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 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 #include "eval.h" 77 78 79 /* 80 * A job structure contains information about a job. A job is either a 81 * single process or a set of processes contained in a pipeline. In the 82 * latter case, pidlist will be non-NULL, and will point to a -1 terminated 83 * array of pids. 84 */ 85 86 struct procstat { 87 pid_t pid; /* process id */ 88 int status; /* status flags (defined above) */ 89 char *cmd; /* text of command being run */ 90 }; 91 92 93 /* states */ 94 #define JOBSTOPPED 1 /* all procs are stopped */ 95 #define JOBDONE 2 /* all procs are completed */ 96 97 98 struct job { 99 struct procstat ps0; /* status of process */ 100 struct procstat *ps; /* status or processes when more than one */ 101 short nprocs; /* number of processes */ 102 pid_t pgrp; /* process group of this job */ 103 char state; /* true if job is finished */ 104 char used; /* true if this entry is in used */ 105 char changed; /* true if status has changed */ 106 char foreground; /* true if running in the foreground */ 107 char remembered; /* true if $! referenced */ 108 char pipefail; /* pass any non-zero status */ 109 #if JOBS 110 char jobctl; /* job running under job control */ 111 struct job *next; /* job used after this one */ 112 #endif 113 }; 114 115 116 static struct job *jobtab; /* array of jobs */ 117 static int njobs; /* size of array */ 118 static pid_t backgndpid = -1; /* pid of last background process */ 119 static struct job *bgjob = NULL; /* last background process */ 120 #if JOBS 121 static struct job *jobmru; /* most recently used job list */ 122 static pid_t initialpgrp; /* pgrp of shell on invocation */ 123 #endif 124 static int ttyfd = -1; 125 126 /* mode flags for dowait */ 127 #define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 128 #define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signal */ 129 #define DOWAIT_SIG_TRAP 0x4 /* if DOWAIT_SIG, abort on trapped signal only */ 130 131 #if JOBS 132 static void restartjob(struct job *); 133 #endif 134 static void freejob(struct job *); 135 static int waitcmdloop(struct job *); 136 static struct job *getjob_nonotfound(const char *); 137 static struct job *getjob(const char *); 138 pid_t killjob(const char *, int); 139 static pid_t dowait(int, struct job *); 140 static void checkzombies(void); 141 static void cmdtxt(union node *); 142 static void cmdputs(const char *); 143 #if JOBS 144 static void setcurjob(struct job *); 145 static void deljob(struct job *); 146 static struct job *getcurjob(struct job *); 147 #endif 148 static int getjobstatus(const struct job *); 149 static void printjobcmd(struct job *); 150 static void showjob(struct job *, int); 151 152 153 /* 154 * Turn job control on and off. 155 */ 156 157 static int jobctl; 158 159 #if JOBS 160 static void 161 jobctl_notty(void) 162 { 163 if (ttyfd >= 0) { 164 close(ttyfd); 165 ttyfd = -1; 166 } 167 if (!iflag) { 168 setsignal(SIGTSTP); 169 setsignal(SIGTTOU); 170 setsignal(SIGTTIN); 171 jobctl = 1; 172 return; 173 } 174 out2fmt_flush("sh: can't access tty; job control turned off\n"); 175 mflag = 0; 176 } 177 178 void 179 setjobctl(int on) 180 { 181 int i; 182 183 if (on == jobctl || rootshell == 0) 184 return; 185 if (on) { 186 if (ttyfd != -1) 187 close(ttyfd); 188 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 189 i = 0; 190 while (i <= 2 && !isatty(i)) 191 i++; 192 if (i > 2 || 193 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) { 194 jobctl_notty(); 195 return; 196 } 197 } 198 if (ttyfd < 10) { 199 /* 200 * Keep our TTY file descriptor out of the way of 201 * the user's redirections. 