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 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/ioctl.h> 42 #include <sys/param.h> 43 #include <sys/resource.h> 44 #include <sys/time.h> 45 #include <sys/wait.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <paths.h> 49 #include <signal.h> 50 #include <stddef.h> 51 #include <stdlib.h> 52 #include <unistd.h> 53 54 #include "shell.h" 55 #if JOBS 56 #include <termios.h> 57 #undef CEOF /* syntax.h redefines this */ 58 #endif 59 #include "redir.h" 60 #include "show.h" 61 #include "main.h" 62 #include "parser.h" 63 #include "nodes.h" 64 #include "jobs.h" 65 #include "options.h" 66 #include "trap.h" 67 #include "syntax.h" 68 #include "input.h" 69 #include "output.h" 70 #include "memalloc.h" 71 #include "error.h" 72 #include "mystring.h" 73 74 75 static struct job *jobtab; /* array of jobs */ 76 static int njobs; /* size of array */ 77 MKINIT pid_t backgndpid = -1; /* pid of last background process */ 78 MKINIT struct job *bgjob = NULL; /* last background process */ 79 #if JOBS 80 static struct job *jobmru; /* most recently used job list */ 81 static pid_t initialpgrp; /* pgrp of shell on invocation */ 82 #endif 83 int in_waitcmd = 0; /* are we in waitcmd()? */ 84 int in_dowait = 0; /* are we in dowait()? */ 85 volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 86 static int ttyfd = -1; 87 88 #if JOBS 89 static void restartjob(struct job *); 90 #endif 91 static void freejob(struct job *); 92 static struct job *getjob(char *); 93 static pid_t dowait(int, struct job *); 94 static pid_t waitproc(int, int *); 95 static void checkzombies(void); 96 static void cmdtxt(union node *); 97 static void cmdputs(const char *); 98 #if JOBS 99 static void setcurjob(struct job *); 100 static void deljob(struct job *); 101 static struct job *getcurjob(struct job *); 102 #endif 103 static void showjob(struct job *, pid_t, int); 104 105 106 /* 107 * Turn job control on and off. 108 */ 109 110 MKINIT int jobctl; 111 112 #if JOBS 113 void 114 setjobctl(int on) 115 { 116 int i; 117 118 if (on == jobctl || rootshell == 0) 119 return; 120 if (on) { 121 if (ttyfd != -1) 122 close(ttyfd); 123 if ((ttyfd = open(_PATH_TTY, O_RDWR)) < 0) { 124 i = 0; 125 while (i <= 2 && !isatty(i)) 126 i++; 127 if (i > 2 || (ttyfd = fcntl(i, F_DUPFD, 10)) < 0) 128 goto out; 129 } 130 if (ttyfd < 10) { 131 /* 132 * Keep our TTY file descriptor out of the way of 133 * the user's redirections. 134 */ 135 if ((i = fcntl(ttyfd, F_DUPFD, 10)) < 0) { 136 close(ttyfd); 137 ttyfd = -1; 138 goto out; 139 } 140 close(ttyfd); 141 ttyfd = i; 142 } 143 if (fcntl(ttyfd, F_SETFD, FD_CLOEXEC) < 0) { 144 close(ttyfd); 145 ttyfd = -1; 146 goto out; 147 } 148 do { /* while we are in the background */ 149 initialpgrp = tcgetpgrp(ttyfd); 150 if (initialpgrp < 0) { 151 out: out2fmt_flush("sh: can't access tty; job control turned off\n"); 152 mflag = 0; 153 return; 154 } 155 if (initialpgrp == -1) 156 initialpgrp = getpgrp(); 157 else if (initialpgrp != getpgrp()) { 158 killpg(0, SIGTTIN); 159 continue; 160 } 161 } while (0); 162 setsignal(SIGTSTP); 163 setsignal(SIGTTOU); 164 setsignal(SIGTTIN); 165 setpgid(0, rootpid); 166 tcsetpgrp(ttyfd, rootpid); 167 } else { /* turning job control off */ 168 setpgid(0, initialpgrp); 169 tcsetpgrp(ttyfd, initialpgrp); 170 close(ttyfd); 171 ttyfd = -1; 172 setsignal(SIGTSTP); 173 setsignal(SIGTTOU); 174 setsignal(SIGTTIN); 175 } 176 jobctl = on; 177 } 178 #endif 179 180 181 #ifdef mkinit 182 INCLUDE <sys/types.h> 183 INCLUDE <stdlib.h> 184 185 SHELLPROC { 186 backgndpid = -1; 187 bgjob = NULL; 188 #if JOBS 