 597 jobmru = cj; 598} 599 600STATIC void 601deljob(struct job *j) 602{ 603 struct job *jp, *prev; 604 605 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 606 if (jp == j) { 607 if (prev != NULL) 608 prev->next = jp->next; 609 else 610 jobmru = jp->next; 611 return; 612 } 613 } 614} 615 616/* 617 * Return the most recently used job that isn't `nj', and preferably one 618 * that is stopped. 619 */ 620STATIC struct job * 621getcurjob(struct job *nj) 622{ 623 struct job *jp; 624 625 /* Try to find a stopped one.. */ 626 for (jp = jobmru; jp != NULL; jp = jp->next) 627 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 628 return (jp); 629 /* Otherwise the most recently used job that isn't `nj' */ 630 for (jp = jobmru; jp != NULL; jp = jp->next) 631 if (jp->used && jp != nj) 632 return (jp); 633 634 return (NULL); 635} 636 637#endif 638 639/* 640 * Fork of a subshell. If we are doing job control, give the subshell its 641 * own process group. Jp is a job structure that the job is to be added to. 642 * N is the command that will be evaluated by the child. Both jp and n may 643 * be NULL. The mode parameter can be one of the following: 644 * FORK_FG - Fork off a foreground process. 645 * FORK_BG - Fork off a background process. 646 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 647 * process group even if job control is on. 648 * 649 * When job control is turned off, background processes have their standard 650 * input redirected to /dev/null (except for the second and later processes 651 * in a pipeline). 652 */ 653 654int 655forkshell(struct job *jp, union node *n, int mode) 656{ 657 int pid; 658 int pgrp; 659 660 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 661 mode)); 662 INTOFF; 663 pid = fork(); 664 if (pid == -1) { 665 TRACE(("Fork failed, errno=%d\n", errno)); 666 INTON; 667 error("Cannot fork: %s", strerror(errno)); 668 } 669 if (pid == 0) { 670 struct job *p; 671 int wasroot; 672 int i; 673 674 TRACE(("Child shell %d\n", getpid())); 675 wasroot = rootshell; 676 rootshell = 0; 677 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 678 if (p->used) 679 freejob(p); 680 closescript(); 681 INTON; 682 clear_traps(); 683#if JOBS 684 jobctl = 0; /* do job control only in root shell */ 685 if (wasroot && mode != FORK_NOJOB && mflag) { 686 if (jp == NULL || jp->nprocs == 0) 687 pgrp = getpid(); 688 else 689 pgrp = jp->ps[0].pid; 690 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 691 /*** this causes superfluous TIOCSPGRPS ***/ 692#ifdef OLD_TTY_DRIVER 693 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 694 error("TIOCSPGRP failed, errno=%d", errno); 695#else 696 if (tcsetpgrp(2, pgrp) < 0) 697 error("tcsetpgrp failed, errno=%d", errno); 698#endif 699 } 700 setsignal(SIGTSTP); 701 setsignal(SIGTTOU); 702 } else if (mode == FORK_BG) { 703 ignoresig(SIGINT); 704 ignoresig(SIGQUIT); 705 if ((jp == NULL || jp->nprocs == 0) && 706 ! fd0_redirected_p ()) { 707 close(0); 708 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 709 error("Can't open %s: %s", 710 _PATH_DEVNULL, strerror(errno)); 711 } 712 } 713#else 714 if (mode == FORK_BG) { 715 ignoresig(SIGINT); 716 ignoresig(SIGQUIT); 717 if ((jp == NULL || jp->nprocs == 0) && 718 ! fd0_redirected_p ()) { 719 close(0); 720 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 721 error("Can't open %s: %s", 722 _PATH_DEVNULL, strerror(errno)); 723 } 724 } 725#endif 726 if (wasroot && iflag) { 727 setsignal(SIGINT); 728 setsignal(SIGQUIT); 729 setsignal(SIGTERM); 730 } 731 return pid; 732 } 733 if (rootshell && mode != FORK_NOJOB && mflag) { 734 if (jp == NULL || jp->nprocs == 0) 735 pgrp = pid; 736 else 737 pgrp = jp->ps[0].pid; 738 setpgid(pid, pgrp); 739 } 740 if (mode == FORK_BG) 741 backgndpid = pid; /* set $! */ 742 if (jp) { 743 struct procstat *ps = &jp->ps[jp->nprocs++]; 744 ps->pid = pid; 745 ps->status = -1; 746 ps->cmd = nullstr; 747 if (iflag && rootshell && n) 748 ps->cmd = commandtext(n); 749#if JOBS 750 setcurjob(jp); 751#endif 752 } 753 INTON; 754 TRACE(("In parent shell: child = %d\n", pid)); 755 return pid; 756} 757 758 759 760/* 761 * Wait for job to finish. 