jobs.c revision 99760
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 41#endif /* not lint */ 42#include <sys/cdefs.h> 43__FBSDID("$FreeBSD: head/bin/sh/jobs.c 99760 2002-07-11 04:22:41Z tjr $"); 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 *, pid_t, 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 char *id; 277 int ch, sformat, lformat; 278 279 optind = optreset = 1; 280 sformat = lformat = 0; 281 while ((ch = getopt(argc, argv, "ls")) != -1) { 282 switch (ch) { 283 case 'l': 284 lformat = 1; 285 break; 286 case 's': 287 sformat = 1; 288 break; 289 case '?': 290 default: 291 error("unknown option: -%c", optopt); 292 } 293 } 294 argc -= optind; 295 argv += optind; 296 297 if (argc == 0) 298 showjobs(0, sformat, lformat); 299 else 300 while ((id = *argv++) != NULL) 301 showjob(getjob(id), 0, sformat, lformat); 302 303 return (0); 304} 305 306STATIC void 307showjob(struct job *jp, pid_t pid, int sformat, int lformat) 308{ 309 char s[64]; 310 struct procstat *ps; 311 struct job *j; 312 int col, curr, i, jobno, prev, procno; 313 char c; 314 315 procno = jp->nprocs; 316 jobno = jp - jobtab + 1; 317 curr = prev = 0; 318#if JOBS 319 if ((j = getcurjob(NULL)) != NULL) { 320 curr = j - jobtab + 1; 321 if ((j = getcurjob(j)) != NULL) 322 prev = j - jobtab + 1; 323 } 324#endif 325 for (ps = jp->ps ; ; ps++) { /* for each process */ 326 if (sformat) { 327 out1fmt("%d\n", ps->pid); 328 goto skip; 329 } 330 if (!lformat && ps != jp->ps && pid == 0) 331 goto skip; 332 if (pid != 0 && pid != ps->pid) 333 goto skip; 334 if (jobno == curr && ps == jp->ps) 335 c = '+'; 336 else if (jobno == prev && ps == jp->ps) 337 c = '-'; 338 else 339 c = ' '; 340 if (ps == jp->ps) 341 fmtstr(s, 64, "[%d] %c ", jobno, c); 342 else 343 fmtstr(s, 64, " %c ", c); 344 out1str(s); 345 col = strlen(s); 346 if (lformat) { 347 fmtstr(s, 64, "%d ", ps->pid); 348 out1str(s); 349 col += strlen(s); 350 } 351 s[0] = '\0'; 352 if (ps != jp->ps) { 353 *s = '\0'; 354 } else if (ps->status == -1) { 355 strcpy(s, "Running"); 356 } else if (WIFEXITED(ps->status)) { 357 if (WEXITSTATUS(ps->status) == 0) 358 strcpy(s, "Done"); 359 else 360 fmtstr(s, 64, "Done (%d)", 361 WEXITSTATUS(ps->status)); 362 } else { 363#if JOBS 364 if (WIFSTOPPED(ps->status)) 365 i = WSTOPSIG(ps->status); 366 else 367#endif 368 i = WTERMSIG(ps->status); 369 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 370 scopy(sys_siglist[i & 0x7F], s); 371 else 372 fmtstr(s, 64, "Signal %d", i & 0x7F); 373 if (WCOREDUMP(ps->status)) 374 strcat(s, " (core dumped)"); 375 } 376 out1str(s); 377 col += strlen(s); 378 do { 379 out1c(' '); 380 col++; 381 } while (col < 30); 382 out1str(ps->cmd); 383 out1c('\n'); 384skip: if (--procno <= 0) 385 break; 386 } 387} 388 389/* 390 * Print a list of jobs. If "change" is nonzero, only print jobs whose 391 * statuses have changed since the last call to showjobs. 392 * 393 * If the shell is interrupted in the process of creating a job, the 394 * result may be a job structure containing zero processes. Such structures 395 * will be freed here. 396 */ 397 398void 399showjobs(int change, int sformat, int lformat) 400{ 401 int jobno; 402 struct job *jp; 403 404 TRACE(("showjobs(%d) called\n", change)); 405 while (dowait(0, (struct job *)NULL) > 0); 406 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 407 if (! jp->used) 408 continue; 409 if (jp->nprocs == 0) { 410 freejob(jp); 411 continue; 412 } 413 if (change && ! jp->changed) 414 continue; 415 showjob(jp, 0, sformat, lformat); 416 jp->changed = 0; 417 if (jp->state == JOBDONE) { 418 freejob(jp); 419 } 420 } 421} 422 423 424/* 425 * Mark a job structure as unused. 