jobs.c revision 96933
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 96933 2002-05-19 07:27:26Z 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 88int initialpgrp; /* pgrp of shell on invocation */ 89int curjob; /* current job */ 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 *); 107 108 109/* 110 * Turn job control on and off. 111 * 112 * Note: This code assumes that the third arg to ioctl is a character 113 * pointer, which is true on Berkeley systems but not System V. Since 114 * System V doesn't have job control yet, this isn't a problem now. 115 */ 116 117MKINIT int jobctl; 118 119#if JOBS 120void 121setjobctl(int on) 122{ 123#ifdef OLD_TTY_DRIVER 124 int ldisc; 125#endif 126 127 if (on == jobctl || rootshell == 0) 128 return; 129 if (on) { 130 do { /* while we are in the background */ 131#ifdef OLD_TTY_DRIVER 132 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 133#else 134 initialpgrp = tcgetpgrp(2); 135 if (initialpgrp < 0) { 136#endif 137 out2str("sh: can't access tty; job control turned off\n"); 138 mflag = 0; 139 return; 140 } 141 if (initialpgrp == -1) 142 initialpgrp = getpgrp(); 143 else if (initialpgrp != getpgrp()) { 144 killpg(initialpgrp, SIGTTIN); 145 continue; 146 } 147 } while (0); 148#ifdef OLD_TTY_DRIVER 149 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 150 out2str("sh: need new tty driver to run job control; job control turned off\n"); 151 mflag = 0; 152 return; 153 } 154#endif 155 setsignal(SIGTSTP); 156 setsignal(SIGTTOU); 157 setsignal(SIGTTIN); 158 setpgid(0, rootpid); 159#ifdef OLD_TTY_DRIVER 160 ioctl(2, TIOCSPGRP, (char *)&rootpid); 161#else 162 tcsetpgrp(2, rootpid); 163#endif 164 } else { /* turning job control off */ 165 setpgid(0, initialpgrp); 166#ifdef OLD_TTY_DRIVER 167 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 168#else 169 tcsetpgrp(2, initialpgrp); 170#endif 171 setsignal(SIGTSTP); 172 setsignal(SIGTTOU); 173 setsignal(SIGTTIN); 174 } 175 jobctl = on; 176} 177#endif 178 179 180#ifdef mkinit 181INCLUDE <sys/types.h> 182INCLUDE <stdlib.h> 183 184SHELLPROC { 185 backgndpid = -1; 186#if JOBS 187 jobctl = 0; 188#endif 189} 190 191#endif 192 193 194 195#if JOBS 196int 197fgcmd(int argc __unused, char **argv) 198{ 199 struct job *jp; 200 int pgrp; 201 int status; 202 203 jp = getjob(argv[1]); 204 if (jp->jobctl == 0) 205 error("job not created under job control"); 206 out1str(jp->ps[0].cmd); 207 out1c('\n'); 208 flushout(&output); 209 pgrp = jp->ps[0].pid; 210#ifdef OLD_TTY_DRIVER 211 ioctl(2, TIOCSPGRP, (char *)&pgrp); 212#else 213 tcsetpgrp(2, pgrp); 214#endif 215 restartjob(jp); 216 INTOFF; 217 status = waitforjob(jp, (int *)NULL); 218 INTON; 219 return status; 220} 221 222 223int 224bgcmd(int argc, char **argv) 225{ 226 char s[64]; 227 struct job *jp; 228 229 do { 230 jp = getjob(*++argv); 231 if (jp->jobctl == 0) 232 error("job not created under job control"); 233 if (jp->state == JOBDONE) 234 continue; 235 restartjob(jp); 236 fmtstr(s, 64, "[%d] ", jp - jobtab + 1); 237 out1str(s); 238 out1str(jp->ps[0].cmd); 239 out1c('\n'); 240 } while (--argc > 1); 241 return 0; 242} 243 244 245STATIC void 246restartjob(struct job *jp) 247{ 248 struct procstat *ps; 249 int i; 250 251 if (jp->state == JOBDONE) 252 return; 253 INTOFF; 254 killpg(jp->ps[0].pid, SIGCONT); 255 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 256 if (WIFSTOPPED(ps->status)) { 257 ps->status = -1; 258 jp->state = 0; 259 } 260 } 261 INTON; 262} 263#endif 264 265 266int 267jobscmd(int argc __unused, char **argv __unused) 268{ 269 showjobs(0); 270 return 0; 271} 272 273 274/* 275 * Print a list of jobs. If "change" is nonzero, only print jobs whose 276 * statuses have changed since the last call to showjobs. 