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 "exec.h" 61 #include "show.h" 62 #include "main.h" 63 #include "parser.h" 64 #include "nodes.h" 65 #include "jobs.h" 66 #include "options.h" 67 #include "trap.h" 68 #include "syntax.h" 69 #include "input.h" 70 #include "output.h" 71 #include "memalloc.h" 72 #include "error.h" 73 #include "mystring.h" 74 #include "var.h" 75 #include "builtins.h" 76 77 78 static struct job *jobtab; /* array of jobs */ 79 static int njobs; /* size of array */ 80 MKINIT pid_t backgndpid = -1; /* pid of last background process */ 81 MKINIT struct job *bgjob = NULL; /* last background process */ 82 #if JOBS 83 static struct job *jobmru; /* most recently used job list */ 84 static pid_t initialpgrp; /* pgrp of shell on invocation */ 85 #endif 86 int in_waitcmd = 0; /* are we in waitcmd()? */ 87 volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 88 static int ttyfd = -1; 89 90 /* mode flags for dowait */ 91 #define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 92 #define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signals */ 93 94 #if JOBS 95 static void restartjob(struct job *); 96 #endif 97 static void freejob(struct job *); 98 static struct job *getjob(char *); 99 pid_t getjobpgrp(char *); 100 static pid_t dowait(int, struct job *); 101 static void checkzombies(void); 102 static void cmdtxt(union node *); 103 static void cmdputs(const char *); 104 #if JOBS 105 static void setcurjob(struct job *); 106 static void deljob(struct job *); 107 static struct job *getcurjob(struct job *); 108 #endif 109 static void printjobcmd(struct job *); 110 static void showjob(struct job *, int); 111 112 113 /* 114 * Turn job control on and off. 115 */ 116 117 MKINIT int jobctl; 118 119 #if JOBS 120 void 121 setjobctl(int on) 122 { 123 int i; 124 125 if (on == jobctl || rootshell == 0) 126 return; 127 if (on) { 128 if (ttyfd != -1) 129 close(ttyfd); 130 if ((ttyfd = open(_PATH_TTY, O_RDWR)) < 0) { 131 i = 0; 132 while (i <= 2 && !isatty(i)) 133 i++; 134 if (i > 2 || (ttyfd = fcntl(i, F_DUPFD, 10)) < 0) 135 goto out; 136 } 137 if (ttyfd < 10) { 138 /* 139 * Keep our TTY file descriptor out of the way of 140 * the user's redirections. 141 */ 142 if ((i = fcntl(ttyfd, F_DUPFD, 10)) < 0) { 143 close(ttyfd); 144 ttyfd = -1; 145 goto out; 146 } 147 close(ttyfd); 148 ttyfd = i; 149 } 150 if (fcntl(ttyfd, F_SETFD, FD_CLOEXEC) < 0) { 151 close(ttyfd); 152 ttyfd = -1; 153 goto out; 154 } 155 do { /* while we are in the background */ 156 initialpgrp = tcgetpgrp(ttyfd); 157 if (initialpgrp < 0) { 158 out: out2fmt_flush("sh: can't access tty; job control turned off\n"); 159 mflag = 0; 160 return; 161 } 162 if (initialpgrp != getpgrp()) { 163 kill(0, SIGTTIN); 164 continue; 165 } 166 } while (0); 167 setsignal(SIGTSTP); 168 setsignal(SIGTTOU); 169 setsignal(SIGTTIN); 170 setpgid(0, rootpid); 171 tcsetpgrp(ttyfd, rootpid); 172 } else { /* turning job control off */ 173 setpgid(0, initialpgrp); 174 tcsetpgrp(ttyfd, initialpgrp); 175 close(ttyfd); 176 ttyfd = -1; 177 setsignal(SIGTSTP); 178 setsignal(SIGTTOU); 179 setsignal(SIGTTIN); 180 } 181 jobctl = on; 182 } 183 #endif 184 185 186 #if JOBS 187 int 188 fgcmd(int argc __unused, char **argv) 189 { 190 struct job *jp; 191 pid_t pgrp; 192 int status; 193 194 jp = getjob(argv[1]); 195 if (jp->jobctl == 0) 196 error("job not created under job control"); 197 printjobcmd(jp); 198 flushout(&output); 199 pgrp = jp->ps[0].pid; 200 tcsetpgrp(ttyfd, pgrp); 201 restartjob(jp); 202 jp->foreground = 1; 203 INTOFF; 204 status = waitforjob(jp, (int *)NULL); 205 INTON; 206 return status; 207 } 208 209 210 int 211 bgcmd(int argc, char **argv) 212 { 213 struct job *jp; 214 215 do { 216 jp = getjob(*++argv); 217 if (jp->jobctl == 0) 218 error("job not created under job control"); 219 if (jp->state == JOBDONE) 220 continue; 221 restartjob(jp); 222 jp->foreground = 0; 223 out1fmt("[%td] ", jp - jobtab + 1); 224 printjobcmd(jp); 225 } while (--argc > 1); 226 return 0; 227 } 228 229 230 static void 231 restartjob(struct job *jp) 232 { 233 struct procstat *ps; 234 int i; 235 236 if (jp->state == JOBDONE) 237 return; 238 setcurjob(jp); 239 INTOFF; 240 kill(-jp->ps[0].pid, SIGCONT); 241 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 242 if (WIFSTOPPED(ps->status)) { 243 ps->status = -1; 244 jp->state = 0; 245 } 246 } 247 INTON; 248 } 249 #endif 250 251 252 int 253 jobscmd(int argc __unused, char *argv[] __unused) 254 { 255 char *id; 256 int ch, mode; 257 258 mode = SHOWJOBS_DEFAULT; 259 while ((ch = nextopt("lps")) != '\0') { 260 switch (ch) { 261 case 'l': 262 mode = SHOWJOBS_VERBOSE; 263 break; 264 case 'p': 265 mode = SHOWJOBS_PGIDS; 266 break; 267 case 's': 268 mode = SHOWJOBS_PIDS; 269 break; 270 } 271 } 272 273 if (*argptr == NULL) 274 showjobs(0, mode); 275 else 276 while ((id = *argptr++) != NULL) 277 showjob(getjob(id), mode); 278 279 return (0); 280 } 281 282 static void 283 printjobcmd(struct job *jp) 284 { 285 struct procstat *ps; 286 int i; 287 288 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 289 out1str(ps->cmd); 290 if (i > 0) 291 out1str(" | "); 292 } 293 out1c('\n'); 294 } 295 296 static void 297 showjob(struct job *jp, int mode) 298 { 299 char s[64]; 300 char statestr[64]; 301 const char *sigstr; 302 struct procstat *ps; 303 struct job *j; 304 int col, curr, i, jobno, prev, procno; 305 char c; 306 307 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 308 jobno = jp - jobtab + 1; 309 curr = prev = 0; 310 #if JOBS 311 if ((j = getcurjob(NULL)) != NULL) { 312 curr = j - jobtab + 1; 313 if ((j = getcurjob(j)) != NULL) 314 prev = j - jobtab + 1; 315 } 316 #endif 317 ps = jp->ps + jp->nprocs - 1; 318 if (jp->state == 0) { 319 strcpy(statestr, "Running"); 320 #if JOBS 321 } else if (jp->state == JOBSTOPPED) { 322 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 323 ps--; 324 if (WIFSTOPPED(ps->status)) 325 i = WSTOPSIG(ps->status); 326 else 327 i = -1; 328 sigstr = strsignal(i); 329 if (sigstr != NULL) 330 strcpy(statestr, sigstr); 331 else 332 strcpy(statestr, "Suspended"); 333 #endif 334 } else if (WIFEXITED(ps->status)) { 335 if (WEXITSTATUS(ps->status) == 0) 336 strcpy(statestr, "Done"); 337 else 338 fmtstr(statestr, 64, "Done(%d)", 339 WEXITSTATUS(ps->status)); 340 } else { 341 i = WTERMSIG(ps->status); 342 sigstr = strsignal(i); 343 if (sigstr != NULL) 344 strcpy(statestr, sigstr); 345 else 346 strcpy(statestr, "Unknown signal"); 347 if (WCOREDUMP(ps->status)) 348 strcat(statestr, " (core dumped)"); 349 } 350 351 for (ps = jp->ps ; ; ps++) { /* for each process */ 352 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 353 out1fmt("%d\n", (int)ps->pid); 354 goto skip; 355 } 356 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 357 goto skip; 358 if (jobno == curr && ps == jp->ps) 359 c = '+'; 360 else if (jobno == prev && ps == jp->ps) 361 c = '-'; 362 else 363 c = ' '; 364 if (ps == jp->ps) 365 fmtstr(s, 64, "[%d] %c ", jobno, c); 366 else 367 fmtstr(s, 64, " %c ", c); 368 out1str(s); 369 col = strlen(s); 370 if (mode == SHOWJOBS_VERBOSE) { 371 fmtstr(s, 64, "%d ", (int)ps->pid); 372 out1str(s); 373 col += strlen(s); 374 } 375 if (ps == jp->ps) { 376 out1str(statestr); 377 col += strlen(statestr); 378 } 379 do { 380 out1c(' '); 381 col++; 382 } while (col < 30); 383 if (mode == SHOWJOBS_VERBOSE) { 384 out1str(ps->cmd); 385 out1c('\n'); 386 } else 387 printjobcmd(jp); 388 skip: if (--procno <= 0) 389 break; 390 } 391 } 392 393 /* 394 * Print a list of jobs. If "change" is nonzero, only print jobs whose 395 * statuses have changed since the last call to showjobs. 