426 */ 427 428STATIC void 429freejob(struct job *jp) 430{ 431 struct procstat *ps; 432 int i; 433 434 INTOFF; 435 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 436 if (ps->cmd != nullstr) 437 ckfree(ps->cmd); 438 } 439 if (jp->ps != &jp->ps0) 440 ckfree(jp->ps); 441 jp->used = 0; 442#if JOBS 443 deljob(jp); 444#endif 445 INTON; 446} 447 448 449 450int 451waitcmd(int argc, char **argv) 452{ 453 struct job *job; 454 int status, retval; 455 struct job *jp; 456 457 if (argc > 1) { 458 job = getjob(argv[1]); 459 } else { 460 job = NULL; 461 } 462 463 /* 464 * Loop until a process is terminated or stopped, or a SIGINT is 465 * received. 466 */ 467 468 in_waitcmd++; 469 do { 470 if (job != NULL) { 471 if (job->state) { 472 status = job->ps[job->nprocs - 1].status; 473 if (WIFEXITED(status)) 474 retval = WEXITSTATUS(status); 475#if JOBS 476 else if (WIFSTOPPED(status)) 477 retval = WSTOPSIG(status) + 128; 478#endif 479 else 480 retval = WTERMSIG(status) + 128; 481 if (! iflag) 482 freejob(job); 483 in_waitcmd--; 484 return retval; 485 } 486 } else { 487 for (jp = jobtab ; ; jp++) { 488 if (jp >= jobtab + njobs) { /* no running procs */ 489 in_waitcmd--; 490 return 0; 491 } 492 if (jp->used && jp->state == 0) 493 break; 494 } 495 } 496 } while (dowait(1, (struct job *)NULL) != -1); 497 in_waitcmd--; 498 499 return 0; 500} 501 502 503 504int 505jobidcmd(int argc __unused, char **argv) 506{ 507 struct job *jp; 508 int i; 509 510 jp = getjob(argv[1]); 511 for (i = 0 ; i < jp->nprocs ; ) { 512 out1fmt("%d", jp->ps[i].pid); 513 out1c(++i < jp->nprocs? ' ' : '\n'); 514 } 515 return 0; 516} 517 518 519 520/* 521 * Convert a job name to a job structure. 522 */ 523 524STATIC struct job * 525getjob(char *name) 526{ 527 int jobno; 528 struct job *found, *jp; 529 int pid; 530 int i; 531 532 if (name == NULL) { 533#if JOBS 534currentjob: if ((jp = getcurjob(NULL)) == NULL) 535 error("No current job"); 536 return (jp); 537#else 538 error("No current job"); 539#endif 540 } else if (name[0] == '%') { 541 if (is_digit(name[1])) { 542 jobno = number(name + 1); 543 if (jobno > 0 && jobno <= njobs 544 && jobtab[jobno - 1].used != 0) 545 return &jobtab[jobno - 1]; 546#if JOBS 547 } else if (name[1] == '%' && name[2] == '\0') { 548 goto currentjob; 549 } else if (name[1] == '+' && name[2] == '\0') { 550 goto currentjob; 551 } else if (name[1] == '-' && name[2] == '\0') { 552 if ((jp = getcurjob(NULL)) == NULL || 553 (jp = getcurjob(jp)) == NULL) 554 error("No previous job"); 555 return (jp); 556#endif 557 } else if (name[1] == '?') { 558 found = NULL; 559 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 560 if (jp->used && jp->nprocs > 0 561 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 562 if (found) 563 error("%s: ambiguous", name); 564 found = jp; 565 } 566 } 567 if (found != NULL) 568 return (found); 569 } else { 570 found = NULL; 571 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 572 if (jp->used && jp->nprocs > 0 573 && prefix(name + 1, jp->ps[0].cmd)) { 574 if (found) 575 error("%s: ambiguous", name); 576 found = jp; 577 } 578 } 579 if (found) 580 return found; 581 } 582 } else if (is_number(name)) { 