277 * 278 * If the shell is interrupted in the process of creating a job, the 279 * result may be a job structure containing zero processes. Such structures 280 * will be freed here. 281 */ 282 283void 284showjobs(int change) 285{ 286 int jobno; 287 int procno; 288 int i; 289 struct job *jp; 290 struct procstat *ps; 291 int col; 292 char s[64]; 293 294 TRACE(("showjobs(%d) called\n", change)); 295 while (dowait(0, (struct job *)NULL) > 0); 296 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 297 if (! jp->used) 298 continue; 299 if (jp->nprocs == 0) { 300 freejob(jp); 301 continue; 302 } 303 if (change && ! jp->changed) 304 continue; 305 procno = jp->nprocs; 306 for (ps = jp->ps ; ; ps++) { /* for each process */ 307 if (ps == jp->ps) 308 fmtstr(s, 64, "[%d] %d ", jobno, ps->pid); 309 else 310 fmtstr(s, 64, " %d ", ps->pid); 311 out1str(s); 312 col = strlen(s); 313 s[0] = '\0'; 314 if (ps->status == -1) { 315 /* don't print anything */ 316 } else if (WIFEXITED(ps->status)) { 317 fmtstr(s, 64, "Exit %d", WEXITSTATUS(ps->status)); 318 } else { 319#if JOBS 320 if (WIFSTOPPED(ps->status)) 321 i = WSTOPSIG(ps->status); 322 else 323#endif 324 i = WTERMSIG(ps->status); 325 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 326 scopy(sys_siglist[i & 0x7F], s); 327 else 328 fmtstr(s, 64, "Signal %d", i & 0x7F); 329 if (WCOREDUMP(ps->status)) 330 strcat(s, " (core dumped)"); 331 } 332 out1str(s); 333 col += strlen(s); 334 do { 335 out1c(' '); 336 col++; 337 } while (col < 30); 338 out1str(ps->cmd); 339 out1c('\n'); 340 if (--procno <= 0) 341 break; 342 } 343 jp->changed = 0; 344 if (jp->state == JOBDONE) { 345 freejob(jp); 346 } 347 } 348} 349 350 351/* 352 * Mark a job structure as unused. 353 */ 354 355STATIC void 356freejob(struct job *jp) 357{ 358 struct procstat *ps; 359 int i; 360 361 INTOFF; 362 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 363 if (ps->cmd != nullstr) 364 ckfree(ps->cmd); 365 } 366 if (jp->ps != &jp->ps0) 367 ckfree(jp->ps); 368 jp->used = 0; 369#if JOBS 370 if (curjob == jp - jobtab + 1) 371 curjob = 0; 372#endif 373 INTON; 374} 375 376 377 378int 379waitcmd(int argc, char **argv) 380{ 381 struct job *job; 382 int status, retval; 383 struct job *jp; 384 385 if (argc > 1) { 386 job = getjob(argv[1]); 387 } else { 388 job = NULL; 389 } 390 391 /* 392 * Loop until a process is terminated or stopped, or a SIGINT is 393 * received. 394 */ 395 396 in_waitcmd++; 397 do { 398 if (job != NULL) { 399 if (job->state) { 400 status = job->ps[job->nprocs - 1].status; 401 if (WIFEXITED(status)) 402 retval = WEXITSTATUS(status); 403#if JOBS 404 else if (WIFSTOPPED(status)) 405 retval = WSTOPSIG(status) + 128; 406#endif 407 else 408 retval = WTERMSIG(status) + 128; 409 if (! iflag) 410 freejob(job); 411 in_waitcmd--; 412 return retval; 413 } 414 } else { 415 for (jp = jobtab ; ; jp++) { 416 if (jp >= jobtab + njobs) { /* no running procs */ 417 in_waitcmd--; 418 return 0; 419 } 420 if (jp->used && jp->state == 0) 421 break; 422 } 423 } 424 } while (dowait(1, (struct job *)NULL) != -1); 425 in_waitcmd--; 426 427 return 0; 428} 429 430 431 432int 433jobidcmd(int argc __unused, char **argv) 434{ 435 struct job *jp; 436 int i; 437 438 jp = getjob(argv[1]); 439 for (i = 0 ; i < jp->nprocs ; ) { 440 out1fmt("%d", jp->ps[i].pid); 441 out1c(++i < jp->nprocs? ' ' : '\n'); 442 } 443 return 0; 444} 445 446 447 448/* 449 * Convert a job name to a job structure. 