jobs.c revision 97688
1207753Smm/*- 2207753Smm * Copyright (c) 1991, 1993 3207753Smm * The Regents of the University of California. All rights reserved. 4207753Smm * 5207753Smm * This code is derived from software contributed to Berkeley by 6207753Smm * Kenneth Almquist. 7207753Smm * 8207753Smm * Redistribution and use in source and binary forms, with or without 9207753Smm * modification, are permitted provided that the following conditions 10207753Smm * are met: 11207753Smm * 1. Redistributions of source code must retain the above copyright 12207753Smm * notice, this list of conditions and the following disclaimer. 13207753Smm * 2. Redistributions in binary form must reproduce the above copyright 14207753Smm * notice, this list of conditions and the following disclaimer in the 15207753Smm * documentation and/or other materials provided with the distribution. 16207753Smm * 3. All advertising materials mentioning features or use of this software 17207753Smm * must display the following acknowledgement: 18207753Smm * This product includes software developed by the University of 19207753Smm * California, Berkeley and its contributors. 20207753Smm * 4. Neither the name of the University nor the names of its contributors 21207753Smm * may be used to endorse or promote products derived from this software 22207753Smm * without specific prior written permission. 23207753Smm * 24207753Smm * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25207753Smm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26207753Smm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27207753Smm * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28207753Smm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29207753Smm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30207753Smm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31207753Smm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32207753Smm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33207753Smm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34207753Smm * SUCH DAMAGE. 35207753Smm */ 36207753Smm 37207753Smm#ifndef lint 38207753Smm#if 0 39207753Smmstatic char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 40207753Smm#endif 41207753Smmstatic const char rcsid[] = 42207753Smm "$FreeBSD: head/bin/sh/jobs.c 97688 2002-06-01 01:51:42Z tjr $"; 43207753Smm#endif /* not lint */ 44207753Smm 45207753Smm#include <fcntl.h> 46207753Smm#include <signal.h> 47207753Smm#include <errno.h> 48207753Smm#include <unistd.h> 49207753Smm#include <stdlib.h> 50207753Smm#include <sys/param.h> 51207753Smm#ifdef BSD 52207753Smm#include <sys/wait.h> 53207753Smm#include <sys/time.h> 54207753Smm#include <sys/resource.h> 55207753Smm#include <paths.h> 56207753Smm#endif 57207753Smm#include <sys/ioctl.h> 58 59#include "shell.h" 60#if JOBS 61#if OLD_TTY_DRIVER 62#include "sgtty.h" 63#else 64#include <termios.h> 65#endif 66#undef CEOF /* syntax.h redefines this */ 67#endif 68#include "redir.h" 69#include "show.h" 70#include "main.h" 71#include "parser.h" 72#include "nodes.h" 73#include "jobs.h" 74#include "options.h" 75#include "trap.h" 76#include "syntax.h" 77#include "input.h" 78#include "output.h" 79#include "memalloc.h" 80#include "error.h" 81#include "mystring.h" 82 83 84struct job *jobtab; /* array of jobs */ 85int njobs; /* size of array */ 86MKINIT pid_t backgndpid = -1; /* pid of last background process */ 87#if JOBS 88struct job *jobmru; /* most recently used job list */ 89int initialpgrp; /* pgrp of shell on invocation */ 90#endif 91int in_waitcmd = 0; /* are we in waitcmd()? */ 92int in_dowait = 0; /* are we in dowait()? */ 93volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 94 95#if JOBS 96STATIC void restartjob(struct job *); 97#endif 98STATIC void freejob(struct job *); 99STATIC struct job *getjob(char *); 100STATIC int