762 * 763 * Under job control we have the problem that while a child process is 764 * running interrupts generated by the user are sent to the child but not 765 * to the shell. This means that an infinite loop started by an inter- 766 * active user may be hard to kill. With job control turned off, an 767 * interactive user may place an interactive program inside a loop. If 768 * the interactive program catches interrupts, the user doesn't want 769 * these interrupts to also abort the loop. The approach we take here 770 * is to have the shell ignore interrupt signals while waiting for a 771 * foreground process to terminate, and then send itself an interrupt 772 * signal if the child process was terminated by an interrupt signal. 773 * Unfortunately, some programs want to do a bit of cleanup and then 774 * exit on interrupt; unless these processes terminate themselves by 775 * sending a signal to themselves (instead of calling exit) they will 776 * confuse this approach. 777 */ 778 779int 780waitforjob(struct job *jp, int *origstatus) 781{ 782#if JOBS 783 int mypgrp = getpgrp(); 784#endif 785 int status; 786 int st; 787 788 INTOFF; 789 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 790 while (jp->state == 0) 791 if (dowait(1, jp) == -1) 792 dotrap(); 793#if JOBS 794 if (jp->jobctl) { 795#ifdef OLD_TTY_DRIVER 796 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 797 error("TIOCSPGRP failed, errno=%d\n", errno); 798#else 799 if (tcsetpgrp(2, mypgrp) < 0) 800 error("tcsetpgrp failed, errno=%d\n", errno); 801#endif 802 } 803 if (jp->state == JOBSTOPPED) 804 setcurjob(jp); 805#endif 806 status = jp->ps[jp->nprocs - 1].status; 807 if (origstatus != NULL) 808 *origstatus = status; 809 /* convert to 8 bits */ 810 if (WIFEXITED(status)) 811 st = WEXITSTATUS(status); 812#if JOBS 813 else if (WIFSTOPPED(status)) 814 st = WSTOPSIG(status) + 128; 815#endif 816 else 817 st = WTERMSIG(status) + 128; 818 if (! JOBS || jp->state == JOBDONE) 819 freejob(jp); 820 if (int_pending()) { 821 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 822 kill(getpid(), SIGINT); 823 else 824 CLEAR_PENDING_INT; 825 } 826 INTON; 827 return st; 828} 829 830 831 832/* 833 * Wait for a process to terminate. 834 */ 835 836STATIC int 837dowait(int block, struct job *job) 838{ 839 int pid; 840 int status; 841 struct procstat *sp; 842 struct job *jp; 843 struct job *thisjob; 844 int done; 845 int stopped; 846 int core; 847 int sig; 848 849 in_dowait++; 850 TRACE(("dowait(%d) called\n", block)); 851 do { 852 pid = waitproc(block, &status); 853 TRACE(("wait returns %d, status=%d\n", pid, status)); 854 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 855 (WIFSTOPPED(status) && !iflag)); 856 in_dowait--; 857 if (breakwaitcmd != 0) { 858 breakwaitcmd = 0; 859 return -1; 860 } 861 if (pid <= 0) 862 return pid; 863 INTOFF; 864 thisjob = NULL; 865 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 866 if (jp->used) { 867 done = 1; 868 stopped = 1; 869 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 870 if (sp->pid == -1) 871 continue; 872 if (sp->pid == pid) { 873 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 874 pid, sp->status, status)); 875 sp->status = status; 876 thisjob = jp; 877 } 878 if (sp->status == -1) 879 stopped = 0; 880 else if (WIFSTOPPED(sp->status)) 