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(char *); 99 static struct job *getjob(char *); 100 pid_t getjobpgrp(char *); 101 static pid_t dowait(int, struct job *); 102 static void checkzombies(void); 103 static void cmdtxt(union node *); 104 static void cmdputs(const char *); 105 #if JOBS 106 static void setcurjob(struct job *); 107 static void deljob(struct job *); 108 static struct job *getcurjob(struct job *); 109 #endif 110 static void printjobcmd(struct job *); 111 static void showjob(struct job *, int); 112 113 114 /* 115 * Turn job control on and off. 116 */ 117 118 static int jobctl; 119 120 #if JOBS 121 void 122 setjobctl(int on) 123 { 124 int i; 125 126 if (on == jobctl || rootshell == 0) 127 return; 128 if (on) { 129 if (ttyfd != -1) 130 close(ttyfd); 131 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 132 i = 0; 133 while (i <= 2 && !isatty(i)) 134 i++; 135 if (i > 2 || 136 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) 137 goto out; 138 } 139 if (ttyfd < 10) { 140 /* 141 * Keep our TTY file descriptor out of the way of 142 * the user's redirections. 143 */ 144 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 145 close(ttyfd); 146 ttyfd = -1; 147 goto out; 148 } 149 close(ttyfd); 150 ttyfd = i; 151 } 152 do { /* while we are in the background */ 153 initialpgrp = tcgetpgrp(ttyfd); 154 if (initialpgrp < 0) { 155 out: out2fmt_flush("sh: can't access tty; job control turned off\n"); 156 mflag = 0; 157 return; 158 } 159 if (initialpgrp != getpgrp()) { 160 kill(0, SIGTTIN); 161 continue; 162 } 163 } while (0); 164 setsignal(SIGTSTP); 165 setsignal(SIGTTOU); 166 setsignal(SIGTTIN); 167 setpgid(0, rootpid); 168 tcsetpgrp(ttyfd, rootpid); 169 } else { /* turning job control off */ 170 setpgid(0, initialpgrp); 171 tcsetpgrp(ttyfd, initialpgrp); 172 close(ttyfd); 173 ttyfd = -1; 174 setsignal(SIGTSTP); 175 setsignal(SIGTTOU); 176 setsignal(SIGTTIN); 177 } 178 jobctl = on; 179 } 180 #endif 181 182 183 #if JOBS 184 int 185 fgcmd(int argc __unused, char **argv __unused) 186 { 187 struct job *jp; 188 pid_t pgrp; 189 int status; 190 191 nextopt(""); 192 jp = getjob(*argptr); 193 if (jp->jobctl == 0) 194 error("job not created under job control"); 195 printjobcmd(jp); 196 flushout(&output); 197 pgrp = jp->ps[0].pid; 198 tcsetpgrp(ttyfd, pgrp); 199 restartjob(jp); 200 jp->foreground = 1; 201 INTOFF; 202 status = waitforjob(jp, (int *)NULL); 203 INTON; 204 return status; 205 } 206 207 208 int 209 bgcmd(int argc, char **argv) 210 { 211 struct job *jp; 212 213 nextopt(""); 214 do { 215 jp = getjob(*argptr); 216 if (jp->jobctl == 0) 217 error("job not created under job control"); 218 if (jp->state == JOBDONE) 219 continue; 220 restartjob(jp); 221 jp->foreground = 0; 222 out1fmt("[%td] ", jp - jobtab + 1); 223 printjobcmd(jp); 224 } while (*argptr != NULL && *++argptr != NULL); 225 return 0; 226 } 227 228 229 static void 230 restartjob(struct job *jp) 231 { 232 struct procstat *ps; 233 int i; 234 235 if (jp->state == JOBDONE) 236 return; 237 setcurjob(jp); 238 INTOFF; 239 kill(-jp->ps[0].pid, SIGCONT); 240 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 241 if (WIFSTOPPED(ps->status)) { 242 ps->status = -1; 243 jp->state = 0; 244 } 245 } 246 INTON; 247 } 248 #endif 249 250 251 int 252 jobscmd(int argc __unused, char *argv[] __unused) 253 { 254 char *id; 255 int ch, mode; 256 257 mode = SHOWJOBS_DEFAULT; 258 while ((ch = nextopt("lps")) != '\0') { 259 switch (ch) { 260 case 'l': 261 mode = SHOWJOBS_VERBOSE; 262 break; 263 case 'p': 264 mode = SHOWJOBS_PGIDS; 265 break; 266 case 's': 267 mode = SHOWJOBS_PIDS; 268 break; 269 } 270 } 271 272 if (*argptr == NULL) 273 showjobs(0, mode); 274 else 275 while ((id = *argptr++) != NULL) 276 showjob(getjob(id), mode); 277 278 return (0); 279 } 280 281 static void 282 printjobcmd(struct job *jp) 283 { 284 struct procstat *ps; 285 int i; 286 287 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 288 out1str(ps->cmd); 289 if (i > 0) 290 out1str(" | "); 291 } 292 out1c('\n'); 293 } 294 295 static void 296 showjob(struct job *jp, int mode) 297 { 298 char s[64]; 299 char statestr[64]; 300 const char *sigstr; 301 struct procstat *ps; 302 struct job *j; 303 int col, curr, i, jobno, prev, procno; 304 char c; 305 306 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 307 jobno = jp - jobtab + 1; 308 curr = prev = 0; 309 #if JOBS 310 if ((j = getcurjob(NULL)) != NULL) { 311 curr = j - jobtab + 1; 312 if ((j = getcurjob(j)) != NULL) 313 prev = j - jobtab + 1; 314 } 315 #endif 316 ps = jp->ps + jp->nprocs - 1; 317 if (jp->state == 0) { 318 strcpy(statestr, "Running"); 319 #if JOBS 320 } else if (jp->state == JOBSTOPPED) { 321 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 322 ps--; 323 if (WIFSTOPPED(ps->status)) 324 i = WSTOPSIG(ps->status); 325 else 326 i = -1; 327 sigstr = strsignal(i); 328 if (sigstr != NULL) 329 strcpy(statestr, sigstr); 330 else 331 strcpy(statestr, "Suspended"); 332 #endif 333 } else if (WIFEXITED(ps->status)) { 334 if (WEXITSTATUS(ps->status) == 0) 335 strcpy(statestr, "Done"); 336 else 337 fmtstr(statestr, 64, "Done(%d)", 338 WEXITSTATUS(ps->status)); 339 } else { 340 i = WTERMSIG(ps->status); 341 sigstr = strsignal(i); 342 if (sigstr != NULL) 343 strcpy(statestr, sigstr); 344 else 345 strcpy(statestr, "Unknown signal"); 346 if (WCOREDUMP(ps->status)) 347 strcat(statestr, " (core dumped)"); 348 } 349 350 for (ps = jp->ps ; ; ps++) { /* for each process */ 351 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 352 out1fmt("%d\n", (int)ps->pid); 353 goto skip; 354 } 355 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 356 goto skip; 357 if (jobno == curr && ps == jp->ps) 358 c = '+'; 359 else if (jobno == prev && ps == jp->ps) 360 c = '-'; 361 else 362 c = ' '; 363 if (ps == jp->ps) 364 fmtstr(s, 64, "[%d] %c ", jobno, c); 365 else 366 fmtstr(s, 64, " %c ", c); 367 out1str(s); 368 col = strlen(s); 369 if (mode == SHOWJOBS_VERBOSE) { 370 fmtstr(s, 64, "%d ", (int)ps->pid); 371 out1str(s); 372 col += strlen(s); 373 } 374 if (ps == jp->ps) { 375 out1str(statestr); 376 col += strlen(statestr); 377 } 378 do { 379 out1c(' '); 380 col++; 381 } while (col < 30); 382 if (mode == SHOWJOBS_VERBOSE) { 383 out1str(ps->cmd); 384 out1c('\n'); 385 } else 386 printjobcmd(jp); 387 skip: if (--procno <= 0) 388 break; 389 } 390 } 391 392 /* 393 * Print a list of jobs. If "change" is nonzero, only print jobs whose 394 * statuses have changed since the last call to showjobs. 395 * 396 * If the shell is interrupted in the process of creating a job, the 397 * result may be a job structure containing zero processes. Such structures 398 * will be freed here. 399 */ 400 401 void 402 showjobs(int change, int mode) 403 { 404 int jobno; 405 struct job *jp; 406 407 TRACE(("showjobs(%d) called\n", change)); 408 checkzombies(); 409 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 410 if (! jp->used) 411 continue; 412 if (jp->nprocs == 0) { 413 freejob(jp); 414 continue; 415 } 416 if (change && ! jp->changed) 417 continue; 418 showjob(jp, mode); 419 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 420 jp->changed = 0; 421 /* Hack: discard jobs for which $! has not been 422 * referenced in interactive mode when they terminate. 423 */ 424 if (jp->state == JOBDONE && !jp->remembered && 425 (iflag || jp != bgjob)) { 426 freejob(jp); 427 } 428 } 429 } 430 } 431 432 433 /* 434 * Mark a job structure as unused. 