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 static pid_t backgndpid = -1; /* pid of last background process */ 81 static 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 static int ttyfd = -1; 87 88 /* mode flags for dowait */ 89 #define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 90 #define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on SIGINT/SIGQUIT */ 91 #define DOWAIT_SIG_ANY 0x4 /* if DOWAIT_SIG, abort on any signal */ 92 93 #if JOBS 94 static void restartjob(struct job *); 95 #endif 96 static void freejob(struct job *); 97 static int waitcmdloop(struct job *); 98 static struct job *getjob_nonotfound(const char *); 99 static struct job *getjob(const char *); 100 pid_t killjob(const char *, int); 101 static pid_t dowait(int, struct job *); 102 static void checkzombies(void); 103 static void cmdtxt(union node *); 104 static void cmdputs(const 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 printjobcmd(struct job *); 111 static void showjob(struct job *, int); 112 113 114 /* 115 * Turn job control on and off. 116 */ 117 118 static int jobctl; 119 120 #if JOBS 121 void 122 setjobctl(int on) 123 { 124 int i; 125 126 if (on == jobctl || rootshell == 0) 127 return; 128 if (on) { 129 if (ttyfd != -1) 130 close(ttyfd); 131 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 132 i = 0; 133 while (i <= 2 && !isatty(i)) 134 i++; 135 if (i > 2 || 136 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) 137 goto out; 138 } 139 if (ttyfd < 10) { 140 /* 141 * Keep our TTY file descriptor out of the way of 142 * the user's redirections. 143 */ 144 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 145 close(ttyfd); 146 ttyfd = -1; 147 goto out; 148 } 149 close(ttyfd); 150 ttyfd = i; 151 } 152 do { /* while we are in the background */ 153 initialpgrp = tcgetpgrp(ttyfd); 154 if (initialpgrp < 0) { 155 out: out2fmt_flush("sh: can't access tty; job control turned off\n"); 156 mflag = 0; 157 return; 158 } 159 if (initialpgrp != getpgrp()) { 160 kill(0, SIGTTIN); 161 continue; 162 } 163 } while (0); 164 setsignal(SIGTSTP); 165 setsignal(SIGTTOU); 166 setsignal(SIGTTIN); 167 setpgid(0, rootpid); 168 tcsetpgrp(ttyfd, rootpid); 169 } else { /* turning job control off */ 170 setpgid(0, initialpgrp); 171 tcsetpgrp(ttyfd, initialpgrp); 172 close(ttyfd); 173 ttyfd = -1; 174 setsignal(SIGTSTP); 175 setsignal(SIGTTOU); 176 setsignal(SIGTTIN); 177 } 178 jobctl = on; 179 } 180 #endif 181 182 183 #if JOBS 184 int 185 fgcmd(int argc __unused, char **argv __unused) 186 { 187 struct job *jp; 188 pid_t pgrp; 189 int status; 190 191 nextopt(""); 192 jp = getjob(*argptr); 193 if (jp->jobctl == 0) 194 error("job not created under job control"); 195 printjobcmd(jp); 196 flushout(&output); 197 pgrp = jp->ps[0].pid; 198 tcsetpgrp(ttyfd, pgrp); 199 restartjob(jp); 200 jp->foreground = 1; 201 INTOFF; 202 status = waitforjob(jp, (int *)NULL); 203 INTON; 204 return status; 205 } 206 207 208 int 209 bgcmd(int argc, char **argv) 210 { 211 struct job *jp; 212 213 nextopt(""); 214 do { 215 jp = getjob(*argptr); 216 if (jp->jobctl == 0) 217 error("job not created under job control"); 218 if (jp->state == JOBDONE) 219 continue; 220 restartjob(jp); 221 jp->foreground = 0; 222 out1fmt("[%td] ", jp - jobtab + 1); 223 printjobcmd(jp); 224 } while (*argptr != NULL && *++argptr != NULL); 225 return 0; 226 } 227 228 229 static void 230 restartjob(struct job *jp) 231 { 232 struct procstat *ps; 233 int i; 234 235 if (jp->state == JOBDONE) 236 return; 237 setcurjob(jp); 238 INTOFF; 239 kill(-jp->ps[0].pid, SIGCONT); 240 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 241 if (WIFSTOPPED(ps->status)) { 242 ps->status = -1; 243 jp->state = 0; 244 } 245 } 246 INTON; 247 } 248 #endif 249 250 251 int 252 jobscmd(int argc __unused, char *argv[] __unused) 253 { 254 char *id; 255 int ch, mode; 256 257 mode = SHOWJOBS_DEFAULT; 258 while ((ch = nextopt("lps")) != '\0') { 259 switch (ch) { 260 case 'l': 261 mode = SHOWJOBS_VERBOSE; 262 break; 263 case 'p': 264 mode = SHOWJOBS_PGIDS; 265 break; 266 case 's': 267 mode = SHOWJOBS_PIDS; 268 break; 269 } 270 } 271 272 if (*argptr == NULL) 273 showjobs(0, mode); 274 else 275 while ((id = *argptr++) != NULL) 276 showjob(getjob(id), mode); 277 278 return (0); 279 } 280 281 static void 282 printjobcmd(struct job *jp) 283 { 284 struct procstat *ps; 285 int i; 286 287 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 288 out1str(ps->cmd); 289 if (i > 0) 290 out1str(" | "); 291 } 292 out1c('\n'); 293 } 294 295 static void 296 showjob(struct job *jp, int mode) 297 { 298 char s[64]; 299 char statestr[64]; 300 const char *sigstr; 301 struct procstat *ps; 302 struct job *j; 303 int col, curr, i, jobno, prev, procno; 304 char c; 305 306 procno = (mode == SHOWJOBS_PGIDS) ? 1 : 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 ps = jp->ps + jp->nprocs - 1; 317 if (jp->state == 0) { 318 strcpy(statestr, "Running"); 319 #if JOBS 320 } else if (jp->state == JOBSTOPPED) { 321 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 322 ps--; 323 if (WIFSTOPPED(ps->status)) 324 i = WSTOPSIG(ps->status); 325 else 326 i = -1; 327 sigstr = strsignal(i); 328 if (sigstr != NULL) 329 strcpy(statestr, sigstr); 330 else 331 strcpy(statestr, "Suspended"); 332 #endif 333 } else if (WIFEXITED(ps->status)) { 334 if (WEXITSTATUS(ps->status) == 0) 335 strcpy(statestr, "Done"); 336 else 337 fmtstr(statestr, 64, "Done(%d)", 338 WEXITSTATUS(ps->status)); 339 } else { 340 i = WTERMSIG(ps->status); 341 sigstr = strsignal(i); 342 if (sigstr != NULL) 343 strcpy(statestr, sigstr); 344 else 345 strcpy(statestr, "Unknown signal"); 346 if (WCOREDUMP(ps->status)) 347 strcat(statestr, " (core dumped)"); 348 } 349 350 for (ps = jp->ps ; ; ps++) { /* for each process */ 351 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 352 out1fmt("%d\n", (int)ps->pid); 353 goto skip; 354 } 355 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 356 goto skip; 357 if (jobno == curr && ps == jp->ps) 358 c = '+'; 359 else if (jobno == prev && ps == jp->ps) 360 c = '-'; 361 else 362 c = ' '; 363 if (ps == jp->ps) 364 fmtstr(s, 64, "[%d] %c ", jobno, c); 365 else 366 fmtstr(s, 64, " %c ", c); 367 out1str(s); 368 col = strlen(s); 369 if (mode == SHOWJOBS_VERBOSE) { 370 fmtstr(s, 64, "%d ", (int)ps->pid); 371 out1str(s); 372 col += strlen(s); 373 } 374 if (ps == jp->ps) { 375 out1str(statestr); 376 col += strlen(statestr); 377 } 378 do { 379 out1c(' '); 380 col++; 381 } while (col < 30); 382 if (mode == SHOWJOBS_VERBOSE) { 383 out1str(ps->cmd); 384 out1c('\n'); 385 } else 386 printjobcmd(jp); 387 skip: if (--procno <= 0) 388 break; 389 } 390 } 391 392 /* 393 * Print a list of jobs. If "change" is nonzero, only print jobs whose 394 * statuses have changed since the last call to showjobs. 395 * 396 * If the shell is interrupted in the process of creating a job, the 397 * result may be a job structure containing zero processes. Such structures 398 * will be freed here. 399 */ 400 401 void 402 showjobs(int change, int mode) 403 { 404 int jobno; 405 struct job *jp; 406 407 TRACE(("showjobs(%d) called\n", change)); 408 checkzombies(); 409 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 410 if (! jp->used) 411 continue; 412 if (jp->nprocs == 0) { 413 freejob(jp); 414 continue; 415 } 416 if (change && ! jp->changed) 417 continue; 418 showjob(jp, mode); 419 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 420 jp->changed = 0; 421 /* Hack: discard jobs for which $! has not been 422 * referenced 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 /* 434 * Mark a job structure as unused. 