881 done = 0; 882 } 883 if (stopped) { /* stopped or done */ 884 int state = done? JOBDONE : JOBSTOPPED; 885 if (jp->state != state) { 886 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 887 jp->state = state; 888#if JOBS 889 if (done) 890 deljob(jp); 891#endif 892 } 893 } 894 } 895 } 896 INTON; 897 if (! rootshell || ! iflag || (job && thisjob == job)) { 898#if JOBS 899 if (WIFSTOPPED(status)) 900 sig = WSTOPSIG(status); 901 else 902#endif 903 { 904 if (WIFEXITED(status)) 905 sig = 0; 906 else 907 sig = WTERMSIG(status); 908 } 909 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) 910 showjob(thisjob); 911 } else { 912 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 913 if (thisjob) 914 thisjob->changed = 1; 915 } 916 return pid; 917} 918 919 920 921/* 922 * Do a wait system call. If job control is compiled in, we accept 923 * stopped processes. If block is zero, we return a value of zero 924 * rather than blocking. 925 * 926 * System V doesn't have a non-blocking wait system call. It does 927 * have a SIGCLD signal that is sent to a process when one of it's 928 * children dies. The obvious way to use SIGCLD would be to install 929 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 930 * was received, and have waitproc bump another counter when it got 931 * the status of a process. Waitproc would then know that a wait 932 * system call would not block if the two counters were different. 933 * This approach doesn't work because if a process has children that 934 * have not been waited for, System V will send it a SIGCLD when it 935 * installs a signal handler for SIGCLD. What this means is that when 936 * a child exits, the shell will be sent SIGCLD signals continuously 937 * until is runs out of stack space, unless it does a wait call before 938 * restoring the signal handler. The code below takes advantage of 939 * this (mis)feature by installing a signal handler for SIGCLD and 940 * then checking to see whether it was called. If there are any 941 * children to be waited for, it will be. 942 * 943 * If neither SYSV nor BSD is defined, we don't implement nonblocking 944 * waits at all. In this case, the user will not be informed when 945 * a background process until the next time she runs a real program 946 * (as opposed to running a builtin command or just typing return), 947 * and the jobs command may give out of date information. 948 */ 949 950#ifdef SYSV 951STATIC sig_atomic_t gotsigchild; 952 953STATIC int onsigchild() { 954 gotsigchild = 1; 955} 956#endif 957 958 959STATIC int 960waitproc(int block, int *status) 961{ 962#ifdef BSD 963 int flags; 964 965#if JOBS 966 flags = WUNTRACED; 967#else 968 flags = 0; 969#endif 970 if (block == 0) 971 flags |= WNOHANG; 972 return wait3(status, flags, (struct rusage *)NULL); 973#else 974#ifdef SYSV 975 int (*save)(); 976 977 if (block == 0) { 978 gotsigchild = 0; 979 save = signal(SIGCLD, onsigchild); 980 signal(SIGCLD, save); 981 if (gotsigchild == 0) 982 return 0; 983 } 984 return wait(status); 985#else 986 if (block == 0) 987 return 0; 988 return wait(status); 989#endif 990#endif 991} 992 993/* 994 * return 1 if there are stopped jobs, otherwise 0 995 */ 996int job_warning = 0; 997int 998stoppedjobs(void) 999{ 1000 int jobno; 1001 struct job *jp; 1002 1003 if (job_warning) 1004 return (0); 1005 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1006 if (jp->used == 0) 1007 continue; 1008 if (jp->state == JOBSTOPPED) { 1009 out2str("You have stopped jobs.\n"); 1010 job_warning = 2; 1011 return (1); 1012 } 1013 } 1014 1015 return (0); 1016} 1017 1018/* 1019 * Return a string identifying a command (to be printed by the 1020 * jobs command. 