396 * 397 * If the shell is interrupted in the process of creating a job, the 398 * result may be a job structure containing zero processes. Such structures 399 * will be freed here. 400 */ 401 402 void 403 showjobs(int change, int mode) 404 { 405 int jobno; 406 struct job *jp; 407 408 TRACE(("showjobs(%d) called\n", change)); 409 checkzombies(); 410 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 411 if (! jp->used) 412 continue; 413 if (jp->nprocs == 0) { 414 freejob(jp); 415 continue; 416 } 417 if (change && ! jp->changed) 418 continue; 419 showjob(jp, mode); 420 jp->changed = 0; 421 /* Hack: discard jobs for which $! has not been referenced 422 * in interactive mode when they terminate. 423 */ 424 if (jp->state == JOBDONE && !jp->remembered && 425 (iflag || jp != bgjob)) { 426 freejob(jp); 427 } 428 } 429 } 430 431 432 /* 433 * Mark a job structure as unused. 434 */ 435 436 static void 437 freejob(struct job *jp) 438 { 439 struct procstat *ps; 440 int i; 441 442 INTOFF; 443 if (bgjob == jp) 444 bgjob = NULL; 445 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 446 if (ps->cmd != nullstr) 447 ckfree(ps->cmd); 448 } 449 if (jp->ps != &jp->ps0) 450 ckfree(jp->ps); 451 jp->used = 0; 452 #if JOBS 453 deljob(jp); 454 #endif 455 INTON; 456 } 457 458 459 460 int 461 waitcmd(int argc __unused, char **argv __unused) 462 { 463 struct job *job; 464 int status, retval; 465 struct job *jp; 466 467 nextopt(""); 468 if (*argptr != NULL) { 469 job = getjob(*argptr); 470 } else { 471 job = NULL; 472 } 473 474 /* 475 * Loop until a process is terminated or stopped, or a SIGINT is 476 * received. 477 */ 478 479 in_waitcmd++; 480 do { 481 if (job != NULL) { 482 if (job->state) { 483 status = job->ps[job->nprocs - 1].status; 484 if (WIFEXITED(status)) 485 retval = WEXITSTATUS(status); 486 #if JOBS 487 else if (WIFSTOPPED(status)) 488 retval = WSTOPSIG(status) + 128; 489 #endif 490 else 491 retval = WTERMSIG(status) + 128; 492 if (! iflag || ! job->changed) 493 freejob(job); 494 else { 495 job->remembered = 0; 496 if (job == bgjob) 497 bgjob = NULL; 498 } 499 in_waitcmd--; 500 return retval; 501 } 502 } else { 503 for (jp = jobtab ; jp < jobtab + njobs; jp++) 504 if (jp->used && jp->state == JOBDONE) { 505 if (! iflag || ! jp->changed) 506 freejob(jp); 507 else { 508 jp->remembered = 0; 509 if (jp == bgjob) 510 bgjob = NULL; 511 } 512 } 513 for (jp = jobtab ; ; jp++) { 514 if (jp >= jobtab + njobs) { /* no running procs */ 515 in_waitcmd--; 516 return 0; 517 } 518 if (jp->used && jp->state == 0) 519 break; 520 } 521 } 522 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 523 in_waitcmd--; 524 525 return pendingsig + 128; 526 } 527 528 529 530 int 531 jobidcmd(int argc __unused, char **argv) 532 { 533 struct job *jp; 534 int i; 535 536 jp = getjob(argv[1]); 537 for (i = 0 ; i < jp->nprocs ; ) { 538 out1fmt("%d", (int)jp->ps[i].pid); 539 out1c(++i < jp->nprocs? ' ' : '\n'); 540 } 541 return 0; 542 } 543 544 545 546 /* 547 * Convert a job name to a job structure. 548 */ 549 550 static struct job * 551 getjob(char *name) 552 { 553 int jobno; 554 struct job *found, *jp; 555 pid_t pid; 556 int i; 557 558 if (name == NULL) { 559 #if JOBS 560 currentjob: if ((jp = getcurjob(NULL)) == NULL) 561 error("No current job"); 562 return (jp); 563 #else 564 error("No current job"); 565 #endif 566 } else if (name[0] == '%') { 567 if (is_digit(name[1])) { 568 jobno = number(name + 1); 569 if (jobno > 0 && jobno <= njobs 570 && jobtab[jobno - 1].used != 0) 571 return &jobtab[jobno - 1]; 572 #if JOBS 573 } else if (name[1] == '%' && name[2] == '\0') { 574 goto currentjob; 575 } else if (name[1] == '+' && name[2] == '\0') { 576 goto currentjob; 577 } else if (name[1] == '-' && name[2] == '\0') { 578 if ((jp = getcurjob(NULL)) == NULL || 579 (jp = getcurjob(jp)) == NULL) 580 error("No previous job"); 581 return (jp); 582 #endif 583 } else if (name[1] == '?') { 584 found = NULL; 585 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 586 if (jp->used && jp->nprocs > 0 587 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 588 if (found) 589 error("%s: ambiguous", name); 590 found = jp; 591 } 592 } 593 if (found != NULL) 594 return (found); 595 } else { 596 found = NULL; 597 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 598 if (jp->used && jp->nprocs > 0 599 && prefix(name + 1, jp->ps[0].cmd)) { 600 if (found) 601 error("%s: ambiguous", name); 602 found = jp; 603 } 604 } 605 if (found) 606 return found; 607 } 608 } else if (is_number(name)) { 609 pid = (pid_t)number(name); 610 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 611 if (jp->used && jp->nprocs > 0 612 && jp->ps[jp->nprocs - 1].pid == pid) 613 return jp; 614 } 615 } 616 error("No such job: %s", name); 617 /*NOTREACHED*/ 618 return NULL; 619 } 620 621 622 pid_t 623 getjobpgrp(char *name) 624 { 625 struct job *jp; 626 627 jp = getjob(name); 628 return -jp->ps[0].pid; 629 } 630 631 /* 632 * Return a new job structure, 633 */ 634 635 struct job * 636 makejob(union node *node __unused, int nprocs) 637 { 638 int i; 639 struct job *jp; 640 641 for (i = njobs, jp = jobtab ; ; jp++) { 642 if (--i < 0) { 643 INTOFF; 644 if (njobs == 0) { 645 jobtab = ckmalloc(4 * sizeof jobtab[0]); 646 #if JOBS 647 jobmru = NULL; 648 #endif 649 } else { 650 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 651 memcpy(jp, jobtab, njobs * sizeof jp[0]); 652 #if JOBS 653 /* Relocate `next' pointers and list head */ 654 if (jobmru != NULL) 655 jobmru = &jp[jobmru - jobtab]; 656 for (i = 0; i < njobs; i++) 657 if (jp[i].next != NULL) 658 jp[i].next = &jp[jp[i].next - 659 jobtab]; 660 #endif 661 if (bgjob != NULL) 662 bgjob = &jp[bgjob - jobtab]; 663 /* Relocate `ps' pointers */ 664 for (i = 0; i < njobs; i++) 665 if (jp[i].ps == &jobtab[i].ps0) 666 jp[i].ps = &jp[i].ps0; 667 ckfree(jobtab); 668 jobtab = jp; 669 } 670 jp = jobtab + njobs; 671 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 672 INTON; 673 break; 674 } 675 if (jp->used == 0) 676 break; 677 } 678 INTOFF; 679 jp->state = 0; 680 jp->used = 1; 681 jp->changed = 0; 682 jp->nprocs = 0; 683 jp->foreground = 0; 684 jp->remembered = 0; 685 #if JOBS 686 jp->jobctl = jobctl; 687 jp->next = NULL; 688 #endif 689 if (nprocs > 1) { 690 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 691 } else { 692 jp->ps = &jp->ps0; 693 } 694 INTON; 695 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 696 jp - jobtab + 1)); 697 return jp; 698 } 699 700 #if JOBS 701 static void 702 setcurjob(struct job *cj) 703 { 704 struct job *jp, *prev; 705 706 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 707 if (jp == cj) { 708 if (prev != NULL) 709 prev->next = jp->next; 710 else 711 jobmru = jp->next; 712 jp->next = jobmru; 713 jobmru = cj; 714 return; 715 } 716 } 717 cj->next = jobmru; 718 jobmru = cj; 719 } 720 721 static void 722 deljob(struct job *j) 723 { 724 struct job *jp, *prev; 725 726 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 727 if (jp == j) { 728 if (prev != NULL) 729 prev->next = jp->next; 730 else 731 jobmru = jp->next; 732 return; 733 } 734 } 735 } 736 737 /* 738 * Return the most recently used job that isn't `nj', and preferably one 739 * that is stopped. 740 */ 741 static struct job * 742 getcurjob(struct job *nj) 743 { 744 struct job *jp; 745 746 /* Try to find a stopped one.. */ 747 for (jp = jobmru; jp != NULL; jp = jp->next) 748 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 749 return (jp); 750 /* Otherwise the most recently used job that isn't `nj' */ 751 for (jp = jobmru; jp != NULL; jp = jp->next) 752 if (jp->used && jp != nj) 753 return (jp); 754 755 return (NULL); 756 } 757 758 #endif 759 760 /* 761 * Fork of a subshell. If we are doing job control, give the subshell its 762 * own process group. Jp is a job structure that the job is to be added to. 763 * N is the command that will be evaluated by the child. Both jp and n may 764 * be NULL. The mode parameter can be one of the following: 765 * FORK_FG - Fork off a foreground process. 766 * FORK_BG - Fork off a background process. 