dowait(int, struct job *); 101#if SYSV 102STATIC int onsigchild(void); 103#endif 104STATIC int waitproc(int, int *); 105STATIC void cmdtxt(union node *); 106STATIC void cmdputs(char *); 107#if JOBS 108STATIC void setcurjob(struct job *); 109STATIC void deljob(struct job *); 110STATIC struct job *getcurjob(struct job *); 111#endif 112STATIC void showjob(struct job *, int, int); 113 114 115/* 116 * Turn job control on and off. 117 * 118 * Note: This code assumes that the third arg to ioctl is a character 119 * pointer, which is true on Berkeley systems but not System V. Since 120 * System V doesn't have job control yet, this isn't a problem now. 121 */ 122 123MKINIT int jobctl; 124 125#if JOBS 126void 127setjobctl(int on) 128{ 129#ifdef OLD_TTY_DRIVER 130 int ldisc; 131#endif 132 133 if (on == jobctl || rootshell == 0) 134 return; 135 if (on) { 136 do { /* while we are in the background */ 137#ifdef OLD_TTY_DRIVER 138 if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { 139#else 140 initialpgrp = tcgetpgrp(2); 141 if (initialpgrp < 0) { 142#endif 143 out2str("sh: can't access tty; job control turned off\n"); 144 mflag = 0; 145 return; 146 } 147 if (initialpgrp == -1) 148 initialpgrp = getpgrp(); 149 else if (initialpgrp != getpgrp()) { 150 killpg(initialpgrp, SIGTTIN); 151 continue; 152 } 153 } while (0); 154#ifdef OLD_TTY_DRIVER 155 if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { 156 out2str("sh: need new tty driver to run job control; job control turned off\n"); 157 mflag = 0; 158 return; 159 } 160#endif 161 setsignal(SIGTSTP); 162 setsignal(SIGTTOU); 163 setsignal(SIGTTIN); 164 setpgid(0, rootpid); 165#ifdef OLD_TTY_DRIVER 166 ioctl(2, TIOCSPGRP, (char *)&rootpid); 167#else 168 tcsetpgrp(2, rootpid); 169#endif 170 } else { /* turning job control off */ 171 setpgid(0, initialpgrp); 172#ifdef OLD_TTY_DRIVER 173 ioctl(2, TIOCSPGRP, (char *)&initialpgrp); 174#else 175 tcsetpgrp(2, initialpgrp); 176#endif 177 setsignal(SIGTSTP); 178 setsignal(SIGTTOU); 179 setsignal(SIGTTIN); 180 } 181 jobctl = on; 182} 183#endif 184 185 186#ifdef mkinit 187INCLUDE <sys/types.h> 188INCLUDE <stdlib.h> 189 190SHELLPROC { 191 backgndpid = -1; 192#if JOBS 193 jobctl = 0; 194#endif 195} 196 197#endif 198 199 200 201#if JOBS 202int 203fgcmd(int argc __unused, char **argv) 204{ 205 struct job *jp; 206 int pgrp; 207 int status; 208 209 jp = getjob(argv[1]); 210 if (jp->jobctl == 0) 211 error("job not created under job control"); 212 out1str(jp->ps[0].cmd); 213 out1c('\n'); 214 flushout(&output); 215 pgrp = jp->ps[0].pid; 216#ifdef OLD_TTY_DRIVER 217 ioctl(2, TIOCSPGRP, (char *)&pgrp); 218#else 219 tcsetpgrp(2, pgrp); 220#endif 221 restartjob(jp); 222 INTOFF; 223 status = waitforjob(jp, (int *)NULL); 224 INTON; 225 return status; 226} 227 228 229int 230bgcmd(int argc, char **argv) 231{ 232 char s[64]; 233 struct job *jp; 234 235 do { 236 jp = getjob(*++argv); 237 if (jp->jobctl == 0) 238 error("job not created under job control"); 239 if (jp->state == JOBDONE) 240 continue; 241 restartjob(jp); 242 fmtstr(s, 64, "[%d] ", jp - jobtab + 1); 243 out1str(s); 244 out1str(jp->ps[0].cmd); 245 out1c('\n'); 246 } while (--argc > 1); 247 return 0; 248} 249 250 251STATIC void 252restartjob(struct job *jp) 253{ 254 struct procstat *ps; 255 int i; 256 257 if (jp->state == JOBDONE) 258 return; 259 setcurjob(jp); 260 INTOFF; 261 killpg(jp->ps[0].pid, SIGCONT); 262 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 263 if (WIFSTOPPED(ps->status)) { 264 ps->status = -1; 265 jp->state = 0; 266 } 267 } 268 INTON; 269} 270#endif 271 272 273int 274jobscmd(int argc, char *argv[]) 275{ 276 struct job *jp; 277 char *id; 278 int ch, sformat, lformat; 279 280 optind = optreset = 1; 281 sformat = lformat = 0; 282 while ((ch = getopt(argc, argv, "ls")) != -1) { 283 switch (ch) { 284 case 'l': 285 lformat = 1; 286 