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 static void 122 jobctl_notty(void) 123 { 124 if (ttyfd >= 0) { 125 close(ttyfd); 126 ttyfd = -1; 127 } 128 if (!iflag) { 129 setsignal(SIGTSTP); 130 setsignal(SIGTTOU); 131 setsignal(SIGTTIN); 132 jobctl = 1; 133 return; 134 } 135 out2fmt_flush("sh: can't access tty; job control turned off\n"); 136 mflag = 0; 137 } 138 139 void 140 setjobctl(int on) 141 { 142 int i; 143 144 if (on == jobctl || rootshell == 0) 145 return; 146 if (on) { 147 if (ttyfd != -1) 148 close(ttyfd); 149 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 150 i = 0; 151 while (i <= 2 && !isatty(i)) 152 i++; 153 if (i > 2 || 154 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) { 155 jobctl_notty(); 156 return; 157 } 158 } 159 if (ttyfd < 10) { 160 /* 161 * Keep our TTY file descriptor out of the way of 162 * the user's redirections. 163 */ 164 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 165 jobctl_notty(); 166 return; 167 } 168 close(ttyfd); 169 ttyfd = i; 170 } 171 do { /* while we are in the background */ 172 initialpgrp = tcgetpgrp(ttyfd); 173 if (initialpgrp < 0) { 174 jobctl_notty(); 175 return; 176 } 177 if (initialpgrp != getpgrp()) { 178 if (!iflag) { 179 initialpgrp = -1; 180 jobctl_notty(); 181 return; 182 } 183 kill(0, SIGTTIN); 184 continue; 185 } 186 } while (0); 187 setsignal(SIGTSTP); 188 setsignal(SIGTTOU); 189 setsignal(SIGTTIN); 190 setpgid(0, rootpid); 191 tcsetpgrp(ttyfd, rootpid); 192 } else { /* turning job control off */ 193 setpgid(0, initialpgrp); 194 if (ttyfd >= 0) { 195 tcsetpgrp(ttyfd, initialpgrp); 196 close(ttyfd); 197 ttyfd = -1; 198 } 199 setsignal(SIGTSTP); 200 setsignal(SIGTTOU); 201 setsignal(SIGTTIN); 202 } 203 jobctl = on; 204 } 205 #endif 206 207 208 #if JOBS 209 int 210 fgcmd(int argc __unused, char **argv __unused) 211 { 212 struct job *jp; 213 pid_t pgrp; 214 int status; 215 216 nextopt(""); 217 jp = getjob(*argptr); 218 if (jp->jobctl == 0) 219 error("job not created under job control"); 220 printjobcmd(jp); 221 flushout(&output); 222 pgrp = jp->ps[0].pid; 223 if (ttyfd >= 0) 224 tcsetpgrp(ttyfd, pgrp); 225 restartjob(jp); 226 jp->foreground = 1; 227 INTOFF; 228 status = waitforjob(jp, (int *)NULL); 229 INTON; 230 return status; 231 } 232 233 234 int 235 bgcmd(int argc, char **argv) 236 { 237 struct job *jp; 238 239 nextopt(""); 240 do { 241 jp = getjob(*argptr); 242 if (jp->jobctl == 0) 243 error("job not created under job control"); 244 if (jp->state == JOBDONE) 245 continue; 246 restartjob(jp); 247 jp->foreground = 0; 248 out1fmt("[%td] ", jp - jobtab + 1); 249 printjobcmd(jp); 250 } while (*argptr != NULL && *++argptr != NULL); 251 return 0; 252 } 253 254 255 static void 256 restartjob(struct job *jp) 257 { 258 struct procstat *ps; 259 int i; 260 261 if (jp->state == JOBDONE) 262 return; 263 setcurjob(jp); 264 INTOFF; 265 kill(-jp->ps[0].pid, SIGCONT); 266 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 267 if (WIFSTOPPED(ps->status)) { 268 ps->status = -1; 269 jp->state = 0; 270 } 271 } 272 INTON; 273 } 274 #endif 275 276 277 int 278 jobscmd(int argc __unused, char *argv[] __unused) 279 { 280 char *id; 281 int ch, mode; 282 283 mode = SHOWJOBS_DEFAULT; 284 while ((ch = nextopt("lps")) != '\0') { 285 switch (ch) { 286 case 'l': 287 mode = SHOWJOBS_VERBOSE; 288 break; 289 case 'p': 290 mode = SHOWJOBS_PGIDS; 291 break; 292 case 's': 293 mode = SHOWJOBS_PIDS; 294 break; 295 } 296 } 297 298 if (*argptr == NULL) 299 showjobs(0, mode); 300 else 301 while ((id = *argptr++) != NULL) 302 showjob(getjob(id), mode); 303 304 return (0); 305 } 306 307 static void 308 printjobcmd(struct job *jp) 309 { 310 struct procstat *ps; 311 int i; 312 313 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 314 out1str(ps->cmd); 315 if (i > 0) 316 out1str(" | "); 317 } 318 out1c('\n'); 319 } 320 321 static void 322 showjob(struct