583 pid = number(name); 584 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 585 if (jp->used && jp->nprocs > 0 586 && jp->ps[jp->nprocs - 1].pid == pid) 587 return jp; 588 } 589 } 590 error("No such job: %s", name); 591 /*NOTREACHED*/ 592 return NULL; 593} 594 595 596 597/* 598 * Return a new job structure, 599 */ 600 601struct job * 602makejob(union node *node __unused, int nprocs) 603{ 604 int i; 605 struct job *jp; 606 607 for (i = njobs, jp = jobtab ; ; jp++) { 608 if (--i < 0) { 609 INTOFF; 610 if (njobs == 0) { 611 jobtab = ckmalloc(4 * sizeof jobtab[0]); 612#if JOBS 613 jobmru = NULL; 614#endif 615 } else { 616 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 617 memcpy(jp, jobtab, njobs * sizeof jp[0]); 618#if JOBS 619 /* Relocate `next' pointers and list head */ 620 if (jobmru != NULL) 621 jobmru = &jp[jobmru - jobtab]; 622 for (i = 0; i < njobs; i++) 623 if (jp[i].next != NULL) 624 jp[i].next = &jp[jp[i].next - 625 jobtab]; 626#endif 627 /* Relocate `ps' pointers */ 628 for (i = 0; i < njobs; i++) 629 if (jp[i].ps == &jobtab[i].ps0) 630 jp[i].ps = &jp[i].ps0; 631 ckfree(jobtab); 632 jobtab = jp; 633 } 634 jp = jobtab + njobs; 635 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 636 INTON; 637 break; 638 } 639 if (jp->used == 0) 640 break; 641 } 642 INTOFF; 643 jp->state = 0; 644 jp->used = 1; 645 jp->changed = 0; 646 jp->nprocs = 0; 647#if JOBS 648 jp->jobctl = jobctl; 649 jp->next = NULL; 650#endif 651 if (nprocs > 1) { 652 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 653 } else { 654 jp->ps = &jp->ps0; 655 } 656 INTON; 657 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 658 jp - jobtab + 1)); 659 return jp; 660} 661 662#if JOBS 663STATIC void 664setcurjob(struct job *cj) 665{ 666 struct job *jp, *prev; 667 668 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 669 if (jp == cj) { 670 if (prev != NULL) 671 prev->next = jp->next; 672 else 673 jobmru = jp->next; 674 jp->next = jobmru; 675 jobmru = cj; 676 return; 677 } 678 } 679 cj->next = jobmru; 680 jobmru = cj; 681} 682 683STATIC void 684deljob(struct job *j) 685{ 686 struct job *jp, *prev; 687 688 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 689 if (jp == j) { 690 if (prev != NULL) 691 prev->next = jp->next; 692 else 693 jobmru = jp->next; 694 return; 695 } 696 } 697} 698 699/* 700 * Return the most recently used job that isn't `nj', and preferably one 701 * that is stopped. 702 */ 703STATIC struct job * 704getcurjob(struct job *nj) 705{ 706 struct job *jp; 707 708 /* Try to find a stopped one.. */ 709 for (jp = jobmru; jp != NULL; jp = jp->next) 710 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 711 return (jp); 712 /* Otherwise the most recently used job that isn't `nj' */ 713 for (jp = jobmru; jp != NULL; jp = jp->next) 714 if (jp->used && jp != nj) 715 return (jp); 716 717 return (NULL); 718} 719 720#endif 721 722/* 723 * Fork of a subshell. If we are doing job control, give the subshell its 724 * own process group. Jp is a job structure that the job is to be added to. 725 * N is the command that will be evaluated by the child. Both jp and n may 726 * be NULL. The mode parameter can be one of the following: 727 * FORK_FG - Fork off a foreground process. 728 * FORK_BG - Fork off a background process. 