767 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 768 * process group even if job control is on. 769 * 770 * When job control is turned off, background processes have their standard 771 * input redirected to /dev/null (except for the second and later processes 772 * in a pipeline). 773 */ 774 775 pid_t 776 forkshell(struct job *jp, union node *n, int mode) 777 { 778 pid_t pid; 779 pid_t pgrp; 780 781 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 782 mode)); 783 INTOFF; 784 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 785 checkzombies(); 786 flushall(); 787 pid = fork(); 788 if (pid == -1) { 789 TRACE(("Fork failed, errno=%d\n", errno)); 790 INTON; 791 error("Cannot fork: %s", strerror(errno)); 792 } 793 if (pid == 0) { 794 struct job *p; 795 int wasroot; 796 int i; 797 798 TRACE(("Child shell %d\n", (int)getpid())); 799 wasroot = rootshell; 800 rootshell = 0; 801 handler = &main_handler; 802 closescript(); 803 INTON; 804 forcelocal = 0; 805 clear_traps(); 806 #if JOBS 807 jobctl = 0; /* do job control only in root shell */ 808 if (wasroot && mode != FORK_NOJOB && mflag) { 809 if (jp == NULL || jp->nprocs == 0) 810 pgrp = getpid(); 811 else 812 pgrp = jp->ps[0].pid; 813 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 814 /*** this causes superfluous TIOCSPGRPS ***/ 815 if (tcsetpgrp(ttyfd, pgrp) < 0) 816 error("tcsetpgrp failed, errno=%d", errno); 817 } 818 setsignal(SIGTSTP); 819 setsignal(SIGTTOU); 820 } else if (mode == FORK_BG) { 821 ignoresig(SIGINT); 822 ignoresig(SIGQUIT); 823 if ((jp == NULL || jp->nprocs == 0) && 824 ! fd0_redirected_p ()) { 825 close(0); 826 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 827 error("cannot open %s: %s", 828 _PATH_DEVNULL, strerror(errno)); 829 } 830 } 831 #else 832 if (mode == FORK_BG) { 833 ignoresig(SIGINT); 834 ignoresig(SIGQUIT); 835 if ((jp == NULL || jp->nprocs == 0) && 836 ! fd0_redirected_p ()) { 837 close(0); 838 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 839 error("cannot open %s: %s", 840 _PATH_DEVNULL, strerror(errno)); 841 } 842 } 843 #endif 844 INTOFF; 845 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 846 if (p->used) 847 freejob(p); 848 INTON; 849 if (wasroot && iflag) { 850 setsignal(SIGINT); 851 setsignal(SIGQUIT); 852 setsignal(SIGTERM); 853 } 854 return pid; 855 } 856 if (rootshell && mode != FORK_NOJOB && mflag) { 857 if (jp == NULL || jp->nprocs == 0) 858 pgrp = pid; 859 else 860 pgrp = jp->ps[0].pid; 861 setpgid(pid, pgrp); 862 } 863 if (mode == FORK_BG) { 864 if (bgjob != NULL && bgjob->state == JOBDONE && 865 !bgjob->remembered && !iflag) 866 freejob(bgjob); 867 backgndpid = pid; /* set $! */ 868 bgjob = jp; 869 } 870 if (jp) { 871 struct procstat *ps = &jp->ps[jp->nprocs++]; 872 ps->pid = pid; 873 ps->status = -1; 874 ps->cmd = nullstr; 875 if (iflag && rootshell && n) 876 ps->cmd = commandtext(n); 877 jp->foreground = mode == FORK_FG; 878 #if JOBS 879 setcurjob(jp); 880 #endif 881 } 882 INTON; 883 TRACE(("In parent shell: child = %d\n", (int)pid)); 884 return pid; 885 } 886 887 888 pid_t 889 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 890 { 891 pid_t pid; 892 struct jmploc jmploc; 893 struct jmploc *savehandler; 894 895 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 896 (void *)pip)); 897 INTOFF; 898 flushall(); 899 savehandler = handler; 900 pid = vfork(); 901 if (pid == -1) { 902 TRACE(("Vfork failed, errno=%d\n", errno)); 903 INTON; 904 error("Cannot fork: %s", strerror(errno)); 905 } 906 if (pid == 0) { 907 TRACE(("Child shell %d\n", (int)getpid())); 908 if (setjmp(jmploc.loc)) 909 _exit(exception == EXEXEC ? exerrno : 2); 910 if (pip != NULL) { 911 close(pip[0]); 912 if (pip[1] != 1) { 913 dup2(pip[1], 1); 914 close(pip[1]); 915 } 916 } 917 handler = &jmploc; 918 shellexec(argv, envp, path, idx); 919 } 920 handler = savehandler; 921 if (jp) { 922 struct procstat *ps = &jp->ps[jp->nprocs++]; 923 ps->pid = pid; 924 ps->status = -1; 925 ps->cmd = nullstr; 926 jp->foreground = 1; 927 #if JOBS 928 setcurjob(jp); 929 #endif 930 } 931 INTON; 932 TRACE(("In parent shell: child = %d\n", (int)pid)); 933 return pid; 934 } 935 936 937 /* 938 * Wait for job to finish. 