202 */ 203 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 204 jobctl_notty(); 205 return; 206 } 207 close(ttyfd); 208 ttyfd = i; 209 } 210 do { /* while we are in the background */ 211 initialpgrp = tcgetpgrp(ttyfd); 212 if (initialpgrp < 0) { 213 jobctl_notty(); 214 return; 215 } 216 if (initialpgrp != getpgrp()) { 217 if (!iflag) { 218 initialpgrp = -1; 219 jobctl_notty(); 220 return; 221 } 222 kill(0, SIGTTIN); 223 continue; 224 } 225 } while (0); 226 setsignal(SIGTSTP); 227 setsignal(SIGTTOU); 228 setsignal(SIGTTIN); 229 setpgid(0, rootpid); 230 tcsetpgrp(ttyfd, rootpid); 231 } else { /* turning job control off */ 232 setpgid(0, initialpgrp); 233 if (ttyfd >= 0) { 234 tcsetpgrp(ttyfd, initialpgrp); 235 close(ttyfd); 236 ttyfd = -1; 237 } 238 setsignal(SIGTSTP); 239 setsignal(SIGTTOU); 240 setsignal(SIGTTIN); 241 } 242 jobctl = on; 243 } 244 #endif 245 246 247 #if JOBS 248 int 249 fgcmd(int argc __unused, char **argv __unused) 250 { 251 struct job *jp; 252 pid_t pgrp; 253 int status; 254 255 nextopt(""); 256 jp = getjob(*argptr); 257 if (jp->jobctl == 0) 258 error("job not created under job control"); 259 printjobcmd(jp); 260 flushout(&output); 261 pgrp = jp->ps[0].pid; 262 if (ttyfd >= 0) 263 tcsetpgrp(ttyfd, pgrp); 264 restartjob(jp); 265 jp->foreground = 1; 266 INTOFF; 267 status = waitforjob(jp, (int *)NULL); 268 INTON; 269 return status; 270 } 271 272 273 int 274 bgcmd(int argc __unused, char **argv __unused) 275 { 276 struct job *jp; 277 278 nextopt(""); 279 do { 280 jp = getjob(*argptr); 281 if (jp->jobctl == 0) 282 error("job not created under job control"); 283 if (jp->state == JOBDONE) 284 continue; 285 restartjob(jp); 286 jp->foreground = 0; 287 out1fmt("[%td] ", jp - jobtab + 1); 288 printjobcmd(jp); 289 } while (*argptr != NULL && *++argptr != NULL); 290 return 0; 291 } 292 293 294 static void 295 restartjob(struct job *jp) 296 { 297 struct procstat *ps; 298 int i; 299 300 if (jp->state == JOBDONE) 301 return; 302 setcurjob(jp); 303 INTOFF; 304 kill(-jp->ps[0].pid, SIGCONT); 305 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 306 if (WIFSTOPPED(ps->status)) { 307 ps->status = -1; 308 jp->state = 0; 309 } 310 } 311 INTON; 312 } 313 #endif 314 315 316 int 317 jobscmd(int argc __unused, char *argv[] __unused) 318 { 319 char *id; 320 int ch, mode; 321 322 mode = SHOWJOBS_DEFAULT; 323 while ((ch = nextopt("lps")) != '\0') { 324 switch (ch) { 325 case 'l': 326 mode = SHOWJOBS_VERBOSE; 327 break; 328 case 'p': 329 mode = SHOWJOBS_PGIDS; 330 break; 331 case 's': 332 mode = SHOWJOBS_PIDS; 333 break; 334 } 335 } 336 337 if (*argptr == NULL) 338 showjobs(0, mode); 339 else 340 while ((id = *argptr++) != NULL) 341 showjob(getjob(id), mode); 342 343 return (0); 344 } 345 346 static int getjobstatus(const struct job *jp) 347 { 348 int i, status; 349 350 if (!jp->pipefail) 351 return (jp->ps[jp->nprocs - 1].status); 352 for (i = jp->nprocs - 1; i >= 0; i--) { 353 status = jp->ps[i].status; 354 if (status != 0) 355 return (status); 356 } 357 return (0); 358 } 359 360 static void 361 printjobcmd(struct job *jp) 362 { 363 struct procstat *ps; 364 int i; 365 366 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 367 out1str(ps->cmd); 368 if (i > 0) 369 out1str(" | "); 370 } 371 out1c('\n'); 372 } 373 374 static void 375 showjob(struct job *jp, int mode) 376 { 377 char s[64]; 378 char statebuf[16]; 379 const char *statestr, *coredump; 380 struct procstat *ps; 381 struct job *j; 382 int col, curr, i, jobno, prev, procno, status; 383 char c; 384 385 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 386 jobno = jp - jobtab + 1; 387 curr = prev = 0; 388 #if JOBS 389 if ((j = getcurjob(NULL)) != NULL) { 390 curr = j - jobtab + 1; 391 if ((j = getcurjob(j)) != NULL) 392 prev = j - jobtab + 1; 393 } 394 #endif 395 coredump = ""; 396 status = getjobstatus(jp); 397 if (jp->state == 0) { 398 statestr = "Running"; 399 #if JOBS 400 } else if (jp->state == JOBSTOPPED) { 401 ps = jp->ps + jp->nprocs - 1; 402 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 403 ps--; 404 if (WIFSTOPPED(ps->status)) 405 i = WSTOPSIG(ps->status); 406 else 407 i = -1; 408 statestr = strsignal(i); 409 if (statestr == NULL) 410 statestr = "Suspended"; 411 #endif 412 } else if (WIFEXITED(status)) { 413 if (WEXITSTATUS(status) == 0) 414 statestr = "Done"; 415 else { 416 