1021 */ 1022 1023STATIC char *cmdnextc; 1024STATIC int cmdnleft; 1025#define MAXCMDTEXT 200 1026 1027char * 1028commandtext(union node *n) 1029{ 1030 char *name; 1031 1032 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1033 cmdnleft = MAXCMDTEXT - 4; 1034 cmdtxt(n); 1035 *cmdnextc = '\0'; 1036 return name; 1037} 1038 1039 1040STATIC void 1041cmdtxt(union node *n) 1042{ 1043 union node *np; 1044 struct nodelist *lp; 1045 char *p; 1046 int i; 1047 char s[2]; 1048 1049 if (n == NULL) 1050 return; 1051 switch (n->type) { 1052 case NSEMI: 1053 cmdtxt(n->nbinary.ch1); 1054 cmdputs("; "); 1055 cmdtxt(n->nbinary.ch2); 1056 break; 1057 case NAND: 1058 cmdtxt(n->nbinary.ch1); 1059 cmdputs(" && "); 1060 cmdtxt(n->nbinary.ch2); 1061 break; 1062 case NOR: 1063 cmdtxt(n->nbinary.ch1); 1064 cmdputs(" || "); 1065 cmdtxt(n->nbinary.ch2); 1066 break; 1067 case NPIPE: 1068 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1069 cmdtxt(lp->n); 1070 if (lp->next) 1071 cmdputs(" | "); 1072 } 1073 break; 1074 case NSUBSHELL: 1075 cmdputs("("); 1076 cmdtxt(n->nredir.n); 1077 cmdputs(")"); 1078 break; 1079 case NREDIR: 1080 case NBACKGND: 1081 cmdtxt(n->nredir.n); 1082 break; 1083 case NIF: 1084 cmdputs("if "); 1085 cmdtxt(n->nif.test); 1086 cmdputs("; then "); 1087 cmdtxt(n->nif.ifpart); 1088 cmdputs("..."); 1089 break; 1090 case NWHILE: 1091 cmdputs("while "); 1092 goto until; 1093 case NUNTIL: 1094 cmdputs("until "); 1095until: 1096 cmdtxt(n->nbinary.ch1); 1097 cmdputs("; do "); 1098 cmdtxt(n->nbinary.ch2); 1099 cmdputs("; done"); 1100 break; 1101 case NFOR: 1102 cmdputs("for "); 1103 cmdputs(n->nfor.var); 1104 cmdputs(" in ..."); 1105 break; 1106 case NCASE: 1107 cmdputs("case "); 1108 cmdputs(n->ncase.expr->narg.text); 1109 cmdputs(" in ..."); 1110 break; 1111 case NDEFUN: 1112 cmdputs(n->narg.text); 1113 cmdputs("() ..."); 1114 break; 1115 case NCMD: 1116 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1117 cmdtxt(np); 1118 if (np->narg.next) 1119 cmdputs(" "); 1120 } 1121 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1122 cmdputs(" "); 1123 cmdtxt(np); 1124 } 1125 break; 1126 case NARG: 1127 cmdputs(n->narg.text); 1128 break; 1129 case NTO: 1130 p = ">"; i = 1; goto redir; 1131 case NAPPEND: 1132 p = ">>"; i = 1; goto redir; 1133 case NTOFD: 1134 p = ">&"; i = 1; goto redir; 1135 case NCLOBBER: 1136 p = ">|"; i = 1; goto redir; 1137 case NFROM: 1138 p = "<"; i = 0; goto redir; 1139 case NFROMTO: 1140 p = "<>"; i = 0; goto redir; 1141 case NFROMFD: 1142 p = "<&"; i = 0; goto redir; 1143redir: 1144 if (n->nfile.fd != i) { 1145 s[0] = n->nfile.fd + '0'; 1146 s[1] = '\0'; 1147 cmdputs(s); 1148 } 1149 cmdputs(p); 1150 if (n->type == NTOFD || n->type == NFROMFD) { 1151 s[0] = n->ndup.dupfd + '0'; 1152 s[1] = '\0'; 1153 cmdputs(s); 1154 } else { 1155 cmdtxt(n->nfile.fname); 1156 } 1157 break; 1158 case NHERE: 1159 case NXHERE: 1160 cmdputs("<<..."); 1161 break; 1162 default: 1163 cmdputs("???"); 1164 break; 1165 } 1166} 1167 1168 1169 1170STATIC void 1171cmdputs(char *s) 1172{ 1173 char *p, *q; 1174 char c; 1175 int subtype = 0; 1176 1177 if (cmdnleft <= 0) 1178 return; 1179 p = s; 1180 q = cmdnextc; 1181 while ((c = *p++) != '\0') { 1182 if (c == CTLESC) 1183 *q++ = *p++; 1184 else if (c == CTLVAR) { 1185 *q++ = '$'; 1186 if (--cmdnleft > 0) 1187 *q++ = '{'; 1188 subtype = *p++; 1189 } else if (c == '=' && subtype != 0) { 1190 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1191 subtype = 0; 1192 } else if (c == CTLENDVAR) { 1193 *q++ = '}'; 1194 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1195 cmdnleft++; /* ignore it */ 1196 else 1197 *q++ = c; 1198 if (--cmdnleft <= 0) { 1199 *q++ = '.'; 1200 *q++ = '.'; 1201 *q++ = '.'; 1202 break; 1203 } 1204 } 1205 cmdnextc = q; 1206} 1207