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 * 3. 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 * @(#)jobs.c 8.5 (Berkeley) 5/4/95 33 * $FreeBSD: head/bin/sh/jobs.c 253658 2013-07-25 19:48:15Z jilles $ 34 */ 35 36 #include <sys/ioctl.h> 37 #include <sys/param.h> 38 #include <sys/resource.h> 39 #include <sys/time.h> 40 #include <sys/wait.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <paths.h> 44 #include <signal.h> 45 #include <stddef.h> 46 #include <stdlib.h> 47 #include <unistd.h> 48 49 #include "shell.h" 50 #if JOBS 51 #include <termios.h> 52 #undef CEOF /* syntax.h redefines this */ 53 #endif 54 #include "redir.h" 55 #include "exec.h" 56 #include "show.h" 57 #include "main.h" 58 #include "parser.h" 59 #include "nodes.h" 60 #include "jobs.h" 61 #include "options.h" 62 #include "trap.h" 63 #include "syntax.h" 64 #include "input.h" 65 #include "output.h" 66 #include "memalloc.h" 67 #include "error.h" 68 #include "mystring.h" 69 #include "var.h" 70 #include "builtins.h" 71 72 73 static struct job *jobtab; /* array of jobs */ 74 static int njobs; /* size of array */ 75 static pid_t backgndpid = -1; /* pid of last background process */ 76 static struct job *bgjob = NULL; /* last background process */ 77 #if JOBS 78 static struct job *jobmru; /* most recently used job list */ 79 static pid_t initialpgrp; /* pgrp of shell on invocation */ 80 #endif 81 int in_waitcmd = 0; /* are we in waitcmd()? */ 82 volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 83 static int ttyfd = -1; 84 85 /* mode flags for dowait */ 86 #define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 87 #define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signals */ 88 89 #if JOBS 90 static void restartjob(struct job *); 91 #endif 92 static void freejob(struct job *); 93 static int waitcmdloop(struct job *); 94 static struct job *getjob_nonotfound(char *); 95 static struct job *getjob(char *); 96 static pid_t dowait(int, struct job *); 97 static void checkzombies(void); 98 static void cmdtxt(union node *); 99 static void cmdputs(const char *); 100 #if JOBS 101 static void setcurjob(struct job *); 102 static void deljob(struct job *); 103 static struct job *getcurjob(struct job *); 104 #endif 105 static void printjobcmd(struct job *); 106 static void showjob(struct job *, int); 107 108 109 /* 110 * Turn job control on and off. 111 */ 112 113 static int jobctl; 114 115 #if JOBS 116 void 117 setjobctl(int on) 118 { 119 int i; 120 121 if (on == jobctl || rootshell == 0) 122 return; 123 if (on) { 124 if (ttyfd != -1) 125 close(ttyfd); 126 #ifndef O_CLOEXEC 127 if ((ttyfd = open(_PATH_TTY, O_RDWR)) < 0) { 128 #else 129 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 130 #endif 131 i = 0; 132 while (i <= 2 && !isatty(i)) 133 i++; 134 if (i > 2 || 135 #ifndef F_DUPFD_CLOEXEC 136 (ttyfd = fcntl(i, F_DUPFD, 10)) < 0) 137 #else 138 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) 139 #endif 140 goto out; 141 } 142 if (ttyfd < 10) { 143 /* 144 * Keep our TTY file descriptor out of the way of 145 * the user's redirections. 146 */ 147 #ifndef F_DUPFD_CLOEXEC 148 if ((i = fcntl(ttyfd, F_DUPFD, 10)) < 0) { 149 #else 150 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 151 #endif 152 close(ttyfd); 153 ttyfd = -1; 154 goto out; 155 } 156 close(ttyfd); 157 ttyfd = i; 158 } 159 #if !defined(O_CLOEXEC) || !defined(F_DUPFD_CLOEXEC) 160 if (fcntl(ttyfd, F_SETFD, FD_CLOEXEC) < 0) { 161 close(ttyfd); 162 ttyfd = -1; 163 goto out; 164 } 165 #endif 166 do { /* while we are in the background */ 167 initialpgrp = tcgetpgrp(ttyfd); 168 if (initialpgrp < 0) { 169 out: out2fmt_flush("sh: can't access tty; job control turned off\n"); 170 mflag = 0; 171 return; 172 } 173 if (initialpgrp != getpgrp()) { 174 kill(0, SIGTTIN); 175 continue; 176 } 177 } while (0); 178 setsignal(SIGTSTP); 179 setsignal(SIGTTOU); 180 setsignal(SIGTTIN); 181 setpgid(0, rootpid); 182 tcsetpgrp(ttyfd, rootpid); 183 } else { /* turning job control off */ 184 setpgid(0, initialpgrp); 185 tcsetpgrp(ttyfd, initialpgrp); 186 close(ttyfd); 187 ttyfd = -1; 188 setsignal(SIGTSTP); 189 setsignal(SIGTTOU); 