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 39 static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 40 #endif 41 #endif /* not lint */ 42 #include <sys/cdefs.h> 43 __FBSDID("$FreeBSD$"); 44 45 #include <fcntl.h> 46 #include <signal.h> 47 #include <errno.h> 48 #include <paths.h> 49 #include <unistd.h> 50 #include <stdlib.h> 51 #include <sys/param.h> 52 #ifdef BSD 53 #include <sys/wait.h> 54 #include <sys/time.h> 55 #include <sys/resource.h> 56 #include <paths.h> 57 #endif 58 #include <sys/ioctl.h> 59 60 #include "shell.h" 61 #if JOBS 62 #include <termios.h> 63 #undef CEOF /* syntax.h redefines this */ 64 #endif 65 #include "redir.h" 66 #include "show.h" 67 #include "main.h" 68 #include "parser.h" 69 #include "nodes.h" 70 #include "jobs.h" 71 #include "options.h" 72 #include "trap.h" 73 #include "syntax.h" 74 #include "input.h" 75 #include "output.h" 76 #include "memalloc.h" 77 #include "error.h" 78 #include "mystring.h" 79 80 81 struct job *jobtab; /* array of jobs */ 82 int njobs; /* size of array */ 83 MKINIT pid_t backgndpid = -1; /* pid of last background process */ 84 #if JOBS 85 struct job *jobmru; /* most recently used job list */ 86 pid_t initialpgrp; /* pgrp of shell on invocation */ 87 #endif 88 int in_waitcmd = 0; /* are we in waitcmd()? */ 89 int in_dowait = 0; /* are we in dowait()? */ 90 volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 91 static int ttyfd = -1; 92 93 #if JOBS 94 STATIC void restartjob(struct job *); 95 #endif 96 STATIC void freejob(struct job *); 97 STATIC struct job *getjob(char *); 98 STATIC pid_t dowait(int, struct job *); 99 #if SYSV 100 STATIC int onsigchild(void); 101 #endif 102 STATIC pid_t waitproc(int, int *); 103 STATIC void cmdtxt(union node *); 104 STATIC void cmdputs(char *); 105 #if JOBS 106 STATIC void setcurjob(struct job *); 107 STATIC void deljob(struct job *); 108 STATIC struct job *getcurjob(struct job *); 109 #endif 110 STATIC void showjob(struct job *, pid_t, int, int); 111 112 113 /* 114 * Turn job control on and off. 115 * 116 * Note: This code assumes that the third arg to ioctl is a character 117 * pointer, which is true on Berkeley systems but not System V. Since 118 * System V doesn't have job control yet, this isn't a problem now. 119 */ 120 121 MKINIT int jobctl; 122 123 #if JOBS 124 void 125 setjobctl(int on) 126 { 127 int i; 128 129 if (on == jobctl || rootshell == 0) 130 return; 131 if (on) { 132 if (ttyfd != -1) 133 close(ttyfd); 134 if ((ttyfd = open(_PATH_TTY, O_RDWR)) < 0) { 135 i = 0; 136 while (i <= 2 && !isatty(i)) 137 i++; 138 if (i > 2 || (ttyfd = dup(i)) < 0) 139 goto out; 140 } 141 if (fcntl(ttyfd, FD_CLOEXEC, 1) < 0) { 142 close(ttyfd); 143 ttyfd = -1; 144 goto out; 145 } 146 do { /* while we are in the background */ 147 initialpgrp = tcgetpgrp(ttyfd); 148 if (initialpgrp < 0) { 149 out: out2str("sh: can't access tty; job control turned off\n"); 150 mflag = 0; 151 return; 152 } 153 if (initialpgrp == -1) 154 initialpgrp = getpgrp(); 155 else if (initialpgrp != getpgrp()) { 156 killpg(0, SIGTTIN); 157 continue; 158 } 159 } while (0); 160 setsignal(SIGTSTP); 161 setsignal(SIGTTOU); 162 setsignal(SIGTTIN); 163 setpgid(0, rootpid); 164 tcsetpgrp(ttyfd, rootpid); 165 } else { /* turning job control off */ 166 setpgid(0, initialpgrp); 