729 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 730 * process group even if job control is on. 731 * 732 * When job control is turned off, background processes have their standard 733 * input redirected to /dev/null (except for the second and later processes 734 * in a pipeline). 735 */ 736 737int 738forkshell(struct job *jp, union node *n, int mode) 739{ 740 int pid; 741 int pgrp; 742 743 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 744 mode)); 745 INTOFF; 746 pid = fork(); 747 if (pid == -1) { 748 TRACE(("Fork failed, errno=%d\n", errno)); 749 INTON; 750 error("Cannot fork: %s", strerror(errno)); 751 } 752 if (pid == 0) { 753 struct job *p; 754 int wasroot; 755 int i; 756 757 TRACE(("Child shell %d\n", getpid())); 758 wasroot = rootshell; 759 rootshell = 0; 760 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 761 if (p->used) 762 freejob(p); 763 closescript(); 764 INTON; 765 clear_traps(); 766#if JOBS 767 jobctl = 0; /* do job control only in root shell */ 768 if (wasroot && mode != FORK_NOJOB && mflag) { 769 if (jp == NULL || jp->nprocs == 0) 770 pgrp = getpid(); 771 else 772 pgrp = jp->ps[0].pid; 773 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 774 /*** this causes superfluous TIOCSPGRPS ***/ 775#ifdef OLD_TTY_DRIVER 776 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 777 error("TIOCSPGRP failed, errno=%d", errno); 778#else 779 if (tcsetpgrp(2, pgrp) < 0) 780 error("tcsetpgrp failed, errno=%d", errno); 781#endif 782 } 783 setsignal(SIGTSTP); 784 setsignal(SIGTTOU); 785 } else if (mode == FORK_BG) { 786 ignoresig(SIGINT); 787 ignoresig(SIGQUIT); 788 if ((jp == NULL || jp->nprocs == 0) && 789 ! fd0_redirected_p ()) { 790 close(0); 791 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 792 error("Can't open %s: %s", 793 _PATH_DEVNULL, strerror(errno)); 794 } 795 } 796#else 797 if (mode == FORK_BG) { 798 ignoresig(SIGINT); 799 ignoresig(SIGQUIT); 800 if ((jp == NULL || jp->nprocs == 0) && 801 ! fd0_redirected_p ()) { 802 close(0); 803 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 804 error("Can't open %s: %s", 805 _PATH_DEVNULL, strerror(errno)); 806 } 807 } 808#endif 809 if (wasroot && iflag) { 810 setsignal(SIGINT); 811 setsignal(SIGQUIT); 812 setsignal(SIGTERM); 813 } 814 return pid; 815 } 816 if (rootshell && mode != FORK_NOJOB && mflag) { 817 if (jp == NULL || jp->nprocs == 0) 818 pgrp = pid; 819 else 820 pgrp = jp->ps[0].pid; 821 setpgid(pid, pgrp); 822 } 823 if (mode == FORK_BG) 824 backgndpid = pid; /* set $! */ 825 if (jp) { 826 struct procstat *ps = &jp->ps[jp->nprocs++]; 827 ps->pid = pid; 828 ps->status = -1; 829 ps->cmd = nullstr; 830 if (iflag && rootshell && n) 831 ps->cmd = commandtext(n); 832#if JOBS 833 setcurjob(jp); 834#endif 835 } 836 INTON; 837 TRACE(("In parent shell: child = %d\n", pid)); 838 return pid; 839} 840 841 842 843/* 844 * Wait for job to finish. 845 * 846 * Under job control we have the problem that while a child process is 847 * running interrupts generated by the user are sent to the child but not 848 * to the shell. This means that an infinite loop started by an inter- 849 * active user may be hard to kill. With job control turned off, an 850 * interactive user may place an interactive program inside a loop. If 851 * the interactive program catches interrupts, the user doesn't want 852 * these interrupts to also abort the loop. The approach we take here 853 * is to have the shell ignore interrupt signals while waiting for a 854 * foreground process to terminate, and then send itself an interrupt 855 * signal if the child process was terminated by an interrupt signal. 