190 setsignal(SIGTTIN); 191 } 192 jobctl = on; 193 } 194 #endif 195 196 197 #if JOBS 198 int 199 fgcmd(int argc __unused, char **argv) 200 { 201 struct job *jp; 202 pid_t pgrp; 203 int status; 204 205 jp = getjob(argv[1]); 206 if (jp->jobctl == 0) 207 error("job not created under job control"); 208 printjobcmd(jp); 209 flushout(&output); 210 pgrp = jp->ps[0].pid; 211 tcsetpgrp(ttyfd, pgrp); 212 restartjob(jp); 213 jp->foreground = 1; 214 INTOFF; 215 status = waitforjob(jp, NULL); 216 INTON; 217 return status; 218 } 219 220 221 int 222 bgcmd(int argc, char **argv) 223 { 224 struct job *jp; 225 226 do { 227 jp = getjob(*++argv); 228 if (jp->jobctl == 0) 229 error("job not created under job control"); 230 if (jp->state == JOBDONE) 231 continue; 232 restartjob(jp); 233 jp->foreground = 0; 234 out1fmt("[%td] ", jp - jobtab + 1); 235 printjobcmd(jp); 236 } while (--argc > 1); 237 return 0; 238 } 239 240 241 static void 242 restartjob(struct job *jp) 243 { 244 struct procstat *ps; 245 int i; 246 247 if (jp->state == JOBDONE) 248 return; 249 setcurjob(jp); 250 INTOFF; 251 kill(-jp->ps[0].pid, SIGCONT); 252 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 253 if (WIFSTOPPED(ps->status)) { 254 ps->status = -1; 255 jp->state = 0; 256 } 257 } 258 INTON; 259 } 260 #endif 261 262 263 int 264 jobscmd(int argc __unused, char *argv[] __unused) 265 { 266 char *id; 267 int ch, mode; 268 269 mode = SHOWJOBS_DEFAULT; 270 while ((ch = nextopt("lps")) != '\0') { 271 switch (ch) { 272 case 'l': 273 mode = SHOWJOBS_VERBOSE; 274 break; 275 case 'p': 276 mode = SHOWJOBS_PGIDS; 277 break; 278 case 's': 279 mode = SHOWJOBS_PIDS; 280 break; 281 } 282 } 283 284 if (*argptr == NULL) 285 showjobs(0, mode); 286 else 287 while ((id = *argptr++) != NULL) 288 showjob(getjob(id), mode); 289 290 return (0); 291 } 292 293 static void 294 printjobcmd(struct job *jp) 295 { 296 struct procstat *ps; 297 int i; 298 299 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 300 out1str(ps->cmd); 301 if (i > 0) 302 out1str(" | "); 303 } 304 out1c('\n'); 305 } 306 307 static void 308 showjob(struct job *jp, int mode) 309 { 310 char s[64]; 311 char statestr[64]; 312 const char *sigstr; 313 struct procstat *ps; 314 struct job *j; 315 int col, curr, i, jobno, prev, procno; 316 char c; 317 318 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 319 jobno = jp - jobtab + 1; 320 curr = prev = 0; 321 #if JOBS 322 if ((j = getcurjob(NULL)) != NULL) { 323 curr = j - jobtab + 1; 324 if ((j = getcurjob(j)) != NULL) 325 prev = j - jobtab + 1; 326 } 327 #endif 328 ps = jp->ps + jp->nprocs - 1; 329 if (jp->state == 0) { 330 strcpy(statestr, "Running"); 331 #if JOBS 332 } else if (jp->state == JOBSTOPPED) { 333 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 334 ps--; 335 if (WIFSTOPPED(ps->status)) 336 i = WSTOPSIG(ps->status); 337 else 338 i = -1; 339 sigstr = strsignal(i); 340 if (sigstr != NULL) 341 strcpy(statestr, sigstr); 342 else 343 strcpy(statestr, "Suspended"); 344 #endif 345 } else if (WIFEXITED(ps->status)) { 346 if (WEXITSTATUS(ps->status) == 0) 347 strcpy(statestr, "Done"); 348 else 349 fmtstr(statestr, 64, "Done(%d)", 350 WEXITSTATUS(ps->status)); 351 } else { 352 i = WTERMSIG(ps->status); 353 sigstr = strsignal(i); 354 if (sigstr != NULL) 355 strcpy(statestr, sigstr); 356 else 357 strcpy(statestr, "Unknown signal"); 358 if (WCOREDUMP(ps->status)) 359 strcat(statestr, " (core dumped)"); 360 } 361 362 for (ps = jp->ps ; ; ps++) { /* for each process */ 363 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 364 out1fmt("%d\n", (int)ps->pid); 365 goto skip; 366 } 367 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 368 goto skip; 369 if (jobno == curr && ps == jp->ps) 370 c = '+'; 371 else if (jobno == prev && ps == jp->ps) 372 c = '-'; 373 else 374 c = ' '; 375 if (ps == jp->ps) 376 fmtstr(s, 64, "[%d] %c ", jobno, c); 377 else 378 fmtstr(s, 64, " %c ", c); 379 out1str(s); 380 col = strlen(s); 381 if (mode == SHOWJOBS_VERBOSE) { 382 fmtstr(s, 64, "%d ", (int)ps->pid); 383 out1str(s); 384 col += strlen(s); 385 } 386 if (ps == jp->ps) { 387 out1str(statestr); 388 col += strlen(statestr); 389 } 390 do { 391 out1c(' '); 392 col++; 393 } while (col < 30); 394 if (mode == SHOWJOBS_VERBOSE) { 395 out1str(ps->cmd); 396 out1c('\n'); 397 } else 398 printjobcmd(jp); 399 skip: if (--procno <= 0) 400 break; 401 } 402 } 403 404 /* 405 * Print a list of jobs. If "change" is nonzero, only print jobs whose 406 * statuses have changed since the last call to showjobs. 