435 */ 436 437 static void 438 freejob(struct job *jp) 439 { 440 struct procstat *ps; 441 int i; 442 443 INTOFF; 444 if (bgjob == jp) 445 bgjob = NULL; 446 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 447 if (ps->cmd != nullstr) 448 ckfree(ps->cmd); 449 } 450 if (jp->ps != &jp->ps0) 451 ckfree(jp->ps); 452 jp->used = 0; 453 #if JOBS 454 deljob(jp); 455 #endif 456 INTON; 457 } 458 459 460 461 int 462 waitcmd(int argc __unused, char **argv __unused) 463 { 464 struct job *job; 465 int retval; 466 467 nextopt(""); 468 if (*argptr == NULL) 469 return (waitcmdloop(NULL)); 470 471 do { 472 job = getjob_nonotfound(*argptr); 473 if (job == NULL) 474 retval = 127; 475 else 476 retval = waitcmdloop(job); 477 argptr++; 478 } while (*argptr != NULL); 479 480 return (retval); 481 } 482 483 static int 484 waitcmdloop(struct job *job) 485 { 486 int status, retval, sig; 487 struct job *jp; 488 489 /* 490 * Loop until a process is terminated or stopped, or a SIGINT is 491 * received. 492 */ 493 494 do { 495 if (job != NULL) { 496 if (job->state == JOBDONE) { 497 status = job->ps[job->nprocs - 1].status; 498 if (WIFEXITED(status)) 499 retval = WEXITSTATUS(status); 500 else 501 retval = WTERMSIG(status) + 128; 502 if (! iflag || ! job->changed) 503 freejob(job); 504 else { 505 job->remembered = 0; 506 if (job == bgjob) 507 bgjob = NULL; 508 } 509 return retval; 510 } 511 } else { 512 for (jp = jobtab ; jp < jobtab + njobs; jp++) 513 if (jp->used && jp->state == JOBDONE) { 514 if (! iflag || ! jp->changed) 515 freejob(jp); 516 else { 517 jp->remembered = 0; 518 if (jp == bgjob) 519 bgjob = NULL; 520 } 521 } 522 for (jp = jobtab ; ; jp++) { 523 if (jp >= jobtab + njobs) { /* no running procs */ 524 return 0; 525 } 526 if (jp->used && jp->state == 0) 527 break; 528 } 529 } 530 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 531 532 sig = pendingsig_waitcmd; 533 pendingsig_waitcmd = 0; 534 return sig + 128; 535 } 536 537 538 539 int 540 jobidcmd(int argc __unused, char **argv __unused) 541 { 542 struct job *jp; 543 int i; 544 545 nextopt(""); 546 jp = getjob(*argptr); 547 for (i = 0 ; i < jp->nprocs ; ) { 548 out1fmt("%d", (int)jp->ps[i].pid); 549 out1c(++i < jp->nprocs? ' ' : '\n'); 550 } 551 return 0; 552 } 553 554 555 556 /* 557 * Convert a job name to a job structure. 558 */ 559 560 static struct job * 561 getjob_nonotfound(const char *name) 562 { 563 int jobno; 564 struct job *found, *jp; 565 pid_t pid; 566 int i; 567 568 if (name == NULL) { 569 #if JOBS 570 currentjob: if ((jp = getcurjob(NULL)) == NULL) 571 error("No current job"); 572 return (jp); 573 #else 574 error("No current job"); 575 #endif 576 } else if (name[0] == '%') { 577 if (is_digit(name[1])) { 578 jobno = number(name + 1); 579 if (jobno > 0 && jobno <= njobs 580 && jobtab[jobno - 1].used != 0) 581 return &jobtab[jobno - 1]; 582 #if JOBS 583 } else if (name[1] == '%' && name[2] == '\0') { 584 goto currentjob; 585 } else if (name[1] == '+' && name[2] == '\0') { 586 goto currentjob; 587 } else if (name[1] == '-' && name[2] == '\0') { 588 if ((jp = getcurjob(NULL)) == NULL || 589 (jp = getcurjob(jp)) == NULL) 590 error("No previous job"); 591 return (jp); 592 #endif 593 } else if (name[1] == '?') { 594 found = NULL; 595 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 596 if (jp->used && jp->nprocs > 0 597 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 598 if (found) 599 error("%s: ambiguous", name); 600 found = jp; 601 } 602 } 603 if (found != NULL) 604 return (found); 605 } else { 606 found = NULL; 607 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 608 if (jp->used && jp->nprocs > 0 609 && prefix(name + 1, jp->ps[0].cmd)) { 610 if (found) 611 error("%s: ambiguous", name); 612 found = jp; 613 } 614 } 615 if (found) 616 return found; 617 } 618 } else if (is_number(name)) { 619 pid = (pid_t)number(name); 620 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 621 if (jp->used && jp->nprocs > 0 622 && jp->ps[jp->nprocs - 1].pid == pid) 623 return jp; 624 } 625 } 626 return NULL; 627 } 628 629 630 static struct job * 631 getjob(const char *name) 