167 tcsetpgrp(ttyfd, initialpgrp); 168 close(ttyfd); 169 ttyfd = -1; 170 setsignal(SIGTSTP); 171 setsignal(SIGTTOU); 172 setsignal(SIGTTIN); 173 } 174 jobctl = on; 175 } 176 #endif 177 178 179 #ifdef mkinit 180 INCLUDE <sys/types.h> 181 INCLUDE <stdlib.h> 182 183 SHELLPROC { 184 backgndpid = -1; 185 #if JOBS 186 jobctl = 0; 187 #endif 188 } 189 190 #endif 191 192 193 194 #if JOBS 195 int 196 fgcmd(int argc __unused, char **argv) 197 { 198 struct job *jp; 199 pid_t pgrp; 200 int status; 201 202 jp = getjob(argv[1]); 203 if (jp->jobctl == 0) 204 error("job not created under job control"); 205 out1str(jp->ps[0].cmd); 206 out1c('\n'); 207 flushout(&output); 208 pgrp = jp->ps[0].pid; 209 tcsetpgrp(ttyfd, pgrp); 210 restartjob(jp); 211 jp->foreground = 1; 212 INTOFF; 213 status = waitforjob(jp, (int *)NULL); 214 INTON; 215 return status; 216 } 217 218 219 int 220 bgcmd(int argc, char **argv) 221 { 222 char s[64]; 223 struct job *jp; 224 225 do { 226 jp = getjob(*++argv); 227 if (jp->jobctl == 0) 228 error("job not created under job control"); 229 if (jp->state == JOBDONE) 230 continue; 231 restartjob(jp); 232 jp->foreground = 0; 233 fmtstr(s, 64, "[%d] ", jp - jobtab + 1); 234 out1str(s); 235 out1str(jp->ps[0].cmd); 236 out1c('\n'); 237 } while (--argc > 1); 238 return 0; 239 } 240 241 242 STATIC void 243 restartjob(struct job *jp) 244 { 245 struct procstat *ps; 246 int i; 247 248 if (jp->state == JOBDONE) 249 return; 250 setcurjob(jp); 251 INTOFF; 252 killpg(jp->ps[0].pid, SIGCONT); 253 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 254 if (WIFSTOPPED(ps->status)) { 255 ps->status = -1; 256 jp->state = 0; 257 } 258 } 259 INTON; 260 } 261 #endif 262 263 264 int 265 jobscmd(int argc, char *argv[]) 266 { 267 char *id; 268 int ch, sformat, lformat; 269 270 optind = optreset = 1; 271 sformat = lformat = 0; 272 while ((ch = getopt(argc, argv, "ls")) != -1) { 273 switch (ch) { 274 case 'l': 275 lformat = 1; 276 break; 277 case 's': 278 sformat = 1; 279 break; 280 case '?': 281 default: 282 error("unknown option: -%c", optopt); 283 } 284 } 285 argc -= optind; 286 argv += optind; 287 288 if (argc == 0) 289 showjobs(0, sformat, lformat); 290 else 291 while ((id = *argv++) != NULL) 292 showjob(getjob(id), 0, sformat, lformat); 293 294 return (0); 295 } 296 297 STATIC void 298 showjob(struct job *jp, pid_t pid, int sformat, int lformat) 299 { 300 char s[64]; 301 struct procstat *ps; 302 struct job *j; 303 int col, curr, i, jobno, prev, procno; 304 char c; 305 306 procno = jp->nprocs; 307 jobno = jp - jobtab + 1; 308 curr = prev = 0; 309 #if JOBS 310 if ((j = getcurjob(NULL)) != NULL) { 311 curr = j - jobtab + 1; 312 if ((j = getcurjob(j)) != NULL) 313 prev = j - jobtab + 1; 314 } 315 #endif 316 for (ps = jp->ps ; ; ps++) { /* for each process */ 317 if (sformat) { 318 out1fmt("%d\n", (int)ps->pid); 319 goto skip; 320 } 321 if (!lformat && ps != jp->ps && pid == 0) 322 goto skip; 323 if (pid != 0 && pid != ps->pid) 324 goto skip; 325 if (jobno == curr && ps == jp->ps) 326 c = '+'; 327 else if (jobno == prev && ps == jp->ps) 328 c = '-'; 329 else 330 c = ' '; 331 if (ps == jp->ps) 332 fmtstr(s, 64, "[%d] %c ", jobno, c); 333 else 334 fmtstr(s, 64, " %c ", c); 335 out1str(s); 336 col = strlen(s); 337 if (lformat) { 338 fmtstr(s, 64, "%d ", (int)ps->pid); 339 out1str(s); 340 col += strlen(s); 341 } 342 s[0] = '\0'; 343 if (ps != jp->ps) { 344 *s = '\0'; 345 } else if (ps->status == -1) { 346 strcpy(s, "Running"); 347 } else if (WIFEXITED(ps->status)) { 348 if (WEXITSTATUS(ps->status) == 0) 349 strcpy(s, "Done"); 350 else 351 fmtstr(s, 64, "Done (%d)", 352 WEXITSTATUS(ps->status)); 353 } else { 354 #if JOBS 355 if (WIFSTOPPED(ps->status)) 356 i = WSTOPSIG(ps->status); 357 else 358 #endif 359 i = WTERMSIG(ps->status); 360 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 361 scopy(sys_siglist[i & 0x7F], s); 362 else 363 fmtstr(s, 64, "Signal %d", i & 0x7F); 364 if (WCOREDUMP(ps->status)) 365 strcat(s, " (core dumped)"); 366 } 367 out1str(s); 368 col += strlen(s); 369 do { 370 out1c(' '); 371 col++; 372 } while (col < 30); 373 out1str(ps->cmd); 374 out1c('\n'); 375 skip: if (--procno <= 0) 376 break; 377 } 378 } 379 380 /* 381 * Print a list of jobs. If "change" is nonzero, only print jobs whose 382 * statuses have changed since the last call to showjobs. 383 * 384 * If the shell is interrupted in the process of creating a job, the 385 * result may be a job structure containing zero processes. Such structures 386 * will be freed here. 387 */ 388 389 void 390 showjobs(int change, int sformat, int lformat) 391 { 392 int jobno; 393 struct job *jp; 394 395 TRACE(("showjobs(%d) called\n", change)); 396 while (dowait(0, (struct job *)NULL) > 0); 397 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 398 if (! jp->used) 399 continue; 400 if (jp->nprocs == 0) { 401 freejob(jp); 402 continue; 403 } 404 if (change && ! jp->changed) 405 continue; 406 showjob(jp, 0, sformat, lformat); 407 jp->changed = 0; 408 if (jp->state == JOBDONE) { 409 freejob(jp); 410 } 411 } 412 } 413 414 415 /* 416 * Mark a job structure as unused. 417 */ 418 419 STATIC void 420 freejob(struct job *jp) 421 { 422 struct procstat *ps; 423 int i; 424 425 INTOFF; 426 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 427 if (ps->cmd != nullstr) 428 ckfree(ps->cmd); 429 } 430 if (jp->ps != &jp->ps0) 431 ckfree(jp->ps); 432 jp->used = 0; 433 #if JOBS 434 deljob(jp); 435 #endif 436 INTON; 437 } 438 439 440 441 int 442 waitcmd(int argc, char **argv) 443 { 444 struct job *job; 445 int status, retval; 446 struct job *jp; 447 448 if (argc > 1) { 449 job = getjob(argv[1]); 450 } else { 451 job = NULL; 452 } 453 454 /* 455 * Loop until a process is terminated or stopped, or a SIGINT is 456 * received. 457 */ 458 459 in_waitcmd++; 460 do { 461 if (job != NULL) { 462 if (job->state) { 463 status = job->ps[job->nprocs - 1].status; 464 if (WIFEXITED(status)) 465 retval = WEXITSTATUS(status); 466 #if JOBS 467 else if (WIFSTOPPED(status)) 468 retval = WSTOPSIG(status) + 128; 469 #endif 470 else 471 retval = WTERMSIG(status) + 128; 472 if (! iflag) 473 freejob(job); 474 in_waitcmd--; 475 return retval; 476 } 477 } else { 478 for (jp = jobtab ; ; jp++) { 479 if (jp >= jobtab + njobs) { /* no running procs */ 480 in_waitcmd--; 481 return 0; 482 } 483 if (jp->used && jp->state == 0) 484 break; 485 } 486 } 487 } while (dowait(1, (struct job *)NULL) != -1); 488 in_waitcmd--; 489 490 return 0; 491 } 492 493 494 495 int 496 jobidcmd(int argc __unused, char **argv) 497 { 498 struct job *jp; 499 int i; 500 501 jp = getjob(argv[1]); 502 for (i = 0 ; i < jp->nprocs ; ) { 503 out1fmt("%d", (int)jp->ps[i].pid); 504 out1c(++i < jp->nprocs? ' ' : '\n'); 505 } 506 return 0; 507 } 508 509 510 511 /* 512 * Convert a job name to a job structure. 