435 */ 436 437 static void 438 freejob(struct job *jp) 439 { 440 struct procstat *ps; 441 int i; 442 443 INTOFF; 444 if (bgjob == jp) 445 bgjob = NULL; 446 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 447 if (ps->cmd != nullstr) 448 ckfree(ps->cmd); 449 } 450 if (jp->ps != &jp->ps0) 451 ckfree(jp->ps); 452 jp->used = 0; 453 #if JOBS 454 deljob(jp); 455 #endif 456 INTON; 457 } 458 459 460 461 int 462 waitcmd(int argc __unused, char **argv __unused) 463 { 464 struct job *job; 465 int retval; 466 467 nextopt(""); 468 if (*argptr == NULL) 469 return (waitcmdloop(NULL)); 470 471 do { 472 job = getjob_nonotfound(*argptr); 473 if (job == NULL) 474 retval = 127; 475 else 476 retval = waitcmdloop(job); 477 argptr++; 478 } while (*argptr != NULL); 479 480 return (retval); 481 } 482 483 static int 484 waitcmdloop(struct job *job) 485 { 486 int status, retval, sig; 487 struct job *jp; 488 489 /* 490 * Loop until a process is terminated or stopped, or a SIGINT is 491 * received. 492 */ 493 494 do { 495 if (job != NULL) { 496 if (job->state == JOBDONE) { 497 status = job->ps[job->nprocs - 1].status; 498 if (WIFEXITED(status)) 499 retval = WEXITSTATUS(status); 500 else 501 retval = WTERMSIG(status) + 128; 502 if (! iflag || ! job->changed) 503 freejob(job); 504 else { 505 job->remembered = 0; 506 if (job == bgjob) 507 bgjob = NULL; 508 } 509 return retval; 510 } 511 } else { 512 for (jp = jobtab ; jp < jobtab + njobs; jp++) 513 if (jp->used && jp->state == JOBDONE) { 514 if (! iflag || ! jp->changed) 515 freejob(jp); 516 else { 517 jp->remembered = 0; 518 if (jp == bgjob) 519 bgjob = NULL; 520 } 521 } 522 for (jp = jobtab ; ; jp++) { 523 if (jp >= jobtab + njobs) { /* no running procs */ 524 return 0; 525 } 526 if (jp->used && jp->state == 0) 527 break; 528 } 529 } 530 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 531 532 sig = pendingsig_waitcmd; 533 pendingsig_waitcmd = 0; 534 return sig + 128; 535 } 536 537 538 539 int 540 jobidcmd(int argc __unused, char **argv __unused) 541 { 542 struct job *jp; 543 int i; 544 545 nextopt(""); 546 jp = getjob(*argptr); 547 for (i = 0 ; i < jp->nprocs ; ) { 548 out1fmt("%d", (int)jp->ps[i].pid); 549 out1c(++i < jp->nprocs? ' ' : '\n'); 550 } 551 return 0; 552 } 553 554 555 556 /* 557 * Convert a job name to a job structure. 558 */ 559 560 static struct job * 561 getjob_nonotfound(char *name) 562 { 563 int jobno; 564 struct job *found, *jp; 565 pid_t pid; 566 int i; 567 568 if (name == NULL) { 569 #if JOBS 570 currentjob: if ((jp = getcurjob(NULL)) == NULL) 571 error("No current job"); 572 return (jp); 573 #else 574 error("No current job"); 575 #endif 576 } else if (name[0] == '%') { 577 if (is_digit(name[1])) { 578 jobno = number(name + 1); 579 if (jobno > 0 && jobno <= njobs 580 && jobtab[jobno - 1].used != 0) 581 return &jobtab[jobno - 1]; 582 #if JOBS 583 } else if (name[1] == '%' && name[2] == '\0') { 584 goto currentjob; 585 } else if (name[1] == '+' && name[2] == '\0') { 586 goto currentjob; 587 } else if (name[1] == '-' && name[2] == '\0') { 588 if ((jp = getcurjob(NULL)) == NULL || 589 (jp = getcurjob(jp)) == NULL) 590 error("No previous job"); 591 return (jp); 592 #endif 593 } else if (name[1] == '?') { 594 found = NULL; 595 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 596 if (jp->used && jp->nprocs > 0 597 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 598 if (found) 599 error("%s: ambiguous", name); 600 found = jp; 601 } 602 } 603 if (found != NULL) 604 return (found); 605 } else { 606 found = NULL; 607 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 608 if (jp->used && jp->nprocs > 0 609 && prefix(name + 1, jp->ps[0].cmd)) { 610 if (found) 611 error("%s: ambiguous", name); 612 found = jp; 613 } 614 } 615 if (found) 616 return found; 617 } 618 } else if (is_number(name)) { 619 pid = (pid_t)number(name); 620 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 621 if (jp->used && jp->nprocs > 0 622 && jp->ps[jp->nprocs - 1].pid == pid) 623 return jp; 624 } 625 } 626 return NULL; 627 } 628 629 630 static struct job * 631 getjob(char *name) 632 { 633 struct job *jp; 634 635 jp = getjob_nonotfound(name); 636 if (jp == NULL) 637 error("No such job: %s", name); 638 return (jp); 639 } 640 641 642 pid_t 643 getjobpgrp(char *name) 644 { 645 struct job *jp; 646 647 jp = getjob(name); 648 if (jp->state == JOBDONE) 649 return 0; 650 return -jp->ps[0].pid; 651 } 652 653 /* 654 * Return a new job structure, 655 */ 656 657 struct job * 658 makejob(union node *node __unused, int nprocs) 659 { 660 int i; 661 struct job *jp; 662 663 for (i = njobs, jp = jobtab ; ; jp++) { 664 if (--i < 0) { 665 INTOFF; 666 if (njobs == 0) { 667 jobtab = ckmalloc(4 * sizeof jobtab[0]); 668 #if JOBS 669 jobmru = NULL; 670 #endif 671 } else { 672 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 673 memcpy(jp, jobtab, njobs * sizeof jp[0]); 674 #if JOBS 675 /* Relocate `next' pointers and list head */ 676 if (jobmru != NULL) 677 jobmru = &jp[jobmru - jobtab]; 678 for (i = 0; i < njobs; i++) 679 if (jp[i].next != NULL) 680 jp[i].next = &jp[jp[i].next - 681 jobtab]; 682 #endif 683 if (bgjob != NULL) 684 bgjob = &jp[bgjob - jobtab]; 685 /* Relocate `ps' pointers */ 686 for (i = 0; i < njobs; i++) 687 if (jp[i].ps == &jobtab[i].ps0) 688 jp[i].ps = &jp[i].ps0; 689 ckfree(jobtab); 690 jobtab = jp; 691 } 692 jp = jobtab + njobs; 693 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 694 ; 695 INTON; 696 break; 697 } 698 if (jp->used == 0) 699 break; 700 } 701 INTOFF; 702 jp->state = 0; 703 jp->used = 1; 704 jp->changed = 0; 705 jp->nprocs = 0; 706 jp->foreground = 0; 707 jp->remembered = 0; 708 #if JOBS 709 jp->jobctl = jobctl; 710 jp->next = NULL; 711 #endif 712 if (nprocs > 1) { 713 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 714 } else { 715 jp->ps = &jp->ps0; 716 } 717 INTON; 718 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 719 jp - jobtab + 1)); 720 return jp; 721 } 722 723 #if JOBS 724 static void 725 setcurjob(struct job *cj) 726 { 727 struct job *jp, *prev; 728 729 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 730 if (jp == cj) { 731 if (prev != NULL) 732 prev->next = jp->next; 733 else 734 jobmru = jp->next; 735 jp->next = jobmru; 736 jobmru = cj; 737 return; 738 } 739 } 740 cj->next = jobmru; 741 jobmru = cj; 742 } 743 744 static void 745 deljob(struct job *j) 746 { 747 struct job *jp, *prev; 748 749 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 750 if (jp == j) { 751 if (prev != NULL) 752 prev->next = jp->next; 753 else 754 jobmru = jp->next; 755 return; 756 } 757 } 758 } 759 760 /* 761 * Return the most recently used job that isn't `nj', and preferably one 762 * that is stopped. 763 */ 764 static struct job * 765 getcurjob(struct job *nj) 766 { 767 struct job *jp; 768 769 /* Try to find a stopped one.. */ 770 for (jp = jobmru; jp != NULL; jp = jp->next) 771 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 772 return (jp); 773 /* Otherwise the most recently used job that isn't `nj' */ 774 for (jp = jobmru; jp != NULL; jp = jp->next) 775 if (jp->used && jp != nj) 776 return (jp); 777 778 return (NULL); 779 } 780 781 #endif 782 783 /* 784 * Fork of a subshell. If we are doing job control, give the subshell its 785 * own process group. Jp is a job structure that the job is to be added to. 786 * N is the command that will be evaluated by the child. Both jp and n may 787 * be NULL. The mode parameter can be one of the following: 788 * FORK_FG - Fork off a foreground process. 789 * FORK_BG - Fork off a background process. 790 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 791 * process group even if job control is on. 792 * 793 * When job control is turned off, background processes have their standard 794 * input redirected to /dev/null (except for the second and later processes 795 * in a pipeline). 