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 ; procno > 0 ; ps++, procno--) { /* for each process */ 377 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 378 out1fmt("%d\n", (int)ps->pid); 379 continue; 380 } 381 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 382 continue; 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 } 414 } 415 416 /* 417 * Print a list of jobs. If "change" is nonzero, only print jobs whose 418 * statuses have changed since the last call to showjobs. 419 * 420 * If the shell is interrupted in the process of creating a job, the 421 * result may be a job structure containing zero processes. Such structures 422 * will be freed here. 423 */ 424 425 void 426 showjobs(int change, int mode) 427 { 428 int jobno; 429 struct job *jp; 430 431 TRACE(("showjobs(%d) called\n", change)); 432 checkzombies(); 433 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 434 if (! jp->used) 435 continue; 436 if (jp->nprocs == 0) { 437 freejob(jp); 438 continue; 439 } 440 if (change && ! jp->changed) 441 continue; 442 showjob(jp, mode); 443 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 444 jp->changed = 0; 445 /* Hack: discard jobs for which $! has not been 446 * referenced in interactive mode when they terminate. 447 */ 448 if (jp->state == JOBDONE && !jp->remembered && 449 (iflag || jp != bgjob)) { 450 freejob(jp); 451 } 452 } 453 } 454 } 455 456 457 /* 458 * Mark a job structure as unused. 459 */ 460 461 static void 462 freejob(struct job *jp) 463 { 464 struct procstat *ps; 465 int i; 466 467 INTOFF; 468 if (bgjob == jp) 469 bgjob = NULL; 470 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 471 if (ps->cmd != nullstr) 472 ckfree(ps->cmd); 473 } 474 if (jp->ps != &jp->ps0) 475 ckfree(jp->ps); 476 jp->used = 0; 477 #if JOBS 478 deljob(jp); 479 #endif 480 INTON; 481 } 482 483 484 485 int 486 waitcmd(int argc __unused, char **argv __unused) 487 { 488 struct job *job; 489 int retval; 490 491 nextopt(""); 492 if (*argptr == NULL) 493 return (waitcmdloop(NULL)); 494 495 do { 496 job = getjob_nonotfound(*argptr); 497 if (job == NULL) 498 retval = 127; 499 else 500 retval = waitcmdloop(job); 501 argptr++; 502 } while (*argptr != NULL); 503 504 return (retval); 505 } 506 507 static int 508 waitcmdloop(struct job *job) 509 { 510 int status, retval, sig; 511 struct job *jp; 512 513 /* 514 * Loop until a process is terminated or stopped, or a SIGINT is 515 * received. 516 */ 517 518 do { 519 if (job != NULL) { 520 if (job->state == JOBDONE) { 521 status = job->ps[job->nprocs - 1].status; 522 if (WIFEXITED(status)) 523 retval = WEXITSTATUS(status); 524 else 525 retval = WTERMSIG(status) + 128; 526 if (! iflag || ! job->changed) 527 freejob(job); 528 else { 529 job->remembered = 0; 530 if (job == bgjob) 531 bgjob = NULL; 532 } 533 return retval; 534 } 535 } else { 536 for (jp = jobtab ; jp < jobtab + njobs; jp++) 537 if (jp->used && jp->state == JOBDONE) { 538 if (! iflag || ! jp->changed) 539 freejob(jp); 540 else { 541 jp->remembered = 0; 542 if (jp == bgjob) 543 bgjob = NULL; 544 } 545 } 546 for (jp = jobtab ; ; jp++) { 547 if (jp >= jobtab + njobs) { /* no running procs */ 548 return 