632 { 633 struct job *jp; 634 635 jp = getjob_nonotfound(name); 636 if (jp == NULL) 637 error("No such job: %s", name); 638 return (jp); 639 } 640 641 642 int 643 killjob(const char *name, int sig) 644 { 645 struct job *jp; 646 int i, ret; 647 648 jp = getjob(name); 649 if (jp->state == JOBDONE) 650 return 0; 651 if (jp->jobctl) 652 return kill(-jp->ps[0].pid, sig); 653 ret = -1; 654 errno = ESRCH; 655 for (i = 0; i < jp->nprocs; i++) 656 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 657 if (kill(jp->ps[i].pid, sig) == 0) 658 ret = 0; 659 } else 660 ret = 0; 661 return ret; 662 } 663 664 /* 665 * Return a new job structure, 666 */ 667 668 struct job * 669 makejob(union node *node __unused, int nprocs) 670 { 671 int i; 672 struct job *jp; 673 674 for (i = njobs, jp = jobtab ; ; jp++) { 675 if (--i < 0) { 676 INTOFF; 677 if (njobs == 0) { 678 jobtab = ckmalloc(4 * sizeof jobtab[0]); 679 #if JOBS 680 jobmru = NULL; 681 #endif 682 } else { 683 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 684 memcpy(jp, jobtab, njobs * sizeof jp[0]); 685 #if JOBS 686 /* Relocate `next' pointers and list head */ 687 if (jobmru != NULL) 688 jobmru = &jp[jobmru - jobtab]; 689 for (i = 0; i < njobs; i++) 690 if (jp[i].next != NULL) 691 jp[i].next = &jp[jp[i].next - 692 jobtab]; 693 #endif 694 if (bgjob != NULL) 695 bgjob = &jp[bgjob - jobtab]; 696 /* Relocate `ps' pointers */ 697 for (i = 0; i < njobs; i++) 698 if (jp[i].ps == &jobtab[i].ps0) 699 jp[i].ps = &jp[i].ps0; 700 ckfree(jobtab); 701 jobtab = jp; 702 } 703 jp = jobtab + njobs; 704 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 705 ; 706 INTON; 707 break; 708 } 709 if (jp->used == 0) 710 break; 711 } 712 INTOFF; 713 jp->state = 0; 714 jp->used = 1; 715 jp->changed = 0; 716 jp->nprocs = 0; 717 jp->foreground = 0; 718 jp->remembered = 0; 719 #if JOBS 720 jp->jobctl = jobctl; 721 jp->next = NULL; 722 #endif 723 if (nprocs > 1) { 724 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 725 } else { 726 jp->ps = &jp->ps0; 727 } 728 INTON; 729 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 730 jp - jobtab + 1)); 731 return jp; 732 } 733 734 #if JOBS 735 static void 736 setcurjob(struct job *cj) 737 { 738 struct job *jp, *prev; 739 740 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 741 if (jp == cj) { 742 if (prev != NULL) 743 prev->next = jp->next; 744 else 745 jobmru = jp->next; 746 jp->next = jobmru; 747 jobmru = cj; 748 return; 749 } 750 } 751 cj->next = jobmru; 752 jobmru = cj; 753 } 754 755 static void 756 deljob(struct job *j) 757 { 758 struct job *jp, *prev; 759 760 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 761 if (jp == j) { 762 if (prev != NULL) 763 prev->next = jp->next; 764 else 765 jobmru = jp->next; 766 return; 767 } 768 } 769 } 770 771 /* 772 * Return the most recently used job that isn't `nj', and preferably one 773 * that is stopped. 774 */ 775 static struct job * 776 getcurjob(struct job *nj) 777 { 778 struct job *jp; 779 780 /* Try to find a stopped one.. */ 781 for (jp = jobmru; jp != NULL; jp = jp->next) 782 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 783 return (jp); 784 /* Otherwise the most recently used job that isn't `nj' */ 785 for (jp = jobmru; jp != NULL; jp = jp->next) 786 if (jp->used && jp != nj) 787 return (jp); 788 789 return (NULL); 790 } 791 792 #endif 793 794 /* 795 * Fork of a subshell. If we are doing job control, give the subshell its 796 * own process group. Jp is a job structure that the job is to be added to. 797 * N is the command that will be evaluated by the child. Both jp and n may 798 * be NULL. The mode parameter can be one of the following: 799 * FORK_FG - Fork off a foreground process. 800 * FORK_BG - Fork off a background process. 801 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 802 * process group even if job control is on. 803 * 804 * When job control is turned off, background processes have their standard 805 * input redirected to /dev/null (except for the second and later processes 806 * in a pipeline). 