939 * 940 * Under job control we have the problem that while a child process is 941 * running interrupts generated by the user are sent to the child but not 942 * to the shell. This means that an infinite loop started by an inter- 943 * active user may be hard to kill. With job control turned off, an 944 * interactive user may place an interactive program inside a loop. If 945 * the interactive program catches interrupts, the user doesn't want 946 * these interrupts to also abort the loop. The approach we take here 947 * is to have the shell ignore interrupt signals while waiting for a 948 * foreground process to terminate, and then send itself an interrupt 949 * signal if the child process was terminated by an interrupt signal. 950 * Unfortunately, some programs want to do a bit of cleanup and then 951 * exit on interrupt; unless these processes terminate themselves by 952 * sending a signal to themselves (instead of calling exit) they will 953 * confuse this approach. 954 */ 955 956 int 957 waitforjob(struct job *jp, int *origstatus) 958 { 959 #if JOBS 960 pid_t mypgrp = getpgrp(); 961 int propagate_int = jp->jobctl && jp->foreground; 962 #endif 963 int status; 964 int st; 965 966 INTOFF; 967 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 968 while (jp->state == 0) 969 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG : 0), jp) == -1) 970 dotrap(); 971 #if JOBS 972 if (jp->jobctl) { 973 if (tcsetpgrp(ttyfd, mypgrp) < 0) 974 error("tcsetpgrp failed, errno=%d\n", errno); 975 } 976 if (jp->state == JOBSTOPPED) 977 setcurjob(jp); 978 #endif 979 status = jp->ps[jp->nprocs - 1].status; 980 if (origstatus != NULL) 981 *origstatus = status; 982 /* convert to 8 bits */ 983 if (WIFEXITED(status)) 984 st = WEXITSTATUS(status); 985 #if JOBS 986 else if (WIFSTOPPED(status)) 987 st = WSTOPSIG(status) + 128; 988 #endif 989 else 990 st = WTERMSIG(status) + 128; 991 if (! JOBS || jp->state == JOBDONE) 992 freejob(jp); 993 if (int_pending()) { 994 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 995 CLEAR_PENDING_INT; 996 } 997 #if JOBS 998 else if (rootshell && iflag && propagate_int && 999 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1000 kill(getpid(), SIGINT); 1001 #endif 1002 INTON; 1003 return st; 1004 } 1005 1006 1007 static void 1008 dummy_handler(int sig) 1009 { 1010 } 1011 1012 /* 1013 * Wait for a process to terminate. 1014 */ 1015 1016 static pid_t 1017 dowait(int mode, struct job *job) 1018 { 1019 struct sigaction sa, osa; 1020 sigset_t mask, omask; 1021 pid_t pid; 1022 int status; 1023 struct procstat *sp; 1024 struct job *jp; 1025 struct job *thisjob; 1026 const char *sigstr; 1027 int done; 1028 int stopped; 1029 int sig; 1030 int coredump; 1031 int wflags; 1032 int restore_sigchld; 1033 1034 TRACE(("dowait(%d, %p) called\n", mode, job)); 1035 restore_sigchld = 0; 1036 if ((mode & DOWAIT_SIG) != 0) { 1037 sigfillset(&mask); 1038 sigprocmask(SIG_BLOCK, &mask, &omask); 1039 INTOFF; 1040 if (!issigchldtrapped()) { 1041 restore_sigchld = 1; 1042 sa.sa_handler = dummy_handler; 1043 sa.sa_flags = 0; 1044 sigemptyset(&sa.sa_mask); 1045 sigaction(SIGCHLD, &sa, &osa); 1046 } 1047 } 1048 do { 1049 #if JOBS 1050 if (iflag) 1051 wflags = WUNTRACED | WCONTINUED; 1052 else 1053 #endif 1054 wflags = 0; 1055 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1056 wflags |= WNOHANG; 1057 pid = wait3(&status, wflags, (struct rusage *)NULL); 1058 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1059 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1060 sigsuspend(&omask); 1061 pid = -1; 1062 if (int_pending()) 1063 break; 1064 } 1065 } while (pid == -1 && errno == EINTR && breakwaitcmd == 0); 1066 if (pid == -1 && errno == ECHILD && job != NULL) 1067 job->state = JOBDONE; 1068 if ((mode & DOWAIT_SIG) != 0) { 1069 if (restore_sigchld) 1070 sigaction(SIGCHLD, &osa, NULL); 1071 sigprocmask(SIG_SETMASK, &omask, NULL); 1072 INTON; 1073 } 1074 if (breakwaitcmd != 0) { 1075 breakwaitcmd = 0; 1076 if (pid <= 0) 1077 return -1; 1078 } 1079 if (pid <= 0) 1080 return pid; 1081 INTOFF; 1082 thisjob = NULL; 1083 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1084 if (jp->used && jp->nprocs > 0) { 1085 done = 1; 1086 stopped = 1; 1087 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1088 if (sp->pid == -1) 1089 continue; 1090 if (sp->pid == pid) { 1091 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1092 (int)pid, sp->status, 1093 status)); 1094 if (WIFCONTINUED(status)) { 1095 sp->status = -1; 1096 jp->state = 0; 1097 } else 1098 sp->status = status; 1099 thisjob = jp; 1100 } 1101 if (sp->status == -1) 1102 stopped = 0; 1103 else if (WIFSTOPPED(sp->status)) 1104 done = 0; 1105 } 1106 if (stopped) { /* stopped or done */ 1107 int state = done? JOBDONE : JOBSTOPPED; 1108 if (jp->state != state) { 1109 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1110 jp->state = state; 1111 if (jp != job) { 1112 if (done && !jp->remembered && 1113 !iflag && jp != bgjob) 1114 freejob(jp); 1115 #if JOBS 1116 else if (done) 1117 deljob(jp); 1118 #endif 1119 } 1120 } 1121 } 1122 } 1123 } 1124 INTON; 1125 if (!thisjob || thisjob->state == 0) 1126 ; 1127 else if ((!rootshell || !iflag || thisjob == job) && 1128 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1129 sig = 0; 1130 coredump = 0; 1131 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1132 if (WIFSIGNALED(sp->status)) { 1133 sig = WTERMSIG(sp->status); 1134 coredump = WCOREDUMP(sp->status); 1135 } 1136 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1137 sigstr = strsignal(sig); 1138 if (sigstr != NULL) 1139 out2str(sigstr); 1140 else 1141 out2str("Unknown signal"); 1142 if (coredump) 1143 out2str(" (core dumped)"); 1144 out2c('\n'); 1145 flushout(out2); 1146 } 1147 } else { 1148 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1149 thisjob->changed = 1; 1150 } 1151 return pid; 1152 } 1153 1154 1155 1156 /* 1157 * return 1 if there are stopped jobs, otherwise 0 1158 */ 1159 int job_warning = 0; 1160 int 1161 stoppedjobs(void) 1162 { 1163 int jobno; 1164 struct job *jp; 1165 1166 if (job_warning) 1167 return (0); 1168 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1169 if (jp->used == 0) 1170 continue; 1171 if (jp->state == JOBSTOPPED) { 1172 out2fmt_flush("You have stopped jobs.\n"); 1173 job_warning = 2; 1174 return (1); 1175 } 1176 } 1177 1178 return (0); 1179 } 1180 1181 1182 static void 1183 checkzombies(void) 1184 { 1185 while (njobs > 0 && dowait(0, NULL) > 0) 1186 ; 1187 } 1188 1189 1190 int 1191 backgndpidset(void) 1192 { 1193 return backgndpid != -1; 1194 } 1195 1196 1197 pid_t 1198 backgndpidval(void) 1199 { 1200 if (bgjob != NULL && !forcelocal) 1201 bgjob->remembered = 1; 1202 return backgndpid; 1203 } 1204 1205 /* 1206 * Return a string identifying a command (to be printed by the 1207 * jobs command. 1208 */ 1209 1210 static char *cmdnextc; 1211 static int cmdnleft; 1212 #define MAXCMDTEXT 200 1213 1214 char * 1215 commandtext(union node *n) 1216 { 1217 char *name; 1218 1219 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1220 cmdnleft = MAXCMDTEXT - 4; 1221 cmdtxt(n); 1222 *cmdnextc = '\0'; 1223 return name; 1224 } 1225 1226 1227 static void 1228 cmdtxt(union node *n) 1229 { 1230 union node *np; 1231 struct nodelist *lp; 1232 const char *p; 1233 int i; 1234 char s[2]; 1235 1236 if (n == NULL) 1237 return; 1238 switch (n->type) { 1239 case NSEMI: 1240 cmdtxt(n->nbinary.ch1); 1241 cmdputs("; "); 1242 cmdtxt(n->nbinary.ch2); 1243 break; 1244 case NAND: 1245 cmdtxt(n->nbinary.ch1); 1246 cmdputs(" && "); 1247 cmdtxt(n->nbinary.ch2); 1248 break; 