job *jp, int mode) 323 { 324 char s[64]; 325 char statestr[64]; 326 const char *sigstr; 327 struct procstat *ps; 328 struct job *j; 329 int col, curr, i, jobno, prev, procno; 330 char c; 331 332 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 333 jobno = jp - jobtab + 1; 334 curr = prev = 0; 335 #if JOBS 336 if ((j = getcurjob(NULL)) != NULL) { 337 curr = j - jobtab + 1; 338 if ((j = getcurjob(j)) != NULL) 339 prev = j - jobtab + 1; 340 } 341 #endif 342 ps = jp->ps + jp->nprocs - 1; 343 if (jp->state == 0) { 344 strcpy(statestr, "Running"); 345 #if JOBS 346 } else if (jp->state == JOBSTOPPED) { 347 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 348 ps--; 349 if (WIFSTOPPED(ps->status)) 350 i = WSTOPSIG(ps->status); 351 else 352 i = -1; 353 sigstr = strsignal(i); 354 if (sigstr != NULL) 355 strcpy(statestr, sigstr); 356 else 357 strcpy(statestr, "Suspended"); 358 #endif 359 } else if (WIFEXITED(ps->status)) { 360 if (WEXITSTATUS(ps->status) == 0) 361 strcpy(statestr, "Done"); 362 else 363 fmtstr(statestr, 64, "Done(%d)", 364 WEXITSTATUS(ps->status)); 365 } else { 366 i = WTERMSIG(ps->status); 367 sigstr = strsignal(i); 368 if (sigstr != NULL) 369 strcpy(statestr, sigstr); 370 else 371 strcpy(statestr, "Unknown signal"); 372 if (WCOREDUMP(ps->status)) 373 strcat(statestr, " (core dumped)"); 374 } 375 376 for (ps = jp->ps ; ; ps++) { /* for each process */ 377 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 378 out1fmt("%d\n", (int)ps->pid); 379 goto skip; 380 } 381 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 382 goto skip; 383 if (jobno == curr && ps == jp->ps) 384 c = '+'; 385 else if (jobno == prev && ps == jp->ps) 386 c = '-'; 387 else 388 c = ' '; 389 if (ps == jp->ps) 390 fmtstr(s, 64, "[%d] %c ", jobno, c); 391 else 392 fmtstr(s, 64, " %c ", c); 393 out1str(s); 394 col = strlen(s); 395 if (mode == SHOWJOBS_VERBOSE) { 396 fmtstr(s, 64, "%d ", (int)ps->pid); 397 out1str(s); 398 col += strlen(s); 399 } 400 if (ps == jp->ps) { 401 out1str(statestr); 402 col += strlen(statestr); 403 } 404 do { 405 out1c(' '); 406 col++; 407 } while (col < 30); 408 if (mode == SHOWJOBS_VERBOSE) { 409 out1str(ps->cmd); 410 out1c('\n'); 411 } else 412 printjobcmd(jp); 413 skip: if (--procno <= 0) 414 break; 415 } 416 } 417 418 /* 419 * Print a list of jobs. If "change" is nonzero, only print jobs whose 420 * statuses have changed since the last call to showjobs. 421 * 422 * If the shell is interrupted in the process of creating a job, the 423 * result may be a job structure containing zero processes. Such structures 424 * will be freed here. 425 */ 426 427 void 428 showjobs(int change, int mode) 429 { 430 int jobno; 431 struct job *jp; 432 433 TRACE(("showjobs(%d) called\n", change)); 434 checkzombies(); 435 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 436 if (! jp->used) 437 continue; 438 if (jp->nprocs == 0) { 439 freejob(jp); 440 continue; 441 } 442 if (change && ! jp->changed) 443 continue; 444 showjob(jp, mode); 445 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 446 jp->changed = 0; 447 /* Hack: discard jobs for which $! has not been 448 * referenced in interactive mode when they terminate. 449 */ 450 if (jp->state == JOBDONE && !jp->remembered && 451 (iflag || jp != bgjob)) { 452 freejob(jp); 453 } 454 } 455 } 456 } 457 458 459 /* 460 * Mark a job structure as unused. 461 */ 462 463 static void 464 freejob(struct job *jp) 465 { 466 struct procstat *ps; 467 int i; 468 469 INTOFF; 470 if (bgjob == jp) 471 bgjob = NULL; 472 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 473 if (ps->cmd != nullstr) 474 ckfree(ps->cmd); 475 } 476 if (jp->ps != &jp->ps0) 477 ckfree(jp->ps); 478 jp->used = 0; 479 #if JOBS 480 deljob(jp); 481 #endif 482 INTON; 483 } 484 485 486 487 int 488 waitcmd(int argc __unused, char **argv __unused) 489 { 490 struct job *job; 491 int retval; 492 493 nextopt(""); 494 if (*argptr == NULL) 495 return (waitcmdloop(NULL)); 496 497 do { 498 job = getjob_nonotfound(*argptr); 499 if (job == NULL) 500 retval = 127; 501 else 502 retval = waitcmdloop(job); 503 argptr++; 504 } while (*argptr != NULL); 505 506 return (retval); 507 } 508 509 static int 510 waitcmdloop(struct job *job) 511 { 512 int status, retval, sig; 513 struct job *jp; 514 515 /* 516 * Loop until a process is terminated or stopped, or a SIGINT is 517 * received. 