189 jobctl = 0; 190 #endif 191 } 192 193 #endif 194 195 196 197 #if JOBS 198 int 199 fgcmd(int argc __unused, char **argv) 200 { 201 struct job *jp; 202 pid_t pgrp; 203 int status; 204 205 jp = getjob(argv[1]); 206 if (jp->jobctl == 0) 207 error("job not created under job control"); 208 out1str(jp->ps[0].cmd); 209 out1c('\n'); 210 flushout(&output); 211 pgrp = jp->ps[0].pid; 212 tcsetpgrp(ttyfd, pgrp); 213 restartjob(jp); 214 jp->foreground = 1; 215 INTOFF; 216 status = waitforjob(jp, (int *)NULL); 217 INTON; 218 return status; 219 } 220 221 222 int 223 bgcmd(int argc, char **argv) 224 { 225 char s[64]; 226 struct job *jp; 227 228 do { 229 jp = getjob(*++argv); 230 if (jp->jobctl == 0) 231 error("job not created under job control"); 232 if (jp->state == JOBDONE) 233 continue; 234 restartjob(jp); 235 jp->foreground = 0; 236 fmtstr(s, 64, "[%td] ", jp - jobtab + 1); 237 out1str(s); 238 out1str(jp->ps[0].cmd); 239 out1c('\n'); 240 } while (--argc > 1); 241 return 0; 242 } 243 244 245 static void 246 restartjob(struct job *jp) 247 { 248 struct procstat *ps; 249 int i; 250 251 if (jp->state == JOBDONE) 252 return; 253 setcurjob(jp); 254 INTOFF; 255 killpg(jp->ps[0].pid, SIGCONT); 256 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 257 if (WIFSTOPPED(ps->status)) { 258 ps->status = -1; 259 jp->state = 0; 260 } 261 } 262 INTON; 263 } 264 #endif 265 266 267 int 268 jobscmd(int argc, char *argv[]) 269 { 270 char *id; 271 int ch, mode; 272 273 optind = optreset = 1; 274 opterr = 0; 275 mode = SHOWJOBS_DEFAULT; 276 while ((ch = getopt(argc, argv, "lps")) != -1) { 277 switch (ch) { 278 case 'l': 279 mode = SHOWJOBS_VERBOSE; 280 break; 281 case 'p': 282 mode = SHOWJOBS_PGIDS; 283 break; 284 case 's': 285 mode = SHOWJOBS_PIDS; 286 break; 287 case '?': 288 default: 289 error("unknown option: -%c", optopt); 290 } 291 } 292 argc -= optind; 293 argv += optind; 294 295 if (argc == 0) 296 showjobs(0, mode); 297 else 298 while ((id = *argv++) != NULL) 299 showjob(getjob(id), 0, mode); 300 301 return (0); 302 } 303 304 static void 305 showjob(struct job *jp, pid_t pid, int mode) 306 { 307 char s[64]; 308 struct procstat *ps; 309 struct job *j; 310 int col, curr, i, jobno, prev, procno; 311 pid_t ppid; 312 char c; 313 314 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 315 jobno = jp - jobtab + 1; 316 curr = prev = 0; 317 #if JOBS 318 if ((j = getcurjob(NULL)) != NULL) { 319 curr = j - jobtab + 1; 320 if ((j = getcurjob(j)) != NULL) 321 prev = j - jobtab + 1; 322 } 323 #endif 324 for (ps = jp->ps ; ; ps++) { /* for each process */ 325 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 326 ppid = (mode == SHOWJOBS_PIDS) ? ps->pid : 327 getpgid(ps->pid); 328 out1fmt("%d\n", (int)ppid); 329 goto skip; 330 } 331 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps && pid == 0) 332 goto skip; 333 if (pid != 0 && pid != ps->pid) 334 goto skip; 335 if (jobno == curr && ps == jp->ps) 336 c = '+'; 337 else if (jobno == prev && ps == jp->ps) 338 c = '-'; 339 else 340 c = ' '; 341 if (ps == jp->ps) 342 fmtstr(s, 64, "[%d] %c ", jobno, c); 343 else 344 fmtstr(s, 64, " %c ", c); 345 out1str(s); 346 col = strlen(s); 347 if (mode == SHOWJOBS_VERBOSE) { 348 fmtstr(s, 64, "%d ", (int)ps->pid); 349 out1str(s); 350 col += strlen(s); 351 } 352 s[0] = '\0'; 353 if (ps != jp->ps) { 354 *s = '\0'; 355 } else if (ps->status == -1) { 356 strcpy(s, "Running"); 357 } else if (WIFEXITED(ps->status)) { 358 if (WEXITSTATUS(ps->status) == 0) 359 strcpy(s, "Done"); 360 else 361 fmtstr(s, 64, "Done (%d)", 362 WEXITSTATUS(ps->status)); 363 } else { 364 #if JOBS 365 if (WIFSTOPPED(ps->status)) 366 i = WSTOPSIG(ps->status); 367 else 368 #endif 369 i = WTERMSIG(ps->status); 370 if ((i & 0x7F) < sys_nsig && sys_siglist[i & 0x7F]) 371 scopy(sys_siglist[i & 0x7F], s); 372 else 373 fmtstr(s, 64, "Signal %d", i & 0x7F); 374 if (WCOREDUMP(ps->status)) 375 strcat(s, " (core dumped)"); 376 } 377 out1str(s); 378 col += strlen(s); 379 do { 380 out1c(' '); 381 col++; 382 } while (col < 30); 383 out1str(ps->cmd); 384 out1c('\n'); 385 skip: if (--procno <= 0) 386 break; 387 } 388 } 389 390 /* 391 * Print a list of jobs. If "change" is nonzero, only print jobs whose 392 * statuses have changed since the last call to showjobs. 393 * 394 * If the shell is interrupted in the process of creating a job, the 395 * result may be a job structure containing zero processes. Such structures 396 * will be freed here. 397 */ 398 399 void 400 showjobs(int change, int mode) 401 { 402 int jobno; 403 struct job *jp; 404 405 TRACE(("showjobs(%d) called\n", change)); 406 checkzombies(); 407 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 408 if (! jp->used) 409 continue; 410 if (jp->nprocs == 0) { 411 freejob(jp); 412 continue; 413 } 414 if (change && ! jp->changed) 415 continue; 416 showjob(jp, 0, mode); 417 jp->changed = 0; 418 /* Hack: discard jobs for which $! has not been referenced 419 * in interactive mode when they terminate. 420 */ 421 if (jp->state == JOBDONE && !jp->remembered && 422 (iflag || jp != bgjob)) { 423 freejob(jp); 424 } 425 } 426 } 427 428 429 /* 430 * Mark a job structure as unused. 431 */ 432 433 static void 434 freejob(struct job *jp) 435 { 436 struct procstat *ps; 437 int i; 438 439 INTOFF; 440 if (bgjob == jp) 441 bgjob = NULL; 442 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 443 if (ps->cmd != nullstr) 444 ckfree(ps->cmd); 445 } 446 if (jp->ps != &jp->ps0) 447 ckfree(jp->ps); 448 jp->used = 0; 449 #if JOBS 450 deljob(jp); 451 #endif 452 INTON; 453 } 454 455 456 457 int 458 waitcmd(int argc, char **argv) 459 { 460 struct job *job; 461 int status, retval; 462 struct job *jp; 463 464 if (argc > 1) { 465 job = getjob(argv[1]); 466 } else { 467 job = NULL; 468 } 469 470 /* 471 * Loop until a process is terminated or stopped, or a SIGINT is 472 * received. 473 */ 474 475 in_waitcmd++; 476 do { 477 if (job != NULL) { 478 if (job->state) { 479 status = job->ps[job->nprocs - 1].status; 480 if (WIFEXITED(status)) 481 retval = WEXITSTATUS(status); 482 #if JOBS 483 else if (WIFSTOPPED(status)) 484 retval = WSTOPSIG(status) + 128; 485 #endif 486 else 487 retval = WTERMSIG(status) + 128; 488 if (! iflag || ! job->changed) 489 freejob(job); 490 else { 491 job->remembered = 0; 492 if (job == bgjob) 493 bgjob = NULL; 494 } 495 in_waitcmd--; 496 return retval; 497 } 498 } else { 499 for (jp = jobtab ; jp < jobtab + njobs; jp++) 500 if (jp->used && jp->state == JOBDONE) { 501 if (! iflag || ! jp->changed) 502 freejob(jp); 503 else { 504 jp->remembered = 0; 505 if (jp == bgjob) 506 bgjob = NULL; 507 } 508 } 509 for (jp = jobtab ; ; jp++) { 510 if (jp >= jobtab + njobs) { /* no running procs */ 511 in_waitcmd--; 512 return 0; 513 } 514 if (jp->used && jp->state == 0) 515 break; 516 } 517 } 518 } while (dowait(1, (struct job *)NULL) != -1); 519 in_waitcmd--; 520 521 return 0; 522 } 523 524 525 526 int 527 jobidcmd(int argc __unused, char **argv) 528 { 529 struct job *jp; 530 int i; 531 532 jp = getjob(argv[1]); 533 for (i = 0 ; i < jp->nprocs ; ) { 534 out1fmt("%d", (int)jp->ps[i].pid); 535 out1c(++i < jp->nprocs? ' ' : '\n'); 536 } 537 return 0; 538 } 539 540 541 542 /* 543 * Convert a job name to a job structure. 