break; 287 case 's': 288 sformat = 1; 289 break; 290 case '?': 291 default: 292 error("unknown option: -%c", optopt); 293 } 294 } 295 argc -= optind; 296 argv += optind; 297 298 if (argc == 0) 299 showjobs(0, sformat, lformat); 300 else 301 while ((id = *argv++) != NULL) 302 showjob(getjob(id), sformat, lformat); 303 304 return (0); 305} 306 307STATIC void 308showjob(struct job *jp, int sformat, int lformat) 309{ 310 char s[64]; 311 struct procstat *ps; 312 struct job *j; 313 int col, curr, i, jobno, prev, procno; 314 char c; 315 316 procno = jp->nprocs; 317 jobno = jp - jobtab + 1; 318 curr = prev = 0; 319#if JOBS 320 if ((j = getcurjob(NULL)) != NULL) { 321 curr = j - jobtab + 1; 322 if ((j = getcurjob(j)) != NULL) 323 prev = j - jobtab + 1; 324 } 325#endif 326 for (ps = jp->ps ; ; ps++) { /* for each process */ 327 if (sformat) { 328 out1fmt("%d\n", ps->pid); 329 goto skip; 330 } 331 if (!lformat && ps != jp->ps) 332 goto skip; 333 if (jobno == curr) 334 c = '+'; 335 else if (jobno == prev) 336 c = '-'; 337 else 338 c = ' '; 339 if (ps == jp->ps) 340 fmtstr(s, 64, "[%d] %c ", jobno, c); 341 else 342 fmtstr(s, 64, " %c ", c); 343 out1str(s); 344 col = strlen(s); 345 if (lformat) { 346 fmtstr(s, 64, "%d ", ps->pid); 347 out1str(s); 348 col += strlen(s); 349 } 350 s[0] = '\0'; 351 if (ps->status == -1) { 352 strcpy(s, "Running"); 353 } else if (WIFEXITED(ps->status)) { 354 fmtstr(s, 64, "Exit %d", WEXITSTATUS(ps->status)); 355 } else { 356#if JOBS 357 if (WIFSTOPPED(ps->status)) 358 i = WSTOPSIG(ps->status); 359 else 360#endif 361 i = WTERMSIG(ps->status); 362 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 363 scopy(sys_siglist[i & 0x7F], s); 364 else 365 fmtstr(s, 64, "Signal %d", i & 0x7F); 366 if (WCOREDUMP(ps->status)) 367 strcat(s, " (core dumped)"); 368 } 369 out1str(s); 370 col += strlen(s); 371 do { 372 out1c(' '); 373 col++; 374 } while (col < 30); 375 out1str(ps->cmd); 376 out1c('\n'); 377skip: if (--procno <= 0) 378 break; 379 } 380} 381 382/* 383 * Print a list of jobs. If "change" is nonzero, only print jobs whose 384 * statuses have changed since the last call to showjobs. 385 * 386 * If the shell is interrupted in the process of creating a job, the 387 * result may be a job structure containing zero processes. Such structures 388 * will be freed here. 389 */ 390 391void 392showjobs(int change, int sformat, int lformat) 393{ 394 int jobno; 395 struct job *jp; 396 397 TRACE(("showjobs(%d) called\n", change)); 398 while (dowait(0, (struct job *)NULL) > 0); 399 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 400 if (! jp->used) 401 continue; 402 if (jp->nprocs == 0) { 403 freejob(jp); 404 continue; 405 } 406 if (change && ! jp->changed) 407 continue; 408 showjob(jp, sformat, lformat); 409 jp->changed = 0; 410 if (jp->state == JOBDONE) { 411 freejob(jp); 412 } 413 } 414} 415 416 417/* 418 * Mark a job structure as unused. 419 */ 420 421STATIC void 422freejob(struct job *jp) 423{ 424 struct procstat *ps; 425 int i; 426 427 INTOFF; 428 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 429 if (ps->cmd != nullstr) 430 ckfree(ps->cmd); 431 } 432 if (jp->ps != &jp->ps0) 433 ckfree(jp->ps); 434 jp->used = 0; 435#if JOBS 436 deljob(jp); 437#endif 438 INTON; 439} 440 441 442 443int 444waitcmd(int argc, char **argv) 445{ 446 struct job *job; 447 int status, retval; 448 struct job *jp; 449 450 if (argc > 1) { 451 job = getjob(argv[1]); 452 } else { 453 job = NULL; 454 } 455 456 /* 457 * Loop until a process is terminated or stopped, or a SIGINT is 458 * received. 