518 */ 519 520 do { 521 if (job != NULL) { 522 if (job->state == JOBDONE) { 523 status = job->ps[job->nprocs - 1].status; 524 if (WIFEXITED(status)) 525 retval = WEXITSTATUS(status); 526 else 527 retval = WTERMSIG(status) + 128; 528 if (! iflag || ! job->changed) 529 freejob(job); 530 else { 531 job->remembered = 0; 532 if (job == bgjob) 533 bgjob = NULL; 534 } 535 return retval; 536 } 537 } else { 538 for (jp = jobtab ; jp < jobtab + njobs; jp++) 539 if (jp->used && jp->state == JOBDONE) { 540 if (! iflag || ! jp->changed) 541 freejob(jp); 542 else { 543 jp->remembered = 0; 544 if (jp == bgjob) 545 bgjob = NULL; 546 } 547 } 548 for (jp = jobtab ; ; jp++) { 549 if (jp >= jobtab + njobs) { /* no running procs */ 550 return 0; 551 } 552 if (jp->used && jp->state == 0) 553 break; 554 } 555 } 556 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 557 558 sig = pendingsig_waitcmd; 559 pendingsig_waitcmd = 0; 560 return sig + 128; 561 } 562 563 564 565 int 566 jobidcmd(int argc __unused, char **argv __unused) 567 { 568 struct job *jp; 569 int i; 570 571 nextopt(""); 572 jp = getjob(*argptr); 573 for (i = 0 ; i < jp->nprocs ; ) { 574 out1fmt("%d", (int)jp->ps[i].pid); 575 out1c(++i < jp->nprocs? ' ' : '\n'); 576 } 577 return 0; 578 } 579 580 581 582 /* 583 * Convert a job name to a job structure. 584 */ 585 586 static struct job * 587 getjob_nonotfound(const char *name) 588 { 589 int jobno; 590 struct job *found, *jp; 591 size_t namelen; 592 pid_t pid; 593 int i; 594 595 if (name == NULL) { 596 #if JOBS 597 currentjob: if ((jp = getcurjob(NULL)) == NULL) 598 error("No current job"); 599 return (jp); 600 #else 601 error("No current job"); 602 #endif 603 } else if (name[0] == '%') { 604 if (is_digit(name[1])) { 605 jobno = number(name + 1); 606 if (jobno > 0 && jobno <= njobs 607 && jobtab[jobno - 1].used != 0) 608 return &jobtab[jobno - 1]; 609 #if JOBS 610 } else if (name[1] == '%' && name[2] == '\0') { 611 goto currentjob; 612 } else if (name[1] == '+' && name[2] == '\0') { 613 goto currentjob; 614 } else if (name[1] == '-' && name[2] == '\0') { 615 if ((jp = getcurjob(NULL)) == NULL || 616 (jp = getcurjob(jp)) == NULL) 617 error("No previous job"); 618 return (jp); 619 #endif 620 } else if (name[1] == '?') { 621 found = NULL; 622 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 623 if (jp->used && jp->nprocs > 0 624 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 625 if (found) 626 error("%s: ambiguous", name); 627 found = jp; 628 } 629 } 630 if (found != NULL) 631 return (found); 632 } else { 633 namelen = strlen(name); 634 found = NULL; 635 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 636 if (jp->used && jp->nprocs > 0 637 && strncmp(jp->ps[0].cmd, name + 1, 638 namelen - 1) == 0) { 639 if (found) 640 error("%s: ambiguous", name); 641 found = jp; 642 } 643 } 644 if (found) 645 return found; 646 } 647 } else if (is_number(name)) { 648 pid = (pid_t)number(name); 649 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 650 if (jp->used && jp->nprocs > 0 651 && jp->ps[jp->nprocs - 1].pid == pid) 652 return jp; 653 } 654 } 655 return NULL; 656 } 657 658 659 static struct job * 660 getjob(const char *name) 661 { 662 struct job *jp; 663 664 jp = getjob_nonotfound(name); 665 if (jp == NULL) 666 error("No such job: %s", name); 667 return (jp); 668 } 669 670 671 int 672 killjob(const char *name, int sig) 673 { 674 