513 */ 514 515 STATIC struct job * 516 getjob(char *name) 517 { 518 int jobno; 519 struct job *found, *jp; 520 pid_t pid; 521 int i; 522 523 if (name == NULL) { 524 #if JOBS 525 currentjob: if ((jp = getcurjob(NULL)) == NULL) 526 error("No current job"); 527 return (jp); 528 #else 529 error("No current job"); 530 #endif 531 } else if (name[0] == '%') { 532 if (is_digit(name[1])) { 533 jobno = number(name + 1); 534 if (jobno > 0 && jobno <= njobs 535 && jobtab[jobno - 1].used != 0) 536 return &jobtab[jobno - 1]; 537 #if JOBS 538 } else if (name[1] == '%' && name[2] == '\0') { 539 goto currentjob; 540 } else if (name[1] == '+' && name[2] == '\0') { 541 goto currentjob; 542 } else if (name[1] == '-' && name[2] == '\0') { 543 if ((jp = getcurjob(NULL)) == NULL || 544 (jp = getcurjob(jp)) == NULL) 545 error("No previous job"); 546 return (jp); 547 #endif 548 } else if (name[1] == '?') { 549 found = NULL; 550 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 551 if (jp->used && jp->nprocs > 0 552 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 553 if (found) 554 error("%s: ambiguous", name); 555 found = jp; 556 } 557 } 558 if (found != NULL) 559 return (found); 560 } else { 561 found = NULL; 562 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 563 if (jp->used && jp->nprocs > 0 564 && prefix(name + 1, jp->ps[0].cmd)) { 565 if (found) 566 error("%s: ambiguous", name); 567 found = jp; 568 } 569 } 570 if (found) 571 return found; 572 } 573 } else if (is_number(name)) { 574 pid = (pid_t)number(name); 575 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 576 if (jp->used && jp->nprocs > 0 577 && jp->ps[jp->nprocs - 1].pid == pid) 578 return jp; 579 } 580 } 581 error("No such job: %s", name); 582 /*NOTREACHED*/ 583 return NULL; 584 } 585 586 587 588 /* 589 * Return a new job structure, 590 */ 591 592 struct job * 593 makejob(union node *node __unused, int nprocs) 594 { 595 int i; 596 struct job *jp; 597 598 for (i = njobs, jp = jobtab ; ; jp++) { 599 if (--i < 0) { 600 INTOFF; 601 if (njobs == 0) { 602 jobtab = ckmalloc(4 * sizeof jobtab[0]); 603 #if JOBS 604 jobmru = NULL; 605 #endif 606 } else { 607 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 608 memcpy(jp, jobtab, njobs * sizeof jp[0]); 609 #if JOBS 610 /* Relocate `next' pointers and list head */ 611 if (jobmru != NULL) 612 jobmru = &jp[jobmru - jobtab]; 613 for (i = 0; i < njobs; i++) 614 if (jp[i].next != NULL) 615 jp[i].next = &jp[jp[i].next - 616 jobtab]; 617 #endif 618 /* Relocate `ps' pointers */ 619 for (i = 0; i < njobs; i++) 620 if (jp[i].ps == &jobtab[i].ps0) 621 jp[i].ps = &jp[i].ps0; 622 ckfree(jobtab); 623 jobtab = jp; 624 } 625 jp = jobtab + njobs; 626 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 627 INTON; 628 break; 629 } 630 if (jp->used == 0) 631 break; 632 } 633 INTOFF; 634 jp->state = 0; 635 jp->used = 1; 636 jp->changed = 0; 637 jp->nprocs = 0; 638 jp->foreground = 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 655 STATIC void 656 setcurjob(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 } 674 675 STATIC void 676 deljob(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 */ 695 STATIC struct job * 696 getcurjob(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 */ 728 729 pid_t 730 forkshell(struct job *jp, union node *n, int mode) 731 { 732 pid_t pid; 733 pid_t 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", (int)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 if (tcsetpgrp(ttyfd, pgrp) < 0) 768 error("tcsetpgrp failed, errno=%d", errno); 769 } 770 setsignal(SIGTSTP); 771 setsignal(SIGTTOU); 772 } else if (mode == FORK_BG) { 773 ignoresig(SIGINT); 774 ignoresig(SIGQUIT); 775 if ((jp == NULL || jp->nprocs == 0) && 776 ! fd0_redirected_p ()) { 777 close(0); 778 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 779 error("Can't open %s: %s", 780 _PATH_DEVNULL, strerror(errno)); 781 } 782 } 783 #else 784 if (mode == FORK_BG) { 785 ignoresig(SIGINT); 786 ignoresig(SIGQUIT); 787 if ((jp == NULL || jp->nprocs == 0) && 788 ! fd0_redirected_p ()) { 789 close(0); 790 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 791 error("Can't open %s: %s", 792 _PATH_DEVNULL, strerror(errno)); 793 } 794 } 795 #endif 796 if (wasroot && iflag) { 797 setsignal(SIGINT); 798 setsignal(SIGQUIT); 799 setsignal(SIGTERM); 800 } 801 return pid; 802 } 803 if (rootshell && mode != FORK_NOJOB && mflag) { 804 if (jp == NULL || jp->nprocs == 0) 805 pgrp = pid; 806 else 807 pgrp = jp->ps[0].pid; 808 setpgid(pid, pgrp); 809 } 810 if (mode == FORK_BG) 811 backgndpid = pid; /* set $! */ 812 if (jp) { 813 struct procstat *ps = &jp->ps[jp->nprocs++]; 814 ps->pid = pid; 815 ps->status = -1; 816 ps->cmd = nullstr; 817 if (iflag && rootshell && n) 818 ps->cmd = commandtext(n); 819 jp->foreground = mode == FORK_FG; 820 #if JOBS 821 setcurjob(jp); 822 #endif 823 } 824 INTON; 825 TRACE(("In parent shell: child = %d\n", (int)pid)); 826 return pid; 827 } 828 829 830 831 /* 832 * Wait for job to finish. 833 * 834 * Under job control we have the problem that while a child process is 835 * running interrupts generated by the user are sent to the child but not 836 * to the shell. This means that an infinite loop started by an inter- 837 * active user may be hard to kill. With job control turned off, an 838 * interactive user may place an interactive program inside a loop. If 839 * the interactive program catches interrupts, the user doesn't want 840 * these interrupts to also abort the loop. The approach we take here 841 * is to have the shell ignore interrupt signals while waiting for a 842 * foreground process to terminate, and then send itself an interrupt 843 * signal if the child process was terminated by an interrupt signal. 844 * Unfortunately, some programs want to do a bit of cleanup and then 845 * exit on interrupt; unless these processes terminate themselves by 846 * sending a signal to themselves (instead of calling exit) they will 847 * confuse this approach. 