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 size_t namelen; 566 pid_t pid; 567 int i; 568 569 if (name == NULL) { 570 #if JOBS 571 currentjob: if ((jp = getcurjob(NULL)) == NULL) 572 error("No current job"); 573 return (jp); 574 #else 575 error("No current job"); 576 #endif 577 } else if (name[0] == '%') { 578 if (is_digit(name[1])) { 579 jobno = number(name + 1); 580 if (jobno > 0 && jobno <= njobs 581 && jobtab[jobno - 1].used != 0) 582 return &jobtab[jobno - 1]; 583 #if JOBS 584 } else if (name[1] == '%' && name[2] == '\0') { 585 goto currentjob; 586 } else if (name[1] == '+' && name[2] == '\0') { 587 goto currentjob; 588 } else if (name[1] == '-' && name[2] == '\0') { 589 if ((jp = getcurjob(NULL)) == NULL || 590 (jp = getcurjob(jp)) == NULL) 591 error("No previous job"); 592 return (jp); 593 #endif 594 } else if (name[1] == '?') { 595 found = NULL; 596 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 597 if (jp->used && jp->nprocs > 0 598 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 599 if (found) 600 error("%s: ambiguous", name); 601 found = jp; 602 } 603 } 604 if (found != NULL) 605 return (found); 606 } else { 607 namelen = strlen(name); 608 found = NULL; 609 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 610 if (jp->used && jp->nprocs > 0 611 && strncmp(jp->ps[0].cmd, name + 1, 612 namelen - 1) == 0) { 613 if (found) 614 error("%s: ambiguous", name); 615 found = jp; 616 } 617 } 618 if (found) 619 return found; 620 } 621 } else if (is_number(name)) { 622 pid = (pid_t)number(name); 623 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 624 if (jp->used && jp->nprocs > 0 625 && jp->ps[jp->nprocs - 1].pid == pid) 626 return jp; 627 } 628 } 629 return NULL; 630 } 631 632 633 static struct job * 634 getjob(const char *name) 635 { 636 struct job *jp; 637 638 jp = getjob_nonotfound(name); 639 if (jp == NULL) 640 error("No such job: %s", name); 641 return (jp); 642 } 643 644 645 int 646 killjob(const char *name, int sig) 647 { 648 struct job *jp; 649 int i, ret; 650 651 jp = getjob(name); 652 if (jp->state == JOBDONE) 653 return 0; 654 if (jp->jobctl) 655 return kill(-jp->ps[0].pid, sig); 656 ret = -1; 657 errno = ESRCH; 658 for (i = 0; i < jp->nprocs; i++) 659 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 660 if (kill(jp->ps[i].pid, sig) == 0) 661 ret = 0; 662 } else 663 ret = 0; 664 return ret; 665 } 666 667 /* 668 * Return a new job structure, 669 */ 670 671 struct job * 672 makejob(union node *node __unused, int nprocs) 673 { 674 int i; 675 struct job *jp; 676 677 for (i = njobs, jp = jobtab ; ; jp++) { 678 if (--i < 0) { 679 INTOFF; 680 if (njobs == 0) { 681 jobtab = ckmalloc(4 * sizeof jobtab[0]); 682 #if JOBS 683 jobmru = NULL; 684 #endif 685 } else { 686 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 687 memcpy(jp, jobtab, njobs * sizeof jp[0]); 688 #if JOBS 689 /* Relocate `next' pointers and list head */ 690 if (jobmru != NULL) 691 jobmru = &jp[jobmru - jobtab]; 692 for (i = 0; i < njobs; i++) 693 if (jp[i].next != NULL) 694 jp[i].next = &jp[jp[i].next - 695 jobtab]; 696 #endif 697 if (bgjob != NULL) 698 bgjob = &jp[bgjob - jobtab]; 699 /* Relocate `ps' pointers */ 700 for (i = 0; i < njobs; i++) 701 if (jp[i].ps == &jobtab[i].ps0) 702 jp[i].ps = &jp[i].ps0; 703 ckfree(jobtab); 704 jobtab = jp; 705 } 706 jp = jobtab + njobs; 707 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 708 ; 709 INTON; 710 break; 711 } 712 if (jp->used == 0) 713 break; 714 } 715 INTOFF; 716 jp->state = 0; 717 jp->used = 1; 718 jp->changed = 0; 719 