807 */ 808 809 pid_t 810 forkshell(struct job *jp, union node *n, int mode) 811 { 812 pid_t pid; 813 pid_t pgrp; 814 815 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 816 mode)); 817 INTOFF; 818 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 819 checkzombies(); 820 flushall(); 821 pid = fork(); 822 if (pid == -1) { 823 TRACE(("Fork failed, errno=%d\n", errno)); 824 INTON; 825 error("Cannot fork: %s", strerror(errno)); 826 } 827 if (pid == 0) { 828 struct job *p; 829 int wasroot; 830 int i; 831 832 TRACE(("Child shell %d\n", (int)getpid())); 833 wasroot = rootshell; 834 rootshell = 0; 835 handler = &main_handler; 836 closescript(); 837 INTON; 838 forcelocal = 0; 839 clear_traps(); 840 #if JOBS 841 jobctl = 0; /* do job control only in root shell */ 842 if (wasroot && mode != FORK_NOJOB && mflag) { 843 if (jp == NULL || jp->nprocs == 0) 844 pgrp = getpid(); 845 else 846 pgrp = jp->ps[0].pid; 847 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 848 /*** this causes superfluous TIOCSPGRPS ***/ 849 if (tcsetpgrp(ttyfd, pgrp) < 0) 850 error("tcsetpgrp failed, errno=%d", errno); 851 } 852 setsignal(SIGTSTP); 853 setsignal(SIGTTOU); 854 } else if (mode == FORK_BG) { 855 ignoresig(SIGINT); 856 ignoresig(SIGQUIT); 857 if ((jp == NULL || jp->nprocs == 0) && 858 ! fd0_redirected_p ()) { 859 close(0); 860 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 861 error("cannot open %s: %s", 862 _PATH_DEVNULL, strerror(errno)); 863 } 864 } 865 #else 866 if (mode == FORK_BG) { 867 ignoresig(SIGINT); 868 ignoresig(SIGQUIT); 869 if ((jp == NULL || jp->nprocs == 0) && 870 ! fd0_redirected_p ()) { 871 close(0); 872 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 873 error("cannot open %s: %s", 874 _PATH_DEVNULL, strerror(errno)); 875 } 876 } 877 #endif 878 INTOFF; 879 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 880 if (p->used) 881 freejob(p); 882 INTON; 883 if (wasroot && iflag) { 884 setsignal(SIGINT); 885 setsignal(SIGQUIT); 886 setsignal(SIGTERM); 887 } 888 return pid; 889 } 890 if (rootshell && mode != FORK_NOJOB && mflag) { 891 if (jp == NULL || jp->nprocs == 0) 892 pgrp = pid; 893 else 894 pgrp = jp->ps[0].pid; 895 setpgid(pid, pgrp); 896 } 897 if (mode == FORK_BG) { 898 if (bgjob != NULL && bgjob->state == JOBDONE && 899 !bgjob->remembered && !iflag) 900 freejob(bgjob); 901 backgndpid = pid; /* set $! */ 902 bgjob = jp; 903 } 904 if (jp) { 905 struct procstat *ps = &jp->ps[jp->nprocs++]; 906 ps->pid = pid; 907 ps->status = -1; 908 ps->cmd = nullstr; 909 if (iflag && rootshell && n) 910 ps->cmd = commandtext(n); 911 jp->foreground = mode == FORK_FG; 912 #if JOBS 913 setcurjob(jp); 914 #endif 915 } 916 INTON; 917 TRACE(("In parent shell: child = %d\n", (int)pid)); 918 return pid; 919 } 920 921 922 pid_t 923 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 924 { 925 pid_t pid; 926 struct jmploc jmploc; 927 struct jmploc *savehandler; 928 929 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 930 (void *)pip)); 931 INTOFF; 932 flushall(); 933 savehandler = handler; 934 pid = vfork(); 935 if (pid == -1) { 936 TRACE(("Vfork failed, errno=%d\n", errno)); 937 INTON; 938 error("Cannot fork: %s", strerror(errno)); 939 } 940 if (pid == 0) { 941 TRACE(("Child shell %d\n", (int)getpid())); 942 if (setjmp(jmploc.loc)) 943 _exit(exception == EXEXEC ? exerrno : 2); 944 if (pip != NULL) { 945 close(pip[0]); 946 if (pip[1] != 1) { 947 dup2(pip[1], 1); 948 close(pip[1]); 949 } 950 } 951 handler = &jmploc; 952 shellexec(argv, envp, path, idx); 953 } 954 handler = savehandler; 955 if (jp) { 956 struct procstat *ps = &jp->ps[jp->nprocs++]; 957 ps->pid = pid; 958 ps->status = -1; 959 ps->cmd = nullstr; 960 jp->foreground = 1; 961 #if JOBS 962 setcurjob(jp); 963 #endif 964 } 965 INTON; 966 TRACE(("In parent shell: child = %d\n", (int)pid)); 967 return pid; 968 } 969 970 971 /* 972 * Wait for job to finish. 