450 */ 451 452STATIC struct job * 453getjob(char *name) 454{ 455 int jobno; 456 struct job *jp; 457 int pid; 458 int i; 459 460 if (name == NULL) { 461#if JOBS 462currentjob: 463 if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) 464 error("No current job"); 465 return &jobtab[jobno - 1]; 466#else 467 error("No current job"); 468#endif 469 } else if (name[0] == '%') { 470 if (is_digit(name[1])) { 471 jobno = number(name + 1); 472 if (jobno > 0 && jobno <= njobs 473 && jobtab[jobno - 1].used != 0) 474 return &jobtab[jobno - 1]; 475#if JOBS 476 } else if (name[1] == '%' && name[2] == '\0') { 477 goto currentjob; 478#endif 479 } else { 480 struct job *found = NULL; 481 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 482 if (jp->used && jp->nprocs > 0 483 && prefix(name + 1, jp->ps[0].cmd)) { 484 if (found) 485 error("%s: ambiguous", name); 486 found = jp; 487 } 488 } 489 if (found) 490 return found; 491 } 492 } else if (is_number(name)) { 493 pid = number(name); 494 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 495 if (jp->used && jp->nprocs > 0 496 && jp->ps[jp->nprocs - 1].pid == pid) 497 return jp; 498 } 499 } 500 error("No such job: %s", name); 501 /*NOTREACHED*/ 502 return NULL; 503} 504 505 506 507/* 508 * Return a new job structure, 509 */ 510 511struct job * 512makejob(union node *node __unused, int nprocs) 513{ 514 int i; 515 struct job *jp; 516 517 for (i = njobs, jp = jobtab ; ; jp++) { 518 if (--i < 0) { 519 INTOFF; 520 if (njobs == 0) { 521 jobtab = ckmalloc(4 * sizeof jobtab[0]); 522 } else { 523 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 524 memcpy(jp, jobtab, njobs * sizeof jp[0]); 525 /* Relocate `ps' pointers */ 526 for (i = 0; i < njobs; i++) 527 if (jp[i].ps == &jobtab[i].ps0) 528 jp[i].ps = &jp[i].ps0; 529 ckfree(jobtab); 530 jobtab = jp; 531 } 532 jp = jobtab + njobs; 533 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 534 INTON; 535 break; 536 } 537 if (jp->used == 0) 538 break; 539 } 540 INTOFF; 541 jp->state = 0; 542 jp->used = 1; 543 jp->changed = 0; 544 jp->nprocs = 0; 545#if JOBS 546 jp->jobctl = jobctl; 547#endif 548 if (nprocs > 1) { 549 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 550 } else { 551 jp->ps = &jp->ps0; 552 } 553 INTON; 554 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 555 jp - jobtab + 1)); 556 return jp; 557} 558 559 560/* 561 * Fork of a subshell. If we are doing job control, give the subshell its 562 * own process group. Jp is a job structure that the job is to be added to. 563 * N is the command that will be evaluated by the child. Both jp and n may 564 * be NULL. The mode parameter can be one of the following: 565 * FORK_FG - Fork off a foreground process. 566 * FORK_BG - Fork off a background process. 567 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 568 * process group even if job control is on. 569 * 570 * When job control is turned off, background processes have their standard 571 * input redirected to /dev/null (except for the second and later processes 572 * in a pipeline). 