459 */ 460 461 in_waitcmd++; 462 do { 463 if (job != NULL) { 464 if (job->state) { 465 status = job->ps[job->nprocs - 1].status; 466 if (WIFEXITED(status)) 467 retval = WEXITSTATUS(status); 468#if JOBS 469 else if (WIFSTOPPED(status)) 470 retval = WSTOPSIG(status) + 128; 471#endif 472 else 473 retval = WTERMSIG(status) + 128; 474 if (! iflag) 475 freejob(job); 476 in_waitcmd--; 477 return retval; 478 } 479 } else { 480 for (jp = jobtab ; ; jp++) { 481 if (jp >= jobtab + njobs) { /* no running procs */ 482 in_waitcmd--; 483 return 0; 484 } 485 if (jp->used && jp->state == 0) 486 break; 487 } 488 } 489 } while (dowait(1, (struct job *)NULL) != -1); 490 in_waitcmd--; 491 492 return 0; 493} 494 495 496 497int 498jobidcmd(int argc __unused, char **argv) 499{ 500 struct job *jp; 501 int i; 502 503 jp = getjob(argv[1]); 504 for (i = 0 ; i < jp->nprocs ; ) { 505 out1fmt("%d", jp->ps[i].pid); 506 out1c(++i < jp->nprocs? ' ' : '\n'); 507 } 508 return 0; 509} 510 511 512 513/* 514 * Convert a job name to a job structure. 515 */ 516 517STATIC struct job * 518getjob(char *name) 519{ 520 int jobno; 521 struct job *found, *jp; 522 int pid; 523 int i; 524 525 if (name == NULL) { 526#if JOBS 527currentjob: if ((jp = getcurjob(NULL)) == NULL) 528 error("No current job"); 529 return (jp); 530#else 531 error("No current job"); 532#endif 533 } else if (name[0] == '%') { 534 if (is_digit(name[1])) { 535 jobno = number(name + 1); 536 if (jobno > 0 && jobno <= njobs 537 && jobtab[jobno - 1].used != 0) 538 return &jobtab[jobno - 1]; 539#if JOBS 540 } else if (name[1] == '%' && name[2] == '\0') { 541 goto currentjob; 542 } else if (name[1] == '+' && name[2] == '\0') { 543 goto currentjob; 544 } else if (name[1] == '-' && name[2] == '\0') { 545 if ((jp = getcurjob(NULL)) == NULL || 546 (jp = getcurjob(jp)) == NULL) 547 error("No previous job"); 548 return (jp); 549#endif 550 } else if (name[1] == '?') { 551 found = NULL; 552 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 553 if (jp->used && jp->nprocs > 0 554 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 555 if (found) 556 error("%s: ambiguous", name); 557 found = jp; 558 } 559 } 560 if (found != NULL) 561 return (found); 562 } else { 563 found = NULL; 564 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 565 if (jp->used && jp->nprocs > 0 566 && prefix(name + 1, jp->ps[0].cmd)) { 567 if (found) 568 error("%s: ambiguous", name); 569 found = jp; 570 } 571 } 572 if (found) 573 return found; 574 } 575 } else if (is_number(name)) { 576 pid = number(name); 577 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 578 if (jp->used && jp->nprocs > 0 579 && jp->ps[jp->nprocs - 1].pid == pid) 580 return jp; 581 } 582 } 583 error("No such job: %s", name); 584 /*NOTREACHED*/ 585 return NULL; 586} 587 588 589 590/* 591 * Return a new job structure, 592 */ 593 594struct job * 595makejob(union node *node __unused, int nprocs) 596{ 597 int i; 598 struct job *jp; 599 600 for (i = njobs, jp = jobtab ; ; jp++) { 601 if (--i < 0) { 602 INTOFF; 603 if (njobs == 0) { 604 jobtab = ckmalloc(4 * sizeof jobtab[0]); 605#if JOBS 606 jobmru = NULL; 607#endif 608 } else { 609 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 610 memcpy(jp, jobtab, njobs * sizeof jp[0]); 611#if JOBS 612 /* Relocate `next' pointers and list head */ 613 jobmru = &jp[jobmru - jobtab]; 614 for (i = 0; i < njobs; i++) 615 if (jp[i].next != NULL) 616 jp[i].next = &jp[jp[i].next - 617 jobtab]; 618#endif 619 /* Relocate `ps' pointers */ 620 for (i = 0; i < njobs; i++) 621 if (jp[i].ps == &jobtab[i].ps0) 622 jp[i].ps = &jp[i].ps0; 623 ckfree(jobtab); 624 jobtab = jp; 625 } 626 jp = jobtab + njobs; 627 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 628 INTON; 629 break; 630 } 631 if (jp->used == 0) 632 break; 633 } 634 INTOFF; 635 jp->state = 0; 636 jp->used = 1; 637 jp->changed = 0; 638 jp->nprocs = 0; 639#if JOBS 640 jp->jobctl = jobctl; 641 jp->next = NULL; 642#endif 643 if (nprocs > 1) { 644 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 645 } else { 646 jp->ps = &jp->ps0; 647 } 648 INTON; 649 TRACE(("makejob(0x%lx, %d) returns %%%d\n", (long)node, nprocs, 