407 * 408 * If the shell is interrupted in the process of creating a job, the 409 * result may be a job structure containing zero processes. Such structures 410 * will be freed here. 411 */ 412 413 void 414 showjobs(int change, int mode) 415 { 416 int jobno; 417 struct job *jp; 418 419 TRACE(("showjobs(%d) called\n", change)); 420 checkzombies(); 421 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 422 if (! jp->used) 423 continue; 424 if (jp->nprocs == 0) { 425 freejob(jp); 426 continue; 427 } 428 if (change && ! jp->changed) 429 continue; 430 showjob(jp, mode); 431 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 432 jp->changed = 0; 433 /* Hack: discard jobs for which $! has not been 434 * referenced in interactive mode when they terminate. 435 */ 436 if (jp->state == JOBDONE && !jp->remembered && 437 (iflag || jp != bgjob)) { 438 freejob(jp); 439 } 440 } 441 } 442 } 443 444 445 /* 446 * Mark a job structure as unused. 447 */ 448 449 static void 450 freejob(struct job *jp) 451 { 452 struct procstat *ps; 453 int i; 454 455 INTOFF; 456 if (bgjob == jp) 457 bgjob = NULL; 458 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 459 if (ps->cmd != nullstr) 460 ckfree(ps->cmd); 461 } 462 if (jp->ps != &jp->ps0) 463 ckfree(jp->ps); 464 jp->used = 0; 465 #if JOBS 466 deljob(jp); 467 #endif 468 INTON; 469 } 470 471 472 473 int 474 waitcmd(int argc __unused, char **argv __unused) 475 { 476 struct job *job; 477 int retval; 478 479 nextopt(""); 480 if (*argptr == NULL) 481 return (waitcmdloop(NULL)); 482 483 do { 484 job = getjob_nonotfound(*argptr); 485 if (job == NULL) 486 retval = 127; 487 else 488 retval = waitcmdloop(job); 489 argptr++; 490 } while (*argptr != NULL); 491 492 return (retval); 493 } 494 495 static int 496 waitcmdloop(struct job *job) 497 { 498 int status, retval; 499 struct job *jp; 500 501 /* 502 * Loop until a process is terminated or stopped, or a SIGINT is 503 * received. 504 */ 505 506 in_waitcmd++; 507 do { 508 if (job != NULL) { 509 if (job->state) { 510 status = job->ps[job->nprocs - 1].status; 511 if (WIFEXITED(status)) 512 retval = WEXITSTATUS(status); 513 #if JOBS 514 else if (WIFSTOPPED(status)) 515 retval = WSTOPSIG(status) + 128; 516 #endif 517 else 518 retval = WTERMSIG(status) + 128; 519 if (! iflag || ! job->changed) 520 freejob(job); 521 else { 522 job->remembered = 0; 523 if (job == bgjob) 524 bgjob = NULL; 525 } 526 in_waitcmd--; 527 return retval; 528 } 529 } else { 530 for (jp = jobtab ; jp < jobtab + njobs; jp++) 531 if (jp->used && jp->state == JOBDONE) { 532 if (! iflag || ! jp->changed) 533 freejob(jp); 534 else { 535 jp->remembered = 0; 536 if (jp == bgjob) 537 bgjob = NULL; 538 } 539 } 540 for (jp = jobtab ; ; jp++) { 541 if (jp >= jobtab + njobs) { /* no running procs */ 542 in_waitcmd--; 543 return 0; 544 } 545 if (jp->used && jp->state == 0) 546 break; 547 } 548 } 549 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, NULL) != -1); 550 in_waitcmd--; 551 552 return pendingsig + 128; 553 } 554 555 556 557 int 558 jobidcmd(int argc __unused, char **argv) 559 { 560 struct job *jp; 561 int i; 562 563 jp = getjob(argv[1]); 564 for (i = 0 ; i < jp->nprocs ; ) { 565 out1fmt("%d", (int)jp->ps[i].pid); 566 out1c(++i < jp->nprocs? ' ' : '\n'); 567 } 568 return 0; 569 } 570 571 572 573 /* 574 * Convert a job name to a job structure. 