0; 549 } 550 if (jp->used && jp->state == 0) 551 break; 552 } 553 } 554 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 555 556 sig = pendingsig_waitcmd; 557 pendingsig_waitcmd = 0; 558 return sig + 128; 559 } 560 561 562 563 int 564 jobidcmd(int argc __unused, char **argv __unused) 565 { 566 struct job *jp; 567 int i; 568 569 nextopt(""); 570 jp = getjob(*argptr); 571 for (i = 0 ; i < jp->nprocs ; ) { 572 out1fmt("%d", (int)jp->ps[i].pid); 573 out1c(++i < jp->nprocs? ' ' : '\n'); 574 } 575 return 0; 576 } 577 578 579 580 /* 581 * Convert a job name to a job structure. 582 */ 583 584 static struct job * 585 getjob_nonotfound(const char *name) 586 { 587 int jobno; 588 struct job *found, *jp; 589 size_t namelen; 590 pid_t pid; 591 int i; 592 593 if (name == NULL) { 594 #if JOBS 595 name = "%+"; 596 #else 597 error("No current job"); 598 #endif 599 } 600 if (name[0] == '%') { 601 if (is_digit(name[1])) { 602 jobno = number(name + 1); 603 if (jobno > 0 && jobno <= njobs 604 && jobtab[jobno - 1].used != 0) 605 return &jobtab[jobno - 1]; 606 #if JOBS 607 } else if ((name[1] == '%' || name[1] == '+') && 608 name[2] == '\0') { 609 if ((jp = getcurjob(NULL)) == NULL) 610 error("No current job"); 611 return (jp); 612 } else if (name[1] == '-' && name[2] == '\0') { 613 if ((jp = getcurjob(NULL)) == NULL || 614 (jp = getcurjob(jp)) == NULL) 615 error("No previous job"); 616 return (jp); 617 #endif 618 } else if (name[1] == '?') { 619 found = NULL; 620 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 621 if (jp->used && jp->nprocs > 0 622 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 623 if (found) 624 error("%s: ambiguous", name); 625 found = jp; 626 } 627 } 628 if (found != NULL) 629 return (found); 630 } else { 631 namelen = strlen(name); 632 found = NULL; 633 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 634 if (jp->used && jp->nprocs > 0 635 && strncmp(jp->ps[0].cmd, name + 1, 636 namelen - 1) == 0) { 637 if (found) 638 error("%s: ambiguous", name); 639 found = jp; 640 } 641 } 642 if (found) 643 return found; 644 } 645 } else if (is_number(name)) { 646 pid = (pid_t)number(name); 647 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 648 if (jp->used && jp->nprocs > 0 649 && jp->ps[jp->nprocs - 1].pid == pid) 650 return jp; 651 } 652 } 653 return NULL; 654 } 655 656 657 static struct job * 658 getjob(const char *name) 659 { 660 struct job *jp; 661 662 jp = getjob_nonotfound(name); 663 if (jp == NULL) 664 error("No such job: %s", name); 665 return (jp); 666 } 667 668 669 int 670 killjob(const char *name, int sig) 671 { 672 struct job *jp; 673 int i, ret; 674 675 jp = getjob(name); 676 if (jp->state == JOBDONE) 677 return 0; 678 if (jp->jobctl) 679 return kill(-jp->ps[0].pid, sig); 680 ret = -1; 681 errno = ESRCH; 682 for (i = 0; i < jp->nprocs; i++) 683 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 684 if (kill(jp->ps[i].pid, sig) == 0) 685 ret = 0; 686 } else 687 ret = 0; 688 return ret; 689 } 690 691 /* 692 * Return a new job structure, 693 */ 694 695 struct job * 696 makejob(union node *node __unused, int nprocs) 697 { 698 int i; 699 struct job *jp; 700 701 for (i = njobs, jp = jobtab ; ; jp++) { 702 if (--i < 0) { 703 INTOFF; 704 if (njobs == 0) { 705 jobtab = ckmalloc(4 * sizeof jobtab[0]); 706 #if JOBS 707 jobmru = NULL; 708 #endif 709 } else { 710 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 711 memcpy(jp, jobtab, njobs * sizeof jp[0]); 712 #if JOBS 713 /* Relocate `next' pointers and list head */ 714 if (jobmru != NULL) 715 jobmru = &jp[jobmru - jobtab]; 716 for (i = 0; i < njobs; i++) 717 if (jp[i].next != NULL) 718 jp[i].next = &jp[jp[i].next - 719 jobtab]; 720 #endif 721 if (bgjob != NULL) 722 bgjob = &jp[bgjob - jobtab]; 723 /* Relocate `ps' pointers */ 724 for (i = 0; i < njobs; i++) 725 if (jp[i].ps == &jobtab[i].ps0) 726 jp[i].ps = &jp[i].ps0; 727 ckfree(jobtab); 728 jobtab = jp; 729 } 730 jp = jobtab + njobs; 731 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 732 ; 733 INTON; 734 break; 735 } 736 if (jp->used == 0) 737 break; 738 } 739 INTOFF; 740 jp->state = 0; 741 jp->used = 1; 742 jp->changed = 0; 743 jp->nprocs = 0; 744 jp->foreground = 0; 745 jp->remembered = 0; 746 #if JOBS 747 jp->jobctl = jobctl; 748 jp->next = NULL; 749 #endif 750 if (nprocs > 1) { 751 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 752 } else { 753 jp->ps = &jp->ps0; 754 } 755 INTON; 756 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 757 jp - jobtab + 1)); 758 return jp; 759 } 760 761 #if JOBS 762 static void 763 setcurjob(struct job *cj) 764 { 765 struct job *jp, *prev; 766 767 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 768 if (jp == cj) { 769 if (prev != NULL) 770 prev->next = jp->next; 771 else 772 jobmru = jp->next; 773 jp->next = jobmru; 774 jobmru = cj; 775 return; 776 } 777 } 778 cj->next = jobmru; 779 jobmru = cj; 780 } 781 782 static void 783 deljob(struct job *j) 784 { 785 struct job *jp, *prev; 786 787 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 788 if (jp == j) { 789 if (prev != NULL) 790 prev->next = jp->next; 791 else 792 jobmru = jp->next; 793 return; 794 } 795 } 796 } 797 798 /* 799 * Return the most recently used job that isn't `nj', and preferably one 800 * that is stopped. 801 */ 802 static struct job * 803 getcurjob(struct job *nj) 804 { 805 struct job *jp; 806 807 /* Try to find a stopped one.. */ 808 for (jp = jobmru; jp != NULL; jp = jp->next) 809 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 810 return (jp); 811 /* Otherwise the most recently used job that isn't `nj' */ 812 for (jp = jobmru; jp != NULL; jp = jp->next) 813 if (jp->used && jp != nj) 814 return (jp); 815 816 return (NULL); 817 } 818 819 #endif 820 821 /* 822 * Fork of a subshell. If we are doing job control, give the subshell its 823 * own process group. Jp is a job structure that the job is to be added to. 824 * N is the command that will be evaluated by the child. Both jp and n may 825 * be NULL. The mode parameter can be one of the following: 826 * FORK_FG - Fork off a foreground process. 827 * FORK_BG - Fork off a background process. 828 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 829 * process group even if job control is on. 830 * 831 * When job control is turned off, background processes have their standard 832 * input redirected to /dev/null (except for the second and later processes 833 * in a pipeline). 