struct job *jp; 675 int i, ret; 676 677 jp = getjob(name); 678 if (jp->state == JOBDONE) 679 return 0; 680 if (jp->jobctl) 681 return kill(-jp->ps[0].pid, sig); 682 ret = -1; 683 errno = ESRCH; 684 for (i = 0; i < jp->nprocs; i++) 685 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 686 if (kill(jp->ps[i].pid, sig) == 0) 687 ret = 0; 688 } else 689 ret = 0; 690 return ret; 691 } 692 693 /* 694 * Return a new job structure, 695 */ 696 697 struct job * 698 makejob(union node *node __unused, int nprocs) 699 { 700 int i; 701 struct job *jp; 702 703 for (i = njobs, jp = jobtab ; ; jp++) { 704 if (--i < 0) { 705 INTOFF; 706 if (njobs == 0) { 707 jobtab = ckmalloc(4 * sizeof jobtab[0]); 708 #if JOBS 709 jobmru = NULL; 710 #endif 711 } else { 712 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 713 memcpy(jp, jobtab, njobs * sizeof jp[0]); 714 #if JOBS 715 /* Relocate `next' pointers and list head */ 716 if (jobmru != NULL) 717 jobmru = &jp[jobmru - jobtab]; 718 for (i = 0; i < njobs; i++) 719 if (jp[i].next != NULL) 720 jp[i].next = &jp[jp[i].next - 721 jobtab]; 722 #endif 723 if (bgjob != NULL) 724 bgjob = &jp[bgjob - jobtab]; 725 /* Relocate `ps' pointers */ 726 for (i = 0; i < njobs; i++) 727 if (jp[i].ps == &jobtab[i].ps0) 728 jp[i].ps = &jp[i].ps0; 729 ckfree(jobtab); 730 jobtab = jp; 731 } 732 jp = jobtab + njobs; 733 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 734 ; 735 INTON; 736 break; 737 } 738 if (jp->used == 0) 739 break; 740 } 741 INTOFF; 742 jp->state = 0; 743 jp->used = 1; 744 jp->changed = 0; 745 jp->nprocs = 0; 746 jp->foreground = 0; 747 jp->remembered = 0; 748 #if JOBS 749 jp->jobctl = jobctl; 750 jp->next = NULL; 751 #endif 752 if (nprocs > 1) { 753 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 754 } else { 755 jp->ps = &jp->ps0; 756 } 757 INTON; 758 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 759 jp - jobtab + 1)); 760 return jp; 761 } 762 763 #if JOBS 764 static void 765 setcurjob(struct job *cj) 766 { 767 struct job *jp, *prev; 768 769 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 770 if (jp == cj) { 771 if (prev != NULL) 772 prev->next = jp->next; 773 else 774 jobmru = jp->next; 775 jp->next = jobmru; 776 jobmru = cj; 777 return; 778 } 779 } 780 cj->next = jobmru; 781 jobmru = cj; 782 } 783 784 static void 785 deljob(struct job *j) 786 { 787 struct job *jp, *prev; 788 789 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 790 if (jp == j) { 791 if (prev != NULL) 792 prev->next = jp->next; 793 else 794 jobmru = jp->next; 795 return; 796 } 797 } 798 } 799 800 /* 801 * Return the most recently used job that isn't `nj', and preferably one 802 * that is stopped. 803 */ 804 static struct job * 805 getcurjob(struct job *nj) 806 { 807 struct job *jp; 808 809 /* Try to find a stopped one.. */ 810 for (jp = jobmru; jp != NULL; jp = jp->next) 811 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 812 return (jp); 813 /* Otherwise the most recently used job that isn't `nj' */ 814 for (jp = jobmru; jp != NULL; jp = jp->next) 815 if (jp->used && jp != nj) 816 return (jp); 817 818 return (NULL); 819 } 820 821 #endif 822 823 /* 824 * Fork of a subshell. If we are doing job control, give the subshell its 825 * own process group. Jp is a job structure that the job is to be added to. 826 * N is the command that will be evaluated by the child. Both jp and n may 827 * be NULL. The mode parameter can be one of the following: 828 * FORK_FG - Fork off a foreground process. 829 * FORK_BG - Fork off a background process. 830 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 831 * process group even if job control is on. 832 * 833 * When job control is turned off, background processes have their standard 834 * input redirected to /dev/null (except for the second and later processes 835 * in a pipeline). 