575 */ 576 577 static struct job * 578 getjob_nonotfound(char *name) 579 { 580 int jobno; 581 struct job *found, *jp; 582 pid_t pid; 583 int i; 584 585 if (name == NULL) { 586 #if JOBS 587 currentjob: if ((jp = getcurjob(NULL)) == NULL) 588 error("No current job"); 589 return (jp); 590 #else 591 error("No current job"); 592 #endif 593 } else if (name[0] == '%') { 594 if (is_digit(name[1])) { 595 jobno = number(name + 1); 596 if (jobno > 0 && jobno <= njobs 597 && jobtab[jobno - 1].used != 0) 598 return &jobtab[jobno - 1]; 599 #if JOBS 600 } else if (name[1] == '%' && name[2] == '\0') { 601 goto currentjob; 602 } else if (name[1] == '+' && name[2] == '\0') { 603 goto currentjob; 604 } else if (name[1] == '-' && name[2] == '\0') { 605 if ((jp = getcurjob(NULL)) == NULL || 606 (jp = getcurjob(jp)) == NULL) 607 error("No previous job"); 608 return (jp); 609 #endif 610 } else if (name[1] == '?') { 611 found = NULL; 612 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 613 if (jp->used && jp->nprocs > 0 614 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 615 if (found) 616 error("%s: ambiguous", name); 617 found = jp; 618 } 619 } 620 if (found != NULL) 621 return (found); 622 } else { 623 found = NULL; 624 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 625 if (jp->used && jp->nprocs > 0 626 && prefix(name + 1, jp->ps[0].cmd)) { 627 if (found) 628 error("%s: ambiguous", name); 629 found = jp; 630 } 631 } 632 if (found) 633 return found; 634 } 635 } else if (is_number(name)) { 636 pid = (pid_t)number(name); 637 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 638 if (jp->used && jp->nprocs > 0 639 && jp->ps[jp->nprocs - 1].pid == pid) 640 return jp; 641 } 642 } 643 return NULL; 644 } 645 646 647 static struct job * 648 getjob(char *name) 649 { 650 struct job *jp; 651 652 jp = getjob_nonotfound(name); 653 if (jp == NULL) 654 error("No such job: %s", name); 655 return (jp); 656 } 657 658 659 pid_t 660 getjobpgrp(char *name) 661 { 662 struct job *jp; 663 664 jp = getjob(name); 665 return -jp->ps[0].pid; 666 } 667 668 /* 669 * Return a new job structure, 670 */ 671 672 struct job * 673 makejob(union node *node __unused, int nprocs) 674 { 675 int i; 676 struct job *jp; 677 678 for (i = njobs, jp = jobtab ; ; jp++) { 679 if (--i < 0) { 680 INTOFF; 681 if (njobs == 0) { 682 jobtab = ckmalloc(4 * sizeof jobtab[0]); 683 #if JOBS 684 jobmru = NULL; 685 #endif 686 } else { 687 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 688 memcpy(jp, jobtab, njobs * sizeof jp[0]); 689 #if JOBS 690 /* Relocate `next' pointers and list head */ 691 if (jobmru != NULL) 692 jobmru = &jp[jobmru - jobtab]; 693 for (i = 0; i < njobs; i++) 694 if (jp[i].next != NULL) 695 jp[i].next = &jp[jp[i].next - 696 jobtab]; 697 #endif 698 if (bgjob != NULL) 699 bgjob = &jp[bgjob - jobtab]; 700 /* Relocate `ps' pointers */ 701 for (i = 0; i < njobs; i++) 702 if (jp[i].ps == &jobtab[i].ps0) 703 jp[i].ps = &jp[i].ps0; 704 ckfree(jobtab); 705 jobtab = jp; 706 } 707 jp = jobtab + njobs; 708 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 709 ; 710 INTON; 711 break; 712 } 713 if (jp->used == 0) 714 break; 715 } 716 INTOFF; 717 jp->state = 0; 718 jp->used = 1; 719 jp->changed = 0; 720 jp->nprocs = 0; 721 jp->foreground = 0; 722 jp->remembered = 0; 723 #if JOBS 724 jp->jobctl = jobctl; 725 jp->next = NULL; 726 #endif 727 if (nprocs > 1) { 728 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 729 } else { 730 jp->ps = &jp->ps0; 731 } 732 INTON; 733 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 734 jp - jobtab + 1)); 735 return jp; 736 } 737 738 #if JOBS 739 static void 740 setcurjob(struct job *cj) 741 { 742 struct job *jp, *prev; 743 744 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 745 if (jp == cj) { 746 if (prev != NULL) 747 prev->next = jp->next; 748 else 749 jobmru = jp->next; 750 jp->next = jobmru; 751 jobmru = cj; 752 return; 753 } 754 } 755 cj->next = jobmru; 756 jobmru = cj; 757 } 758 759 static void 760 deljob(struct job *j) 761 { 762 struct job *jp, *prev; 763 764 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 765 if (jp == j) { 766 if (prev != NULL) 767 prev->next = jp->next; 768 else 769 jobmru = jp->next; 770 return; 771 } 772 } 773 } 774 775 /* 776 * Return the most recently used job that isn't `nj', and preferably one 777 * that is stopped. 