856 * Unfortunately, some programs want to do a bit of cleanup and then 857 * exit on interrupt; unless these processes terminate themselves by 858 * sending a signal to themselves (instead of calling exit) they will 859 * confuse this approach. 860 */ 861 862int 863waitforjob(struct job *jp, int *origstatus) 864{ 865#if JOBS 866 int mypgrp = getpgrp(); 867#endif 868 int status; 869 int st; 870 871 INTOFF; 872 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 873 while (jp->state == 0) 874 if (dowait(1, jp) == -1) 875 dotrap(); 876#if JOBS 877 if (jp->jobctl) { 878#ifdef OLD_TTY_DRIVER 879 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 880 error("TIOCSPGRP failed, errno=%d\n", errno); 881#else 882 if (tcsetpgrp(2, mypgrp) < 0) 883 error("tcsetpgrp failed, errno=%d\n", errno); 884#endif 885 } 886 if (jp->state == JOBSTOPPED) 887 setcurjob(jp); 888#endif 889 status = jp->ps[jp->nprocs - 1].status; 890 if (origstatus != NULL) 891 *origstatus = status; 892 /* convert to 8 bits */ 893 if (WIFEXITED(status)) 894 st = WEXITSTATUS(status); 895#if JOBS 896 else if (WIFSTOPPED(status)) 897 st = WSTOPSIG(status) + 128; 898#endif 899 else 900 st = WTERMSIG(status) + 128; 901 if (! JOBS || jp->state == JOBDONE) 902 freejob(jp); 903 if (int_pending()) { 904 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 905 kill(getpid(), SIGINT); 906 else 907 CLEAR_PENDING_INT; 908 } 909 INTON; 910 return st; 911} 912 913 914 915/* 916 * Wait for a process to terminate. 917 */ 918 919STATIC int 920dowait(int block, struct job *job) 921{ 922 int pid; 923 int status; 924 struct procstat *sp; 925 struct job *jp; 926 struct job *thisjob; 927 int done; 928 int stopped; 929 int sig; 930 931 in_dowait++; 932 TRACE(("dowait(%d) called\n", block)); 933 do { 934 pid = waitproc(block, &status); 935 TRACE(("wait returns %d, status=%d\n", pid, status)); 936 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 937 (WIFSTOPPED(status) && !iflag)); 938 in_dowait--; 939 if (breakwaitcmd != 0) { 940 breakwaitcmd = 0; 941 return -1; 942 } 943 if (pid <= 0) 944 return pid; 945 INTOFF; 946 thisjob = NULL; 947 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 948 if (jp->used) { 949 done = 1; 950 stopped = 1; 951 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 952 if (sp->pid == -1) 953 continue; 954 if (sp->pid == pid) { 955 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 956 pid, sp->status, status)); 957 sp->status = status; 958 thisjob = jp; 959 } 960 if (sp->status == -1) 961 stopped = 0; 962 else if (WIFSTOPPED(sp->status)) 963 done = 0; 964 } 965 if (stopped) { /* stopped or done */ 966 int state = done? JOBDONE : JOBSTOPPED; 967 if (jp->state != state) { 968 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 969 jp->state = state; 970#if JOBS 971 if (done) 972 deljob(jp); 973#endif 974 } 975 } 976 } 977 } 978 INTON; 979 if (! rootshell || ! iflag || (job && thisjob == job)) { 980#if JOBS 981 if (WIFSTOPPED(status)) 982 sig = WSTOPSIG(status); 983 else 984#endif 985 { 986 if (WIFEXITED(status)) 987 sig = 0; 988 else 989 sig = WTERMSIG(status); 990 } 991 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) 992 showjob(thisjob, pid, 0, 1); 993 } else { 994 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 995 if (thisjob) 996 thisjob->changed = 1; 997 } 998 return pid; 999} 1000 1001 1002 1003/* 1004 * Do a wait system call. If job control is compiled in, we accept 1005 * stopped processes. If block is zero, we return a value of zero 1006 * rather than blocking. 