834 */ 835 836 pid_t 837 forkshell(struct job *jp, union node *n, int mode) 838 { 839 pid_t pid; 840 pid_t pgrp; 841 842 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 843 mode)); 844 INTOFF; 845 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 846 checkzombies(); 847 flushall(); 848 pid = fork(); 849 if (pid == -1) { 850 TRACE(("Fork failed, errno=%d\n", errno)); 851 INTON; 852 error("Cannot fork: %s", strerror(errno)); 853 } 854 if (pid == 0) { 855 struct job *p; 856 int wasroot; 857 int i; 858 859 TRACE(("Child shell %d\n", (int)getpid())); 860 wasroot = rootshell; 861 rootshell = 0; 862 handler = &main_handler; 863 closescript(); 864 INTON; 865 forcelocal = 0; 866 clear_traps(); 867 #if JOBS 868 jobctl = 0; /* do job control only in root shell */ 869 if (wasroot && mode != FORK_NOJOB && mflag) { 870 if (jp == NULL || jp->nprocs == 0) 871 pgrp = getpid(); 872 else 873 pgrp = jp->ps[0].pid; 874 if (setpgid(0, pgrp) == 0 && mode == FORK_FG && 875 ttyfd >= 0) { 876 /*** this causes superfluous TIOCSPGRPS ***/ 877 if (tcsetpgrp(ttyfd, pgrp) < 0) 878 error("tcsetpgrp failed, errno=%d", errno); 879 } 880 setsignal(SIGTSTP); 881 setsignal(SIGTTOU); 882 } else if (mode == FORK_BG) { 883 ignoresig(SIGINT); 884 ignoresig(SIGQUIT); 885 if ((jp == NULL || jp->nprocs == 0) && 886 ! fd0_redirected_p ()) { 887 close(0); 888 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 889 error("cannot open %s: %s", 890 _PATH_DEVNULL, strerror(errno)); 891 } 892 } 893 #else 894 if (mode == FORK_BG) { 895 ignoresig(SIGINT); 896 ignoresig(SIGQUIT); 897 if ((jp == NULL || jp->nprocs == 0) && 898 ! fd0_redirected_p ()) { 899 close(0); 900 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 901 error("cannot open %s: %s", 902 _PATH_DEVNULL, strerror(errno)); 903 } 904 } 905 #endif 906 INTOFF; 907 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 908 if (p->used) 909 freejob(p); 910 INTON; 911 if (wasroot && iflag) { 912 setsignal(SIGINT); 913 setsignal(SIGQUIT); 914 setsignal(SIGTERM); 915 } 916 return pid; 917 } 918 if (rootshell && mode != FORK_NOJOB && mflag) { 919 if (jp == NULL || jp->nprocs == 0) 920 pgrp = pid; 921 else 922 pgrp = jp->ps[0].pid; 923 setpgid(pid, pgrp); 924 } 925 if (mode == FORK_BG) { 926 if (bgjob != NULL && bgjob->state == JOBDONE && 927 !bgjob->remembered && !iflag) 928 freejob(bgjob); 929 backgndpid = pid; /* set $! */ 930 bgjob = jp; 931 } 932 if (jp) { 933 struct procstat *ps = &jp->ps[jp->nprocs++]; 934 ps->pid = pid; 935 ps->status = -1; 936 ps->cmd = nullstr; 937 if (iflag && rootshell && n) 938 ps->cmd = commandtext(n); 939 jp->foreground = mode == FORK_FG; 940 #if JOBS 941 setcurjob(jp); 942 #endif 943 } 944 INTON; 945 TRACE(("In parent shell: child = %d\n", (int)pid)); 946 return pid; 947 } 948 949 950 pid_t 951 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 952 { 953 pid_t pid; 954 struct jmploc jmploc; 955 struct jmploc *savehandler; 956 957 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 958 (void *)pip)); 959 INTOFF; 960 flushall(); 961 savehandler = handler; 962 pid = vfork(); 963 if (pid == -1) { 964 