973 * 974 * Under job control we have the problem that while a child process is 975 * running interrupts generated by the user are sent to the child but not 976 * to the shell. This means that an infinite loop started by an inter- 977 * active user may be hard to kill. With job control turned off, an 978 * interactive user may place an interactive program inside a loop. If 979 * the interactive program catches interrupts, the user doesn't want 980 * these interrupts to also abort the loop. The approach we take here 981 * is to have the shell ignore interrupt signals while waiting for a 982 * foreground process to terminate, and then send itself an interrupt 983 * signal if the child process was terminated by an interrupt signal. 984 * Unfortunately, some programs want to do a bit of cleanup and then 985 * exit on interrupt; unless these processes terminate themselves by 986 * sending a signal to themselves (instead of calling exit) they will 987 * confuse this approach. 988 */ 989 990 int 991 waitforjob(struct job *jp, int *origstatus) 992 { 993 #if JOBS 994 int propagate_int = jp->jobctl && jp->foreground; 995 #endif 996 int status; 997 int st; 998 999 INTOFF; 1000 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1001 while (jp->state == 0) 1002 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1003 DOWAIT_SIG_ANY : 0), jp) == -1) 1004 dotrap(); 1005 #if JOBS 1006 if (jp->jobctl) { 1007 if (tcsetpgrp(ttyfd, rootpid) < 0) 1008 error("tcsetpgrp failed, errno=%d\n", errno); 1009 } 1010 if (jp->state == JOBSTOPPED) 1011 setcurjob(jp); 1012 #endif 1013 status = jp->ps[jp->nprocs - 1].status; 1014 if (origstatus != NULL) 1015 *origstatus = status; 1016 /* convert to 8 bits */ 1017 if (WIFEXITED(status)) 1018 st = WEXITSTATUS(status); 1019 #if JOBS 1020 else if (WIFSTOPPED(status)) 1021 st = WSTOPSIG(status) + 128; 1022 #endif 1023 else 1024 st = WTERMSIG(status) + 128; 1025 if (! JOBS || jp->state == JOBDONE) 1026 freejob(jp); 1027 if (int_pending()) { 1028 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1029 CLEAR_PENDING_INT; 1030 } 1031 #if JOBS 1032 else if (rootshell && iflag && propagate_int && 1033 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1034 kill(getpid(), SIGINT); 1035 #endif 1036 INTON; 1037 return st; 1038 } 1039 1040 1041 static void 1042 dummy_handler(int sig __unused) 1043 { 1044 } 1045 1046 /* 1047 * Wait for a process to terminate. 1048 */ 1049 1050 static pid_t 1051 dowait(int mode, struct job *job) 1052 { 1053 struct sigaction sa, osa; 1054 sigset_t mask, omask; 1055 pid_t pid; 1056 int status; 1057 struct procstat *sp; 1058 struct job *jp; 1059 struct job *thisjob; 1060 const char *sigstr; 1061 int done; 1062 int stopped; 1063 int sig; 1064 int coredump; 1065 int wflags; 1066 int restore_sigchld; 1067 1068 TRACE(("dowait(%d, %p) called\n", mode, job)); 1069 restore_sigchld = 0; 1070 if ((mode & DOWAIT_SIG) != 0) { 1071 sigfillset(&mask); 1072 sigprocmask(SIG_BLOCK, &mask, &omask); 1073 INTOFF; 1074 if (!issigchldtrapped()) { 1075 restore_sigchld = 1; 1076 sa.sa_handler = dummy_handler; 1077 sa.sa_flags = 0; 1078 sigemptyset(&sa.sa_mask); 1079 sigaction(SIGCHLD, &sa, &osa); 1080 } 1081 } 1082 do { 1083 #if JOBS 1084 if (iflag) 1085 wflags = WUNTRACED | WCONTINUED; 1086 else 1087 #endif 1088 wflags = 0; 1089 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1090 wflags |= WNOHANG; 1091 pid = wait3(&status, wflags, (struct rusage *)NULL); 1092 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1093 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1094 pid = -1; 1095 if (((mode & DOWAIT_SIG_ANY) != 0 ? 