1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 4. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/ioctl.h> 42 #include <sys/param.h> 43 #include <sys/resource.h> 44 #include <sys/time.h> 45 #include <sys/wait.h> 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <paths.h> 49 #include <signal.h> 50 #include <stddef.h> 51 #include <stdlib.h> 52 #include <unistd.h> 53 54 #include "shell.h" 55 #if JOBS 56 #include <termios.h> 57 #undef CEOF /* syntax.h redefines this */ 58 #endif 59 #include "redir.h" 60 #include "exec.h" 61 #include "show.h" 62 #include "main.h" 63 #include "parser.h" 64 #include "nodes.h" 65 #include "jobs.h" 66 #include "options.h" 67 #include "trap.h" 68 #include "syntax.h" 69 #include "input.h" 70 #include "output.h" 71 #include "memalloc.h" 72 #include "error.h" 73 #include "mystring.h" 74 #include "var.h" 75 #include "builtins.h" 76 77 78 static struct job *jobtab; /* array of jobs */ 79 static int njobs; /* size of array */ 80 MKINIT pid_t backgndpid = -1; /* pid of last background process */ 81 MKINIT struct job *bgjob = NULL; /* last background process */ 82 #if JOBS 83 static struct job *jobmru; /* most recently used job list */ 84 static pid_t initialpgrp; /* pgrp of shell on invocation */ 85 #endif 86 int in_waitcmd = 0; /* are we in waitcmd()? */ 87 volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 88 static int ttyfd = -1; 89 90 /* mode flags for dowait */ 91 #define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 92 #define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signals */ 93 94 #if JOBS 95 static void restartjob(struct job *); 96 #endif 97 static void freejob(struct job *); 98 static int waitcmdloop(struct job *); 99 static struct job *getjob_nonotfound(char *); 100 static struct job *getjob(char *); 101 pid_t getjobpgrp(char *); 102 static pid_t dowait(int, struct job *); 103 static void checkzombies(void); 104 static void cmdtxt(union node *); 105 static void cmdputs(const char *); 106 #if JOBS 107 static void setcurjob(struct job *); 108 static void deljob(struct job *); 109 static struct job *getcurjob(struct job *); 110 #endif 111 static void printjobcmd(struct job *); 112 static void showjob(struct job *, int); 113 114 115 /* 116 * Turn job control on and off. 117 */ 118 119 MKINIT int jobctl; 120 121 #if JOBS 122 void 123 setjobctl(int on) 124 { 125 int i; 126 127 if (on == jobctl || rootshell == 0) 128 return; 129 if (on) { 130 if (ttyfd != -1) 131 close(ttyfd); 132 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 133 i = 0; 134 while (i <= 2 && !isatty(i)) 135 i++; 136 if (i > 2 || 137 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) 138 goto out; 139 } 140 if (ttyfd < 10) { 141 /* 142 * Keep our TTY file descriptor out of the way of 143 * the user's redirections. 144 */ 145 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 146 close(ttyfd); 147 ttyfd = -1; 148 goto out; 149 } 150 close(ttyfd); 151 ttyfd = i; 152 } 153 do { /* while we are in the background */ 154 initialpgrp = tcgetpgrp(ttyfd); 155 if (initialpgrp < 0) { 156 out: out2fmt_flush("sh: can't access tty; job control turned off\n"); 157 mflag = 0; 158 return; 159 } 160 if (initialpgrp != getpgrp()) { 161 kill(0, SIGTTIN); 162 continue; 163 } 164 } while (0); 165 setsignal(SIGTSTP); 166 setsignal(SIGTTOU); 167 setsignal(SIGTTIN); 168 setpgid(0, rootpid); 169 tcsetpgrp(ttyfd, rootpid); 170 } else { /* turning job control off */ 171 setpgid(0, initialpgrp); 172 tcsetpgrp(ttyfd, initialpgrp); 173 close(ttyfd); 174 ttyfd = -1; 175 setsignal(SIGTSTP); 176 setsignal(SIGTTOU); 177 setsignal(SIGTTIN); 178 } 179 jobctl = on; 180 } 181 #endif 182 183 184 #if JOBS 185 int 186 fgcmd(int argc __unused, char **argv) 187 { 188 struct job *jp; 189 pid_t pgrp; 190 int status; 191 192 jp = getjob(argv[1]); 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 do { 214 jp = getjob(*++argv); 215 if (jp->jobctl == 0) 216 error("job not created under job control"); 