jp->nprocs = 0; 720 jp->foreground = 0; 721 jp->remembered = 0; 722 #if JOBS 723 jp->jobctl = jobctl; 724 jp->next = NULL; 725 #endif 726 if (nprocs > 1) { 727 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 728 } else { 729 jp->ps = &jp->ps0; 730 } 731 INTON; 732 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 733 jp - jobtab + 1)); 734 return jp; 735 } 736 737 #if JOBS 738 static void 739 setcurjob(struct job *cj) 740 { 741 struct job *jp, *prev; 742 743 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 744 if (jp == cj) { 745 if (prev != NULL) 746 prev->next = jp->next; 747 else 748 jobmru = jp->next; 749 jp->next = jobmru; 750 jobmru = cj; 751 return; 752 } 753 } 754 cj->next = jobmru; 755 jobmru = cj; 756 } 757 758 static void 759 deljob(struct job *j) 760 { 761 struct job *jp, *prev; 762 763 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 764 if (jp == j) { 765 if (prev != NULL) 766 prev->next = jp->next; 767 else 768 jobmru = jp->next; 769 return; 770 } 771 } 772 } 773 774 /* 775 * Return the most recently used job that isn't `nj', and preferably one 776 * that is stopped. 777 */ 778 static struct job * 779 getcurjob(struct job *nj) 780 { 781 struct job *jp; 782 783 /* Try to find a stopped one.. */ 784 for (jp = jobmru; jp != NULL; jp = jp->next) 785 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 786 return (jp); 787 /* Otherwise the most recently used job that isn't `nj' */ 788 for (jp = jobmru; jp != NULL; jp = jp->next) 789 if (jp->used && jp != nj) 790 return (jp); 791 792 return (NULL); 793 } 794 795 #endif 796 797 /* 798 * Fork of a subshell. If we are doing job control, give the subshell its 799 * own process group. Jp is a job structure that the job is to be added to. 800 * N is the command that will be evaluated by the child. Both jp and n may 801 * be NULL. The mode parameter can be one of the following: 802 * FORK_FG - Fork off a foreground process. 803 * FORK_BG - Fork off a background process. 804 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 805 * process group even if job control is on. 806 * 807 * When job control is turned off, background processes have their standard 808 * input redirected to /dev/null (except for the second and later processes 809 * in a pipeline). 810 */ 811 812 pid_t 813 forkshell(struct job *jp, union node *n, int mode) 814 { 815 pid_t pid; 816 pid_t pgrp; 817 818 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 819 mode)); 820 INTOFF; 821 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 822 checkzombies(); 823 flushall(); 824 pid = fork(); 825 if (pid == -1) { 826 TRACE(("Fork failed, errno=%d\n", errno)); 827 INTON; 828 error("Cannot fork: %s", strerror(errno)); 829 } 830 if (pid == 0) { 831 struct job *p; 832 int wasroot; 833 int i; 834 835 TRACE(("Child shell %d\n", (int)getpid())); 836 wasroot = rootshell; 837 rootshell = 0; 838 handler = &main_handler; 839 closescript(); 840 INTON; 841 forcelocal = 0; 842 clear_traps(); 843 #if JOBS 844 jobctl = 0; /* do job control only in root shell */ 845 if (wasroot && mode != FORK_NOJOB && mflag) { 846 if (jp == NULL || jp->nprocs == 0) 847 pgrp = getpid(); 848 else 849 pgrp = jp->ps[0].pid; 850 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 851 /*** this causes superfluous TIOCSPGRPS ***/ 852 if (tcsetpgrp(ttyfd, pgrp) < 0) 853 error("tcsetpgrp failed, errno=%d", errno); 854 } 855 setsignal(SIGTSTP); 856 setsignal(SIGTTOU); 857 } else if (mode == FORK_BG) { 858 ignoresig(SIGINT); 859 ignoresig(SIGQUIT); 860 if ((jp == NULL || jp->nprocs == 