1096 pendingsig : pendingsig_waitcmd) != 0) { 1097 errno = EINTR; 1098 break; 1099 } 1100 sigsuspend(&omask); 1101 if (int_pending()) 1102 break; 1103 } 1104 } while (pid == -1 && errno == EINTR); 1105 if (pid == -1 && errno == ECHILD && job != NULL) 1106 job->state = JOBDONE; 1107 if ((mode & DOWAIT_SIG) != 0) { 1108 if (restore_sigchld) 1109 sigaction(SIGCHLD, &osa, NULL); 1110 sigprocmask(SIG_SETMASK, &omask, NULL); 1111 INTON; 1112 } 1113 if (pid <= 0) 1114 return pid; 1115 INTOFF; 1116 thisjob = NULL; 1117 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1118 if (jp->used && jp->nprocs > 0) { 1119 done = 1; 1120 stopped = 1; 1121 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1122 if (sp->pid == -1) 1123 continue; 1124 if (sp->pid == pid && (sp->status == -1 || 1125 WIFSTOPPED(sp->status))) { 1126 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1127 (int)pid, sp->status, 1128 status)); 1129 if (WIFCONTINUED(status)) { 1130 sp->status = -1; 1131 jp->state = 0; 1132 } else 1133 sp->status = status; 1134 thisjob = jp; 1135 } 1136 if (sp->status == -1) 1137 stopped = 0; 1138 else if (WIFSTOPPED(sp->status)) 1139 done = 0; 1140 } 1141 if (stopped) { /* stopped or done */ 1142 int state = done? JOBDONE : JOBSTOPPED; 1143 if (jp->state != state) { 1144 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1145 jp->state = state; 1146 if (jp != job) { 1147 if (done && !jp->remembered && 1148 !iflag && jp != bgjob) 1149 freejob(jp); 1150 #if JOBS 1151 else if (done) 1152 deljob(jp); 1153 #endif 1154 } 1155 } 1156 } 1157 } 1158 } 1159 INTON; 1160 if (!thisjob || thisjob->state == 0) 1161 ; 1162 else if ((!rootshell || !iflag || thisjob == job) && 1163 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1164 sig = 0; 1165 coredump = 0; 1166 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1167 if (WIFSIGNALED(sp->status)) { 1168 sig = WTERMSIG(sp->status); 1169 coredump = WCOREDUMP(sp->status); 1170 } 1171 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1172 sigstr = strsignal(sig); 1173 if (sigstr != NULL) 1174 out2str(sigstr); 1175 else 1176 out2str("Unknown signal"); 1177 if (coredump) 1178 out2str(" (core dumped)"); 1179 out2c('\n'); 1180 flushout(out2); 1181 } 1182 } else { 1183 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1184 thisjob->changed = 1; 1185 } 1186 return pid; 1187 } 1188 1189 1190 1191 /* 1192 * return 1 if there are stopped jobs, otherwise 0 1193 */ 1194 int job_warning = 0; 1195 int 1196 stoppedjobs(void) 1197 { 1198 int jobno; 1199 struct job *jp; 1200 1201 if (job_warning) 1202 return (0); 1203 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1204 if (jp->used == 0) 1205 continue; 1206 if (jp->state == JOBSTOPPED) { 1207 out2fmt_flush("You have stopped jobs.\n"); 1208 job_warning = 2; 1209 return (1); 1210 } 1211 } 1212 1213 return (0); 1214 } 1215 1216 1217 static void 1218 checkzombies(void) 1219 { 1220 while (njobs > 0 && dowait(0, NULL) > 0) 1221 ; 1222 } 1223 1224 1225 int 1226 backgndpidset(void) 1227 { 1228 return backgndpid != -1; 1229 } 1230 1231 1232 pid_t 1233 backgndpidval(void) 1234 { 1235 if (bgjob != NULL && !forcelocal) 1236 bgjob->remembered = 1; 1237 return backgndpid; 1238 } 1239 1240 /* 1241 * Return a string identifying a command (to be printed by the 1242 * jobs command. 1243 */ 1244 1245 static char *cmdnextc; 1246 static int cmdnleft; 1247 #define MAXCMDTEXT 200 1248 1249 char * 1250 commandtext(union node *n) 1251 { 1252 char *name; 1253 1254 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1255 cmdnleft = MAXCMDTEXT - 4; 1256 cmdtxt(n); 1257 *cmdnextc = '\0'; 1258 return name; 1259 } 1260 1261 1262 static void 1263 cmdtxt(union node *n) 1264 { 1265 union node *np; 1266 struct nodelist *lp; 1267 const char *p; 1268 int i; 1269 char s[2]; 1270 1271 if (n == NULL) 1272 return; 1273 switch (n->type) { 1274 case NSEMI: 1275 cmdtxt(n->nbinary.ch1); 1276 cmdputs("; "); 1277 cmdtxt(n->nbinary.ch2); 1278 break; 1279 case NAND: 1280 cmdtxt(n->nbinary.ch1); 1281 cmdputs(" && "); 1282 cmdtxt(n->nbinary.ch2); 1283 break; 1284 case