848 */ 849 850 int 851 waitforjob(struct job *jp, int *origstatus) 852 { 853 #if JOBS 854 pid_t mypgrp = getpgrp(); 855 #endif 856 int status; 857 int st; 858 859 INTOFF; 860 TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); 861 while (jp->state == 0) 862 if (dowait(1, jp) == -1) 863 dotrap(); 864 #if JOBS 865 if (jp->jobctl) { 866 if (tcsetpgrp(ttyfd, mypgrp) < 0) 867 error("tcsetpgrp failed, errno=%d\n", errno); 868 } 869 if (jp->state == JOBSTOPPED) 870 setcurjob(jp); 871 #endif 872 status = jp->ps[jp->nprocs - 1].status; 873 if (origstatus != NULL) 874 *origstatus = status; 875 /* convert to 8 bits */ 876 if (WIFEXITED(status)) 877 st = WEXITSTATUS(status); 878 #if JOBS 879 else if (WIFSTOPPED(status)) 880 st = WSTOPSIG(status) + 128; 881 #endif 882 else 883 st = WTERMSIG(status) + 128; 884 if (! JOBS || jp->state == JOBDONE) 885 freejob(jp); 886 if (int_pending()) { 887 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 888 kill(getpid(), SIGINT); 889 else 890 CLEAR_PENDING_INT; 891 } 892 INTON; 893 return st; 894 } 895 896 897 898 /* 899 * Wait for a process to terminate. 900 */ 901 902 STATIC pid_t 903 dowait(int block, struct job *job) 904 { 905 pid_t pid; 906 int status; 907 struct procstat *sp; 908 struct job *jp; 909 struct job *thisjob; 910 int done; 911 int stopped; 912 int sig; 913 int i; 914 915 in_dowait++; 916 TRACE(("dowait(%d) called\n", block)); 917 do { 918 pid = waitproc(block, &status); 919 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 920 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 921 (WIFSTOPPED(status) && !iflag)); 922 in_dowait--; 923 if (breakwaitcmd != 0) { 924 breakwaitcmd = 0; 925 return -1; 926 } 927 if (pid <= 0) 928 return pid; 929 INTOFF; 930 thisjob = NULL; 931 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 932 if (jp->used) { 933 done = 1; 934 stopped = 1; 935 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 936 if (sp->pid == -1) 937 continue; 938 if (sp->pid == pid) { 939 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 940 (int)pid, sp->status, 941 status)); 942 sp->status = status; 943 thisjob = jp; 944 } 945 if (sp->status == -1) 946 stopped = 0; 947 else if (WIFSTOPPED(sp->status)) 948 done = 0; 949 } 950 if (stopped) { /* stopped or done */ 951 int state = done? JOBDONE : JOBSTOPPED; 952 if (jp->state != state) { 953 TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 954 jp->state = state; 955 #if JOBS 956 if (done) 957 deljob(jp); 958 #endif 959 } 960 } 961 } 962 } 963 INTON; 964 if (! rootshell || ! iflag || (job && thisjob == job)) { 965 #if JOBS 966 if (WIFSTOPPED(status)) 967 sig = WSTOPSIG(status); 968 else 969 #endif 970 { 971 if (WIFEXITED(status)) 972 sig = 0; 973 else 974 sig = WTERMSIG(status); 975 } 976 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 977 if (jp->foreground) { 978 #if JOBS 979 if (WIFSTOPPED(status)) 980 i = WSTOPSIG(status); 981 else 982 #endif 983 i = WTERMSIG(status); 984 if ((i & 0x7F) < NSIG && sys_siglist[i & 0x7F]) 985 out1str(sys_siglist[i & 0x7F]); 986 else 987 out1fmt("Signal %d", i & 0x7F); 988 if (WCOREDUMP(status)) 989 out1str(" (core dumped)"); 990 out1c('\n'); 991 } else 992 showjob(thisjob, pid, 0, 1); 993 } 994 } else { 995 TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); 996 if (thisjob) 997 thisjob->changed = 1; 998 } 999 return pid; 1000 } 1001 1002 1003 1004 /* 1005 * Do a wait system call. If job control is compiled in, we accept 1006 * stopped processes. If block is zero, we return a value of zero 1007 * rather than blocking. 