836 */ 837 838 pid_t 839 forkshell(struct job *jp, union node *n, int mode) 840 { 841 pid_t pid; 842 pid_t pgrp; 843 844 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 845 mode)); 846 INTOFF; 847 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 848 checkzombies(); 849 flushall(); 850 pid = fork(); 851 if (pid == -1) { 852 TRACE(("Fork failed, errno=%d\n", errno)); 853 INTON; 854 error("Cannot fork: %s", strerror(errno)); 855 } 856 if (pid == 0) { 857 struct job *p; 858 int wasroot; 859 int i; 860 861 TRACE(("Child shell %d\n", (int)getpid())); 862 wasroot = rootshell; 863 rootshell = 0; 864 handler = &main_handler; 865 closescript(); 866 INTON; 867 forcelocal = 0; 868 clear_traps(); 869 #if JOBS 870 jobctl = 0; /* do job control only in root shell */ 871 if (wasroot && mode != FORK_NOJOB && mflag) { 872 if (jp == NULL || jp->nprocs == 0) 873 pgrp = getpid(); 874 else 875 pgrp = jp->ps[0].pid; 876 if (setpgid(0, pgrp) == 0 && mode == FORK_FG && 877 ttyfd >= 0) { 878 /*** this causes superfluous TIOCSPGRPS ***/ 879 if (tcsetpgrp(ttyfd, pgrp) < 0) 880 error("tcsetpgrp failed, errno=%d", errno); 881 } 882 setsignal(SIGTSTP); 883 setsignal(SIGTTOU); 884 } else if (mode == FORK_BG) { 885 ignoresig(SIGINT); 886 ignoresig(SIGQUIT); 887 if ((jp == NULL || jp->nprocs == 0) && 888 ! fd0_redirected_p ()) { 889 close(0); 890 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 891 error("cannot open %s: %s", 892 _PATH_DEVNULL, strerror(errno)); 893 } 894 } 895 #else 896 if (mode == FORK_BG) { 897 ignoresig(SIGINT); 898 ignoresig(SIGQUIT); 899 if ((jp == NULL || jp->nprocs == 0) && 900 ! fd0_redirected_p ()) { 901 close(0); 902 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 903 error("cannot open %s: %s", 904 _PATH_DEVNULL, strerror(errno)); 905 } 906 } 907 #endif 908 INTOFF; 909 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 910 if (p->used) 911 freejob(p); 912 INTON; 913 if (wasroot && iflag) { 914 setsignal(SIGINT); 915 setsignal(SIGQUIT); 916 setsignal(SIGTERM); 917 } 918 return pid; 919 } 920 if (rootshell && mode != FORK_NOJOB && mflag) { 921 if (jp == NULL || jp->nprocs == 0) 922 pgrp = pid; 923 else 924 pgrp = jp->ps[0].pid; 925 setpgid(pid, pgrp); 926 } 927 if (mode == FORK_BG) { 928 if (bgjob != NULL && bgjob->state == JOBDONE && 929 !bgjob->remembered && !iflag) 930 freejob(bgjob); 931 backgndpid = pid; /* set $! */ 932 bgjob = jp; 933 } 934 if (jp) { 935 struct procstat *ps = &jp->ps[jp->nprocs++]; 936 ps->pid = pid; 937 ps->status = -1; 938 ps->cmd = nullstr; 939 if (iflag && rootshell && n) 940 ps->cmd = commandtext(n); 941 jp->foreground = mode == FORK_FG; 942 #if JOBS 943 setcurjob(jp); 944 #endif 945 } 946 INTON; 947 TRACE(("In parent shell: child = %d\n", (int)pid)); 948 return pid; 949 } 950 951 952 pid_t 953 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 954 { 955 pid_t pid; 956 struct jmploc jmploc; 957 struct jmploc *savehandler; 958 959 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 960 (void *)pip)); 961 INTOFF; 962 flushall(); 963 savehandler = handler; 964 pid = vfork(); 965 if (pid == -1) { 966 TRACE(("Vfork failed, errno=%d\n", errno)); 967 INTON; 968 error("Cannot fork: %s", strerror(errno)); 969 } 970 if (pid == 0) { 971 TRACE(("Child shell %d\n", (int)getpid())); 972 if (setjmp(jmploc.loc)) 973 _exit(exception == EXEXEC ? exerrno : 2); 974 if (pip != NULL) { 975 close(pip[0]); 976 if (pip[1] != 1) { 977 dup2(pip[1], 1); 978 close(pip[1]); 979 } 980 } 981 handler = &jmploc; 982 shellexec(argv, envp, path, idx); 983 } 984 handler = savehandler; 985 if (jp) { 986 struct procstat *ps = &jp->ps[jp->nprocs++]; 987 ps->pid = pid; 988 ps->status = -1; 989 ps->cmd = nullstr; 990 jp->foreground = 1; 991 #if JOBS 992 setcurjob(jp); 993 #endif 994 } 995 INTON; 996 TRACE(("In parent shell: child = %d\n", (int)pid)); 997 return pid; 998 } 999 1000 1001 /* 1002 * Wait for job to finish. 