573 */ 574 575int 576forkshell(struct job *jp, union node *n, int mode) 577{ 578 int pid; 579 int pgrp; 580 581 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 582 mode)); 583 INTOFF; 584 pid = fork(); 585 if (pid == -1) { 586 TRACE(("Fork failed, errno=%d\n", errno)); 587 INTON; 588 error("Cannot fork: %s", strerror(errno)); 589 } 590 if (pid == 0) { 591 struct job *p; 592 int wasroot; 593 int i; 594 595 TRACE(("Child shell %d\n", getpid())); 596 wasroot = rootshell; 597 rootshell = 0; 598 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 599 if (p->used) 600 freejob(p); 601 closescript(); 602 INTON; 603 clear_traps(); 604#if JOBS 605 jobctl = 0; /* do job control only in root shell */ 606 if (wasroot && mode != FORK_NOJOB && mflag) { 607 if (jp == NULL || jp->nprocs == 0) 608 pgrp = getpid(); 609 else 610 pgrp = jp->ps[0].pid; 611 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 612 /*** this causes superfluous TIOCSPGRPS ***/ 613#ifdef OLD_TTY_DRIVER 614 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 615 error("TIOCSPGRP failed, errno=%d", errno); 616#else 617 if (tcsetpgrp(2, pgrp) < 0) 618 error("tcsetpgrp failed, errno=%d", errno); 619#endif 620 } 621 setsignal(SIGTSTP); 622 setsignal(SIGTTOU); 623 } else if (mode == FORK_BG) { 624 ignoresig(SIGINT); 625 ignoresig(SIGQUIT); 626 if ((jp == NULL || jp->nprocs == 0) && 627 ! fd0_redirected_p ()) { 628 close(0); 629 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 630 error("Can't open %s: %s", 631 _PATH_DEVNULL, strerror(errno)); 632 } 633 } 634#else 635 if (mode == FORK_BG) { 636 ignoresig(SIGINT); 637 ignoresig(SIGQUIT); 638 if ((jp == NULL || jp->nprocs == 0) && 639 ! fd0_redirected_p ()) { 640 close(0); 641 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 642 error("Can't open %s: %s", 643 _PATH_DEVNULL, strerror(errno)); 644 } 645 } 646#endif 647 if (wasroot && iflag) { 648 setsignal(SIGINT); 649 setsignal(SIGQUIT); 650 setsignal(SIGTERM); 651 } 652 return pid; 653 } 654 if (rootshell && mode != FORK_NOJOB && mflag) { 655 if (jp == NULL || jp->nprocs == 0) 656 pgrp = pid; 657 else 658 pgrp = jp->ps[0].pid; 659 setpgid(pid, pgrp); 660 } 661 if (mode == FORK_BG) 662 backgndpid = pid; /* set $! */ 663 if (jp) { 664 struct procstat *ps = &jp->ps[jp->nprocs++]; 665 ps->pid = pid; 666 ps->status = -1; 667 ps->cmd = nullstr; 668 if (iflag && rootshell && n) 669 ps->cmd = commandtext(n); 670 } 671 INTON; 672 TRACE(("In parent shell: child = %d\n", pid)); 673 return pid; 674} 675 676 677 678/* 679 * Wait for job to finish. 680 * 681 * Under job control we have the problem that while a child process is 682 * running interrupts generated by the user are sent to the child but not 683 * to the shell. This means that an infinite loop started by an inter- 684 * active user may be hard to kill. With job control turned off, an 685 * interactive user may place an interactive program inside a loop. If 686 * the interactive program catches interrupts, the user doesn't want 687 * these interrupts to also abort the loop. The approach we take here 688 * is to have the shell ignore interrupt signals while waiting for a 689 * foreground process to terminate, and then send itself an interrupt 690 * signal if the child process was terminated by an interrupt signal. 691 * Unfortunately, some programs want to do a bit of cleanup and then 692 * exit on interrupt; unless these processes terminate themselves by 693 * sending a signal to themselves (instead of calling exit) they will 694 * confuse this approach. 