1008 * 1009 * System V doesn't have a non-blocking wait system call. It does 1010 * have a SIGCLD signal that is sent to a process when one of it's 1011 * children dies. The obvious way to use SIGCLD would be to install 1012 * a handler for SIGCLD which simply bumped a counter when a SIGCLD 1013 * was received, and have waitproc bump another counter when it got 1014 * the status of a process. Waitproc would then know that a wait 1015 * system call would not block if the two counters were different. 1016 * This approach doesn't work because if a process has children that 1017 * have not been waited for, System V will send it a SIGCLD when it 1018 * installs a signal handler for SIGCLD. What this means is that when 1019 * a child exits, the shell will be sent SIGCLD signals continuously 1020 * until is runs out of stack space, unless it does a wait call before 1021 * restoring the signal handler. The code below takes advantage of 1022 * this (mis)feature by installing a signal handler for SIGCLD and 1023 * then checking to see whether it was called. If there are any 1024 * children to be waited for, it will be. 1025 * 1026 * If neither SYSV nor BSD is defined, we don't implement nonblocking 1027 * waits at all. In this case, the user will not be informed when 1028 * a background process until the next time she runs a real program 1029 * (as opposed to running a builtin command or just typing return), 1030 * and the jobs command may give out of date information. 1031 */ 1032 1033 #ifdef SYSV 1034 STATIC sig_atomic_t gotsigchild; 1035 1036 STATIC int onsigchild() { 1037 gotsigchild = 1; 1038 } 1039 #endif 1040 1041 1042 STATIC pid_t 1043 waitproc(int block, int *status) 1044 { 1045 #ifdef BSD 1046 int flags; 1047 1048 #if JOBS 1049 flags = WUNTRACED; 1050 #else 1051 flags = 0; 1052 #endif 1053 if (block == 0) 1054 flags |= WNOHANG; 1055 return wait3(status, flags, (struct rusage *)NULL); 1056 #else 1057 #ifdef SYSV 1058 int (*save)(); 1059 1060 if (block == 0) { 1061 gotsigchild = 0; 1062 save = signal(SIGCLD, onsigchild); 1063 signal(SIGCLD, save); 1064 if (gotsigchild == 0) 1065 return 0; 1066 } 1067 return wait(status); 1068 #else 1069 if (block == 0) 1070 return 0; 1071 return wait(status); 1072 #endif 1073 #endif 1074 } 1075 1076 /* 1077 * return 1 if there are stopped jobs, otherwise 0 1078 */ 1079 int job_warning = 0; 1080 int 1081 stoppedjobs(void) 1082 { 1083 int jobno; 1084 struct job *jp; 1085 1086 if (job_warning) 1087 return (0); 1088 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1089 if (jp->used == 0) 1090 continue; 1091 if (jp->state == JOBSTOPPED) { 1092 out2str("You have stopped jobs.\n"); 1093 job_warning = 2; 1094 return (1); 1095 } 1096 } 1097 1098 return (0); 1099 } 1100 1101 /* 1102 * Return a string identifying a command (to be printed by the 1103 * jobs command. 1104 */ 1105 1106 STATIC char *cmdnextc; 1107 STATIC int cmdnleft; 1108 #define MAXCMDTEXT 200 1109 1110 char * 1111 commandtext(union node *n) 1112 { 1113 char *name; 1114 1115 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1116 cmdnleft = MAXCMDTEXT - 4; 1117 cmdtxt(n); 1118 *cmdnextc = '\0'; 1119 return name; 1120 } 1121 1122 1123 STATIC void 1124 cmdtxt(union node *n) 1125 { 1126 union node *np; 1127 struct nodelist *lp; 1128 char *p; 1129 int i; 1130 char s[2]; 1131 1132 if (n == NULL) 1133 return; 1134 switch (n->type) { 1135 