1003 * 1004 * Under job control we have the problem that while a child process is 1005 * running interrupts generated by the user are sent to the child but not 1006 * to the shell. This means that an infinite loop started by an inter- 1007 * active user may be hard to kill. With job control turned off, an 1008 * interactive user may place an interactive program inside a loop. If 1009 * the interactive program catches interrupts, the user doesn't want 1010 * these interrupts to also abort the loop. The approach we take here 1011 * is to have the shell ignore interrupt signals while waiting for a 1012 * foreground process to terminate, and then send itself an interrupt 1013 * signal if the child process was terminated by an interrupt signal. 1014 * Unfortunately, some programs want to do a bit of cleanup and then 1015 * exit on interrupt; unless these processes terminate themselves by 1016 * sending a signal to themselves (instead of calling exit) they will 1017 * confuse this approach. 1018 */ 1019 1020 int 1021 waitforjob(struct job *jp, int *origstatus) 1022 { 1023 #if JOBS 1024 int propagate_int = jp->jobctl && jp->foreground; 1025 #endif 1026 int status; 1027 int st; 1028 1029 INTOFF; 1030 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1031 while (jp->state == 0) 1032 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1033 DOWAIT_SIG_ANY : 0), jp) == -1) 1034 dotrap(); 1035 #if JOBS 1036 if (jp->jobctl) { 1037 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0) 1038 error("tcsetpgrp failed, errno=%d\n", errno); 1039 } 1040 if (jp->state == JOBSTOPPED) 1041 setcurjob(jp); 1042 #endif 1043 status = jp->ps[jp->nprocs - 1].status; 1044 if (origstatus != NULL) 1045 *origstatus = status; 1046 /* convert to 8 bits */ 1047 if (WIFEXITED(status)) 1048 st = WEXITSTATUS(status); 1049 #if JOBS 1050 else if (WIFSTOPPED(status)) 1051 st = WSTOPSIG(status) + 128; 1052 #endif 1053 else 1054 st = WTERMSIG(status) + 128; 1055 if (! JOBS || jp->state == JOBDONE) 1056 freejob(jp); 1057 if (int_pending()) { 1058 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1059 CLEAR_PENDING_INT; 1060 } 1061 #if JOBS 1062 else if (rootshell && iflag && propagate_int && 1063 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1064 kill(getpid(), SIGINT); 1065 #endif 1066 INTON; 1067 return st; 1068 } 1069 1070 1071 static void 1072 dummy_handler(int sig __unused) 1073 { 1074 } 1075 1076 /* 1077 * Wait for a process to terminate. 1078 */ 1079 1080 static pid_t 1081 dowait(int mode, struct job *job) 1082 { 1083 struct sigaction sa, osa; 1084 sigset_t mask, omask; 1085 pid_t pid; 1086 int status; 1087 struct procstat *sp; 1088 struct job *jp; 1089 struct job *thisjob; 1090 const char *sigstr; 1091 int done; 1092 int stopped; 1093 int sig; 1094 int coredump; 1095 int wflags; 1096 int restore_sigchld; 1097 1098 TRACE(("dowait(%d, %p) called\n", mode, job)); 1099 restore_sigchld = 0; 1100 if ((mode & DOWAIT_SIG) != 0) { 1101 sigfillset(&mask); 1102 sigprocmask(SIG_BLOCK, &mask, &omask); 1103 INTOFF; 1104 if (!issigchldtrapped()) { 1105 restore_sigchld = 1; 1106 sa.sa_handler = dummy_handler; 1107 sa.sa_flags = 0; 1108 sigemptyset(&sa.sa_mask); 1109 sigaction(SIGCHLD, &sa, &osa); 1110 } 1111 } 1112 do { 1113 #if JOBS 1114 if (iflag) 1115 wflags = WUNTRACED | WCONTINUED; 1116 else 1117 #endif 1118 wflags = 0; 1119 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1120 wflags |= WNOHANG; 1121 pid = wait3(&status, wflags, (struct rusage *)NULL); 1122 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1123 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1124 pid = -1; 1125 if (((mode & DOWAIT_SIG_ANY) != 0 ? 