650 jp - jobtab + 1)); 651 return jp; 652} 653 654#if JOBS 655STATIC void 656setcurjob(struct job *cj) 657{ 658 struct job *jp, *prev; 659 660 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 661 if (jp == cj) { 662 if (prev != NULL) 663 prev->next = jp->next; 664 else 665 jobmru = jp->next; 666 jp->next = jobmru; 667 jobmru = cj; 668 return; 669 } 670 } 671 cj->next = jobmru; 672 jobmru = cj; 673} 674 675STATIC void 676deljob(struct job *j) 677{ 678 struct job *jp, *prev; 679 680 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 681 if (jp == j) { 682 if (prev != NULL) 683 prev->next = jp->next; 684 else 685 jobmru = jp->next; 686 return; 687 } 688 } 689} 690 691/* 692 * Return the most recently used job that isn't `nj', and preferably one 693 * that is stopped. 694 */ 695STATIC struct job * 696getcurjob(struct job *nj) 697{ 698 struct job *jp; 699 700 /* Try to find a stopped one.. */ 701 for (jp = jobmru; jp != NULL; jp = jp->next) 702 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 703 return (jp); 704 /* Otherwise the most recently used job that isn't `nj' */ 705 for (jp = jobmru; jp != NULL; jp = jp->next) 706 if (jp->used && jp != nj) 707 return (jp); 708 709 return (NULL); 710} 711 712#endif 713 714/* 715 * Fork of a subshell. If we are doing job control, give the subshell its 716 * own process group. Jp is a job structure that the job is to be added to. 717 * N is the command that will be evaluated by the child. Both jp and n may 718 * be NULL. The mode parameter can be one of the following: 719 * FORK_FG - Fork off a foreground process. 720 * FORK_BG - Fork off a background process. 721 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 722 * process group even if job control is on. 723 * 724 * When job control is turned off, background processes have their standard 725 * input redirected to /dev/null (except for the second and later processes 726 * in a pipeline). 727 */ 728 729int 730forkshell(struct job *jp, union node *n, int mode) 731{ 732 int pid; 733 int pgrp; 734 735 TRACE(("forkshell(%%%d, 0x%lx, %d) called\n", jp - jobtab, (long)n, 736 mode)); 737 INTOFF; 738 pid = fork(); 739 if (pid == -1) { 740 TRACE(("Fork failed, errno=%d\n", errno)); 741 INTON; 742 error("Cannot fork: %s", strerror(errno)); 743 } 744 if (pid == 0) { 745 struct job *p; 746 int wasroot; 747 int i; 748 749 TRACE(("Child shell %d\n", getpid())); 750 wasroot = rootshell; 751 rootshell = 0; 752 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 753 if (p->used) 754 freejob(p); 755 closescript(); 756 INTON; 757 clear_traps(); 758#if JOBS 759 jobctl = 0; /* do job control only in root shell */ 760 if (wasroot && mode != FORK_NOJOB && mflag) { 761 if (jp == NULL || jp->nprocs == 0) 762 pgrp = getpid(); 763 else 764 pgrp = jp->ps[0].pid; 765 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 766 /*** this causes superfluous TIOCSPGRPS ***/ 767#ifdef OLD_TTY_DRIVER 768 if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) 769 error("TIOCSPGRP failed, errno=%d", errno); 770#else 771 if (tcsetpgrp(2, pgrp) < 0) 772 error("tcsetpgrp failed, errno=%d", errno); 773#endif 774 } 775 setsignal(SIGTSTP); 776 setsignal(SIGTTOU); 777 } else if (mode == FORK_BG) { 778 ignoresig(SIGINT); 779 ignoresig(SIGQUIT); 780 if ((jp == NULL || jp->nprocs == 0) && 781 ! fd0_redirected_p ()) { 782 close(0); 783 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 784 error("Can't open %s: %s", 785 _PATH_DEVNULL, strerror(errno)); 786 } 787 } 788#else 789 if (mode == FORK_BG) { 790 ignoresig(SIGINT); 791 ignoresig(SIGQUIT); 792 if ((jp == NULL || jp->nprocs == 0) && 793 ! fd0_redirected_p ()) { 794 close(0); 795 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 796 error("Can't open %s: %s", 797 _PATH_DEVNULL, strerror(errno)); 798 } 799 } 800#endif 801 if (wasroot && iflag) { 802 