544 */ 545 546 static struct job * 547 getjob(char *name) 548 { 549 int jobno; 550 struct job *found, *jp; 551 pid_t pid; 552 int i; 553 554 if (name == NULL) { 555 #if JOBS 556 currentjob: if ((jp = getcurjob(NULL)) == NULL) 557 error("No current job"); 558 return (jp); 559 #else 560 error("No current job"); 561 #endif 562 } else if (name[0] == '%') { 563 if (is_digit(name[1])) { 564 jobno = number(name + 1); 565 if (jobno > 0 && jobno <= njobs 566 && jobtab[jobno - 1].used != 0) 567 return &jobtab[jobno - 1]; 568 #if JOBS 569 } else if (name[1] == '%' && name[2] == '\0') { 570 goto currentjob; 571 } else if (name[1] == '+' && name[2] == '\0') { 572 goto currentjob; 573 } else if (name[1] == '-' && name[2] == '\0') { 574 if ((jp = getcurjob(NULL)) == NULL || 575 (jp = getcurjob(jp)) == NULL) 576 error("No previous job"); 577 return (jp); 578 #endif 579 } else if (name[1] == '?') { 580 found = NULL; 581 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 582 if (jp->used && jp->nprocs > 0 583 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 584 if (found) 585 error("%s: ambiguous", name); 586 found = jp; 587 } 588 } 589 if (found != NULL) 590 return (found); 591 } else { 592 found = NULL; 593 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 594 if (jp->used && jp->nprocs > 0 595 && prefix(name + 1, jp->ps[0].cmd)) { 596 if (found) 597 error("%s: ambiguous", name); 598 found = jp; 599 } 600 } 601 if (found) 602 return found; 603 } 604 } else if (is_number(name)) { 605 pid = (pid_t)number(name); 606 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 607 if (jp->used && jp->nprocs > 0 608 && jp->ps[jp->nprocs - 1].pid == pid) 609 return jp; 610 } 611 } 612 error("No such job: %s", name); 613 /*NOTREACHED*/ 614 return NULL; 615 } 616 617 618 619 /* 620 * Return a new job structure, 621 */ 622 623 struct job * 624 makejob(union node *node __unused, int nprocs) 625 { 626 int i; 627 struct job *jp; 628 629 for (i = njobs, jp = jobtab ; ; jp++) { 630 if (--i < 0) { 631 INTOFF; 632 if (njobs == 0) { 633 jobtab = ckmalloc(4 * sizeof jobtab[0]); 634 #if JOBS 635 jobmru = NULL; 636 #endif 637 } else { 638 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 639 memcpy(jp, jobtab, njobs * sizeof jp[0]); 640 #if JOBS 641 /* Relocate `next' pointers and list head */ 642 if (jobmru != NULL) 643 jobmru = &jp[jobmru - jobtab]; 644 for (i = 0; i < njobs; i++) 645 if (jp[i].next != NULL) 646 jp[i].next = &jp[jp[i].next - 647 jobtab]; 648 #endif 649 if (bgjob != NULL) 650 bgjob = &jp[bgjob - jobtab]; 651 /* Relocate `ps' pointers */ 652 for (i = 0; i < njobs; i++) 653 if (jp[i].ps == &jobtab[i].ps0) 654 jp[i].ps = &jp[i].ps0; 655 ckfree(jobtab); 656 jobtab = jp; 657 } 658 jp = jobtab + njobs; 659 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 660 INTON; 661 break; 662 } 663 if (jp->used == 0) 664 break; 665 } 666 INTOFF; 667 jp->state = 0; 668 jp->used = 1; 669 jp->changed = 0; 670 jp->nprocs = 0; 671 jp->foreground = 0; 672 jp->remembered = 0; 673 #if JOBS 674 jp->jobctl = jobctl; 675 jp->next = NULL; 676 #endif 677 if (nprocs > 1) { 678 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 679 } else { 680 jp->ps = &jp->ps0; 681 } 682 INTON; 683 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 684 jp - jobtab + 1)); 685 return jp; 686 } 687 688 #if JOBS 689 static void 690 setcurjob(struct job *cj) 691 { 692 struct job *jp, *prev; 693 694 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 695 if (jp == cj) { 696 if (prev != NULL) 697 prev->next = jp->next; 698 else 699 jobmru = jp->next; 700 jp->next = jobmru; 701 jobmru = cj; 702 return; 703 } 704 } 705 cj->next = jobmru; 706 jobmru = cj; 707 } 708 709 static void 710 deljob(struct job *j) 711 { 712 struct job *jp, *prev; 713 714 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 715 if (jp == j) { 716 if (prev != NULL) 717 prev->next = jp->next; 718 else 719 jobmru = jp->next; 720 return; 721 } 722 } 723 } 724 725 /* 726 * Return the most recently used job that isn't `nj', and preferably one 727 * that is stopped. 