217 if (jp->state == JOBDONE) 218 continue; 219 restartjob(jp); 220 jp->foreground = 0; 221 out1fmt("[%td] ", jp - jobtab + 1); 222 printjobcmd(jp); 223 } while (--argc > 1); 224 return 0; 225 } 226 227 228 static void 229 restartjob(struct job *jp) 230 { 231 struct procstat *ps; 232 int i; 233 234 if (jp->state == JOBDONE) 235 return; 236 setcurjob(jp); 237 INTOFF; 238 kill(-jp->ps[0].pid, SIGCONT); 239 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 240 if (WIFSTOPPED(ps->status)) { 241 ps->status = -1; 242 jp->state = 0; 243 } 244 } 245 INTON; 246 } 247 #endif 248 249 250 int 251 jobscmd(int argc __unused, char *argv[] __unused) 252 { 253 char *id; 254 int ch, mode; 255 256 mode = SHOWJOBS_DEFAULT; 257 while ((ch = nextopt("lps")) != '\0') { 258 switch (ch) { 259 case 'l': 260 mode = SHOWJOBS_VERBOSE; 261 break; 262 case 'p': 263 mode = SHOWJOBS_PGIDS; 264 break; 265 case 's': 266 mode = SHOWJOBS_PIDS; 267 break; 268 } 269 } 270 271 if (*argptr == NULL) 272 showjobs(0, mode); 273 else 274 while ((id = *argptr++) != NULL) 275 showjob(getjob(id), mode); 276 277 return (0); 278 } 279 280 static void 281 printjobcmd(struct job *jp) 282 { 283 struct procstat *ps; 284 int i; 285 286 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 287 out1str(ps->cmd); 288 if (i > 0) 289 out1str(" | "); 290 } 291 out1c('\n'); 292 } 293 294 static void 295 showjob(struct job *jp, int mode) 296 { 297 char s[64]; 298 char statestr[64]; 299 const char *sigstr; 300 struct procstat *ps; 301 struct job *j; 302 int col, curr, i, jobno, prev, procno; 303 char c; 304 305 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 306 jobno = jp - jobtab + 1; 307 curr = prev = 0; 308 #if JOBS 309 if ((j = getcurjob(NULL)) != NULL) { 310 curr = j - jobtab + 1; 311 if ((j = getcurjob(j)) != NULL) 312 prev = j - jobtab + 1; 313 } 314 #endif 315 ps = jp->ps + jp->nprocs - 1; 316 if (jp->state == 0) { 317 strcpy(statestr, "Running"); 318 #if JOBS 319 } else if (jp->state == JOBSTOPPED) { 320 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 321 ps--; 322 if (WIFSTOPPED(ps->status)) 323 i = WSTOPSIG(ps->status); 324 else 325 i = -1; 326 sigstr = strsignal(i); 327 if (sigstr != NULL) 328 strcpy(statestr, sigstr); 329 else 330 strcpy(statestr, "Suspended"); 331 #endif 332 } else if (WIFEXITED(ps->status)) { 333 if (WEXITSTATUS(ps->status) == 0) 334 strcpy(statestr, "Done"); 335 else 336 fmtstr(statestr, 64, "Done(%d)", 337 WEXITSTATUS(ps->status)); 338 } else { 339 i = WTERMSIG(ps->status); 340 sigstr = strsignal(i); 341 if (sigstr != NULL) 342 strcpy(statestr, sigstr); 343 else 344 strcpy(statestr, "Unknown signal"); 345 if (WCOREDUMP(ps->status)) 346 strcat(statestr, " (core dumped)"); 347 } 348 349 for (ps = jp->ps ; ; ps++) { /* for each process */ 350 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 351 out1fmt("%d\n", (int)ps->pid); 352 goto skip; 353 } 354 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 355 goto skip; 356 if (jobno == curr && ps == jp->ps) 357 c = '+'; 358 else if (jobno == prev && ps == jp->ps) 359 c = '-'; 360 else 361 c = ' '; 362 if (ps == jp->ps) 363 fmtstr(s, 64, "[%d] %c ", jobno, c); 364 else 365 fmtstr(s, 64, " %c ", c); 366 out1str(s); 367 col = strlen(s); 368 if (mode == SHOWJOBS_VERBOSE) { 369 fmtstr(s, 64, "%d ", (int)ps->pid); 370 out1str(s); 371 col += strlen(s); 372 } 373 if (ps == jp->ps) { 374 out1str(statestr); 375 col += strlen(statestr); 376 } 377 do { 378 out1c(' '); 379 col++; 380 } while (col < 30); 381 if (mode == SHOWJOBS_VERBOSE) { 382 out1str(ps->cmd); 383 out1c('\n'); 384 } else 385 printjobcmd(jp); 386 skip: if (--procno <= 0) 387 break; 388 } 389 } 390 391 /* 392 * Print a list of jobs. If "change" is nonzero, only print jobs whose 393 * statuses have changed since the last call to showjobs. 