796 */ 797 798 pid_t 799 forkshell(struct job *jp, union node *n, int mode) 800 { 801 pid_t pid; 802 pid_t pgrp; 803 804 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 805 mode)); 806 INTOFF; 807 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 808 checkzombies(); 809 flushall(); 810 pid = fork(); 811 if (pid == -1) { 812 TRACE(("Fork failed, errno=%d\n", errno)); 813 INTON; 814 error("Cannot fork: %s", strerror(errno)); 815 } 816 if (pid == 0) { 817 struct job *p; 818 int wasroot; 819 int i; 820 821 TRACE(("Child shell %d\n", (int)getpid())); 822 wasroot = rootshell; 823 rootshell = 0; 824 handler = &main_handler; 825 closescript(); 826 INTON; 827 forcelocal = 0; 828 clear_traps(); 829 #if JOBS 830 jobctl = 0; /* do job control only in root shell */ 831 if (wasroot && mode != FORK_NOJOB && mflag) { 832 if (jp == NULL || jp->nprocs == 0) 833 pgrp = getpid(); 834 else 835 pgrp = jp->ps[0].pid; 836 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 837 /*** this causes superfluous TIOCSPGRPS ***/ 838 if (tcsetpgrp(ttyfd, pgrp) < 0) 839 error("tcsetpgrp failed, errno=%d", errno); 840 } 841 setsignal(SIGTSTP); 842 setsignal(SIGTTOU); 843 } else if (mode == FORK_BG) { 844 ignoresig(SIGINT); 845 ignoresig(SIGQUIT); 846 if ((jp == NULL || jp->nprocs == 0) && 847 ! fd0_redirected_p ()) { 848 close(0); 849 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 850 error("cannot open %s: %s", 851 _PATH_DEVNULL, strerror(errno)); 852 } 853 } 854 #else 855 if (mode == FORK_BG) { 856 ignoresig(SIGINT); 857 ignoresig(SIGQUIT); 858 if ((jp == NULL || jp->nprocs == 0) && 859 ! fd0_redirected_p ()) { 860 close(0); 861 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 862 error("cannot open %s: %s", 863 _PATH_DEVNULL, strerror(errno)); 864 } 865 } 866 #endif 867 INTOFF; 868 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 869 if (p->used) 870 freejob(p); 871 INTON; 872 if (wasroot && iflag) { 873 setsignal(SIGINT); 874 setsignal(SIGQUIT); 875 setsignal(SIGTERM); 876 } 877 return pid; 878 } 879 if (rootshell && mode != FORK_NOJOB && mflag) { 880 if (jp == NULL || jp->nprocs == 0) 881 pgrp = pid; 882 else 883 pgrp = jp->ps[0].pid; 884 setpgid(pid, pgrp); 885 } 886 if (mode == FORK_BG) { 887 if (bgjob != NULL && bgjob->state == JOBDONE && 888 !bgjob->remembered && !iflag) 889 freejob(bgjob); 890 backgndpid = pid; /* set $! */ 891 bgjob = jp; 892 } 893 if (jp) { 894 struct procstat *ps = &jp->ps[jp->nprocs++]; 895 ps->pid = pid; 896 ps->status = -1; 897 ps->cmd = nullstr; 898 if (iflag && rootshell && n) 899 ps->cmd = commandtext(n); 900 jp->foreground = mode == FORK_FG; 901 #if JOBS 902 setcurjob(jp); 903 #endif 904 } 905 INTON; 906 TRACE(("In parent shell: child = %d\n", (int)pid)); 907 return pid; 908 } 909 910 911 pid_t 912 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 913 { 914 pid_t pid; 915 struct jmploc jmploc; 916 struct jmploc *savehandler; 917 918 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 919 (void *)pip)); 920 INTOFF; 921 flushall(); 922 savehandler = handler; 923 pid = vfork(); 924 if (pid == -1) { 925 TRACE(("Vfork failed, errno=%d\n", errno)); 926 INTON; 927 error("Cannot fork: %s", strerror(errno)); 928 } 929 if (pid == 0) { 930 TRACE(("Child shell %d\n", (int)getpid())); 931 if (setjmp(jmploc.loc)) 932 _exit(exception == EXEXEC ? exerrno : 2); 933 if (pip != NULL) { 934 close(pip[0]); 935 if (pip[1] != 1) { 936 dup2(pip[1], 1); 937 close(pip[1]); 938 } 939 } 940 handler = &jmploc; 941 shellexec(argv, envp, path, idx); 942 } 943 handler = savehandler; 944 if (jp) { 945 struct procstat *ps = &jp->ps[jp->nprocs++]; 946 ps->pid = pid; 947 ps->status = -1; 948 ps->cmd = nullstr; 949 jp->foreground = 1; 950 #if JOBS 951 setcurjob(jp); 952 #endif 953 } 954 INTON; 955 TRACE(("In parent shell: child = %d\n", (int)pid)); 956 return pid; 957 } 958 959 960 /* 961 * Wait for job to finish. 