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