394 * 395 * If the shell is interrupted in the process of creating a job, the 396 * result may be a job structure containing zero processes. Such structures 397 * will be freed here. 398 */ 399 400 void 401 showjobs(int change, int mode) 402 { 403 int jobno; 404 struct job *jp; 405 406 TRACE(("showjobs(%d) called\n", change)); 407 checkzombies(); 408 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 409 if (! jp->used) 410 continue; 411 if (jp->nprocs == 0) { 412 freejob(jp); 413 continue; 414 } 415 if (change && ! jp->changed) 416 continue; 417 showjob(jp, mode); 418 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 419 jp->changed = 0; 420 /* Hack: discard jobs for which $! has not been 421 * referenced in interactive mode when they terminate. 422 */ 423 if (jp->state == JOBDONE && !jp->remembered && 424 (iflag || jp != bgjob)) { 425 freejob(jp); 426 } 427 } 428 } 429 } 430 431 432 /* 433 * Mark a job structure as unused. 434 */ 435 436 static void 437 freejob(struct job *jp) 438 { 439 struct procstat *ps; 440 int i; 441 442 INTOFF; 443 if (bgjob == jp) 444 bgjob = NULL; 445 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 446 if (ps->cmd != nullstr) 447 ckfree(ps->cmd); 448 } 449 if (jp->ps != &jp->ps0) 450 ckfree(jp->ps); 451 jp->used = 0; 452 #if JOBS 453 deljob(jp); 454 #endif 455 INTON; 456 } 457 458 459 460 int 461 waitcmd(int argc __unused, char **argv __unused) 462 { 463 struct job *job; 464 int retval; 465 466 nextopt(""); 467 if (*argptr == NULL) 468 return (waitcmdloop(NULL)); 469 470 do { 471 job = getjob_nonotfound(*argptr); 472 if (job == NULL) 473 retval = 127; 474 else 475 retval = waitcmdloop(job); 476 argptr++; 477 } while (*argptr != NULL); 478 479 return (retval); 480 } 481 482 static int 483 waitcmdloop(struct job *job) 484 { 485 int status, retval; 486 struct job *jp; 487 488 /* 489 * Loop until a process is terminated or stopped, or a SIGINT is 490 * received. 491 */ 492 493 in_waitcmd++; 494 do { 495 if (job != NULL) { 496 if (job->state) { 497 status = job->ps[job->nprocs - 1].status; 498 if (WIFEXITED(status)) 499 retval = WEXITSTATUS(status); 500 #if JOBS 501 else if (WIFSTOPPED(status)) 502 retval = WSTOPSIG(status) + 128; 503 #endif 504 else 505 retval = WTERMSIG(status) + 128; 506 if (! iflag || ! job->changed) 507 freejob(job); 508 else { 509 job->remembered = 0; 510 if (job == bgjob) 511 bgjob = NULL; 512 } 513 in_waitcmd--; 514 return retval; 515 } 516 } else { 517 for (jp = jobtab ; jp < jobtab + njobs; jp++) 518 if (jp->used && jp->state == JOBDONE) { 519 if (! iflag || ! jp->changed) 520 freejob(jp); 521 else { 522 jp->remembered = 0; 523 if (jp == bgjob) 524 bgjob = NULL; 525 } 526 } 527 for (jp = jobtab ; ; jp++) { 528 if (jp >= jobtab + njobs) { /* no running procs */ 529 in_waitcmd--; 530 return 0; 531 } 532 if (jp->used && jp->state == 0) 533 break; 534 } 535 } 536 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 537 in_waitcmd--; 538 539 return pendingsig + 128; 540 } 541 542 543 544 int 545 jobidcmd(int argc __unused, char **argv) 546 { 547 struct job *jp; 548 int i; 549 550 jp = getjob(argv[1]); 551 for (i = 0 ; i < jp->nprocs ; ) { 552 out1fmt("%d", (int)jp->ps[i].pid); 553 out1c(++i < jp->nprocs? ' ' : '\n'); 554 } 555 return 0; 556 } 557 558 559 560 /* 561 * Convert a job name to a job structure. 562 */ 563 564 static struct job * 565 getjob_nonotfound(char *name) 566 { 567 int jobno; 568 struct job *found, *jp; 569 pid_t pid; 570 int i; 571 572 if (name == NULL) { 573 #if JOBS 574 currentjob: if ((jp = getcurjob(NULL)) == NULL) 575 error("No current job"); 576 return (jp); 577 #else 578 error("No current job"); 579 #endif 580 } else if (name[0] == '%') { 581 if (is_digit(name[1])) { 582 jobno = number(name + 1); 583 if (jobno > 0 && jobno <= njobs 584 && jobtab[jobno - 1].used != 0) 585 return &jobtab[jobno - 1]; 586 #if JOBS 587 } else if (name[1] == '%' && name[2] == '\0') { 588 goto currentjob; 589 } else if (name[1] == '+' && name[2] == '\0') { 590 goto currentjob; 591 } else if (name[1] == '-' && name[2] == '\0') { 592 if ((jp = getcurjob(NULL)) == NULL || 593 (jp = getcurjob(jp)) == NULL) 