case NSEMI: 1136 cmdtxt(n->nbinary.ch1); 1137 cmdputs("; "); 1138 cmdtxt(n->nbinary.ch2); 1139 break; 1140 case NAND: 1141 cmdtxt(n->nbinary.ch1); 1142 cmdputs(" && "); 1143 cmdtxt(n->nbinary.ch2); 1144 break; 1145 case NOR: 1146 cmdtxt(n->nbinary.ch1); 1147 cmdputs(" || "); 1148 cmdtxt(n->nbinary.ch2); 1149 break; 1150 case NPIPE: 1151 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1152 cmdtxt(lp->n); 1153 if (lp->next) 1154 cmdputs(" | "); 1155 } 1156 break; 1157 case NSUBSHELL: 1158 cmdputs("("); 1159 cmdtxt(n->nredir.n); 1160 cmdputs(")"); 1161 break; 1162 case NREDIR: 1163 case NBACKGND: 1164 cmdtxt(n->nredir.n); 1165 break; 1166 case NIF: 1167 cmdputs("if "); 1168 cmdtxt(n->nif.test); 1169 cmdputs("; then "); 1170 cmdtxt(n->nif.ifpart); 1171 cmdputs("..."); 1172 break; 1173 case NWHILE: 1174 cmdputs("while "); 1175 goto until; 1176 case NUNTIL: 1177 cmdputs("until "); 1178 until: 1179 cmdtxt(n->nbinary.ch1); 1180 cmdputs("; do "); 1181 cmdtxt(n->nbinary.ch2); 1182 cmdputs("; done"); 1183 break; 1184 case NFOR: 1185 cmdputs("for "); 1186 cmdputs(n->nfor.var); 1187 cmdputs(" in ..."); 1188 break; 1189 case NCASE: 1190 cmdputs("case "); 1191 cmdputs(n->ncase.expr->narg.text); 1192 cmdputs(" in ..."); 1193 break; 1194 case NDEFUN: 1195 cmdputs(n->narg.text); 1196 cmdputs("() ..."); 1197 break; 1198 case NCMD: 1199 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1200 cmdtxt(np); 1201 if (np->narg.next) 1202 cmdputs(" "); 1203 } 1204 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1205 cmdputs(" "); 1206 cmdtxt(np); 1207 } 1208 break; 1209 case NARG: 1210 cmdputs(n->narg.text); 1211 break; 1212 case NTO: 1213 p = ">"; i = 1; goto redir; 1214 case NAPPEND: 1215 p = ">>"; i = 1; goto redir; 1216 case NTOFD: 1217 p = ">&"; i = 1; goto redir; 1218 case NCLOBBER: 1219 p = ">|"; i = 1; goto redir; 1220 case NFROM: 1221 p = "<"; i = 0; goto redir; 1222 case NFROMTO: 1223 p = "<>"; i = 0; goto redir; 1224 case NFROMFD: 1225 p = "<&"; i = 0; goto redir; 1226 redir: 1227 if (n->nfile.fd != i) { 1228 s[0] = n->nfile.fd + '0'; 1229 s[1] = '\0'; 1230 cmdputs(s); 1231 } 1232 cmdputs(p); 1233 if (n->type == NTOFD || n->type == NFROMFD) { 1234 if (n->ndup.dupfd >= 0) 1235 s[0] = n->ndup.dupfd + '0'; 1236 else 1237 s[0] = '-'; 1238 s[1] = '\0'; 1239 cmdputs(s); 1240 } else { 1241 cmdtxt(n->nfile.fname); 1242 } 1243 break; 1244 case NHERE: 1245 case NXHERE: 1246 cmdputs("<<..."); 1247 break; 1248 default: 1249 cmdputs("???"); 1250 break; 1251 } 1252 } 1253 1254 1255 1256 STATIC void 1257 cmdputs(char *s) 1258 { 1259 char *p, *q; 1260 char c; 1261 int subtype = 0; 1262 1263 if (cmdnleft <= 0) 1264 return; 1265 p = s; 1266 q = cmdnextc; 1267 while ((c = *p++) != '\0') { 1268 if (c == CTLESC) 1269 *q++ = *p++; 1270 else if (c == CTLVAR) { 1271 *q++ = '$'; 1272 if (--cmdnleft > 0) 1273 *q++ = '{'; 1274 subtype = *p++; 1275 } else if (c == '=' && subtype != 0) { 1276 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1277 subtype = 0; 1278 } else if (c == CTLENDVAR) { 1279 *q++ = '}'; 1280 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1281 cmdnleft++; /* ignore it */ 1282 else 1283 *q++ = c; 1284 if (--cmdnleft <= 0) { 1285 *q++ = '.'; 1286 *q++ = '.'; 1287 *q++ = '.'; 1288 break; 1289 } 1290 } 1291 cmdnextc = q; 1292 } 1293