778 */ 779 static struct job * 780 getcurjob(struct job *nj) 781 { 782 struct job *jp; 783 784 /* Try to find a stopped one.. */ 785 for (jp = jobmru; jp != NULL; jp = jp->next) 786 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 787 return (jp); 788 /* Otherwise the most recently used job that isn't `nj' */ 789 for (jp = jobmru; jp != NULL; jp = jp->next) 790 if (jp->used && jp != nj) 791 return (jp); 792 793 return (NULL); 794 } 795 796 #endif 797 798 /* 799 * Fork of a subshell. If we are doing job control, give the subshell its 800 * own process group. Jp is a job structure that the job is to be added to. 801 * N is the command that will be evaluated by the child. Both jp and n may 802 * be NULL. The mode parameter can be one of the following: 803 * FORK_FG - Fork off a foreground process. 804 * FORK_BG - Fork off a background process. 805 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 806 * process group even if job control is on. 807 * 808 * When job control is turned off, background processes have their standard 809 * input redirected to /dev/null (except for the second and later processes 810 * in a pipeline). 811 */ 812 813 pid_t 814 forkshell(struct job *jp, union node *n, int mode) 815 { 816 pid_t pid; 817 pid_t pgrp; 818 819 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 820 mode)); 821 INTOFF; 822 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 823 checkzombies(); 824 flushall(); 825 pid = fork(); 826 if (pid == -1) { 827 TRACE(("Fork failed, errno=%d\n", errno)); 828 INTON; 829 error("Cannot fork: %s", strerror(errno)); 830 } 831 if (pid == 0) { 832 struct job *p; 833 int wasroot; 834 int i; 835 836 TRACE(("Child shell %d\n", (int)getpid())); 837 wasroot = rootshell; 838 rootshell = 0; 839 handler = &main_handler; 840 closescript(); 841 INTON; 842 forcelocal = 0; 843 clear_traps(); 844 #if JOBS 845 jobctl = 0; /* do job control only in root shell */ 846 if (wasroot && mode != FORK_NOJOB && mflag) { 847 if (jp == NULL || jp->nprocs == 0) 848 pgrp = getpid(); 849 else 850 pgrp = jp->ps[0].pid; 851 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 852 /*** this causes superfluous TIOCSPGRPS ***/ 853 if (tcsetpgrp(ttyfd, pgrp) < 0) 854 error("tcsetpgrp failed, errno=%d", errno); 855 } 856 setsignal(SIGTSTP); 857 setsignal(SIGTTOU); 858 } else if (mode == FORK_BG) { 859 ignoresig(SIGINT); 860 ignoresig(SIGQUIT); 861 if ((jp == NULL || jp->nprocs == 0) && 862 ! fd0_redirected_p ()) { 863 close(0); 864 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 865 error("cannot open %s: %s", 866 _PATH_DEVNULL, strerror(errno)); 867 } 868 } 869 #else 870 if (mode == FORK_BG) { 871 ignoresig(SIGINT); 872 ignoresig(SIGQUIT); 873 if ((jp == NULL || jp->nprocs == 0) && 874 ! fd0_redirected_p ()) { 875 close(0); 876 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 877 error("cannot open %s: %s", 878 _PATH_DEVNULL, strerror(errno)); 879 } 880 } 881 #endif 882 INTOFF; 883 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 884 if (p->used) 885 freejob(p); 886 INTON; 887 if (wasroot && iflag) { 888 setsignal(SIGINT); 889 setsignal(SIGQUIT); 890 setsignal(SIGTERM); 891 } 892 return pid; 893 } 894 if (rootshell && mode != FORK_NOJOB && mflag) { 895 if (jp == NULL || jp->nprocs == 0) 896 pgrp = pid; 897 else 898 pgrp = jp->ps[0].pid; 899 setpgid(pid, pgrp); 900 } 901 if (mode == FORK_BG) { 902 if (bgjob != NULL && bgjob->state == JOBDONE && 903 !bgjob->remembered && !iflag) 904 freejob(bgjob); 905 backgndpid = pid; /* set $! */ 906 bgjob = jp; 907 } 908 if (jp) { 909 struct procstat *ps = &jp->ps[jp->nprocs++]; 910 ps->pid = pid; 911 ps->status = -1; 912 ps->cmd = nullstr; 913 if (iflag && rootshell && n) 914 ps->cmd = commandtext(n); 915 jp->foreground = mode == FORK_FG; 916 #if JOBS 917 setcurjob(jp); 918 #endif 919 } 920 INTON; 921 TRACE(("In parent shell: child = %d\n", (int)pid)); 922 return pid; 923 } 924 925 926 pid_t 927 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 928 { 929 pid_t pid; 930 struct jmploc jmploc; 931 struct jmploc *savehandler; 932 933 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 934 (void *)pip)); 935 INTOFF; 936 flushall(); 937 savehandler = handler; 938 pid = vfork(); 939 if (pid == -1) { 940 TRACE(("Vfork failed, errno=%d\n", errno)); 941 INTON; 942 