594 error("No previous job"); 595 return (jp); 596 #endif 597 } else if (name[1] == '?') { 598 found = NULL; 599 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 600 if (jp->used && jp->nprocs > 0 601 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 602 if (found) 603 error("%s: ambiguous", name); 604 found = jp; 605 } 606 } 607 if (found != NULL) 608 return (found); 609 } else { 610 found = NULL; 611 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 612 if (jp->used && jp->nprocs > 0 613 && prefix(name + 1, jp->ps[0].cmd)) { 614 if (found) 615 error("%s: ambiguous", name); 616 found = jp; 617 } 618 } 619 if (found) 620 return found; 621 } 622 } else if (is_number(name)) { 623 pid = (pid_t)number(name); 624 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 625 if (jp->used && jp->nprocs > 0 626 && jp->ps[jp->nprocs - 1].pid == pid) 627 return jp; 628 } 629 } 630 return NULL; 631 } 632 633 634 static struct job * 635 getjob(char *name) 636 { 637 struct job *jp; 638 639 jp = getjob_nonotfound(name); 640 if (jp == NULL) 641 error("No such job: %s", name); 642 return (jp); 643 } 644 645 646 pid_t 647 getjobpgrp(char *name) 648 { 649 struct job *jp; 650 651 jp = getjob(name); 652 return -jp->ps[0].pid; 653 } 654 655 /* 656 * Return a new job structure, 657 */ 658 659 struct job * 660 makejob(union node *node __unused, int nprocs) 661 { 662 int i; 663 struct job *jp; 664 665 for (i = njobs, jp = jobtab ; ; jp++) { 666 if (--i < 0) { 667 INTOFF; 668 if (njobs == 0) { 669 jobtab = ckmalloc(4 * sizeof jobtab[0]); 670 #if JOBS 671 jobmru = NULL; 672 #endif 673 } else { 674 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 675 memcpy(jp, jobtab, njobs * sizeof jp[0]); 676 #if JOBS 677 /* Relocate `next' pointers and list head */ 678 if (jobmru != NULL) 679 jobmru = &jp[jobmru - jobtab]; 680 for (i = 0; i < njobs; i++) 681 if (jp[i].next != NULL) 682 jp[i].next = &jp[jp[i].next - 683 jobtab]; 684 #endif 685 if (bgjob != NULL) 686 bgjob = &jp[bgjob - jobtab]; 687 /* Relocate `ps' pointers */ 688 for (i = 0; i < njobs; i++) 689 if (jp[i].ps == &jobtab[i].ps0) 690 jp[i].ps = &jp[i].ps0; 691 ckfree(jobtab); 692 jobtab = jp; 693 } 694 jp = jobtab + njobs; 695 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 696 ; 697 INTON; 698 break; 699 } 700 if (jp->used == 0) 701 break; 702 } 703 INTOFF; 704 jp->state = 0; 705 jp->used = 1; 706 jp->changed = 0; 707 jp->nprocs = 0; 708 jp->foreground = 0; 709 jp->remembered = 0; 710 #if JOBS 711 jp->jobctl = jobctl; 712 jp->next = NULL; 713 #endif 714 if (nprocs > 1) { 715 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 716 } else { 717 jp->ps = &jp->ps0; 718 } 719 INTON; 720 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 721 jp - jobtab + 1)); 722 return jp; 723 } 724 725 #if JOBS 726 static void 727 setcurjob(struct job *cj) 728 { 729 struct job *jp, *prev; 730 731 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 732 if (jp == cj) { 733 if (prev != NULL) 734 prev->next = jp->next; 735 else 736 jobmru = jp->next; 737 jp->next = jobmru; 738 jobmru = cj; 739 return; 740 } 741 } 742 cj->next = jobmru; 743 jobmru = cj; 744 } 745 746 static void 747 deljob(struct job *j) 748 { 749 struct job *jp, *prev; 750 751 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 752 if (jp == j) { 753 if (prev != NULL) 754 prev->next = jp->next; 755 else 756 jobmru = jp->next; 757 return; 758 } 759 } 760 } 761 762 /* 763 * Return the most recently used job that isn't `nj', and preferably one 764 * that is stopped. 765 */ 766 static struct job * 767 getcurjob(struct job *nj) 768 { 769 struct job *jp; 770 771 /* Try to find a stopped one.. */ 772 for (jp = jobmru; jp != NULL; jp = jp->next) 773 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 774 return (jp); 775 /* Otherwise the most recently used job that isn't `nj' */ 776 for (jp = jobmru; jp != NULL; jp = jp->next) 777 if (jp->used && jp != nj) 778 return (jp); 779 780 return (NULL); 781 } 782 783 #endif 784 785 /* 786 * Fork of a subshell. If we are doing job control, give the subshell its 787 * own process group. Jp is a job structure that the job is to be added to. 788 * N is the command that will be evaluated by the child. Both jp and n may 789 * be NULL. The mode parameter can be one of the following: 790 * FORK_FG - Fork off a foreground process. 