1126 pendingsig : pendingsig_waitcmd) != 0) { 1127 errno = EINTR; 1128 break; 1129 } 1130 sigsuspend(&omask); 1131 if (int_pending()) 1132 break; 1133 } 1134 } while (pid == -1 && errno == EINTR); 1135 if (pid == -1 && errno == ECHILD && job != NULL) 1136 job->state = JOBDONE; 1137 if ((mode & DOWAIT_SIG) != 0) { 1138 if (restore_sigchld) 1139 sigaction(SIGCHLD, &osa, NULL); 1140 sigprocmask(SIG_SETMASK, &omask, NULL); 1141 INTON; 1142 } 1143 if (pid <= 0) 1144 return pid; 1145 INTOFF; 1146 thisjob = NULL; 1147 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1148 if (jp->used && jp->nprocs > 0) { 1149 done = 1; 1150 stopped = 1; 1151 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1152 if (sp->pid == -1) 1153 continue; 1154 if (sp->pid == pid && (sp->status == -1 || 1155 WIFSTOPPED(sp->status))) { 1156 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1157 (int)pid, sp->status, 1158 status)); 1159 if (WIFCONTINUED(status)) { 1160 sp->status = -1; 1161 jp->state = 0; 1162 } else 1163 sp->status = status; 1164 thisjob = jp; 1165 } 1166 if (sp->status == -1) 1167 stopped = 0; 1168 else if (WIFSTOPPED(sp->status)) 1169 done = 0; 1170 } 1171 if (stopped) { /* stopped or done */ 1172 int state = done? JOBDONE : JOBSTOPPED; 1173 if (jp->state != state) { 1174 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1175 jp->state = state; 1176 if (jp != job) { 1177 if (done && !jp->remembered && 1178 !iflag && jp != bgjob) 1179 freejob(jp); 1180 #if JOBS 1181 else if (done) 1182 deljob(jp); 1183 #endif 1184 } 1185 } 1186 } 1187 } 1188 } 1189 INTON; 1190 if (!thisjob || thisjob->state == 0) 1191 ; 1192 else if ((!rootshell || !iflag || thisjob == job) && 1193 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1194 sig = 0; 1195 coredump = 0; 1196 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1197 if (WIFSIGNALED(sp->status)) { 1198 sig = WTERMSIG(sp->status); 1199 coredump = WCOREDUMP(sp->status); 1200 } 1201 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1202 sigstr = strsignal(sig); 1203 if (sigstr != NULL) 1204 out2str(sigstr); 1205 else 1206 out2str("Unknown signal"); 1207 if (coredump) 1208 out2str(" (core dumped)"); 1209 out2c('\n'); 1210 flushout(out2); 1211 } 1212 } else { 1213 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1214 thisjob->changed = 1; 1215 } 1216 return pid; 1217 } 1218 1219 1220 1221 /* 1222 * return 1 if there are stopped jobs, otherwise 0 1223 */ 1224 int job_warning = 0; 1225 int 1226 stoppedjobs(void) 1227 { 1228 int jobno; 1229 struct job *jp; 1230 1231 if (job_warning) 1232 return (0); 1233 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1234 if (jp->used == 0) 1235 continue; 1236 if (jp->state == JOBSTOPPED) { 1237 out2fmt_flush("You have stopped jobs.\n"); 1238 job_warning = 2; 1239 return (1); 1240 } 1241 } 1242 1243 return (0); 1244 } 1245 1246 1247 static void 1248 checkzombies(void) 1249 { 1250 while (njobs > 0 && dowait(0, NULL) > 0) 1251 ; 1252 } 1253 1254 1255 int 1256 backgndpidset(void) 1257 { 1258 return backgndpid != -1; 1259 } 1260 1261 1262 pid_t 1263 backgndpidval(void) 1264 { 1265 if (bgjob != NULL && !forcelocal) 1266 bgjob->remembered = 1; 1267 return backgndpid; 1268 } 1269 1270 /* 1271 * Return a string identifying a command (to be printed by the 1272 * jobs command. 1273 */ 1274 1275 static char *cmdnextc; 1276 static int cmdnleft; 1277 #define MAXCMDTEXT 200 1278 1279 char * 1280 commandtext(union node *n) 1281 { 1282 char *name; 1283 1284 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1285 cmdnleft = MAXCMDTEXT - 4; 1286 cmdtxt(n); 1287 *cmdnextc = '\0'; 1288 return name; 1289 } 1290 1291 1292 static void 1293 cmdtxt(union node *n) 1294 { 1295 union node *np; 1296 struct nodelist *lp; 1297 const char *p; 1298 int i; 1299 char s[2]; 1300 1301 if (n == NULL) 1302 return; 1303 switch (n->type) { 1304 case NSEMI: 1305 cmdtxt(n->nbinary.ch1); 1306 cmdputs("; "); 1307 cmdtxt(n->nbinary.ch2); 1308 break; 1309 case NAND: 1310 cmdtxt(n->nbinary.ch1); 1311 cmdputs(" && "); 1312 cmdtxt(n->nbinary.ch2); 1313 break; 1314 case NOR: 1315 cmdtxt(n->nbinary.ch1); 