error("Cannot fork: %s", strerror(errno)); 943 } 944 if (pid == 0) { 945 TRACE(("Child shell %d\n", (int)getpid())); 946 if (setjmp(jmploc.loc)) 947 _exit(exception == EXEXEC ? exerrno : 2); 948 if (pip != NULL) { 949 close(pip[0]); 950 if (pip[1] != 1) { 951 dup2(pip[1], 1); 952 close(pip[1]); 953 } 954 } 955 handler = &jmploc; 956 shellexec(argv, envp, path, idx); 957 } 958 handler = savehandler; 959 if (jp) { 960 struct procstat *ps = &jp->ps[jp->nprocs++]; 961 ps->pid = pid; 962 ps->status = -1; 963 ps->cmd = nullstr; 964 jp->foreground = 1; 965 #if JOBS 966 setcurjob(jp); 967 #endif 968 } 969 INTON; 970 TRACE(("In parent shell: child = %d\n", (int)pid)); 971 return pid; 972 } 973 974 975 /* 976 * Wait for job to finish. 977 * 978 * Under job control we have the problem that while a child process is 979 * running interrupts generated by the user are sent to the child but not 980 * to the shell. This means that an infinite loop started by an inter- 981 * active user may be hard to kill. With job control turned off, an 982 * interactive user may place an interactive program inside a loop. If 983 * the interactive program catches interrupts, the user doesn't want 984 * these interrupts to also abort the loop. The approach we take here 985 * is to have the shell ignore interrupt signals while waiting for a 986 * foreground process to terminate, and then send itself an interrupt 987 * signal if the child process was terminated by an interrupt signal. 988 * Unfortunately, some programs want to do a bit of cleanup and then 989 * exit on interrupt; unless these processes terminate themselves by 990 * sending a signal to themselves (instead of calling exit) they will 991 * confuse this approach. 992 */ 993 994 int 995 waitforjob(struct job *jp, int *origstatus) 996 { 997 #if JOBS 998 pid_t mypgrp = getpgrp(); 999 int propagate_int = jp->jobctl && jp->foreground; 1000 #endif 1001 int status; 1002 int st; 1003 1004 INTOFF; 1005 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1006 while (jp->state == 0) 1007 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG : 0), jp) == -1) 1008 dotrap(); 1009 #if JOBS 1010 if (jp->jobctl) { 1011 if (tcsetpgrp(ttyfd, mypgrp) < 0) 1012 error("tcsetpgrp failed, errno=%d\n", errno); 1013 } 1014 if (jp->state == JOBSTOPPED) 1015 setcurjob(jp); 1016 #endif 1017 status = jp->ps[jp->nprocs - 1].status; 1018 if (origstatus != NULL) 1019 *origstatus = status; 1020 /* convert to 8 bits */ 1021 if (WIFEXITED(status)) 1022 st = WEXITSTATUS(status); 1023 #if JOBS 1024 else if (WIFSTOPPED(status)) 1025 st = WSTOPSIG(status) + 128; 1026 #endif 1027 else 1028 st = WTERMSIG(status) + 128; 1029 if (! JOBS || jp->state == JOBDONE) 1030 freejob(jp); 1031 if (int_pending()) { 1032 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1033 CLEAR_PENDING_INT; 1034 } 1035 #if JOBS 1036 else if (rootshell && iflag && propagate_int && 1037 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1038 kill(getpid(), SIGINT); 1039 #endif 1040 INTON; 1041 return st; 1042 } 1043 1044 1045 static void 1046 dummy_handler(int sig __unused) 1047 { 1048 } 1049 1050 /* 1051 * Wait for a process to terminate. 1052 */ 1053 1054 static pid_t 1055 dowait(int mode, struct job *job) 1056 { 1057 struct sigaction sa, osa; 1058 sigset_t mask, omask; 1059 pid_t pid; 1060 int status; 1061 struct procstat *sp; 1062 struct job *jp; 1063 struct job *thisjob; 1064 const char *sigstr; 1065 int done; 1066 int stopped; 1067 int sig; 1068 int coredump; 1069 int wflags; 1070 int restore_sigchld; 1071 1072 TRACE(("dowait(%d, %p) called\n", mode, job)); 1073 restore_sigchld = 0; 1074 if ((mode & DOWAIT_SIG) != 0) { 1075 sigfillset(&mask); 1076 sigprocmask(SIG_BLOCK, &mask, &omask); 1077 INTOFF; 1078 if (!issigchldtrapped()) { 1079 restore_sigchld = 1; 1080 sa.sa_handler = dummy_handler; 1081 sa.sa_flags = 0; 1082 sigemptyset(&sa.sa_mask); 1083 sigaction(SIGCHLD, &sa, &osa); 1084 } 1085 } 1086 do { 1087 #if JOBS 1088 if (iflag) 1089 wflags = WUNTRACED | WCONTINUED; 1090 else 1091 #endif 1092 wflags = 0; 1093 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1094 wflags |= WNOHANG; 