791 * FORK_BG - Fork off a background process. 792 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 793 * process group even if job control is on. 794 * 795 * When job control is turned off, background processes have their standard 796 * input redirected to /dev/null (except for the second and later processes 797 * in a pipeline). 798 */ 799 800 pid_t 801 forkshell(struct job *jp, union node *n, int mode) 802 { 803 pid_t pid; 804 pid_t pgrp; 805 806 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 807 mode)); 808 INTOFF; 809 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 810 checkzombies(); 811 flushall(); 812 pid = fork(); 813 if (pid == -1) { 814 TRACE(("Fork failed, errno=%d\n", errno)); 815 INTON; 816 error("Cannot fork: %s", strerror(errno)); 817 } 818 if (pid == 0) { 819 struct job *p; 820 int wasroot; 821 int i; 822 823 TRACE(("Child shell %d\n", (int)getpid())); 824 wasroot = rootshell; 825 rootshell = 0; 826 handler = &main_handler; 827 closescript(); 828 INTON; 829 forcelocal = 0; 830 clear_traps(); 831 #if JOBS 832 jobctl = 0; /* do job control only in root shell */ 833 if (wasroot && mode != FORK_NOJOB && mflag) { 834 if (jp == NULL || jp->nprocs == 0) 835 pgrp = getpid(); 836 else 837 pgrp = jp->ps[0].pid; 838 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 839 /*** this causes superfluous TIOCSPGRPS ***/ 840 if (tcsetpgrp(ttyfd, pgrp) < 0) 841 error("tcsetpgrp failed, errno=%d", errno); 842 } 843 setsignal(SIGTSTP); 844 setsignal(SIGTTOU); 845 } else if (mode == FORK_BG) { 846 ignoresig(SIGINT); 847 ignoresig(SIGQUIT); 848 if ((jp == NULL || jp->nprocs == 0) && 849 ! fd0_redirected_p ()) { 850 close(0); 851 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 852 error("cannot open %s: %s", 853 _PATH_DEVNULL, strerror(errno)); 854 } 855 } 856 #else 857 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 #endif 869 INTOFF; 870 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 871 if (p->used) 872 freejob(p); 873 INTON; 874 if (wasroot && iflag) { 875 setsignal(SIGINT); 876 setsignal(SIGQUIT); 877 setsignal(SIGTERM); 878 } 879 return pid; 880 } 881 if (rootshell && mode != FORK_NOJOB && mflag) { 882 if (jp == NULL || jp->nprocs == 0) 883 pgrp = pid; 884 else 885 pgrp = jp->ps[0].pid; 886 setpgid(pid, pgrp); 887 } 888 if (mode == FORK_BG) { 889 if (bgjob != NULL && bgjob->state == JOBDONE && 890 !bgjob->remembered && !iflag) 891 freejob(bgjob); 892 backgndpid = pid; /* set $! */ 893 bgjob = jp; 894 } 895 if (jp) { 896 struct procstat *ps = &jp->ps[jp->nprocs++]; 897 ps->pid = pid; 898 ps->status = -1; 899 ps->cmd = nullstr; 900 if (iflag && rootshell && n) 901 ps->cmd = commandtext(n); 902 jp->foreground = mode == FORK_FG; 903 #if JOBS 904 setcurjob(jp); 905 #endif 906 } 907 INTON; 908 TRACE(("In parent shell: child = %d\n", (int)pid)); 909 return pid; 910 } 911 912 913 pid_t 914 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 915 { 916 pid_t pid; 917 struct jmploc jmploc; 918 struct jmploc *savehandler; 919 920 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 921 (void *)pip)); 922 INTOFF; 923 flushall(); 924 savehandler = handler; 925 pid = vfork(); 926 if (pid == -1) { 927 TRACE(("Vfork failed, errno=%d\n", errno)); 928 INTON; 929 error("Cannot fork: %s", strerror(errno)); 930 } 931 if (pid == 0) { 932 TRACE(("Child shell %d\n", (int)getpid())); 933 if (setjmp(jmploc.loc)) 934 _exit(exception == EXEXEC ? exerrno : 2); 935 if (pip != NULL) { 936 close(pip[0]); 937 if (pip[1] != 1) { 938 dup2(pip[1], 1); 939 close(pip[1]); 940 } 941 } 942 handler = &jmploc; 943 shellexec(argv, envp, path, idx); 944 } 945 handler = savehandler; 946 if (jp) { 947 struct procstat *ps = &jp->ps[jp->nprocs++]; 948 ps->pid = pid; 949 ps->status = -1; 950 ps->cmd = nullstr; 951 jp->foreground = 1; 952 #if JOBS 953 setcurjob(jp); 954 #endif 955 } 956 INTON; 957 TRACE(("In parent shell: child = %d\n", (int)pid)); 958 return pid; 959 } 960 961 962 /* 963 * Wait for job to finish. 