setsignal(SIGINT); 803 setsignal(SIGQUIT); 804 setsignal(SIGTERM); 805 } 806 return pid; 807 } 808 if (rootshell && mode != FORK_NOJOB && mflag) { 809 if (jp == NULL || jp->nprocs == 0) 810 pgrp = pid; 811 else 812 pgrp = jp->ps[0].pid; 813 setpgid(pid, pgrp); 814 } 815 if (mode == FORK_BG) 816 backgndpid = pid; /* set $! */ 817 if (jp) { 818 struct procstat *ps = &jp->ps[jp->nprocs++]; 819 ps->pid = pid; 820 ps->status = -1; 821 ps->cmd = nullstr; 822 if (iflag && rootshell && n) 823 ps->cmd = commandtext(n); 824#if JOBS 825 setcurjob(jp); 826#endif 827 } 828 INTON; 829 TRACE(("In parent shell: child = %d\n", pid)); 830 return pid; 831} 832 833 834 835/* 836 * Wait for job to finish. 837 * 838 * Under job control we have the problem that while a child process is 839 * running interrupts generated by the user are sent to the child but not 840 * to the shell. This means that an infinite loop started by an inter- 841 * active user may be hard to kill. With job control turned off, an 842 * interactive user may place an interactive program inside a loop. If 843 * the interactive program catches interrupts, the user doesn't want 844 * these interrupts to also abort the loop. The approach we take here 845 * is to have the shell ignore interrupt signals while waiting for a 846 * foreground process to terminate, and then send itself an interrupt 847 * signal if the child process was terminated by an interrupt signal. 848 * Unfortunately, some programs want to do a bit of cleanup and then 849 * exit on interrupt; unless these processes terminate themselves by 850 * sending a signal to themselves (instead of calling exit) they will 851 * confuse this approach. 852 */ 853 854int 855waitforjob(struct job *jp, int *origstatus) 856{ 857#if JOBS 858 int mypgrp = getpgrp(); 859#endif 860 int status; 861 int st; 862 863 INTOFF; 864 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 865 while (jp->state == 0) 866 if (dowait(1, jp) == -1) 867 dotrap(); 868#if JOBS 869 if (jp->jobctl) { 870#ifdef OLD_TTY_DRIVER 871 if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) 872 error("TIOCSPGRP failed, errno=%d\n", errno); 873#else 874 if (tcsetpgrp(2, mypgrp) < 0) 875 error("tcsetpgrp failed, errno=%d\n", errno); 876#endif 877 } 878 if (jp->state == JOBSTOPPED) 879 setcurjob(jp); 880#endif 881 status = jp->ps[jp->nprocs - 1].status; 882 if (origstatus != NULL) 883 *origstatus = status; 884 /* convert to 8 bits */ 885 if (WIFEXITED(status)) 886 st = WEXITSTATUS(status); 887#if JOBS 888 else if (WIFSTOPPED(status)) 889 st = WSTOPSIG(status) + 128; 890#endif 891 else 892 st = WTERMSIG(status) + 128; 893 if (! JOBS || jp->state == JOBDONE) 894 freejob(jp); 895 if (int_pending()) { 896 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 897 kill(getpid(), SIGINT); 898 else 899 CLEAR_PENDING_INT; 900 } 901 INTON; 902 return st; 903} 904 905 906 907/* 908 * Wait for a process to terminate. 909 */ 910 911STATIC int 912dowait(int block, struct job *job) 913{ 914 int pid; 915 int status; 916 struct procstat *sp; 917 struct job *jp; 918 struct job *thisjob; 919 int done; 920 int stopped; 921 int core; 922 int sig; 923 924 in_dowait++; 925 TRACE(("dowait(%d) called\n", block)); 926 do { 927 pid = waitproc(block, &status); 928 TRACE(("wait returns %d, status=%d\n", pid, status)); 929 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 930 (WIFSTOPPED(status) && !iflag)); 931 in_dowait--; 932 if (breakwaitcmd != 0) { 933 breakwaitcmd = 0; 934 return -1; 935 } 936 if (pid <= 0) 937 return pid; 938 INTOFF; 939 thisjob = NULL; 940 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 941 if (jp->used) { 942 done = 1; 943 stopped = 1; 944 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 945 if (sp->pid == -1) 946 continue; 947 if (sp->pid == pid) { 948 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 