0) && 861 ! fd0_redirected_p ()) { 862 close(0); 863 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 864 error("cannot open %s: %s", 865 _PATH_DEVNULL, strerror(errno)); 866 } 867 } 868 #else 869 if (mode == FORK_BG) { 870 ignoresig(SIGINT); 871 ignoresig(SIGQUIT); 872 if ((jp == NULL || jp->nprocs == 0) && 873 ! fd0_redirected_p ()) { 874 close(0); 875 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 876 error("cannot open %s: %s", 877 _PATH_DEVNULL, strerror(errno)); 878 } 879 } 880 #endif 881 INTOFF; 882 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 883 if (p->used) 884 freejob(p); 885 INTON; 886 if (wasroot && iflag) { 887 setsignal(SIGINT); 888 setsignal(SIGQUIT); 889 setsignal(SIGTERM); 890 } 891 return pid; 892 } 893 if (rootshell && mode != FORK_NOJOB && mflag) { 894 if (jp == NULL || jp->nprocs == 0) 895 pgrp = pid; 896 else 897 pgrp = jp->ps[0].pid; 898 setpgid(pid, pgrp); 899 } 900 if (mode == FORK_BG) { 901 if (bgjob != NULL && bgjob->state == JOBDONE && 902 !bgjob->remembered && !iflag) 903 freejob(bgjob); 904 backgndpid = pid; /* set $! */ 905 bgjob = jp; 906 } 907 if (jp) { 908 struct procstat *ps = &jp->ps[jp->nprocs++]; 909 ps->pid = pid; 910 ps->status = -1; 911 ps->cmd = nullstr; 912 if (iflag && rootshell && n) 913 ps->cmd = commandtext(n); 914 jp->foreground = mode == FORK_FG; 915 #if JOBS 916 setcurjob(jp); 917 #endif 918 } 919 INTON; 920 TRACE(("In parent shell: child = %d\n", (int)pid)); 921 return pid; 922 } 923 924 925 pid_t 926 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 927 { 928 pid_t pid; 929 struct jmploc jmploc; 930 struct jmploc *savehandler; 931 932 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 933 (void *)pip)); 934 INTOFF; 935 flushall(); 936 savehandler = handler; 937 pid = vfork(); 938 if (pid == -1) { 939 TRACE(("Vfork failed, errno=%d\n", errno)); 940 INTON; 941 error("Cannot fork: %s", strerror(errno)); 942 } 943 if (pid == 0) { 944 TRACE(("Child shell %d\n", (int)getpid())); 945 if (setjmp(jmploc.loc)) 946 _exit(exception == EXEXEC ? exerrno : 2); 947 if (pip != NULL) { 948 close(pip[0]); 949 if (pip[1] != 1) { 950 dup2(pip[1], 1); 951 close(pip[1]); 952 } 953 } 954 handler = &jmploc; 955 shellexec(argv, envp, path, idx); 956 } 957 handler = savehandler; 958 if (jp) { 959 struct procstat *ps = &jp->ps[jp->nprocs++]; 960 ps->pid = pid; 961 ps->status = -1; 962 ps->cmd = nullstr; 963 jp->foreground = 1; 964 #if JOBS 965 setcurjob(jp); 966 #endif 967 } 968 INTON; 969 TRACE(("In parent shell: child = %d\n", (int)pid)); 970 return pid; 971 } 972 973 974 /* 975 * Wait for job to finish. 976 * 977 * Under job control we have the problem that while a child process is 978 * running interrupts generated by the user are sent to the child but not 979 * to the shell. This means that an infinite loop started by an inter- 980 * active user may be hard to kill. With job control turned off, an 981 * interactive user may place an interactive program inside a loop. If 982 * the interactive program catches interrupts, the user doesn't want 983 * these interrupts to also abort the loop. The approach we take here 984 * is to have the shell ignore interrupt signals while waiting for a 985 * foreground process to terminate, and then send itself an interrupt 986 * signal if the child process was terminated by an interrupt signal. 987 * Unfortunately, some programs want to do a bit of cleanup and then 988 * exit on interrupt; unless these processes terminate themselves by 989 * sending a signal to themselves (instead of calling exit) they will 990 * confuse this approach. 