1316 cmdputs(" || "); 1317 cmdtxt(n->nbinary.ch2); 1318 break; 1319 case NPIPE: 1320 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1321 cmdtxt(lp->n); 1322 if (lp->next) 1323 cmdputs(" | "); 1324 } 1325 break; 1326 case NSUBSHELL: 1327 cmdputs("("); 1328 cmdtxt(n->nredir.n); 1329 cmdputs(")"); 1330 break; 1331 case NREDIR: 1332 case NBACKGND: 1333 cmdtxt(n->nredir.n); 1334 break; 1335 case NIF: 1336 cmdputs("if "); 1337 cmdtxt(n->nif.test); 1338 cmdputs("; then "); 1339 cmdtxt(n->nif.ifpart); 1340 cmdputs("..."); 1341 break; 1342 case NWHILE: 1343 cmdputs("while "); 1344 goto until; 1345 case NUNTIL: 1346 cmdputs("until "); 1347 until: 1348 cmdtxt(n->nbinary.ch1); 1349 cmdputs("; do "); 1350 cmdtxt(n->nbinary.ch2); 1351 cmdputs("; done"); 1352 break; 1353 case NFOR: 1354 cmdputs("for "); 1355 cmdputs(n->nfor.var); 1356 cmdputs(" in ..."); 1357 break; 1358 case NCASE: 1359 cmdputs("case "); 1360 cmdputs(n->ncase.expr->narg.text); 1361 cmdputs(" in ..."); 1362 break; 1363 case NDEFUN: 1364 cmdputs(n->narg.text); 1365 cmdputs("() ..."); 1366 break; 1367 case NNOT: 1368 cmdputs("! "); 1369 cmdtxt(n->nnot.com); 1370 break; 1371 case NCMD: 1372 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1373 cmdtxt(np); 1374 if (np->narg.next) 1375 cmdputs(" "); 1376 } 1377 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1378 cmdputs(" "); 1379 cmdtxt(np); 1380 } 1381 break; 1382 case NARG: 1383 cmdputs(n->narg.text); 1384 break; 1385 case NTO: 1386 p = ">"; i = 1; goto redir; 1387 case NAPPEND: 1388 p = ">>"; i = 1; goto redir; 1389 case NTOFD: 1390 p = ">&"; i = 1; goto redir; 1391 case NCLOBBER: 1392 p = ">|"; i = 1; goto redir; 1393 case NFROM: 1394 p = "<"; i = 0; goto redir; 1395 case NFROMTO: 1396 p = "<>"; i = 0; goto redir; 1397 case NFROMFD: 1398 p = "<&"; i = 0; goto redir; 1399 redir: 1400 if (n->nfile.fd != i) { 1401 s[0] = n->nfile.fd + '0'; 1402 s[1] = '\0'; 1403 cmdputs(s); 1404 } 1405 cmdputs(p); 1406 if (n->type == NTOFD || n->type == NFROMFD) { 1407 if (n->ndup.dupfd >= 0) 1408 s[0] = n->ndup.dupfd + '0'; 1409 else 1410 s[0] = '-'; 1411 s[1] = '\0'; 1412 cmdputs(s); 1413 } else { 1414 cmdtxt(n->nfile.fname); 1415 } 1416 break; 1417 case NHERE: 1418 case NXHERE: 1419 cmdputs("<<..."); 1420 break; 1421 default: 1422 cmdputs("???"); 1423 break; 1424 } 1425 } 1426 1427 1428 1429 static void 1430 cmdputs(const char *s) 1431 { 1432 const char *p; 1433 char *q; 1434 char c; 1435 int subtype = 0; 1436 1437 if (cmdnleft <= 0) 1438 return; 1439 p = s; 1440 q = cmdnextc; 1441 while ((c = *p++) != '\0') { 1442 if (c == CTLESC) 1443 *q++ = *p++; 1444 else if (c == CTLVAR) { 1445 *q++ = '$'; 1446 if (--cmdnleft > 0) 1447 *q++ = '{'; 1448 subtype = *p++; 1449 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1450 *q++ = '#'; 1451 } else if (c == '=' && subtype != 0) { 1452 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1453 if (*q) 1454 q++; 1455 else 1456 cmdnleft++; 1457 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1458 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1459 --cmdnleft > 0) 1460 *q = q[-1], q++; 1461 subtype = 0; 1462 } else if (c == CTLENDVAR) { 1463 *q++ = '}'; 1464 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1465 cmdnleft -= 5; 1466 if (cmdnleft > 0) { 1467 *q++ = '$'; 1468 *q++ = '('; 1469 *q++ = '.'; 1470 *q++ = '.'; 1471 *q++ = '.'; 1472 *q++ = ')'; 1473 } 1474 } else if (c == CTLARI) { 1475 cmdnleft -= 2; 1476 if (cmdnleft > 0) { 1477 *q++ = '$'; 1478 *q++ = '('; 1479 *q++ = '('; 1480 } 1481 p++; 1482 } else if (c == CTLENDARI) { 1483 if (--cmdnleft > 0) { 1484 *q++ = ')'; 1485 *q++ = ')'; 1486 } 1487 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1488 cmdnleft++; /* ignore */ 1489 else 1490 *q++ = c; 1491 if (--cmdnleft <= 0) { 1492 *q++ = '.'; 1493 *q++ = '.'; 1494 *q++ = '.'; 1495 break; 1496 } 1497 } 1498 cmdnextc = q; 1499 } 1500