695 */ 696 697int 698waitforjob(struct job *jp, int *origstatus) 699{ 700#if JOBS 701 int mypgrp = getpgrp(); 702#endif 703 int status; 704 int st; 705 706 INTOFF; 707 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 708 while (jp->state == 0) 709 if (dowait(1, jp) == -1) 710 dotrap(); 711#if JOBS 712 if (jp->jobctl) { 713#ifdef OLD_TTY_DRIVER 714 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 715 error("TIOCSPGRP failed, errno=%d\n", errno); 716#else 717 if (tcsetpgrp(2, mypgrp) < 0) 718 error("tcsetpgrp failed, errno=%d\n", errno); 719#endif 720 } 721 if (jp->state == JOBSTOPPED) 722 curjob = jp - jobtab + 1; 723#endif 724 status = jp->ps[jp->nprocs - 1].status; 725 if (origstatus != NULL) 726 *origstatus = status; 727 /* convert to 8 bits */ 728 if (WIFEXITED(status)) 729 st = WEXITSTATUS(status); 730#if JOBS 731 else if (WIFSTOPPED(status)) 732 st = WSTOPSIG(status) + 128; 733#endif 734 else 735 st = WTERMSIG(status) + 128; 736 if (! JOBS || jp->state == JOBDONE) 737 freejob(jp); 738 if (int_pending()) { 739 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 740 kill(getpid(), SIGINT); 741 else 742 CLEAR_PENDING_INT; 743 } 744 INTON; 745 return st; 746} 747 748 749 750/* 751 * Wait for a process to terminate. 752 */ 753 754STATIC int 755dowait(int block, struct job *job) 756{ 757 int pid; 758 int status; 759 struct procstat *sp; 760 struct job *jp; 761 struct job *thisjob; 762 int done; 763 int stopped; 764 int core; 765 int sig; 766 767 in_dowait++; 768 TRACE(("dowait(%d) called\n", block)); 769 do { 770 pid = waitproc(block, &status); 771 TRACE(("wait returns %d, status=%d\n", pid, status)); 772 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 773 (WIFSTOPPED(status) && !iflag)); 774 in_dowait--; 775 if (breakwaitcmd != 0) { 776 breakwaitcmd = 0; 777 return -1; 778 } 779 if (pid <= 0) 780 return pid; 781 INTOFF; 782 thisjob = NULL; 783 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 784 if (jp->used) { 785 done = 1; 786 stopped = 1; 787 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 788 if (sp->pid == -1) 789 continue; 790 if (sp->pid == pid) { 791 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 792 pid, sp->status, status)); 793 sp->status = status; 794 thisjob = jp; 795 } 796 if (sp->status == -1) 797 stopped = 0; 798 else if (WIFSTOPPED(sp->status)) 799 done = 0; 800 } 801 if (stopped) { /* stopped or done */ 802 int state = done? JOBDONE : JOBSTOPPED; 803 if (jp->state != state) { 804 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 805 jp->state = state; 806#if JOBS 807 if (done && curjob == jp - jobtab + 1) 808 curjob = 0; /* no current job */ 809#endif 810 } 811 } 812 } 813 } 814 INTON; 815 if (! rootshell || ! iflag || (job && thisjob == job)) { 816 core = WCOREDUMP(status); 817#if JOBS 818 if (WIFSTOPPED(status)) 819 sig = WSTOPSIG(status); 820 else 821#endif 822 if (WIFEXITED(status)) 823 sig = 0; 824 else 825 sig = WTERMSIG(status); 826 827 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 828 if (thisjob != job) 829 outfmt(out2, "%d: ", pid); 830#if JOBS 831 if (sig == SIGTSTP && rootshell && iflag) 832 outfmt(out2, "%%%d ", job - jobtab + 1); 833#endif 834 if (sig < NSIG && sys_siglist[sig]) 835 out2str(sys_siglist[sig]); 836 else 837 outfmt(out2, "Signal %d", sig); 838 if (core) 839 out2str(" - core dumped"); 840 out2c('\n'); 841 flushout(&errout); 842 } else { 843 TRACE(("Not printing status: status=%d, sig=%d\n", 844 status, sig)); 845 } 846 } else { 847 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 848 if (thisjob) 849 thisjob->changed = 1; 850 } 851 return pid; 852} 853 854 855 856/* 857 * Do a wait system call. If job control is compiled in, we accept 858 * stopped processes. If block is zero, we return a value of zero 859 * rather than blocking. 