991 */ 992 993 int 994 waitforjob(struct job *jp, int *origstatus) 995 { 996 #if JOBS 997 int propagate_int = jp->jobctl && jp->foreground; 998 #endif 999 int status; 1000 int st; 1001 1002 INTOFF; 1003 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1004 while (jp->state == 0) 1005 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1006 DOWAIT_SIG_ANY : 0), jp) == -1) 1007 dotrap(); 1008 #if JOBS 1009 if (jp->jobctl) { 1010 if (tcsetpgrp(ttyfd, rootpid) < 0) 1011 error("tcsetpgrp failed, errno=%d\n", errno); 1012 } 1013 if (jp->state == JOBSTOPPED) 1014 setcurjob(jp); 1015 #endif 1016 status = jp->ps[jp->nprocs - 1].status; 1017 if (origstatus != NULL) 1018 *origstatus = status; 1019 /* convert to 8 bits */ 1020 if (WIFEXITED(status)) 1021 st = WEXITSTATUS(status); 1022 #if JOBS 1023 else if (WIFSTOPPED(status)) 1024 st = WSTOPSIG(status) + 128; 1025 #endif 1026 else 1027 st = WTERMSIG(status) + 128; 1028 if (! JOBS || jp->state == JOBDONE) 1029 freejob(jp); 1030 if (int_pending()) { 1031 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1032 CLEAR_PENDING_INT; 1033 } 1034 #if JOBS 1035 else if (rootshell && iflag && propagate_int && 1036 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1037 kill(getpid(), SIGINT); 1038 #endif 1039 INTON; 1040 return st; 1041 } 1042 1043 1044 static void 1045 dummy_handler(int sig __unused) 1046 { 1047 } 1048 1049 /* 1050 * Wait for a process to terminate. 1051 */ 1052 1053 static pid_t 1054 dowait(int mode, struct job *job) 1055 { 1056 struct sigaction sa, osa; 1057 sigset_t mask, omask; 1058 pid_t pid; 1059 int status; 1060 struct procstat *sp; 1061 struct job *jp; 1062 struct job *thisjob; 1063 const char *sigstr; 1064 int done; 1065 int stopped; 1066 int sig; 1067 int coredump; 1068 int wflags; 1069 int restore_sigchld; 1070 1071 TRACE(("dowait(%d, %p) called\n", mode, job)); 1072 restore_sigchld = 0; 1073 if ((mode & DOWAIT_SIG) != 0) { 1074 sigfillset(&mask); 1075 sigprocmask(SIG_BLOCK, &mask, &omask); 1076 INTOFF; 1077 if (!issigchldtrapped()) { 1078 restore_sigchld = 1; 1079 sa.sa_handler = dummy_handler; 1080 sa.sa_flags = 0; 1081 sigemptyset(&sa.sa_mask); 1082 sigaction(SIGCHLD, &sa, &osa); 1083 } 1084 } 1085 do { 1086 #if JOBS 1087 if (iflag) 1088 wflags = WUNTRACED | WCONTINUED; 1089 else 1090 #endif 1091 wflags = 0; 1092 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1093 wflags |= WNOHANG; 1094 pid = wait3(&status, wflags, (struct rusage *)NULL); 1095 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1096 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1097 pid = -1; 1098 if (((mode & DOWAIT_SIG_ANY) != 0 ? 1099 pendingsig : pendingsig_waitcmd) != 0) { 1100 errno = EINTR; 1101 break; 1102 } 1103 sigsuspend(&omask); 1104 if (int_pending()) 1105 break; 1106 } 1107 } while (pid == -1 && errno == EINTR); 1108 if (pid == -1 && errno == ECHILD && job != NULL) 1109 job->state = JOBDONE; 1110 if ((mode & DOWAIT_SIG) != 0) { 1111 if (restore_sigchld) 1112 sigaction(SIGCHLD, &osa, NULL); 1113 sigprocmask(SIG_SETMASK, &omask, NULL); 1114 INTON; 1115 } 1116 if (pid <= 0) 1117 return pid; 1118 INTOFF; 1119 thisjob = NULL; 1120 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1121 if (jp->used && jp->nprocs > 0) { 1122 done = 1; 1123 stopped = 1; 1124 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1125 if (sp->pid == -1) 1126 continue; 1127 if (sp->pid == pid && (sp->status == -1 || 1128 WIFSTOPPED(sp->status))) { 1129 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1130 (int)pid, sp->status, 1131 status)); 1132 if (WIFCONTINUED(status)) { 1133 sp->status = -1; 1134 jp->state = 0; 1135 } else 1136 sp->status = status; 1137 thisjob = jp; 1138 } 1139 if (sp->status == -1) 1140 stopped = 0; 1141 else if (WIFSTOPPED(sp->status)) 1142 done = 0; 1143 } 1144 if (stopped) { /* stopped or done */ 1145 int state = done? JOBDONE : JOBSTOPPED; 1146 if (jp->state != state) { 1147 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1148 jp->state = state; 1149 if (jp != job) { 1150 if (done && !jp->remembered && 1151 !iflag && jp != bgjob) 1152 freejob(jp); 1153 #if JOBS 1154 else if (done) 1155 deljob(jp); 1156 #endif 1157 } 1158 } 1159 } 1160 } 1161 } 1162 INTON; 1163 if (!thisjob || thisjob->state == 0) 1164 ; 1165 else if ((!rootshell || !iflag || thisjob == job) && 1166 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1167 sig = 0; 1168 coredump = 0; 1169 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1170 if (WIFSIGNALED(sp->status)) { 1171 sig = WTERMSIG(sp->status); 1172 coredump = WCOREDUMP(sp->status); 1173 } 1174 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1175 sigstr = strsignal(sig); 1176 if (sigstr != NULL) 1177 out2str(sigstr); 1178 else 1179 out2str("Unknown signal"); 1180 if (coredump) 1181 out2str(" (core dumped)"); 1182 out2c('\n'); 1183 flushout(out2); 1184 } 1185 } else { 1186 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1187 thisjob->changed = 1; 1188 } 1189 return pid; 1190 } 1191 1192 1193 1194 /* 1195 * return 1 if there are stopped jobs, otherwise 0 1196 */ 1197 int job_warning = 0; 1198 int 1199 stoppedjobs(void) 1200 { 1201 int jobno; 1202 struct job *jp; 1203 1204 if (job_warning) 1205 return (0); 1206 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1207 if (jp->used == 0) 1208 continue; 1209 if (jp->state == JOBSTOPPED) { 1210 out2fmt_flush("You have stopped jobs.\n"); 1211 job_warning = 2; 1212 return (1); 1213 } 1214 } 1215 1216 return (0); 1217 } 1218 1219 1220 static void 1221 checkzombies(void) 1222 { 1223 while (njobs > 0 && dowait(0, NULL) > 0) 1224 ; 1225 } 1226 1227 1228 int 1229 backgndpidset(void) 1230 { 1231 return backgndpid != -1; 1232 } 1233 1234 1235 pid_t 1236 backgndpidval(void) 1237 { 1238 if (bgjob != NULL && !forcelocal) 1239 bgjob->remembered = 1; 1240 return backgndpid; 1241 } 1242 1243 /* 1244 * Return a string identifying a command (to be printed by the 1245 * jobs command. 1246 */ 1247 1248 static char *cmdnextc; 1249 static int cmdnleft; 1250 #define MAXCMDTEXT 200 1251 1252 char * 1253 commandtext(union node *n) 1254 { 1255 char *name; 1256 1257 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1258 cmdnleft = MAXCMDTEXT - 4; 1259 cmdtxt(n); 1260 *cmdnextc = '\0'; 1261 return name; 1262 } 1263 1264 1265 static void 1266 cmdtxt(union node *n) 1267 { 1268 union node *np; 1269 struct nodelist *lp; 1270 const char *p; 1271 int i; 1272 char s[2]; 1273 1274 if (n == NULL) 1275 return; 1276 switch (n->type) { 1277 case NSEMI: 1278 cmdtxt(n->nbinary.ch1); 1279 cmdputs("; "); 1280 cmdtxt(n->nbinary.ch2); 1281 break; 1282 case NAND: 1283 cmdtxt(n->nbinary.ch1); 1284 cmdputs(" && "); 1285 cmdtxt(n->nbinary.ch2); 1286 break; 1287 case NOR: 1288 cmdtxt(n->nbinary.ch1); 1289 cmdputs(" || "); 1290 cmdtxt(n->nbinary.ch2); 1291 break; 1292 case NPIPE: 1293 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1294 cmdtxt(lp->n); 1295 if (lp->next) 1296 cmdputs(" | "); 1297 } 1298 break; 1299 case NSUBSHELL: 1300 cmdputs("("); 1301 cmdtxt(n->nredir.n); 1302 cmdputs(")"); 1303 break; 1304 