1007 * 1008 * System V doesn't have a non-blocking wait system call. It does 1009 * have a SIGCLD signal that is sent to a process when one of it's 1010 * children dies. The obvious way to use SIGCLD would be to install 1011 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 1012 * was received, and have waitproc bump another counter when it got 1013 * the status of a process. Waitproc would then know that a wait 1014 * system call would not block if the two counters were different. 1015 * This approach doesn't work because if a process has children that 1016 * have not been waited for, System V will send it a SIGCLD when it 1017 * installs a signal handler for SIGCLD. What this means is that when 1018 * a child exits, the shell will be sent SIGCLD signals continuously 1019 * until is runs out of stack space, unless it does a wait call before 1020 * restoring the signal handler. The code below takes advantage of 1021 * this (mis)feature by installing a signal handler for SIGCLD and 1022 * then checking to see whether it was called. If there are any 1023 * children to be waited for, it will be. 1024 * 1025 * If neither SYSV nor BSD is defined, we don't implement nonblocking 1026 * waits at all. In this case, the user will not be informed when 1027 * a background process until the next time she runs a real program 1028 * (as opposed to running a builtin command or just typing return), 1029 * and the jobs command may give out of date information. 1030 */ 1031 1032#ifdef SYSV 1033STATIC sig_atomic_t gotsigchild; 1034 1035STATIC int onsigchild() { 1036 gotsigchild = 1; 1037} 1038#endif 1039 1040 1041STATIC int 1042waitproc(int block, int *status) 1043{ 1044#ifdef BSD 1045 int flags; 1046 1047#if JOBS 1048 flags = WUNTRACED; 1049#else 1050 flags = 0; 1051#endif 1052 if (block == 0) 1053 flags |= WNOHANG; 1054 return wait3(status, flags, (struct rusage *)NULL); 1055#else 1056#ifdef SYSV 1057 int (*save)(); 1058 1059 if (block == 0) { 1060 gotsigchild = 0; 1061 save = signal(SIGCLD, onsigchild); 1062 signal(SIGCLD, save); 1063 if (gotsigchild == 0) 1064 return 0; 1065 } 1066 return wait(status); 1067#else 1068 if (block == 0) 1069 return 0; 1070 return wait(status); 1071#endif 1072#endif 1073} 1074 1075/* 1076 * return 1 if there are stopped jobs, otherwise 0 1077 */ 1078int job_warning = 0; 1079int 1080stoppedjobs(void) 1081{ 1082 int jobno; 1083 struct job *jp; 1084 1085 if (job_warning) 1086 return (0); 1087 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1088 if (jp->used == 0) 1089 continue; 1090 if (jp->state == JOBSTOPPED) { 1091 out2str("You have stopped jobs.\n"); 1092 job_warning = 2; 1093 return (1); 1094 } 1095 } 1096 1097 return (0); 1098} 1099 1100/* 1101 * Return a string identifying a command (to be printed by the 1102 * jobs command. 