1095 pid = wait3(&status, wflags, NULL); 1096 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1097 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1098 sigsuspend(&omask); 1099 pid = -1; 1100 if (int_pending()) 1101 break; 1102 } 1103 } while (pid == -1 && errno == EINTR && breakwaitcmd == 0); 1104 if (pid == -1 && errno == ECHILD && job != NULL) 1105 job->state = JOBDONE; 1106 if ((mode & DOWAIT_SIG) != 0) { 1107 if (restore_sigchld) 1108 sigaction(SIGCHLD, &osa, NULL); 1109 sigprocmask(SIG_SETMASK, &omask, NULL); 1110 INTON; 1111 } 1112 if (breakwaitcmd != 0) { 1113 breakwaitcmd = 0; 1114 /* 1115 * Do not early terminate if the pid is positive, else the 1116 * job will not be properly recorded. 1117 */ 1118 if (pid <= 0) 1119 return -1; 1120 } 1121 if (pid <= 0) 1122 return pid; 1123 INTOFF; 1124 thisjob = NULL; 1125 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1126 if (jp->used && jp->nprocs > 0) { 1127 done = 1; 1128 stopped = 1; 1129 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1130 if (sp->pid == -1) 1131 continue; 1132 if (sp->pid == pid) { 1133 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1134 (int)pid, sp->status, 1135 status)); 1136 if (WIFCONTINUED(status)) { 1137 sp->status = -1; 1138 jp->state = 0; 1139 } else 1140 sp->status = status; 1141 thisjob = jp; 1142 } 1143 if (sp->status == -1) 1144 stopped = 0; 1145 else if (WIFSTOPPED(sp->status)) 1146 done = 0; 1147 } 1148 if (stopped) { /* stopped or done */ 1149 int state = done? JOBDONE : JOBSTOPPED; 1150 if (jp->state != state) { 1151 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1152 jp->state = state; 1153 if (jp != job) { 1154 if (done && !jp->remembered && 1155 !iflag && jp != bgjob) 1156 freejob(jp); 1157 #if JOBS 1158 else if (done) 1159 deljob(jp); 1160 #endif 1161 } 1162 } 1163 } 1164 } 1165 } 1166 INTON; 1167 if (!thisjob || thisjob->state == 0) 1168 ; 1169 else if ((!rootshell || !iflag || thisjob == job) && 1170 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1171 sig = 0; 1172 coredump = 0; 1173 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1174 if (WIFSIGNALED(sp->status)) { 1175 sig = WTERMSIG(sp->status); 1176 coredump = WCOREDUMP(sp->status); 1177 } 1178 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1179 sigstr = strsignal(sig); 1180 if (sigstr != NULL) 1181 out2str(sigstr); 1182 else 1183 out2str("Unknown signal"); 1184 if (coredump) 1185 out2str(" (core dumped)"); 1186 out2c('\n'); 1187 flushout(out2); 1188 } 1189 } else { 1190 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1191 thisjob->changed = 1; 1192 } 1193 return pid; 1194 } 1195 1196 1197 1198 /* 1199 * return 1 if there are stopped jobs, otherwise 0 1200 */ 1201 int job_warning = 0; 1202 int 1203 stoppedjobs(void) 1204 { 1205 int jobno; 1206 struct job *jp; 1207 1208 if (job_warning) 1209 return (0); 1210 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1211 if (jp->used == 0) 1212 continue; 1213 if (jp->state == JOBSTOPPED) { 1214 out2fmt_flush("You have stopped jobs.\n"); 1215 job_warning = 2; 1216 return (1); 1217 } 1218 } 1219 1220 return (0); 1221 } 1222 1223 1224 static void 1225 checkzombies(void) 1226 { 1227 while (njobs > 0 && dowait(0, NULL) > 0) 1228 ; 1229 } 1230 1231 1232 int 1233 backgndpidset(void) 1234 { 1235 return backgndpid != -1; 1236 } 1237 1238 1239 pid_t 1240 backgndpidval(void) 1241 { 1242 if (bgjob != NULL && !forcelocal) 1243 bgjob->remembered = 1; 1244 return backgndpid; 1245 } 1246 1247 /* 1248 * Return a string identifying a command (to be printed by the 1249 * jobs command. 