949 pid, sp->status, status)); 950 sp->status = status; 951 thisjob = jp; 952 } 953 if (sp->status == -1) 954 stopped = 0; 955 else if (WIFSTOPPED(sp->status)) 956 done = 0; 957 } 958 if (stopped) { /* stopped or done */ 959 int state = done? JOBDONE : JOBSTOPPED; 960 if (jp->state != state) { 961 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 962 jp->state = state; 963#if JOBS 964 if (done) 965 deljob(jp); 966#endif 967 } 968 } 969 } 970 } 971 INTON; 972 if (! rootshell || ! iflag || (job && thisjob == job)) { 973#if JOBS 974 if (WIFSTOPPED(status)) 975 sig = WSTOPSIG(status); 976 else 977#endif 978 { 979 if (WIFEXITED(status)) 980 sig = 0; 981 else 982 sig = WTERMSIG(status); 983 } 984 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) 985 showjob(thisjob, 0, 0); 986 } else { 987 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 988 if (thisjob) 989 thisjob->changed = 1; 990 } 991 return pid; 992} 993 994 995 996/* 997 * Do a wait system call. If job control is compiled in, we accept 998 * stopped processes. If block is zero, we return a value of zero 999 * rather than blocking. 1000 * 1001 * System V doesn't have a non-blocking wait system call. It does 1002 * have a SIGCLD signal that is sent to a process when one of it's 1003 * children dies. The obvious way to use SIGCLD would be to install 1004 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 1005 * was received, and have waitproc bump another counter when it got 1006 * the status of a process. Waitproc would then know that a wait 1007 * system call would not block if the two counters were different. 1008 * This approach doesn't work because if a process has children that 1009 * have not been waited for, System V will send it a SIGCLD when it 1010 * installs a signal handler for SIGCLD. What this means is that when 1011 * a child exits, the shell will be sent SIGCLD signals continuously 1012 * until is runs out of stack space, unless it does a wait call before 1013 * restoring the signal handler. The code below takes advantage of 1014 * this (mis)feature by installing a signal handler for SIGCLD and 1015 * then checking to see whether it was called. If there are any 1016 * children to be waited for, it will be. 1017 * 1018 * If neither SYSV nor BSD is defined, we don't implement nonblocking 1019 * waits at all. In this case, the user will not be informed when 1020 * a background process until the next time she runs a real program 1021 * (as opposed to running a builtin command or just typing return), 1022 * and the jobs command may give out of date information. 1023 */ 1024 1025#ifdef SYSV 1026STATIC sig_atomic_t gotsigchild; 1027 1028STATIC int onsigchild() { 1029 gotsigchild = 1; 1030} 1031#endif 1032 1033 1034STATIC int 1035waitproc(int block, int *status) 1036{ 1037#ifdef BSD 1038 int flags; 1039 1040#if JOBS 1041 flags = WUNTRACED; 1042#else 1043 flags = 0; 1044#endif 1045 if (block == 0) 1046 flags |= WNOHANG; 1047 return wait3(status, flags, (struct rusage *)NULL); 1048#else 1049#ifdef SYSV 1050 int (*save)(); 1051 1052 if (block == 0) { 1053 gotsigchild = 0; 1054 save = signal(SIGCLD, onsigchild); 1055 signal(SIGCLD, save); 1056 if (gotsigchild == 0) 1057 return 0; 1058 } 1059 return wait(status); 1060#else 1061 if (block == 0) 1062 return 0; 1063 return wait(status); 1064#endif 1065#endif 1066} 1067 1068/* 1069 * return 1 if there are stopped jobs, otherwise 0 1070 */ 1071int job_warning = 0; 1072int 1073stoppedjobs(void) 1074{ 1075 int jobno; 1076 struct job *jp; 1077 1078 if (job_warning) 1079 return (0); 1080 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1081 if (jp->used == 0) 1082 continue; 1083 if (jp->state == JOBSTOPPED) { 1084 out2str("You have stopped jobs.\n"); 1085 job_warning = 2; 1086 return (1); 1087 } 1088 } 1089 1090 return (0); 1091} 1092 1093/* 1094 * Return a string identifying a command (to be printed by the 1095 * jobs command. 