1103 */ 1104 1105STATIC char *cmdnextc; 1106STATIC int cmdnleft; 1107#define MAXCMDTEXT 200 1108 1109char * 1110commandtext(union node *n) 1111{ 1112 char *name; 1113 1114 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1115 cmdnleft = MAXCMDTEXT - 4; 1116 cmdtxt(n); 1117 *cmdnextc = '\0'; 1118 return name; 1119} 1120 1121 1122STATIC void 1123cmdtxt(union node *n) 1124{ 1125 union node *np; 1126 struct nodelist *lp; 1127 char *p; 1128 int i; 1129 char s[2]; 1130 1131 if (n == NULL) 1132 return; 1133 switch (n->type) { 1134 case NSEMI: 1135 cmdtxt(n->nbinary.ch1); 1136 cmdputs("; "); 1137 cmdtxt(n->nbinary.ch2); 1138 break; 1139 case NAND: 1140 cmdtxt(n->nbinary.ch1); 1141 cmdputs(" && "); 1142 cmdtxt(n->nbinary.ch2); 1143 break; 1144 case NOR: 1145 cmdtxt(n->nbinary.ch1); 1146 cmdputs(" || "); 1147 cmdtxt(n->nbinary.ch2); 1148 break; 1149 case NPIPE: 1150 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1151 cmdtxt(lp->n); 1152 if (lp->next) 1153 cmdputs(" | "); 1154 } 1155 break; 1156 case NSUBSHELL: 1157 cmdputs("("); 1158 cmdtxt(n->nredir.n); 1159 cmdputs(")"); 1160 break; 1161 case NREDIR: 1162 case NBACKGND: 1163 cmdtxt(n->nredir.n); 1164 break; 1165 case NIF: 1166 cmdputs("if "); 1167 cmdtxt(n->nif.test); 1168 cmdputs("; then "); 1169 cmdtxt(n->nif.ifpart); 1170 cmdputs("..."); 1171 break; 1172 case NWHILE: 1173 cmdputs("while "); 1174 goto until; 1175 case NUNTIL: 1176 cmdputs("until "); 1177until: 1178 cmdtxt(n->nbinary.ch1); 1179 cmdputs("; do "); 1180 cmdtxt(n->nbinary.ch2); 1181 cmdputs("; done"); 1182 break; 1183 case NFOR: 1184 cmdputs("for "); 1185 cmdputs(n->nfor.var); 1186 cmdputs(" in ..."); 1187 break; 1188 case NCASE: 1189 cmdputs("case "); 1190 cmdputs(n->ncase.expr->narg.text); 1191 cmdputs(" in ..."); 1192 break; 1193 case NDEFUN: 1194 cmdputs(n->narg.text); 1195 cmdputs("() ..."); 1196 break; 1197 case NCMD: 1198 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1199 cmdtxt(np); 1200 if (np->narg.next) 1201 cmdputs(" "); 1202 } 1203 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1204 cmdputs(" "); 1205 cmdtxt(np); 1206 } 1207 break; 1208 case NARG: 1209 cmdputs(n->narg.text); 1210 break; 1211 case NTO: 1212 p = ">"; i = 1; goto redir; 1213 case NAPPEND: 1214 p = ">>"; i = 1; goto redir; 1215 case NTOFD: 1216 p = ">&"; i = 1; goto redir; 1217 case NCLOBBER: 1218 p = ">|"; i = 1; goto redir; 1219 case NFROM: 1220 p = "<"; i = 0; goto redir; 1221 case NFROMTO: 1222 p = "<>"; i = 0; goto redir; 1223 case NFROMFD: 1224 p = "<&"; i = 0; goto redir; 1225redir: 1226 if (n->nfile.fd != i) { 1227 s[0] = n->nfile.fd + '0'; 1228 s[1] = '\0'; 1229 cmdputs(s); 1230 } 1231 cmdputs(p); 1232 if (n->type == NTOFD || n->type == NFROMFD) { 1233 if (n->ndup.dupfd >= 0) 1234 s[0] = n->ndup.dupfd + '0'; 1235 else 1236 s[0] = '-'; 1237 s[1] = '\0'; 1238 cmdputs(s); 1239 } else { 1240 cmdtxt(n->nfile.fname); 1241 } 1242 break; 1243 case NHERE: 1244 case NXHERE: 1245 cmdputs("<<..."); 1246 break; 1247 default: 1248 cmdputs("???"); 1249 break; 1250 } 1251} 1252 1253 1254 1255STATIC void 1256cmdputs(char *s) 1257{ 1258 char *p, *q; 1259 char c; 1260 int subtype = 0; 1261 1262 if (cmdnleft <= 0) 1263 return; 1264 p = s; 1265 q = cmdnextc; 1266 while ((c = *p++) != '\0') { 1267 if (c == CTLESC) 1268 *q++ = *p++; 1269 else if (c == CTLVAR) { 1270 *q++ = '$'; 1271 if (--cmdnleft > 0) 1272 *q++ = '{'; 1273 subtype = *p++; 1274 } else if (c == '=' && subtype != 0) { 1275 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1276 subtype = 0; 1277 } else if (c == CTLENDVAR) { 1278 *q++ = '}'; 1279 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1280 cmdnleft++; /* ignore it */ 1281 else 1282 *q++ = c; 1283 if (--cmdnleft <= 0) { 1284 *q++ = '.'; 1285 *q++ = '.'; 1286 *q++ = '.'; 1287 break; 1288 } 1289 } 1290 cmdnextc = q; 1291} 1292