860 * 861 * System V doesn't have a non-blocking wait system call. It does 862 * have a SIGCLD signal that is sent to a process when one of it's 863 * children dies. The obvious way to use SIGCLD would be to install 864 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 865 * was received, and have waitproc bump another counter when it got 866 * the status of a process. Waitproc would then know that a wait 867 * system call would not block if the two counters were different. 868 * This approach doesn't work because if a process has children that 869 * have not been waited for, System V will send it a SIGCLD when it 870 * installs a signal handler for SIGCLD. What this means is that when 871 * a child exits, the shell will be sent SIGCLD signals continuously 872 * until is runs out of stack space, unless it does a wait call before 873 * restoring the signal handler. The code below takes advantage of 874 * this (mis)feature by installing a signal handler for SIGCLD and 875 * then checking to see whether it was called. If there are any 876 * children to be waited for, it will be. 877 * 878 * If neither SYSV nor BSD is defined, we don't implement nonblocking 879 * waits at all. In this case, the user will not be informed when 880 * a background process until the next time she runs a real program 881 * (as opposed to running a builtin command or just typing return), 882 * and the jobs command may give out of date information. 883 */ 884 885#ifdef SYSV 886STATIC sig_atomic_t gotsigchild; 887 888STATIC int onsigchild() { 889 gotsigchild = 1; 890} 891#endif 892 893 894STATIC int 895waitproc(int block, int *status) 896{ 897#ifdef BSD 898 int flags; 899 900#if JOBS 901 flags = WUNTRACED; 902#else 903 flags = 0; 904#endif 905 if (block == 0) 906 flags |= WNOHANG; 907 return wait3(status, flags, (struct rusage *)NULL); 908#else 909#ifdef SYSV 910 int (*save)(); 911 912 if (block == 0) { 913 gotsigchild = 0; 914 save = signal(SIGCLD, onsigchild); 915 signal(SIGCLD, save); 916 if (gotsigchild == 0) 917 return 0; 918 } 919 return wait(status); 920#else 921 if (block == 0) 922 return 0; 923 return wait(status); 924#endif 925#endif 926} 927 928/* 929 * return 1 if there are stopped jobs, otherwise 0 930 */ 931int job_warning = 0; 932int 933stoppedjobs(void) 934{ 935 int jobno; 936 struct job *jp; 937 938 if (job_warning) 939 return (0); 940 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 941 if (jp->used == 0) 942 continue; 943 if (jp->state == JOBSTOPPED) { 944 out2str("You have stopped jobs.\n"); 945 job_warning = 2; 946 return (1); 947 } 948 } 949 950 return (0); 951} 952 953/* 954 * Return a string identifying a command (to be printed by the 955 * jobs command. 