TRACE(("Vfork failed, errno=%d\n", errno)); 965 INTON; 966 error("Cannot fork: %s", strerror(errno)); 967 } 968 if (pid == 0) { 969 TRACE(("Child shell %d\n", (int)getpid())); 970 if (setjmp(jmploc.loc)) 971 _exit(exception == EXEXEC ? exerrno : 2); 972 if (pip != NULL) { 973 close(pip[0]); 974 if (pip[1] != 1) { 975 dup2(pip[1], 1); 976 close(pip[1]); 977 } 978 } 979 handler = &jmploc; 980 shellexec(argv, envp, path, idx); 981 } 982 handler = savehandler; 983 if (jp) { 984 struct procstat *ps = &jp->ps[jp->nprocs++]; 985 ps->pid = pid; 986 ps->status = -1; 987 ps->cmd = nullstr; 988 jp->foreground = 1; 989 #if JOBS 990 setcurjob(jp); 991 #endif 992 } 993 INTON; 994 TRACE(("In parent shell: child = %d\n", (int)pid)); 995 return pid; 996 } 997 998 999 /* 1000 * Wait for job to finish. 1001 * 1002 * Under job control we have the problem that while a child process is 1003 * running interrupts generated by the user are sent to the child but not 1004 * to the shell. This means that an infinite loop started by an inter- 1005 * active user may be hard to kill. With job control turned off, an 1006 * interactive user may place an interactive program inside a loop. If 1007 * the interactive program catches interrupts, the user doesn't want 1008 * these interrupts to also abort the loop. The approach we take here 1009 * is to have the shell ignore interrupt signals while waiting for a 1010 * foreground process to terminate, and then send itself an interrupt 1011 * signal if the child process was terminated by an interrupt signal. 1012 * Unfortunately, some programs want to do a bit of cleanup and then 1013 * exit on interrupt; unless these processes terminate themselves by 1014 * sending a signal to themselves (instead of calling exit) they will 1015 * confuse this approach. 1016 */ 1017 1018 int 1019 waitforjob(struct job *jp, int *origstatus) 1020 { 1021 #if JOBS 1022 int propagate_int = jp->jobctl && jp->foreground; 1023 #endif 1024 int status; 1025 int st; 1026 1027 INTOFF; 1028 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1029 while (jp->state == 0) 1030 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1031 DOWAIT_SIG_ANY : 0), jp) == -1) 1032 dotrap(); 1033 #if JOBS 1034 if (jp->jobctl) { 1035 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0) 1036 error("tcsetpgrp failed, errno=%d\n", errno); 1037 } 1038 if (jp->state == JOBSTOPPED) 1039 setcurjob(jp); 1040 #endif 1041 status = jp->ps[jp->nprocs - 1].status; 1042 if (origstatus != NULL) 1043 *origstatus = status; 1044 /* convert to 8 bits */ 1045 if (WIFEXITED(status)) 1046 st = WEXITSTATUS(status); 1047 #if JOBS 1048 else if (WIFSTOPPED(status)) 1049 st = WSTOPSIG(status) + 128; 1050 #endif 1051 else 1052 st = WTERMSIG(status) + 128; 1053 if (! JOBS || jp->state == JOBDONE) 1054 freejob(jp); 1055 if (int_pending()) { 1056 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1057 CLEAR_PENDING_INT; 1058 } 1059 #if JOBS 1060 else if (rootshell && iflag && propagate_int && 1061 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1062 kill(getpid(), SIGINT); 1063 #endif 1064 INTON; 1065 return st; 1066 } 1067 1068 1069 static void 1070 dummy_handler(int sig __unused) 1071 { 1072 } 1073 1074 /* 1075 * Wait for a process to terminate. 