728 */ 729 static struct job * 730 getcurjob(struct job *nj) 731 { 732 struct job *jp; 733 734 /* Try to find a stopped one.. */ 735 for (jp = jobmru; jp != NULL; jp = jp->next) 736 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 737 return (jp); 738 /* Otherwise the most recently used job that isn't `nj' */ 739 for (jp = jobmru; jp != NULL; jp = jp->next) 740 if (jp->used && jp != nj) 741 return (jp); 742 743 return (NULL); 744 } 745 746 #endif 747 748 /* 749 * Fork of a subshell. If we are doing job control, give the subshell its 750 * own process group. Jp is a job structure that the job is to be added to. 751 * N is the command that will be evaluated by the child. Both jp and n may 752 * be NULL. The mode parameter can be one of the following: 753 * FORK_FG - Fork off a foreground process. 754 * FORK_BG - Fork off a background process. 755 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 756 * process group even if job control is on. 757 * 758 * When job control is turned off, background processes have their standard 759 * input redirected to /dev/null (except for the second and later processes 760 * in a pipeline). 761 */ 762 763 pid_t 764 forkshell(struct job *jp, union node *n, int mode) 765 { 766 pid_t pid; 767 pid_t pgrp; 768 769 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 770 mode)); 771 INTOFF; 772 if (mode == FORK_BG) 773 checkzombies(); 774 flushall(); 775 pid = fork(); 776 if (pid == -1) { 777 TRACE(("Fork failed, errno=%d\n", errno)); 778 INTON; 779 error("Cannot fork: %s", strerror(errno)); 780 } 781 if (pid == 0) { 782 struct job *p; 783 int wasroot; 784 int i; 785 786 TRACE(("Child shell %d\n", (int)getpid())); 787 wasroot = rootshell; 788 rootshell = 0; 789 handler = &main_handler; 790 closescript(); 791 INTON; 792 clear_traps(); 793 #if JOBS 794 jobctl = 0; /* do job control only in root shell */ 795 if (wasroot && mode != FORK_NOJOB && mflag) { 796 if (jp == NULL || jp->nprocs == 0) 797 pgrp = getpid(); 798 else 799 pgrp = jp->ps[0].pid; 800 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 801 /*** this causes superfluous TIOCSPGRPS ***/ 802 if (tcsetpgrp(ttyfd, pgrp) < 0) 803 error("tcsetpgrp failed, errno=%d", errno); 804 } 805 setsignal(SIGTSTP); 806 setsignal(SIGTTOU); 807 } else if (mode == FORK_BG) { 808 ignoresig(SIGINT); 809 ignoresig(SIGQUIT); 810 if ((jp == NULL || jp->nprocs == 0) && 811 ! fd0_redirected_p ()) { 812 close(0); 813 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 814 error("Can't open %s: %s", 815 _PATH_DEVNULL, strerror(errno)); 816 } 817 } 818 #else 819 if (mode == FORK_BG) { 820 ignoresig(SIGINT); 821 ignoresig(SIGQUIT); 822 if ((jp == NULL || jp->nprocs == 0) && 823 ! fd0_redirected_p ()) { 824 close(0); 825 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 826 error("Can't open %s: %s", 827 _PATH_DEVNULL, strerror(errno)); 828 } 829 } 830 #endif 831 INTOFF; 832 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 833 if (p->used) 834 freejob(p); 835 INTON; 836 if (wasroot && iflag) { 837 setsignal(SIGINT); 838 setsignal(SIGQUIT); 839 setsignal(SIGTERM); 840 } 841 return pid; 842 } 843 if (rootshell && mode != FORK_NOJOB && mflag) { 844 if (jp == NULL || jp->nprocs == 0) 845 pgrp = pid; 846 else 847 pgrp = jp->ps[0].pid; 848 setpgid(pid, pgrp); 849 } 850 if (mode == FORK_BG) { 851 if (bgjob != NULL && bgjob->state == JOBDONE && 852 !bgjob->remembered && !iflag) 853 freejob(bgjob); 854 backgndpid = pid; /* set $! */ 855 bgjob = jp; 856 } 857 if (jp) { 858 struct procstat *ps = &jp->ps[jp->nprocs++]; 859 ps->pid = pid; 860 ps->status = -1; 861 ps->cmd = nullstr; 862 if (iflag && rootshell && n) 863 ps->cmd = commandtext(n); 864 jp->foreground = mode == FORK_FG; 865 #if JOBS 866 setcurjob(jp); 867 #endif 868 } 869 INTON; 870 TRACE(("In parent shell: child = %d\n", (int)pid)); 871 return pid; 872 } 873 874 875 876 /* 877 * Wait for job to finish. 878 * 879 * Under job control we have the problem that while a child process is 880 * running interrupts generated by the user are sent to the child but not 881 * to the shell. This means that an infinite loop started by an inter- 882 * active user may be hard to kill. With job control turned off, an 883 * interactive user may place an interactive program inside a loop. If 884 * the interactive program catches interrupts, the user doesn't want 885 * these interrupts to also abort the loop. The approach we take here 886 * is to have the shell ignore interrupt signals while waiting for a 887 * foreground process to terminate, and then send itself an interrupt 888 * signal if the child process was terminated by an interrupt signal. 889 * Unfortunately, some programs want to do a bit of cleanup and then 890 * exit on interrupt; unless these processes terminate themselves by 891 * sending a signal to themselves (instead of calling exit) they will 892 * confuse this approach. 893 */ 894 895 int 896 waitforjob(struct job *jp, int *origstatus) 897 { 898 #if JOBS 899 pid_t mypgrp = getpgrp(); 900 int propagate_int = jp->jobctl && jp->foreground; 901 #endif 902 int status; 903 int st; 904 905 INTOFF; 906 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 907 while (jp->state == 0) 908 if (dowait(1, jp) == -1) 909 dotrap(); 910 #if JOBS 911 if (jp->jobctl) { 912 if (tcsetpgrp(ttyfd, mypgrp) < 0) 913 error("tcsetpgrp failed, errno=%d\n", errno); 914 } 915 if (jp->state == JOBSTOPPED) 916 setcurjob(jp); 917 #endif 918 status = jp->ps[jp->nprocs - 1].status; 919 if (origstatus != NULL) 920 *origstatus = status; 921 /* convert to 8 bits */ 922 if (WIFEXITED(status)) 923 st = WEXITSTATUS(status); 924 #if JOBS 925 else if (WIFSTOPPED(status)) 926 st = WSTOPSIG(status) + 128; 927 #endif 928 else 929 st = WTERMSIG(status) + 128; 930 if (! JOBS || jp->state == JOBDONE) 931 freejob(jp); 932 if (int_pending()) { 933 if (WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 934 kill(getpid(), SIGINT); 935 else 936 CLEAR_PENDING_INT; 937 } 938 #if JOBS 939 else if (rootshell && iflag && propagate_int && 940 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 941 kill(getpid(), SIGINT); 942 #endif 943 INTON; 944 return st; 945 } 946 947 948 949 /* 950 * Wait for a process to terminate. 951 */ 952 953 static pid_t 954 dowait(int block, struct job *job) 955 { 956 pid_t pid; 957 int status; 958 struct procstat *sp; 959 struct job *jp; 960 struct job *thisjob; 961 int done; 962 int stopped; 963 int sig; 964 int i; 965 966 in_dowait++; 967 TRACE(("dowait(%d) called\n", block)); 968 do { 969 pid = waitproc(block, &status); 970 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 971 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 972 (pid > 0 && WIFSTOPPED(status) && !iflag)); 973 in_dowait--; 974 if (pid == -1 && errno == ECHILD && job != NULL) 975 job->state = JOBDONE; 976 if (breakwaitcmd != 0) { 977 breakwaitcmd = 0; 978 if (pid <= 0) 979 return -1; 980 } 981 if (pid <= 0) 982 return pid; 983 INTOFF; 984 thisjob = NULL; 985 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 986 if (jp->used) { 987 done = 1; 988 stopped = 1; 989 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 990 if (sp->pid == -1) 991 continue; 992 if (sp->pid == pid) { 993 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 994 (int)pid, sp->status, 995 status)); 996 sp->status = status; 997 thisjob = jp; 998 } 999 if (sp->status == -1) 1000 stopped = 0; 1001 else if (WIFSTOPPED(sp->status)) 1002 done = 0; 1003 } 1004 if (stopped) { /* stopped or done */ 1005 int state = done? JOBDONE : JOBSTOPPED; 1006 if (jp->state != state) { 1007 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1008 jp->state = state; 1009 if (jp != job) { 1010 if (done && !jp->remembered && 1011 !iflag && jp != bgjob) 1012 freejob(jp); 1013 #if JOBS 1014 else if (done) 1015 deljob(jp); 1016 #endif 1017 } 1018 } 1019 } 1020 } 1021 } 1022 INTON; 1023 if (! rootshell || ! iflag || (job && thisjob == job)) { 1024 #if JOBS 1025 if (WIFSTOPPED(status)) 1026 sig = WSTOPSIG(status); 1027 else 1028 #endif 1029 { 1030 if (WIFEXITED(status)) 1031 sig = 0; 1032 else 1033 sig = WTERMSIG(status); 1034 } 1035 if (sig != 0 && sig != SIGINT && sig != SIGPIPE) { 1036 if (!mflag || 1037 (thisjob->foreground && !WIFSTOPPED(status))) { 1038 i = WTERMSIG(status); 1039 if ((i & 0x7F) < sys_nsig && sys_siglist[i & 0x7F]) 1040 out1str(sys_siglist[i & 0x7F]); 1041 else 1042 out1fmt("Signal %d", i & 0x7F); 1043 if (WCOREDUMP(status)) 1044 out1str(" (core dumped)"); 1045 out1c('\n'); 1046 } else 1047 showjob(thisjob, pid, SHOWJOBS_DEFAULT); 1048 } 1049 } else { 1050 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1051 if (thisjob) 1052 thisjob->changed = 1; 1053 } 1054 return pid; 1055 } 1056 1057 1058 1059 /* 1060 * Do a wait system call. If job control is compiled in, we accept 1061 * stopped processes. If block is zero, we return a value of zero 1062 * rather than blocking. 1063 */ 1064 static pid_t 1065 waitproc(int block, int *status) 1066 { 1067 int flags; 1068 1069 #if JOBS 1070 flags = WUNTRACED; 1071 #else 1072 flags = 0; 1073 #endif 1074 if (block == 0) 1075 flags |= WNOHANG; 1076 return wait3(status, flags, (struct rusage *)NULL); 1077 } 1078 1079 /* 1080 * return 1 if there are stopped jobs, otherwise 0 1081 */ 1082 int job_warning = 0; 1083 int 1084 stoppedjobs(void) 1085 { 1086 int jobno; 1087 struct job *jp; 1088 1089 if (job_warning) 1090 return (0); 1091 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1092 if (jp->used == 0) 1093 continue; 1094 if (jp->state == JOBSTOPPED) { 1095 out2fmt_flush("You have stopped jobs.\n"); 1096 job_warning = 2; 1097 return (1); 1098 } 1099 } 1100 1101 return (0); 1102 } 1103 1104 1105 static void 1106 checkzombies(void) 1107 { 1108 while (njobs > 0 && dowait(0, NULL) > 0) 1109 ; 1110 } 1111 1112 1113 int 1114 backgndpidset(void) 1115 { 1116 return backgndpid != -1; 1117 } 1118 1119 1120 pid_t 1121 backgndpidval(void) 1122 { 1123 if (bgjob != NULL) 1124 bgjob->remembered = 1; 1125 return backgndpid; 1126 } 1127 1128 /* 1129 * Return a string identifying a command (to be printed by the 1130 * jobs command. 