962 * 963 * Under job control we have the problem that while a child process is 964 * running interrupts generated by the user are sent to the child but not 965 * to the shell. This means that an infinite loop started by an inter- 966 * active user may be hard to kill. With job control turned off, an 967 * interactive user may place an interactive program inside a loop. If 968 * the interactive program catches interrupts, the user doesn't want 969 * these interrupts to also abort the loop. The approach we take here 970 * is to have the shell ignore interrupt signals while waiting for a 971 * foreground process to terminate, and then send itself an interrupt 972 * signal if the child process was terminated by an interrupt signal. 973 * Unfortunately, some programs want to do a bit of cleanup and then 974 * exit on interrupt; unless these processes terminate themselves by 975 * sending a signal to themselves (instead of calling exit) they will 976 * confuse this approach. 977 */ 978 979 int 980 waitforjob(struct job *jp, int *origstatus) 981 { 982 #if JOBS 983 int propagate_int = jp->jobctl && jp->foreground; 984 #endif 985 int status; 986 int st; 987 988 INTOFF; 989 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 990 while (jp->state == 0) 991 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 992 DOWAIT_SIG_ANY : 0), jp) == -1) 993 dotrap(); 994 #if JOBS 995 if (jp->jobctl) { 996 if (tcsetpgrp(ttyfd, rootpid) < 0) 997 error("tcsetpgrp failed, errno=%d\n", errno); 998 } 999 if (jp->state == JOBSTOPPED) 1000 setcurjob(jp); 1001 #endif 1002 status = jp->ps[jp->nprocs - 1].status; 1003 if (origstatus != NULL) 1004 *origstatus = status; 1005 /* convert to 8 bits */ 1006 if (WIFEXITED(status)) 1007 st = WEXITSTATUS(status); 1008 #if JOBS 1009 else if (WIFSTOPPED(status)) 1010 st = WSTOPSIG(status) + 128; 1011 #endif 1012 else 1013 st = WTERMSIG(status) + 128; 1014 if (! JOBS || jp->state == JOBDONE) 1015 freejob(jp); 1016 if (int_pending()) { 1017 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1018 CLEAR_PENDING_INT; 1019 } 1020 #if JOBS 1021 else if (rootshell && iflag && propagate_int && 1022 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1023 kill(getpid(), SIGINT); 1024 #endif 1025 INTON; 1026 return st; 1027 } 1028 1029 1030 static void 1031 dummy_handler(int sig __unused) 1032 { 1033 } 1034 1035 /* 1036 * Wait for a process to terminate. 1037 */ 1038 1039 static pid_t 1040 dowait(int mode, struct job *job) 1041 { 1042 struct sigaction sa, osa; 1043 sigset_t mask, omask; 1044 pid_t pid; 1045 int status; 1046 struct procstat *sp; 1047 struct job *jp; 1048 struct job *thisjob; 1049 const char *sigstr; 1050 int done; 1051 int stopped; 1052 int sig; 1053 int coredump; 1054 int wflags; 1055 int restore_sigchld; 1056 1057 TRACE(("dowait(%d, %p) called\n", mode, job)); 1058 restore_sigchld = 0; 1059 if ((mode & DOWAIT_SIG) != 0) { 1060 sigfillset(&mask); 1061 sigprocmask(SIG_BLOCK, &mask, &omask); 1062 INTOFF; 1063 if (!issigchldtrapped()) { 1064 restore_sigchld = 1; 1065 sa.sa_handler = dummy_handler; 1066 sa.sa_flags = 0; 1067 sigemptyset(&sa.sa_mask); 1068 sigaction(SIGCHLD, &sa, &osa); 1069 } 1070 } 1071 do { 1072 #if JOBS 1073 if (iflag) 1074 wflags = WUNTRACED | WCONTINUED; 1075 else 1076 #endif 1077 wflags = 0; 1078 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1079 wflags |= WNOHANG; 1080 pid = wait3(&status, wflags, (struct rusage *)NULL); 1081 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1082 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1083 pid = -1; 1084 if (((mode & DOWAIT_SIG_ANY) != 0 ? 