964 * 965 * Under job control we have the problem that while a child process is 966 * running interrupts generated by the user are sent to the child but not 967 * to the shell. This means that an infinite loop started by an inter- 968 * active user may be hard to kill. With job control turned off, an 969 * interactive user may place an interactive program inside a loop. If 970 * the interactive program catches interrupts, the user doesn't want 971 * these interrupts to also abort the loop. The approach we take here 972 * is to have the shell ignore interrupt signals while waiting for a 973 * foreground process to terminate, and then send itself an interrupt 974 * signal if the child process was terminated by an interrupt signal. 975 * Unfortunately, some programs want to do a bit of cleanup and then 976 * exit on interrupt; unless these processes terminate themselves by 977 * sending a signal to themselves (instead of calling exit) they will 978 * confuse this approach. 979 */ 980 981 int 982 waitforjob(struct job *jp, int *origstatus) 983 { 984 #if JOBS 985 pid_t mypgrp = getpgrp(); 986 int propagate_int = jp->jobctl && jp->foreground; 987 #endif 988 int status; 989 int st; 990 991 INTOFF; 992 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 993 while (jp->state == 0) 994 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG : 0), jp) == -1) 995 dotrap(); 996 #if JOBS 997 if (jp->jobctl) { 998 if (tcsetpgrp(ttyfd, mypgrp) < 0) 999 error("tcsetpgrp failed, errno=%d\n", errno); 1000 } 1001 if (jp->state == JOBSTOPPED) 1002 setcurjob(jp); 1003 #endif 1004 status = jp->ps[jp->nprocs - 1].status; 1005 if (origstatus != NULL) 1006 *origstatus = status; 1007 /* convert to 8 bits */ 1008 if (WIFEXITED(status)) 1009 st = WEXITSTATUS(status); 1010 #if JOBS 1011 else if (WIFSTOPPED(status)) 1012 st = WSTOPSIG(status) + 128; 1013 #endif 1014 else 1015 st = WTERMSIG(status) + 128; 1016 if (! JOBS || jp->state == JOBDONE) 1017 freejob(jp); 1018 if (int_pending()) { 1019 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1020 CLEAR_PENDING_INT; 1021 } 1022 #if JOBS 1023 else if (rootshell && iflag && propagate_int && 1024 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1025 kill(getpid(), SIGINT); 1026 #endif 1027 INTON; 1028 return st; 1029 } 1030 1031 1032 static void 1033 dummy_handler(int sig __unused) 1034 { 1035 } 1036 1037 /* 1038 * Wait for a process to terminate. 1039 */ 1040 1041 static pid_t 1042 dowait(int mode, struct job *job) 1043 { 1044 struct sigaction sa, osa; 1045 sigset_t mask, omask; 1046 pid_t pid; 1047 int status; 1048 struct procstat *sp; 1049 struct job *jp; 1050 struct job *thisjob; 1051 const char *sigstr; 1052 int done; 1053 int stopped; 1054 int sig; 1055 int coredump; 1056 int wflags; 1057 int restore_sigchld; 1058 1059 TRACE(("dowait(%d, %p) called\n", mode, job)); 1060 restore_sigchld = 0; 1061 if ((mode & DOWAIT_SIG) != 0) { 1062 sigfillset(&mask); 1063 sigprocmask(SIG_BLOCK, &mask, &omask); 1064 INTOFF; 1065 if (!issigchldtrapped()) { 1066 restore_sigchld = 1; 1067 sa.sa_handler = dummy_handler; 1068 sa.sa_flags = 0; 1069 sigemptyset(&sa.sa_mask); 1070 sigaction(SIGCHLD, &sa, &osa); 1071 } 1072 } 1073 do { 1074 #if JOBS 1075 if (iflag) 1076 wflags = WUNTRACED | WCONTINUED; 1077 else 1078 #endif 1079 wflags = 0; 1080 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1081 wflags |= WNOHANG; 1082 pid = wait3(&status, wflags, (struct rusage *)NULL); 1083 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1084 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1085 sigsuspend(&omask); 1086 