1131 */ 1132 1133 static char *cmdnextc; 1134 static int cmdnleft; 1135 #define MAXCMDTEXT 200 1136 1137 char * 1138 commandtext(union node *n) 1139 { 1140 char *name; 1141 1142 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1143 cmdnleft = MAXCMDTEXT - 4; 1144 cmdtxt(n); 1145 *cmdnextc = '\0'; 1146 return name; 1147 } 1148 1149 1150 static void 1151 cmdtxt(union node *n) 1152 { 1153 union node *np; 1154 struct nodelist *lp; 1155 const char *p; 1156 int i; 1157 char s[2]; 1158 1159 if (n == NULL) 1160 return; 1161 switch (n->type) { 1162 case NSEMI: 1163 cmdtxt(n->nbinary.ch1); 1164 cmdputs("; "); 1165 cmdtxt(n->nbinary.ch2); 1166 break; 1167 case NAND: 1168 cmdtxt(n->nbinary.ch1); 1169 cmdputs(" && "); 1170 cmdtxt(n->nbinary.ch2); 1171 break; 1172 case NOR: 1173 cmdtxt(n->nbinary.ch1); 1174 cmdputs(" || "); 1175 cmdtxt(n->nbinary.ch2); 1176 break; 1177 case NPIPE: 1178 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1179 cmdtxt(lp->n); 1180 if (lp->next) 1181 cmdputs(" | "); 1182 } 1183 break; 1184 case NSUBSHELL: 1185 cmdputs("("); 1186 cmdtxt(n->nredir.n); 1187 cmdputs(")"); 1188 break; 1189 case NREDIR: 1190 case NBACKGND: 1191 cmdtxt(n->nredir.n); 1192 break; 1193 case NIF: 1194 cmdputs("if "); 1195 cmdtxt(n->nif.test); 1196 cmdputs("; then "); 1197 cmdtxt(n->nif.ifpart); 1198 cmdputs("..."); 1199 break; 1200 case NWHILE: 1201 cmdputs("while "); 1202 goto until; 1203 case NUNTIL: 1204 cmdputs("until "); 1205 until: 1206 cmdtxt(n->nbinary.ch1); 1207 cmdputs("; do "); 1208 cmdtxt(n->nbinary.ch2); 1209 cmdputs("; done"); 1210 break; 1211 case NFOR: 1212 cmdputs("for "); 1213 cmdputs(n->nfor.var); 1214 cmdputs(" in ..."); 1215 break; 1216 case NCASE: 1217 cmdputs("case "); 1218 cmdputs(n->ncase.expr->narg.text); 1219 cmdputs(" in ..."); 1220 break; 1221 case NDEFUN: 1222 cmdputs(n->narg.text); 1223 cmdputs("() ..."); 1224 break; 1225 case NCMD: 1226 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1227 cmdtxt(np); 1228 if (np->narg.next) 1229 cmdputs(" "); 1230 } 1231 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1232 cmdputs(" "); 1233 cmdtxt(np); 1234 } 1235 break; 1236 case NARG: 1237 cmdputs(n->narg.text); 1238 break; 1239 case NTO: 1240 p = ">"; i = 1; goto redir; 1241 case NAPPEND: 1242 p = ">>"; i = 1; goto redir; 1243 case NTOFD: 1244 p = ">&"; i = 1; goto redir; 1245 case NCLOBBER: 1246 p = ">|"; i = 1; goto redir; 1247 case NFROM: 1248 p = "<"; i = 0; goto redir; 1249 case NFROMTO: 1250 p = "<>"; i = 0; goto redir; 1251 case NFROMFD: 1252 p = "<&"; i = 0; goto redir; 1253 redir: 1254 if (n->nfile.fd != i) { 1255 s[0] = n->nfile.fd + '0'; 1256 s[1] = '\0'; 1257 cmdputs(s); 1258 } 1259 cmdputs(p); 1260 if (n->type == NTOFD || n->type == NFROMFD) { 1261 if (n->ndup.dupfd >= 0) 1262 s[0] = n->ndup.dupfd + '0'; 1263 else 1264 s[0] = '-'; 1265 s[1] = '\0'; 1266 cmdputs(s); 1267 } else { 1268 cmdtxt(n->nfile.fname); 1269 } 1270 break; 1271 case NHERE: 1272 case NXHERE: 1273 cmdputs("<<..."); 1274 break; 1275 default: 1276 cmdputs("???"); 1277 break; 1278 } 1279 } 1280 1281 1282 1283 static void 1284 cmdputs(const char *s) 1285 { 1286 const char *p; 1287 char *q; 1288 char c; 1289 int subtype = 0; 1290 1291 if (cmdnleft <= 0) 1292 return; 1293 p = s; 1294 q = cmdnextc; 1295 while ((c = *p++) != '\0') { 1296 if (c == CTLESC) 1297 *q++ = *p++; 1298 else if (c == CTLVAR) { 1299 *q++ = '$'; 1300 if (--cmdnleft > 0) 1301 *q++ = '{'; 1302 subtype = *p++; 1303 } else if (c == '=' && subtype != 0) { 1304 *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; 1305 subtype = 0; 1306 } else if (c == CTLENDVAR) { 1307 *q++ = '}'; 1308 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) 1309 cmdnleft++; /* ignore it */ 1310 else 1311 *q++ = c; 1312 if (--cmdnleft <= 0) { 1313 *q++ = '.'; 1314 *q++ = '.'; 1315 *q++ = '.'; 1316 break; 1317 } 1318 } 1319 cmdnextc = q; 1320 } 1321