1076 */ 1077 1078 static pid_t 1079 dowait(int mode, struct job *job) 1080 { 1081 struct sigaction sa, osa; 1082 sigset_t mask, omask; 1083 pid_t pid; 1084 int status; 1085 struct procstat *sp; 1086 struct job *jp; 1087 struct job *thisjob; 1088 const char *sigstr; 1089 int done; 1090 int stopped; 1091 int sig; 1092 int coredump; 1093 int wflags; 1094 int restore_sigchld; 1095 1096 TRACE(("dowait(%d, %p) called\n", mode, job)); 1097 restore_sigchld = 0; 1098 if ((mode & DOWAIT_SIG) != 0) { 1099 sigfillset(&mask); 1100 sigprocmask(SIG_BLOCK, &mask, &omask); 1101 INTOFF; 1102 if (!issigchldtrapped()) { 1103 restore_sigchld = 1; 1104 sa.sa_handler = dummy_handler; 1105 sa.sa_flags = 0; 1106 sigemptyset(&sa.sa_mask); 1107 sigaction(SIGCHLD, &sa, &osa); 1108 } 1109 } 1110 do { 1111 #if JOBS 1112 if (iflag) 1113 wflags = WUNTRACED | WCONTINUED; 1114 else 1115 #endif 1116 wflags = 0; 1117 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1118 wflags |= WNOHANG; 1119 pid = wait3(&status, wflags, (struct rusage *)NULL); 1120 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1121 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1122 pid = -1; 1123 if (((mode & DOWAIT_SIG_ANY) != 0 ? 1124 pendingsig : pendingsig_waitcmd) != 0) { 1125 errno = EINTR; 1126 break; 1127 } 1128 sigsuspend(&omask); 1129 if (int_pending()) 1130 break; 1131 } 1132 } while (pid == -1 && errno == EINTR); 1133 if (pid == -1 && errno == ECHILD && job != NULL) 1134 job->state = JOBDONE; 1135 if ((mode & DOWAIT_SIG) != 0) { 1136 if (restore_sigchld) 1137 sigaction(SIGCHLD, &osa, NULL); 1138 sigprocmask(SIG_SETMASK, &omask, NULL); 1139 INTON; 1140 } 1141 if (pid <= 0) 1142 return pid; 1143 INTOFF; 1144 thisjob = NULL; 1145 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1146 if (jp->used && jp->nprocs > 0) { 1147 done = 1; 1148 stopped = 1; 1149 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1150 if (sp->pid == -1) 1151 continue; 1152 if (sp->pid == pid && (sp->status == -1 || 1153 WIFSTOPPED(sp->status))) { 1154 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1155 (int)pid, sp->status, 1156 status)); 1157 if (WIFCONTINUED(status)) { 1158 sp->status = -1; 1159 jp->state = 0; 1160 } else 1161 sp->status = status; 1162 thisjob = jp; 1163 } 1164 if (sp->status == -1) 1165 stopped = 0; 1166 else if (WIFSTOPPED(sp->status)) 1167 done = 0; 1168 } 1169 if (stopped) { /* stopped or done */ 1170 int state = done? JOBDONE : JOBSTOPPED; 1171 if (jp->state != state) { 1172 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1173 jp->state = state; 1174 if (jp != job) { 1175 if (done && !jp->remembered && 1176 !iflag && jp != bgjob) 1177 freejob(jp); 1178 #if JOBS 1179 else if (done) 1180 deljob(jp); 1181 #endif 1182 } 1183 } 1184 } 1185 } 1186 } 1187 INTON; 1188 if (!thisjob || thisjob->state == 0) 1189 ; 1190 else if ((!rootshell || !iflag || thisjob == job) && 1191 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1192 sig = 0; 1193 coredump = 0; 1194 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1195 if (WIFSIGNALED(sp->status)) { 1196 sig = WTERMSIG(sp->status); 1197 coredump = WCOREDUMP(sp->status); 1198 } 1199 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1200 sigstr = strsignal(sig); 1201 if (sigstr != NULL) 1202 out2str(sigstr); 1203 else 1204 out2str("Unknown signal"); 1205 if (coredump) 1206 out2str(" (core dumped)"); 1207 out2c('\n'); 1208 flushout(out2); 1209 } 1210 } else { 1211 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1212 thisjob->changed = 1; 1213 } 1214 return pid; 1215 } 1216 1217 1218 1219 /* 1220 * return 1 if there are stopped jobs, otherwise 0 1221 */ 1222 int job_warning = 0; 1223 int 1224 stoppedjobs(void) 1225 { 1226 int jobno; 1227 struct job *jp; 1228 1229 if (job_warning) 1230 return (0); 1231 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1232 if (jp->used == 0) 1233 continue; 1234 if (jp->state == JOBSTOPPED) { 1235 out2fmt_flush("You have stopped jobs.\n"); 1236 job_warning = 2; 1237 return (1); 1238 } 1239 } 1240 1241 return (0); 1242 } 1243 1244 1245 static void 1246 checkzombies(void) 1247 { 1248 while (njobs > 0 && dowait(0, NULL) > 0) 1249 ; 1250 } 1251 1252 1253 int 1254 backgndpidset(void) 1255 { 1256 return backgndpid != -1; 1257 } 1258 1259 1260 pid_t 1261 backgndpidval(void) 1262 { 1263 if (bgjob != NULL && !forcelocal) 1264 bgjob->remembered = 1; 1265 return backgndpid; 1266 } 1267 1268 /* 1269 * Return a string identifying a command (to be printed by the 1270 * jobs command. 1271 */ 1272 1273 static char *cmdnextc; 1274 static int cmdnleft; 1275 #define MAXCMDTEXT 200 1276 1277 char * 1278 commandtext(union node *n) 1279 { 1280 char *name; 1281 1282 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1283 cmdnleft = MAXCMDTEXT - 4; 1284 cmdtxt(n); 1285 *cmdnextc = '\0'; 1286 return name; 1287 } 1288 1289 1290 static void 1291 cmdtxtdogroup(union node *n) 1292 { 1293 cmdputs("; do "); 1294 cmdtxt(n); 1295 cmdputs("; done"); 1296 } 1297 1298 1299 static void 1300 cmdtxtredir(union node *n, const char *op, int deffd) 1301 { 1302 char s[2]; 1303 1304 if (n->nfile.fd != deffd) { 1305 s[0] = n->nfile.fd + '0'; 1306 s[1] = '\0'; 1307 cmdputs(s); 1308 } 1309 cmdputs(op); 1310 if (n->type == NTOFD || n->type == NFROMFD) { 1311 if (n->ndup.dupfd >= 0) 1312 s[0] = n->ndup.dupfd + '0'; 1313 else 1314 s[0] = '-'; 1315 s[1] = '\0'; 1316 cmdputs(s); 1317 } else { 1318 cmdtxt(n->nfile.fname); 1319 } 1320 } 1321 1322 1323 static void 1324 cmdtxt(union node *n) 1325 { 1326 union node *np; 1327 struct nodelist *lp; 1328 1329 if (n == NULL) 1330 return; 1331 switch (n->type) { 1332 case NSEMI: 1333 cmdtxt(n->nbinary.ch1); 1334 cmdputs("; "); 1335 cmdtxt(n->nbinary.ch2); 1336 break; 1337 case NAND: 1338 cmdtxt(n->nbinary.ch1); 1339 cmdputs(" && "); 1340 cmdtxt(n->nbinary.ch2); 1341 break; 1342 case NOR: 1343 cmdtxt(n->nbinary.ch1); 1344 cmdputs(" || "); 1345 cmdtxt(n->nbinary.ch2); 1346 break; 1347 case NPIPE: 1348 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1349 cmdtxt(lp->n); 1350 if (lp->next) 1351 cmdputs(" | "); 1352 } 1353 break; 1354 case NSUBSHELL: 1355 cmdputs("("); 1356 cmdtxt(n->nredir.n); 1357 cmdputs(")"); 1358 break; 1359 case NREDIR: 1360 case NBACKGND: 1361 cmdtxt(n->nredir.n); 1362 break; 