pid = -1; 1087 if (int_pending()) 1088 break; 1089 } 1090 } while (pid == -1 && errno == EINTR && breakwaitcmd == 0); 1091 if (pid == -1 && errno == ECHILD && job != NULL) 1092 job->state = JOBDONE; 1093 if ((mode & DOWAIT_SIG) != 0) { 1094 if (restore_sigchld) 1095 sigaction(SIGCHLD, &osa, NULL); 1096 sigprocmask(SIG_SETMASK, &omask, NULL); 1097 INTON; 1098 } 1099 if (breakwaitcmd != 0) { 1100 breakwaitcmd = 0; 1101 if (pid <= 0) 1102 return -1; 1103 } 1104 if (pid <= 0) 1105 return pid; 1106 INTOFF; 1107 thisjob = NULL; 1108 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1109 if (jp->used && jp->nprocs > 0) { 1110 done = 1; 1111 stopped = 1; 1112 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1113 if (sp->pid == -1) 1114 continue; 1115 if (sp->pid == pid) { 1116 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1117 (int)pid, sp->status, 1118 status)); 1119 if (WIFCONTINUED(status)) { 1120 sp->status = -1; 1121 jp->state = 0; 1122 } else 1123 sp->status = status; 1124 thisjob = jp; 1125 } 1126 if (sp->status == -1) 1127 stopped = 0; 1128 else if (WIFSTOPPED(sp->status)) 1129 done = 0; 1130 } 1131 if (stopped) { /* stopped or done */ 1132 int state = done? JOBDONE : JOBSTOPPED; 1133 if (jp->state != state) { 1134 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1135 jp->state = state; 1136 if (jp != job) { 1137 if (done && !jp->remembered && 1138 !iflag && jp != bgjob) 1139 freejob(jp); 1140 #if JOBS 1141 else if (done) 1142 deljob(jp); 1143 #endif 1144 } 1145 } 1146 } 1147 } 1148 } 1149 INTON; 1150 if (!thisjob || thisjob->state == 0) 1151 ; 1152 else if ((!rootshell || !iflag || thisjob == job) && 1153 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1154 sig = 0; 1155 coredump = 0; 1156 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1157 if (WIFSIGNALED(sp->status)) { 1158 sig = WTERMSIG(sp->status); 1159 coredump = WCOREDUMP(sp->status); 1160 } 1161 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1162 sigstr = strsignal(sig); 1163 if (sigstr != NULL) 1164 out2str(sigstr); 1165 else 1166 out2str("Unknown signal"); 1167 if (coredump) 1168 out2str(" (core dumped)"); 1169 out2c('\n'); 1170 flushout(out2); 1171 } 1172 } else { 1173 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1174 thisjob->changed = 1; 1175 } 1176 return pid; 1177 } 1178 1179 1180 1181 /* 1182 * return 1 if there are stopped jobs, otherwise 0 1183 */ 1184 int job_warning = 0; 1185 int 1186 stoppedjobs(void) 1187 { 1188 int jobno; 1189 struct job *jp; 1190 1191 if (job_warning) 1192 return (0); 1193 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1194 if (jp->used == 0) 1195 continue; 1196 if (jp->state == JOBSTOPPED) { 1197 out2fmt_flush("You have stopped jobs.\n"); 1198 job_warning = 2; 1199 return (1); 1200 } 1201 } 1202 1203 return (0); 1204 } 1205 1206 1207 static void 1208 checkzombies(void) 1209 { 1210 while (njobs > 0 && dowait(0, NULL) > 0) 1211 ; 1212 } 1213 1214 1215 int 1216 backgndpidset(void) 1217 { 1218 return backgndpid != -1; 1219 } 1220 1221 1222 pid_t 1223 backgndpidval(void) 1224 { 1225 if (bgjob != NULL && !forcelocal) 1226 bgjob->remembered = 1; 1227 return backgndpid; 1228 } 1229 1230 /* 1231 * Return a string identifying a command (to be printed by the 1232 * jobs command. 1233 */ 1234 1235 static char *cmdnextc; 1236 static int cmdnleft; 1237 #define MAXCMDTEXT 200 1238 1239 char * 1240 commandtext(union node *n) 1241 { 1242 char *name; 1243 1244 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1245 cmdnleft = MAXCMDTEXT - 4; 1246 cmdtxt(n); 1247 *cmdnextc = '\0'; 1248 return name; 1249 } 1250 1251 1252 static void 1253 cmdtxt(union node *n) 1254 { 1255 union node *np; 1256 struct nodelist *lp; 1257 const char *p; 1258 int i; 1259 char s[2]; 1260 1261 if (n == NULL) 1262 return; 1263 switch (n->type) { 1264 case NSEMI: 1265 cmdtxt(n->nbinary.ch1); 1266 cmdputs("; "); 1267 cmdtxt(n->nbinary.ch2); 1268 break; 1269 case NAND: 1270 cmdtxt(n->nbinary.ch1); 1271 