case NREDIR: 1305 case NBACKGND: 1306 cmdtxt(n->nredir.n); 1307 break; 1308 case NIF: 1309 cmdputs("if "); 1310 cmdtxt(n->nif.test); 1311 cmdputs("; then "); 1312 cmdtxt(n->nif.ifpart); 1313 cmdputs("..."); 1314 break; 1315 case NWHILE: 1316 cmdputs("while "); 1317 goto until; 1318 case NUNTIL: 1319 cmdputs("until "); 1320 until: 1321 cmdtxt(n->nbinary.ch1); 1322 cmdputs("; do "); 1323 cmdtxt(n->nbinary.ch2); 1324 cmdputs("; done"); 1325 break; 1326 case NFOR: 1327 cmdputs("for "); 1328 cmdputs(n->nfor.var); 1329 cmdputs(" in ..."); 1330 break; 1331 case NCASE: 1332 cmdputs("case "); 1333 cmdputs(n->ncase.expr->narg.text); 1334 cmdputs(" in ..."); 1335 break; 1336 case NDEFUN: 1337 cmdputs(n->narg.text); 1338 cmdputs("() ..."); 1339 break; 1340 case NNOT: 1341 cmdputs("! "); 1342 cmdtxt(n->nnot.com); 1343 break; 1344 case NCMD: 1345 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1346 cmdtxt(np); 1347 if (np->narg.next) 1348 cmdputs(" "); 1349 } 1350 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1351 cmdputs(" "); 1352 cmdtxt(np); 1353 } 1354 break; 1355 case NARG: 1356 cmdputs(n->narg.text); 1357 break; 1358 case NTO: 1359 p = ">"; i = 1; goto redir; 1360 case NAPPEND: 1361 p = ">>"; i = 1; goto redir; 1362 case NTOFD: 1363 p = ">&"; i = 1; goto redir; 1364 case NCLOBBER: 1365 p = ">|"; i = 1; goto redir; 1366 case NFROM: 1367 p = "<"; i = 0; goto redir; 1368 case NFROMTO: 1369 p = "<>"; i = 0; goto redir; 1370 case NFROMFD: 1371 p = "<&"; i = 0; goto redir; 1372 redir: 1373 if (n->nfile.fd != i) { 1374 s[0] = n->nfile.fd + '0'; 1375 s[1] = '\0'; 1376 cmdputs(s); 1377 } 1378 cmdputs(p); 1379 if (n->type == NTOFD || n->type == NFROMFD) { 1380 if (n->ndup.dupfd >= 0) 1381 s[0] = n->ndup.dupfd + '0'; 1382 else 1383 s[0] = '-'; 1384 s[1] = '\0'; 1385 cmdputs(s); 1386 } else { 1387 cmdtxt(n->nfile.fname); 1388 } 1389 break; 1390 case NHERE: 1391 case NXHERE: 1392 cmdputs("<<..."); 1393 break; 1394 default: 1395 cmdputs("???"); 1396 break; 1397 } 1398 } 1399 1400 1401 1402 static void 1403 cmdputs(const char *s) 1404 { 1405 const char *p; 1406 char *q; 1407 char c; 1408 int subtype = 0; 1409 1410 if (cmdnleft <= 0) 1411 return; 1412 p = s; 1413 q = cmdnextc; 1414 while ((c = *p++) != '\0') { 1415 if (c == CTLESC) 1416 *q++ = *p++; 1417 else if (c == CTLVAR) { 1418 *q++ = '$'; 1419 if (--cmdnleft > 0) 1420 *q++ = '{'; 1421 subtype = *p++; 1422 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1423 *q++ = '#'; 1424 } else if (c == '=' && subtype != 0) { 1425 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1426 if (*q) 1427 q++; 1428 else 1429 cmdnleft++; 1430 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1431 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1432 --cmdnleft > 0) 1433 *q = q[-1], q++; 1434 subtype = 0; 1435 } else if (c == CTLENDVAR) { 1436 *q++ = '}'; 1437 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1438 cmdnleft -= 5; 1439 if (cmdnleft > 0) { 1440 *q++ = '$'; 1441 *q++ = '('; 1442 *q++ = '.'; 1443 *q++ = '.'; 1444 *q++ = '.'; 1445 *q++ = ')'; 1446 } 1447 } else if (c == CTLARI) { 1448 cmdnleft -= 2; 1449 if (cmdnleft > 0) { 1450 *q++ = '$'; 1451 *q++ = '('; 1452 *q++ = '('; 1453 } 1454 p++; 1455 } else if (c == CTLENDARI) { 1456 if (--cmdnleft > 0) { 1457 *q++ = ')'; 1458 *q++ = ')'; 1459 } 1460 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1461 cmdnleft++; /* ignore */ 1462 else 1463 *q++ = c; 1464 if (--cmdnleft <= 0) { 1465 *q++ = '.'; 1466 *q++ = '.'; 1467 *q++ = '.'; 1468 break; 1469 } 1470 } 1471 cmdnextc = q; 1472 } 1473