1249 case NOR: 1250 cmdtxt(n->nbinary.ch1); 1251 cmdputs(" || "); 1252 cmdtxt(n->nbinary.ch2); 1253 break; 1254 case NPIPE: 1255 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1256 cmdtxt(lp->n); 1257 if (lp->next) 1258 cmdputs(" | "); 1259 } 1260 break; 1261 case NSUBSHELL: 1262 cmdputs("("); 1263 cmdtxt(n->nredir.n); 1264 cmdputs(")"); 1265 break; 1266 case NREDIR: 1267 case NBACKGND: 1268 cmdtxt(n->nredir.n); 1269 break; 1270 case NIF: 1271 cmdputs("if "); 1272 cmdtxt(n->nif.test); 1273 cmdputs("; then "); 1274 cmdtxt(n->nif.ifpart); 1275 cmdputs("..."); 1276 break; 1277 case NWHILE: 1278 cmdputs("while "); 1279 goto until; 1280 case NUNTIL: 1281 cmdputs("until "); 1282 until: 1283 cmdtxt(n->nbinary.ch1); 1284 cmdputs("; do "); 1285 cmdtxt(n->nbinary.ch2); 1286 cmdputs("; done"); 1287 break; 1288 case NFOR: 1289 cmdputs("for "); 1290 cmdputs(n->nfor.var); 1291 cmdputs(" in ..."); 1292 break; 1293 case NCASE: 1294 cmdputs("case "); 1295 cmdputs(n->ncase.expr->narg.text); 1296 cmdputs(" in ..."); 1297 break; 1298 case NDEFUN: 1299 cmdputs(n->narg.text); 1300 cmdputs("() ..."); 1301 break; 1302 case NNOT: 1303 cmdputs("! "); 1304 cmdtxt(n->nnot.com); 1305 break; 1306 case NCMD: 1307 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1308 cmdtxt(np); 1309 if (np->narg.next) 1310 cmdputs(" "); 1311 } 1312 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1313 cmdputs(" "); 1314 cmdtxt(np); 1315 } 1316 break; 1317 case NARG: 1318 cmdputs(n->narg.text); 1319 break; 1320 case NTO: 1321 p = ">"; i = 1; goto redir; 1322 case NAPPEND: 1323 p = ">>"; i = 1; goto redir; 1324 case NTOFD: 1325 p = ">&"; i = 1; goto redir; 1326 case NCLOBBER: 1327 p = ">|"; i = 1; goto redir; 1328 case NFROM: 1329 p = "<"; i = 0; goto redir; 1330 case NFROMTO: 1331 p = "<>"; i = 0; goto redir; 1332 case NFROMFD: 1333 p = "<&"; i = 0; goto redir; 1334 redir: 1335 if (n->nfile.fd != i) { 1336 s[0] = n->nfile.fd + '0'; 1337 s[1] = '\0'; 1338 cmdputs(s); 1339 } 1340 cmdputs(p); 1341 if (n->type == NTOFD || n->type == NFROMFD) { 1342 if (n->ndup.dupfd >= 0) 1343 s[0] = n->ndup.dupfd + '0'; 1344 else 1345 s[0] = '-'; 1346 s[1] = '\0'; 1347 cmdputs(s); 1348 } else { 1349 cmdtxt(n->nfile.fname); 1350 } 1351 break; 1352 case NHERE: 1353 case NXHERE: 1354 cmdputs("<<..."); 1355 break; 1356 default: 1357 cmdputs("???"); 1358 break; 1359 } 1360 } 1361 1362 1363 1364 static void 1365 cmdputs(const char *s) 1366 { 1367 const char *p; 1368 char *q; 1369 char c; 1370 int subtype = 0; 1371 1372 if (cmdnleft <= 0) 1373 return; 1374 p = s; 1375 q = cmdnextc; 1376 while ((c = *p++) != '\0') { 1377 if (c == CTLESC) 1378 *q++ = *p++; 1379 else if (c == CTLVAR) { 1380 *q++ = '$'; 1381 if (--cmdnleft > 0) 1382 *q++ = '{'; 1383 subtype = *p++; 1384 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1385 *q++ = '#'; 1386 } else if (c == '=' && subtype != 0) { 1387 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1388 if (*q) 1389 q++; 1390 else 1391 cmdnleft++; 1392 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1393 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1394 --cmdnleft > 0) 1395 *q = q[-1], q++; 1396 subtype = 0; 1397 } else if (c == CTLENDVAR) { 1398 *q++ = '}'; 1399 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1400 cmdnleft -= 5; 1401 if (cmdnleft > 0) { 1402 *q++ = '$'; 1403 *q++ = '('; 1404 *q++ = '.'; 1405 *q++ = '.'; 1406 *q++ = '.'; 1407 *q++ = ')'; 1408 } 1409 } else if (c == CTLARI) { 1410 cmdnleft -= 2; 1411 if (cmdnleft > 0) { 1412 *q++ = '$'; 1413 *q++ = '('; 1414 *q++ = '('; 1415 } 1416 p++; 1417 } else if (c == CTLENDARI) { 1418 if (--cmdnleft > 0) { 1419 *q++ = ')'; 1420 *q++ = ')'; 1421 } 1422 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1423 cmdnleft++; /* ignore */ 1424 else 1425 *q++ = c; 1426 if (--cmdnleft <= 0) { 1427 *q++ = '.'; 1428 *q++ = '.'; 1429 *q++ = '.'; 1430 break; 1431 } 1432 } 1433 cmdnextc = q; 1434 } 1435