956 */ 957 958STATIC char *cmdnextc; 959STATIC int cmdnleft; 960#define MAXCMDTEXT 200 961 962char * 963commandtext(union node *n) 964{ 965 char *name; 966 967 cmdnextc = name = ckmalloc(MAXCMDTEXT); 968 cmdnleft = MAXCMDTEXT - 4; 969 cmdtxt(n); 970 *cmdnextc = '\0'; 971 return name; 972} 973 974 975STATIC void 976cmdtxt(union node *n) 977{ 978 union node *np; 979 struct nodelist *lp; 980 char *p; 981 int i; 982 char s[2]; 983 984 if (n == NULL) 985 return; 986 switch (n->type) { 987 case NSEMI: 988 cmdtxt(n->nbinary.ch1); 989 cmdputs("; "); 990 cmdtxt(n->nbinary.ch2); 991 break; 992 case NAND: 993 cmdtxt(n->nbinary.ch1); 994 cmdputs(" && "); 995 cmdtxt(n->nbinary.ch2); 996 break; 997 case NOR: 998 cmdtxt(n->nbinary.ch1); 999 cmdputs(" || "); 1000 cmdtxt(n->nbinary.ch2); 1001 break; 1002 case NPIPE: 1003 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1004 cmdtxt(lp->n); 1005 if (lp->next) 1006 cmdputs(" | "); 1007 } 1008 break; 1009 case NSUBSHELL: 1010 cmdputs("("); 1011 cmdtxt(n->nredir.n); 1012 cmdputs(")"); 1013 break; 1014 case NREDIR: 1015 case NBACKGND: 1016 cmdtxt(n->nredir.n); 1017 break; 1018 case NIF: 1019 cmdputs("if "); 1020 cmdtxt(n->nif.test); 1021 cmdputs("; then "); 1022 cmdtxt(n->nif.ifpart); 1023 cmdputs("..."); 1024 break; 1025 case NWHILE: 1026 cmdputs("while "); 1027 goto until; 1028 case NUNTIL: 1029 cmdputs("until "); 1030until: 1031 cmdtxt(n->nbinary.ch1); 1032 cmdputs("; do "); 1033 cmdtxt(n->nbinary.ch2); 1034 cmdputs("; done"); 1035 break; 1036 case NFOR: 1037 cmdputs("for "); 1038 cmdputs(n->nfor.var); 1039 cmdputs(" in ..."); 1040 break; 1041 case NCASE: 1042 cmdputs("case "); 1043 cmdputs(n->ncase.expr->narg.text); 1044 cmdputs(" in ..."); 1045 break; 1046 case NDEFUN: 1047 cmdputs(n->narg.text); 1048 cmdputs("() ..."); 1049 break; 1050 case NCMD: 1051 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1052 cmdtxt(np); 1053 if (np->narg.next) 1054 cmdputs(" "); 1055 } 1056 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1057 cmdputs(" "); 1058 cmdtxt(np); 1059 } 1060 break; 1061 case NARG: 1062 cmdputs(n->narg.text); 1063 break; 1064 case NTO: 1065 p = ">"; i = 1; goto redir; 1066 case NAPPEND: 1067 p = ">>"; i = 1; goto redir; 1068 case NTOFD: 1069 p = ">&"; i = 1; goto redir; 1070 case NCLOBBER: 1071 p = ">|"; i = 1; goto redir; 1072 case NFROM: 1073 p = "<"; i = 0; goto redir; 1074 case NFROMTO: 1075 p = "<>"; i = 0; goto redir; 1076 case NFROMFD: 1077 p = "<&"; i = 0; goto redir; 1078redir: 1079 if (n->nfile.fd != i) { 1080 s[0] = n->nfile.fd + '0'; 1081 s[1] = '\0'; 1082 cmdputs(s); 1083 } 1084 cmdputs(p); 1085 if (n->type == NTOFD || n->type == NFROMFD) { 1086 s[0] = n->ndup.dupfd + '0'; 1087 s[1] = '\0'; 1088 cmdputs(s); 1089 } else { 1090 cmdtxt(n->nfile.fname); 1091 } 1092 break; 1093 case NHERE: 1094 case NXHERE: 1095 cmdputs("<<..."); 1096 break; 1097 default: 1098 cmdputs("???"); 1099 break; 1100 } 1101} 1102 1103 1104 1105STATIC void 1106cmdputs(char *s) 1107{ 1108 char *p, *q; 1109 char c; 1110 int subtype = 0; 1111 1112 if (cmdnleft <= 0) 1113 return; 1114 p = s; 1115 q = cmdnextc; 1116 while ((c = *p++) != '\0') { 1117 if (c == CTLESC) 1118 *q++ = *p++; 1119 else if (c == CTLVAR) { 1120 *q++ = '$'; 1121 if (--cmdnleft > 0) 1122 *q++ = '{'; 1123 subtype = *p++; 1124 } else if (c == '=' && subtype != 0) { 1125 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1126 subtype = 0; 1127 } else if (c == CTLENDVAR) { 1128 *q++ = '}'; 1129 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1130 cmdnleft++; /* ignore it */ 1131 else 1132 *q++ = c; 1133 if (--cmdnleft <= 0) { 1134 *q++ = '.'; 1135 *q++ = '.'; 1136 *q++ = '.'; 1137 break; 1138 } 1139 } 1140 cmdnextc = q; 1141} 1142