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