NOR: 1285 cmdtxt(n->nbinary.ch1); 1286 cmdputs(" || "); 1287 cmdtxt(n->nbinary.ch2); 1288 break; 1289 case NPIPE: 1290 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1291 cmdtxt(lp->n); 1292 if (lp->next) 1293 cmdputs(" | "); 1294 } 1295 break; 1296 case NSUBSHELL: 1297 cmdputs("("); 1298 cmdtxt(n->nredir.n); 1299 cmdputs(")"); 1300 break; 1301 case NREDIR: 1302 case NBACKGND: 1303 cmdtxt(n->nredir.n); 1304 break; 1305 case NIF: 1306 cmdputs("if "); 1307 cmdtxt(n->nif.test); 1308 cmdputs("; then "); 1309 cmdtxt(n->nif.ifpart); 1310 cmdputs("..."); 1311 break; 1312 case NWHILE: 1313 cmdputs("while "); 1314 goto until; 1315 case NUNTIL: 1316 cmdputs("until "); 1317 until: 1318 cmdtxt(n->nbinary.ch1); 1319 cmdputs("; do "); 1320 cmdtxt(n->nbinary.ch2); 1321 cmdputs("; done"); 1322 break; 1323 case NFOR: 1324 cmdputs("for "); 1325 cmdputs(n->nfor.var); 1326 cmdputs(" in ..."); 1327 break; 1328 case NCASE: 1329 cmdputs("case "); 1330 cmdputs(n->ncase.expr->narg.text); 1331 cmdputs(" in ..."); 1332 break; 1333 case NDEFUN: 1334 cmdputs(n->narg.text); 1335 cmdputs("() ..."); 1336 break; 1337 case NNOT: 1338 cmdputs("! "); 1339 cmdtxt(n->nnot.com); 1340 break; 1341 case NCMD: 1342 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1343 cmdtxt(np); 1344 if (np->narg.next) 1345 cmdputs(" "); 1346 } 1347 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1348 cmdputs(" "); 1349 cmdtxt(np); 1350 } 1351 break; 1352 case NARG: 1353 cmdputs(n->narg.text); 1354 break; 1355 case NTO: 1356 p = ">"; i = 1; goto redir; 1357 case NAPPEND: 1358 p = ">>"; i = 1; goto redir; 1359 case NTOFD: 1360 p = ">&"; i = 1; goto redir; 1361 case NCLOBBER: 1362 p = ">|"; i = 1; goto redir; 1363 case NFROM: 1364 p = "<"; i = 0; goto redir; 1365 case NFROMTO: 1366 p = "<>"; i = 0; goto redir; 1367 case NFROMFD: 1368 p = "<&"; i = 0; goto redir; 1369 redir: 1370 if (n->nfile.fd != i) { 1371 s[0] = n->nfile.fd + '0'; 1372 s[1] = '\0'; 1373 cmdputs(s); 1374 } 1375 cmdputs(p); 1376 if (n->type == NTOFD || n->type == NFROMFD) { 1377 if (n->ndup.dupfd >= 0) 1378 s[0] = n->ndup.dupfd + '0'; 1379 else 1380 s[0] = '-'; 1381 s[1] = '\0'; 1382 cmdputs(s); 1383 } else { 1384 cmdtxt(n->nfile.fname); 1385 } 1386 break; 1387 case NHERE: 1388 case NXHERE: 1389 cmdputs("<<..."); 1390 break; 1391 default: 1392 cmdputs("???"); 1393 break; 1394 } 1395 } 1396 1397 1398 1399 static void 1400 cmdputs(const char *s) 1401 { 1402 const char *p; 1403 char *q; 1404 char c; 1405 int subtype = 0; 1406 1407 if (cmdnleft <= 0) 1408 return; 1409 p = s; 1410 q = cmdnextc; 1411 while ((c = *p++) != '\0') { 1412 if (c == CTLESC) 1413 *q++ = *p++; 1414 else if (c == CTLVAR) { 1415 *q++ = '$'; 1416 if (--cmdnleft > 0) 1417 *q++ = '{'; 1418 subtype = *p++; 1419 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1420 *q++ = '#'; 1421 } else if (c == '=' && subtype != 0) { 1422 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1423 if (*q) 1424 q++; 1425 else 1426 cmdnleft++; 1427 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1428 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1429 --cmdnleft > 0) 1430 *q = q[-1], q++; 1431 subtype = 0; 1432 } else if (c == CTLENDVAR) { 1433 *q++ = '}'; 1434 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1435 cmdnleft -= 5; 1436 if (cmdnleft > 0) { 1437 *q++ = '$'; 1438 *q++ = '('; 1439 *q++ = '.'; 1440 *q++ = '.'; 1441 *q++ = '.'; 1442 *q++ = ')'; 1443 } 1444 } else if (c == CTLARI) { 1445 cmdnleft -= 2; 1446 if (cmdnleft > 0) { 1447 *q++ = '$'; 1448 *q++ = '('; 1449 *q++ = '('; 1450 } 1451 p++; 1452 } else if (c == CTLENDARI) { 1453 if (--cmdnleft > 0) { 1454 *q++ = ')'; 1455 *q++ = ')'; 1456 } 1457 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1458 cmdnleft++; /* ignore */ 1459 else 1460 *q++ = c; 1461 if (--cmdnleft <= 0) { 1462 *q++ = '.'; 1463 *q++ = '.'; 1464 *q++ = '.'; 1465 break; 1466 } 1467 } 1468 cmdnextc = q; 1469 } 1470