1250 */ 1251 1252 static char *cmdnextc; 1253 static int cmdnleft; 1254 #define MAXCMDTEXT 200 1255 1256 char * 1257 commandtext(union node *n) 1258 { 1259 char *name; 1260 1261 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1262 cmdnleft = MAXCMDTEXT - 4; 1263 cmdtxt(n); 1264 *cmdnextc = '\0'; 1265 return name; 1266 } 1267 1268 1269 static void 1270 cmdtxt(union node *n) 1271 { 1272 union node *np; 1273 struct nodelist *lp; 1274 const char *p; 1275 int i; 1276 char s[2]; 1277 1278 if (n == NULL) 1279 return; 1280 switch (n->type) { 1281 case NSEMI: 1282 cmdtxt(n->nbinary.ch1); 1283 cmdputs("; "); 1284 cmdtxt(n->nbinary.ch2); 1285 break; 1286 case NAND: 1287 cmdtxt(n->nbinary.ch1); 1288 cmdputs(" && "); 1289 cmdtxt(n->nbinary.ch2); 1290 break; 1291 case NOR: 1292 cmdtxt(n->nbinary.ch1); 1293 cmdputs(" || "); 1294 cmdtxt(n->nbinary.ch2); 1295 break; 1296 case NPIPE: 1297 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1298 cmdtxt(lp->n); 1299 if (lp->next) 1300 cmdputs(" | "); 1301 } 1302 break; 1303 case NSUBSHELL: 1304 cmdputs("("); 1305 cmdtxt(n->nredir.n); 1306 cmdputs(")"); 1307 break; 1308 case NREDIR: 1309 case NBACKGND: 1310 cmdtxt(n->nredir.n); 1311 break; 1312 case NIF: 1313 cmdputs("if "); 1314 cmdtxt(n->nif.test); 1315 cmdputs("; then "); 1316 cmdtxt(n->nif.ifpart); 1317 cmdputs("..."); 1318 break; 1319 case NWHILE: 1320 cmdputs("while "); 1321 goto until; 1322 case NUNTIL: 1323 cmdputs("until "); 1324 until: 1325 cmdtxt(n->nbinary.ch1); 1326 cmdputs("; do "); 1327 cmdtxt(n->nbinary.ch2); 1328 cmdputs("; done"); 1329 break; 1330 case NFOR: 1331 cmdputs("for "); 1332 cmdputs(n->nfor.var); 1333 cmdputs(" in ..."); 1334 break; 1335 case NCASE: 1336 cmdputs("case "); 1337 cmdputs(n->ncase.expr->narg.text); 1338 cmdputs(" in ..."); 1339 break; 1340 case NDEFUN: 1341 cmdputs(n->narg.text); 1342 cmdputs("() ..."); 1343 break; 1344 case NNOT: 1345 cmdputs("! "); 1346 cmdtxt(n->nnot.com); 1347 break; 1348 case NCMD: 1349 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1350 cmdtxt(np); 1351 if (np->narg.next) 1352 cmdputs(" "); 1353 } 1354 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1355 cmdputs(" "); 1356 cmdtxt(np); 1357 } 1358 break; 1359 case NARG: 1360 cmdputs(n->narg.text); 1361 break; 1362 case NTO: 1363 p = ">"; i = 1; goto redir; 1364 case NAPPEND: 1365 p = ">>"; i = 1; goto redir; 1366 case NTOFD: 1367 p = ">&"; i = 1; goto redir; 1368 case NCLOBBER: 1369 p = ">|"; i = 1; goto redir; 1370 case NFROM: 1371 p = "<"; i = 0; goto redir; 1372 case NFROMTO: 1373 p = "<>"; i = 0; goto redir; 1374 case NFROMFD: 1375 p = "<&"; i = 0; goto redir; 1376 redir: 1377 if (n->nfile.fd != i) { 1378 s[0] = n->nfile.fd + '0'; 1379 s[1] = '\0'; 1380 cmdputs(s); 1381 } 1382 cmdputs(p); 1383 if (n->type == NTOFD || n->type == NFROMFD) { 1384 if (n->ndup.dupfd >= 0) 1385 s[0] = n->ndup.dupfd + '0'; 1386 else 1387 s[0] = '-'; 1388 s[1] = '\0'; 1389 cmdputs(s); 1390 } else { 1391 cmdtxt(n->nfile.fname); 1392 } 1393 break; 1394 case NHERE: 1395 case NXHERE: 1396 cmdputs("<<..."); 1397 break; 1398 default: 1399 cmdputs("???"); 1400 break; 1401 } 1402 } 1403 1404 1405 1406 static void 1407 cmdputs(const char *s) 1408 { 1409 const char *p; 1410 char *q; 1411 char c; 1412 int subtype = 0; 1413 1414 if (cmdnleft <= 0) 1415 return; 1416 p = s; 1417 q = cmdnextc; 1418 while ((c = *p++) != '\0') { 1419 if (c == CTLESC) 1420 *q++ = *p++; 1421 else if (c == CTLVAR) { 1422 *q++ = '$'; 1423 if (--cmdnleft > 0) 1424 *q++ = '{'; 1425 subtype = *p++; 1426 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1427 *q++ = '#'; 1428 } else if (c == '=' && subtype != 0) { 1429 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1430 if (*q) 1431 q++; 1432 else 1433 cmdnleft++; 1434 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1435 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1436 --cmdnleft > 0) 1437 *q = q[-1], q++; 1438 subtype = 0; 1439 } else if (c == CTLENDVAR) { 1440 *q++ = '}'; 1441 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1442 cmdnleft -= 5; 1443 if (cmdnleft > 0) { 1444 *q++ = '$'; 1445 *q++ = '('; 1446 *q++ = '.'; 1447 *q++ = '.'; 1448 *q++ = '.'; 1449 *q++ = ')'; 1450 } 1451 } else if (c == CTLARI) { 1452 cmdnleft -= 2; 1453 if (cmdnleft > 0) { 1454 *q++ = '$'; 1455 *q++ = '('; 1456 *q++ = '('; 1457 } 1458 p++; 1459 } else if (c == CTLENDARI) { 1460 if (--cmdnleft > 0) { 1461 *q++ = ')'; 1462 *q++ = ')'; 1463 } 1464 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1465 cmdnleft++; /* ignore */ 1466 else 1467 *q++ = c; 1468 if (--cmdnleft <= 0) { 1469 *q++ = '.'; 1470 *q++ = '.'; 1471 *q++ = '.'; 1472 break; 1473 } 1474 } 1475 cmdnextc = q; 1476 } 1477