1363 case NIF: 1364 cmdputs("if "); 1365 cmdtxt(n->nif.test); 1366 cmdputs("; then "); 1367 cmdtxt(n->nif.ifpart); 1368 cmdputs("..."); 1369 break; 1370 case NWHILE: 1371 cmdputs("while "); 1372 cmdtxt(n->nbinary.ch1); 1373 cmdtxtdogroup(n->nbinary.ch2); 1374 break; 1375 case NUNTIL: 1376 cmdputs("until "); 1377 cmdtxt(n->nbinary.ch1); 1378 cmdtxtdogroup(n->nbinary.ch2); 1379 break; 1380 case NFOR: 1381 cmdputs("for "); 1382 cmdputs(n->nfor.var); 1383 cmdputs(" in ..."); 1384 break; 1385 case NCASE: 1386 cmdputs("case "); 1387 cmdputs(n->ncase.expr->narg.text); 1388 cmdputs(" in ..."); 1389 break; 1390 case NDEFUN: 1391 cmdputs(n->narg.text); 1392 cmdputs("() ..."); 1393 break; 1394 case NNOT: 1395 cmdputs("! "); 1396 cmdtxt(n->nnot.com); 1397 break; 1398 case NCMD: 1399 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1400 cmdtxt(np); 1401 if (np->narg.next) 1402 cmdputs(" "); 1403 } 1404 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1405 cmdputs(" "); 1406 cmdtxt(np); 1407 } 1408 break; 1409 case NARG: 1410 cmdputs(n->narg.text); 1411 break; 1412 case NTO: 1413 cmdtxtredir(n, ">", 1); 1414 break; 1415 case NAPPEND: 1416 cmdtxtredir(n, ">>", 1); 1417 break; 1418 case NTOFD: 1419 cmdtxtredir(n, ">&", 1); 1420 break; 1421 case NCLOBBER: 1422 cmdtxtredir(n, ">|", 1); 1423 break; 1424 case NFROM: 1425 cmdtxtredir(n, "<", 0); 1426 break; 1427 case NFROMTO: 1428 cmdtxtredir(n, "<>", 0); 1429 break; 1430 case NFROMFD: 1431 cmdtxtredir(n, "<&", 0); 1432 break; 1433 case NHERE: 1434 case NXHERE: 1435 cmdputs("<<..."); 1436 break; 1437 default: 1438 cmdputs("???"); 1439 break; 1440 } 1441 } 1442 1443 1444 1445 static void 1446 cmdputs(const char *s) 1447 { 1448 const char *p; 1449 char *q; 1450 char c; 1451 int subtype = 0; 1452 1453 if (cmdnleft <= 0) 1454 return; 1455 p = s; 1456 q = cmdnextc; 1457 while ((c = *p++) != '\0') { 1458 if (c == CTLESC) 1459 *q++ = *p++; 1460 else if (c == CTLVAR) { 1461 *q++ = '$'; 1462 if (--cmdnleft > 0) 1463 *q++ = '{'; 1464 subtype = *p++; 1465 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1466 *q++ = '#'; 1467 } else if (c == '=' && subtype != 0) { 1468 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1469 if (*q) 1470 q++; 1471 else 1472 cmdnleft++; 1473 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1474 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1475 --cmdnleft > 0) 1476 *q = q[-1], q++; 1477 subtype = 0; 1478 } else if (c == CTLENDVAR) { 1479 *q++ = '}'; 1480 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1481 cmdnleft -= 5; 1482 if (cmdnleft > 0) { 1483 *q++ = '$'; 1484 *q++ = '('; 1485 *q++ = '.'; 1486 *q++ = '.'; 1487 *q++ = '.'; 1488 *q++ = ')'; 1489 } 1490 } else if (c == CTLARI) { 1491 cmdnleft -= 2; 1492 if (cmdnleft > 0) { 1493 *q++ = '$'; 1494 *q++ = '('; 1495 *q++ = '('; 1496 } 1497 p++; 1498 } else if (c == CTLENDARI) { 1499 if (--cmdnleft > 0) { 1500 *q++ = ')'; 1501 *q++ = ')'; 1502 } 1503 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1504 cmdnleft++; /* ignore */ 1505 else 1506 *q++ = c; 1507 if (--cmdnleft <= 0) { 1508 *q++ = '.'; 1509 *q++ = '.'; 1510 *q++ = '.'; 1511 break; 1512 } 1513 } 1514 cmdnextc = q; 1515 } 1516