1085 pendingsig : pendingsig_waitcmd) != 0) { 1086 errno = EINTR; 1087 break; 1088 } 1089 sigsuspend(&omask); 1090 if (int_pending()) 1091 break; 1092 } 1093 } while (pid == -1 && errno == EINTR); 1094 if (pid == -1 && errno == ECHILD && job != NULL) 1095 job->state = JOBDONE; 1096 if ((mode & DOWAIT_SIG) != 0) { 1097 if (restore_sigchld) 1098 sigaction(SIGCHLD, &osa, NULL); 1099 sigprocmask(SIG_SETMASK, &omask, NULL); 1100 INTON; 1101 } 1102 if (pid <= 0) 1103 return pid; 1104 INTOFF; 1105 thisjob = NULL; 1106 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1107 if (jp->used && jp->nprocs > 0) { 1108 done = 1; 1109 stopped = 1; 1110 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1111 if (sp->pid == -1) 1112 continue; 1113 if (sp->pid == pid) { 1114 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1115 (int)pid, sp->status, 1116 status)); 1117 if (WIFCONTINUED(status)) { 1118 sp->status = -1; 1119 jp->state = 0; 1120 } else 1121 sp->status = status; 1122 thisjob = jp; 1123 } 1124 if (sp->status == -1) 1125 stopped = 0; 1126 else if (WIFSTOPPED(sp->status)) 1127 done = 0; 1128 } 1129 if (stopped) { /* stopped or done */ 1130 int state = done? JOBDONE : JOBSTOPPED; 1131 if (jp->state != state) { 1132 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1133 jp->state = state; 1134 if (jp != job) { 1135 if (done && !jp->remembered && 1136 !iflag && jp != bgjob) 1137 freejob(jp); 1138 #if JOBS 1139 else if (done) 1140 deljob(jp); 1141 #endif 1142 } 1143 } 1144 } 1145 } 1146 } 1147 INTON; 1148 if (!thisjob || thisjob->state == 0) 1149 ; 1150 else if ((!rootshell || !iflag || thisjob == job) && 1151 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1152 sig = 0; 1153 coredump = 0; 1154 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1155 if (WIFSIGNALED(sp->status)) { 1156 sig = WTERMSIG(sp->status); 1157 coredump = WCOREDUMP(sp->status); 1158 } 1159 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1160 sigstr = strsignal(sig); 1161 if (sigstr != NULL) 1162 out2str(sigstr); 1163 else 1164 out2str("Unknown signal"); 1165 if (coredump) 1166 out2str(" (core dumped)"); 1167 out2c('\n'); 1168 flushout(out2); 1169 } 1170 } else { 1171 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1172 thisjob->changed = 1; 1173 } 1174 return pid; 1175 } 1176 1177 1178 1179 /* 1180 * return 1 if there are stopped jobs, otherwise 0 1181 */ 1182 int job_warning = 0; 1183 int 1184 stoppedjobs(void) 1185 { 1186 int jobno; 1187 struct job *jp; 1188 1189 if (job_warning) 1190 return (0); 1191 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1192 if (jp->used == 0) 1193 continue; 1194 if (jp->state == JOBSTOPPED) { 1195 out2fmt_flush("You have stopped jobs.\n"); 1196 job_warning = 2; 1197 return (1); 1198 } 1199 } 1200 1201 return (0); 1202 } 1203 1204 1205 static void 1206 checkzombies(void) 1207 { 1208 while (njobs > 0 && dowait(0, NULL) > 0) 1209 ; 1210 } 1211 1212 1213 int 1214 backgndpidset(void) 1215 { 1216 return backgndpid != -1; 1217 } 1218 1219 1220 pid_t 1221 backgndpidval(void) 1222 { 1223 if (bgjob != NULL && !forcelocal) 1224 bgjob->remembered = 1; 1225 return backgndpid; 1226 } 1227 1228 /* 1229 * Return a string identifying a command (to be printed by the 1230 * jobs command. 1231 */ 1232 1233 static char *cmdnextc; 1234 static int cmdnleft; 1235 #define MAXCMDTEXT 200 1236 1237 char * 1238 commandtext(union node *n) 1239 { 1240 char *name; 1241 1242 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1243 cmdnleft = MAXCMDTEXT - 4; 1244 cmdtxt(n); 1245 *cmdnextc = '\0'; 1246 return name; 1247 } 1248 1249 1250 static void 1251 cmdtxt(union node *n) 1252 { 1253 union node *np; 1254 struct nodelist *lp; 1255 const char *p; 1256 int i; 1257 char s[2]; 1258 1259 if (n == NULL) 1260 return; 1261 switch (n->type) { 1262 case NSEMI: 1263 cmdtxt(n->nbinary.ch1); 1264 cmdputs("; "); 1265 cmdtxt(n->nbinary.ch2); 1266 break; 1267 case NAND: 1268 cmdtxt(n->nbinary.ch1); 1269 cmdputs(" && "); 1270 cmdtxt(n->nbinary.ch2); 1271 break; 1272 case NOR: 1273 cmdtxt(n->nbinary.ch1); 1274 cmdputs(" || "); 1275 