1096 */ 1097 1098STATIC char *cmdnextc; 1099STATIC int cmdnleft; 1100#define MAXCMDTEXT 200 1101 1102char * 1103commandtext(union node *n) 1104{ 1105 char *name; 1106 1107 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1108 cmdnleft = MAXCMDTEXT - 4; 1109 cmdtxt(n); 1110 *cmdnextc = '\0'; 1111 return name; 1112} 1113 1114 1115STATIC void 1116cmdtxt(union node *n) 1117{ 1118 union node *np; 1119 struct nodelist *lp; 1120 char *p; 1121 int i; 1122 char s[2]; 1123 1124 if (n == NULL) 1125 return; 1126 switch (n->type) { 1127 case NSEMI: 1128 cmdtxt(n->nbinary.ch1); 1129 cmdputs("; "); 1130 cmdtxt(n->nbinary.ch2); 1131 break; 1132 case NAND: 1133 cmdtxt(n->nbinary.ch1); 1134 cmdputs(" && "); 1135 cmdtxt(n->nbinary.ch2); 1136 break; 1137 case NOR: 1138 cmdtxt(n->nbinary.ch1); 1139 cmdputs(" || "); 1140 cmdtxt(n->nbinary.ch2); 1141 break; 1142 case NPIPE: 1143 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1144 cmdtxt(lp->n); 1145 if (lp->next) 1146 cmdputs(" | "); 1147 } 1148 break; 1149 case NSUBSHELL: 1150 cmdputs("("); 1151 cmdtxt(n->nredir.n); 1152 cmdputs(")"); 1153 break; 1154 case NREDIR: 1155 case NBACKGND: 1156 cmdtxt(n->nredir.n); 1157 break; 1158 case NIF: 1159 cmdputs("if "); 1160 cmdtxt(n->nif.test); 1161 cmdputs("; then "); 1162 cmdtxt(n->nif.ifpart); 1163 cmdputs("..."); 1164 break; 1165 case NWHILE: 1166 cmdputs("while "); 1167 goto until; 1168 case NUNTIL: 1169 cmdputs("until "); 1170until: 1171 cmdtxt(n->nbinary.ch1); 1172 cmdputs("; do "); 1173 cmdtxt(n->nbinary.ch2); 1174 cmdputs("; done"); 1175 break; 1176 case NFOR: 1177 cmdputs("for "); 1178 cmdputs(n->nfor.var); 1179 cmdputs(" in ..."); 1180 break; 1181 case NCASE: 1182 cmdputs("case "); 1183 cmdputs(n->ncase.expr->narg.text); 1184 cmdputs(" in ..."); 1185 break; 1186 case NDEFUN: 1187 cmdputs(n->narg.text); 1188 cmdputs("() ..."); 1189 break; 1190 case NCMD: 1191 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1192 cmdtxt(np); 1193 if (np->narg.next) 1194 cmdputs(" "); 1195 } 1196 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1197 cmdputs(" "); 1198 cmdtxt(np); 1199 } 1200 break; 1201 case NARG: 1202 cmdputs(n->narg.text); 1203 break; 1204 case NTO: 1205 p = ">"; i = 1; goto redir; 1206 case NAPPEND: 1207 p = ">>"; i = 1; goto redir; 1208 case NTOFD: 1209 p = ">&"; i = 1; goto redir; 1210 case NCLOBBER: 1211 p = ">|"; i = 1; goto redir; 1212 case NFROM: 1213 p = "<"; i = 0; goto redir; 1214 case NFROMTO: 1215 p = "<>"; i = 0; goto redir; 1216 case NFROMFD: 1217 p = "<&"; i = 0; goto redir; 1218redir: 1219 if (n->nfile.fd != i) { 1220 s[0] = n->nfile.fd + '0'; 1221 s[1] = '\0'; 1222 cmdputs(s); 1223 } 1224 cmdputs(p); 1225 if (n->type == NTOFD || n->type == NFROMFD) { 1226 s[0] = n->ndup.dupfd + '0'; 1227 s[1] = '\0'; 1228 cmdputs(s); 1229 } else { 1230 cmdtxt(n->nfile.fname); 1231 } 1232 break; 1233 case NHERE: 1234 case NXHERE: 1235 cmdputs("<<..."); 1236 break; 1237 default: 1238 cmdputs("???"); 1239 break; 1240 } 1241} 1242 1243 1244 1245STATIC void 1246cmdputs(char *s) 1247{ 1248 char *p, *q; 1249 char c; 1250 int subtype = 0; 1251 1252 if (cmdnleft <= 0) 1253 return; 1254 p = s; 1255 q = cmdnextc; 1256 while ((c = *p++) != '\0') { 1257 if (c == CTLESC) 1258 *q++ = *p++; 1259 else if (c == CTLVAR) { 1260 *q++ = '$'; 1261 if (--cmdnleft > 0) 1262 *q++ = '{'; 1263 subtype = *p++; 1264 } else if (c == '=' && subtype != 0) { 1265 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1266 subtype = 0; 1267 } else if (c == CTLENDVAR) { 1268 *q++ = '}'; 1269 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1270 cmdnleft++; /* ignore it */ 1271 else 1272 *q++ = c; 1273 if (--cmdnleft <= 0) { 1274 *q++ = '.'; 1275 *q++ = '.'; 1276 *q++ = '.'; 1277 break; 1278 } 1279 } 1280 cmdnextc = q; 1281} 1282