cmdputs(" && "); 1272 cmdtxt(n->nbinary.ch2); 1273 break; 1274 case NOR: 1275 cmdtxt(n->nbinary.ch1); 1276 cmdputs(" || "); 1277 cmdtxt(n->nbinary.ch2); 1278 break; 1279 case NPIPE: 1280 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1281 cmdtxt(lp->n); 1282 if (lp->next) 1283 cmdputs(" | "); 1284 } 1285 break; 1286 case NSUBSHELL: 1287 cmdputs("("); 1288 cmdtxt(n->nredir.n); 1289 cmdputs(")"); 1290 break; 1291 case NREDIR: 1292 case NBACKGND: 1293 cmdtxt(n->nredir.n); 1294 break; 1295 case NIF: 1296 cmdputs("if "); 1297 cmdtxt(n->nif.test); 1298 cmdputs("; then "); 1299 cmdtxt(n->nif.ifpart); 1300 cmdputs("..."); 1301 break; 1302 case NWHILE: 1303 cmdputs("while "); 1304 goto until; 1305 case NUNTIL: 1306 cmdputs("until "); 1307 until: 1308 cmdtxt(n->nbinary.ch1); 1309 cmdputs("; do "); 1310 cmdtxt(n->nbinary.ch2); 1311 cmdputs("; done"); 1312 break; 1313 case NFOR: 1314 cmdputs("for "); 1315 cmdputs(n->nfor.var); 1316 cmdputs(" in ..."); 1317 break; 1318 case NCASE: 1319 cmdputs("case "); 1320 cmdputs(n->ncase.expr->narg.text); 1321 cmdputs(" in ..."); 1322 break; 1323 case NDEFUN: 1324 cmdputs(n->narg.text); 1325 cmdputs("() ..."); 1326 break; 1327 case NNOT: 1328 cmdputs("! "); 1329 cmdtxt(n->nnot.com); 1330 break; 1331 case NCMD: 1332 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1333 cmdtxt(np); 1334 if (np->narg.next) 1335 cmdputs(" "); 1336 } 1337 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1338 cmdputs(" "); 1339 cmdtxt(np); 1340 } 1341 break; 1342 case NARG: 1343 cmdputs(n->narg.text); 1344 break; 1345 case NTO: 1346 p = ">"; i = 1; goto redir; 1347 case NAPPEND: 1348 p = ">>"; i = 1; goto redir; 1349 case NTOFD: 1350 p = ">&"; i = 1; goto redir; 1351 case NCLOBBER: 1352 p = ">|"; i = 1; goto redir; 1353 case NFROM: 1354 p = "<"; i = 0; goto redir; 1355 case NFROMTO: 1356 p = "<>"; i = 0; goto redir; 1357 case NFROMFD: 1358 p = "<&"; i = 0; goto redir; 1359 redir: 1360 if (n->nfile.fd != i) { 1361 s[0] = n->nfile.fd + '0'; 1362 s[1] = '\0'; 1363 cmdputs(s); 1364 } 1365 cmdputs(p); 1366 if (n->type == NTOFD || n->type == NFROMFD) { 1367 if (n->ndup.dupfd >= 0) 1368 s[0] = n->ndup.dupfd + '0'; 1369 else 1370 s[0] = '-'; 1371 s[1] = '\0'; 1372 cmdputs(s); 1373 } else { 1374 cmdtxt(n->nfile.fname); 1375 } 1376 break; 1377 case NHERE: 1378 case NXHERE: 1379 cmdputs("<<..."); 1380 break; 1381 default: 1382 cmdputs("???"); 1383 break; 1384 } 1385 } 1386 1387 1388 1389 static void 1390 cmdputs(const char *s) 1391 { 1392 const char *p; 1393 char *q; 1394 char c; 1395 int subtype = 0; 1396 1397 if (cmdnleft <= 0) 1398 return; 1399 p = s; 1400 q = cmdnextc; 1401 while ((c = *p++) != '\0') { 1402 if (c == CTLESC) 1403 *q++ = *p++; 1404 else if (c == CTLVAR) { 1405 *q++ = '$'; 1406 if (--cmdnleft > 0) 1407 *q++ = '{'; 1408 subtype = *p++; 1409 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1410 *q++ = '#'; 1411 } else if (c == '=' && subtype != 0) { 1412 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1413 if (*q) 1414 q++; 1415 else 1416 cmdnleft++; 1417 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1418 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1419 --cmdnleft > 0) 1420 *q = q[-1], q++; 1421 subtype = 0; 1422 } else if (c == CTLENDVAR) { 1423 *q++ = '}'; 1424 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1425 cmdnleft -= 5; 1426 if (cmdnleft > 0) { 1427 *q++ = '$'; 1428 *q++ = '('; 1429 *q++ = '.'; 1430 *q++ = '.'; 1431 *q++ = '.'; 1432 *q++ = ')'; 1433 } 1434 } else if (c == CTLARI) { 1435 cmdnleft -= 2; 1436 if (cmdnleft > 0) { 1437 *q++ = '$'; 1438 *q++ = '('; 1439 *q++ = '('; 1440 } 1441 p++; 1442 } else if (c == CTLENDARI) { 1443 if (--cmdnleft > 0) { 1444 *q++ = ')'; 1445 *q++ = ')'; 1446 } 1447 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1448 cmdnleft++; /* ignore */ 1449 else 1450 *q++ = c; 1451 if (--cmdnleft <= 0) { 1452 *q++ = '.'; 1453 *q++ = '.'; 1454 *q++ = '.'; 1455 break; 1456 } 1457 } 1458 cmdnextc = q; 1459 } 1460