cmdtxt(n->nbinary.ch2); 1276 break; 1277 case NPIPE: 1278 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1279 cmdtxt(lp->n); 1280 if (lp->next) 1281 cmdputs(" | "); 1282 } 1283 break; 1284 case NSUBSHELL: 1285 cmdputs("("); 1286 cmdtxt(n->nredir.n); 1287 cmdputs(")"); 1288 break; 1289 case NREDIR: 1290 case NBACKGND: 1291 cmdtxt(n->nredir.n); 1292 break; 1293 case NIF: 1294 cmdputs("if "); 1295 cmdtxt(n->nif.test); 1296 cmdputs("; then "); 1297 cmdtxt(n->nif.ifpart); 1298 cmdputs("..."); 1299 break; 1300 case NWHILE: 1301 cmdputs("while "); 1302 goto until; 1303 case NUNTIL: 1304 cmdputs("until "); 1305 until: 1306 cmdtxt(n->nbinary.ch1); 1307 cmdputs("; do "); 1308 cmdtxt(n->nbinary.ch2); 1309 cmdputs("; done"); 1310 break; 1311 case NFOR: 1312 cmdputs("for "); 1313 cmdputs(n->nfor.var); 1314 cmdputs(" in ..."); 1315 break; 1316 case NCASE: 1317 cmdputs("case "); 1318 cmdputs(n->ncase.expr->narg.text); 1319 cmdputs(" in ..."); 1320 break; 1321 case NDEFUN: 1322 cmdputs(n->narg.text); 1323 cmdputs("() ..."); 1324 break; 1325 case NNOT: 1326 cmdputs("! "); 1327 cmdtxt(n->nnot.com); 1328 break; 1329 case NCMD: 1330 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1331 cmdtxt(np); 1332 if (np->narg.next) 1333 cmdputs(" "); 1334 } 1335 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1336 cmdputs(" "); 1337 cmdtxt(np); 1338 } 1339 break; 1340 case NARG: 1341 cmdputs(n->narg.text); 1342 break; 1343 case NTO: 1344 p = ">"; i = 1; goto redir; 1345 case NAPPEND: 1346 p = ">>"; i = 1; goto redir; 1347 case NTOFD: 1348 p = ">&"; i = 1; goto redir; 1349 case NCLOBBER: 1350 p = ">|"; i = 1; goto redir; 1351 case NFROM: 1352 p = "<"; i = 0; goto redir; 1353 case NFROMTO: 1354 p = "<>"; i = 0; goto redir; 1355 case NFROMFD: 1356 p = "<&"; i = 0; goto redir; 1357 redir: 1358 if (n->nfile.fd != i) { 1359 s[0] = n->nfile.fd + '0'; 1360 s[1] = '\0'; 1361 cmdputs(s); 1362 } 1363 cmdputs(p); 1364 if (n->type == NTOFD || n->type == NFROMFD) { 1365 if (n->ndup.dupfd >= 0) 1366 s[0] = n->ndup.dupfd + '0'; 1367 else 1368 s[0] = '-'; 1369 s[1] = '\0'; 1370 cmdputs(s); 1371 } else { 1372 cmdtxt(n->nfile.fname); 1373 } 1374 break; 1375 case NHERE: 1376 case NXHERE: 1377 cmdputs("<<..."); 1378 break; 1379 default: 1380 cmdputs("???"); 1381 break; 1382 } 1383 } 1384 1385 1386 1387 static void 1388 cmdputs(const char *s) 1389 { 1390 const char *p; 1391 char *q; 1392 char c; 1393 int subtype = 0; 1394 1395 if (cmdnleft <= 0) 1396 return; 1397 p = s; 1398 q = cmdnextc; 1399 while ((c = *p++) != '\0') { 1400 if (c == CTLESC) 1401 *q++ = *p++; 1402 else if (c == CTLVAR) { 1403 *q++ = '$'; 1404 if (--cmdnleft > 0) 1405 *q++ = '{'; 1406 subtype = *p++; 1407 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1408 *q++ = '#'; 1409 } else if (c == '=' && subtype != 0) { 1410 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1411 if (*q) 1412 q++; 1413 else 1414 cmdnleft++; 1415 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1416 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1417 --cmdnleft > 0) 1418 *q = q[-1], q++; 1419 subtype = 0; 1420 } else if (c == CTLENDVAR) { 1421 *q++ = '}'; 1422 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1423 cmdnleft -= 5; 1424 if (cmdnleft > 0) { 1425 *q++ = '$'; 1426 *q++ = '('; 1427 *q++ = '.'; 1428 *q++ = '.'; 1429 *q++ = '.'; 1430 *q++ = ')'; 1431 } 1432 } else if (c == CTLARI) { 1433 cmdnleft -= 2; 1434 if (cmdnleft > 0) { 1435 *q++ = '$'; 1436 *q++ = '('; 1437 *q++ = '('; 1438 } 1439 p++; 1440 } else if (c == CTLENDARI) { 1441 if (--cmdnleft > 0) { 1442 *q++ = ')'; 1443 *q++ = ')'; 1444 } 1445 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1446 cmdnleft++; /* ignore */ 1447 else 1448 *q++ = c; 1449 if (--cmdnleft <= 0) { 1450 *q++ = '.'; 1451 *q++ = '.'; 1452 *q++ = '.'; 1453 break; 1454 } 1455 } 1456 cmdnextc = q; 1457 } 1458