fmtstr(statebuf, sizeof(statebuf), "Done(%d)", 417 WEXITSTATUS(status)); 418 statestr = statebuf; 419 } 420 } else { 421 i = WTERMSIG(status); 422 statestr = strsignal(i); 423 if (statestr == NULL) 424 statestr = "Unknown signal"; 425 if (WCOREDUMP(status)) 426 coredump = " (core dumped)"; 427 } 428 429 for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */ 430 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 431 out1fmt("%d\n", (int)ps->pid); 432 continue; 433 } 434 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 435 continue; 436 if (jobno == curr && ps == jp->ps) 437 c = '+'; 438 else if (jobno == prev && ps == jp->ps) 439 c = '-'; 440 else 441 c = ' '; 442 if (ps == jp->ps) 443 fmtstr(s, 64, "[%d] %c ", jobno, c); 444 else 445 fmtstr(s, 64, " %c ", c); 446 out1str(s); 447 col = strlen(s); 448 if (mode == SHOWJOBS_VERBOSE) { 449 fmtstr(s, 64, "%d ", (int)ps->pid); 450 out1str(s); 451 col += strlen(s); 452 } 453 if (ps == jp->ps) { 454 out1str(statestr); 455 out1str(coredump); 456 col += strlen(statestr) + strlen(coredump); 457 } 458 do { 459 out1c(' '); 460 col++; 461 } while (col < 30); 462 if (mode == SHOWJOBS_VERBOSE) { 463 out1str(ps->cmd); 464 out1c('\n'); 465 } else 466 printjobcmd(jp); 467 } 468 } 469 470 /* 471 * Print a list of jobs. If "change" is nonzero, only print jobs whose 472 * statuses have changed since the last call to showjobs. 473 * 474 * If the shell is interrupted in the process of creating a job, the 475 * result may be a job structure containing zero processes. Such structures 476 * will be freed here. 477 */ 478 479 void 480 showjobs(int change, int mode) 481 { 482 int jobno; 483 struct job *jp; 484 485 TRACE(("showjobs(%d) called\n", change)); 486 checkzombies(); 487 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 488 if (! jp->used) 489 continue; 490 if (jp->nprocs == 0) { 491 freejob(jp); 492 continue; 493 } 494 if (change && ! jp->changed) 495 continue; 496 showjob(jp, mode); 497 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 498 jp->changed = 0; 499 /* Hack: discard jobs for which $! has not been 500 * referenced in interactive mode when they terminate. 501 */ 502 if (jp->state == JOBDONE && !jp->remembered && 503 (iflag || jp != bgjob)) { 504 freejob(jp); 505 } 506 } 507 } 508 } 509 510 511 /* 512 * Mark a job structure as unused. 513 */ 514 515 static void 516 freejob(struct job *jp) 517 { 518 struct procstat *ps; 519 int i; 520 521 INTOFF; 522 if (bgjob == jp) 523 bgjob = NULL; 524 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 525 if (ps->cmd != nullstr) 526 ckfree(ps->cmd); 527 } 528 if (jp->ps != &jp->ps0) 529 ckfree(jp->ps); 530 jp->used = 0; 531 #if JOBS 532 deljob(jp); 533 #endif 534 INTON; 535 } 536 537 538 539 int 540 waitcmd(int argc __unused, char **argv __unused) 541 { 542 struct job *job; 543 int retval; 544 545 nextopt(""); 546 if (*argptr == NULL) 547 return (waitcmdloop(NULL)); 548 549 do { 550 job = getjob_nonotfound(*argptr); 551 if (job == NULL) 552 retval = 127; 553 else 554 retval = waitcmdloop(job); 555 argptr++; 556 } while (*argptr != NULL); 557 558 return (retval); 559 } 560 561 static int 562 waitcmdloop(struct job *job) 563 { 564 int status, retval, sig; 565 struct job *jp; 566 567 /* 568 * Loop until a process is terminated or stopped, or a SIGINT is 569 * received. 570 */ 571 572 do { 573 if (job != NULL) { 574 if (job->state == JOBDONE) { 575 status = getjobstatus(job); 576 if (WIFEXITED(status)) 577 retval = WEXITSTATUS(status); 578 else 579 retval = WTERMSIG(status) + 128; 580 if (! iflag || ! job->changed) 581 freejob(job); 582 else { 583 job->remembered = 0; 584 if (job == bgjob) 585 bgjob = NULL; 586 } 587 return retval; 588 } 589 } else { 590 if (njobs == 0) 591 return 0; 592 for (jp = jobtab ; jp < jobtab + njobs; jp++) 593 if (jp->used && jp->state == JOBDONE) { 594 if (! iflag || ! jp->changed) 595 freejob(jp); 596 else { 597 jp->remembered = 0; 598 if (jp == bgjob) 599 bgjob = NULL; 600 } 601 } 602 for (jp = jobtab ; ; jp++) { 603 if (jp >= jobtab + njobs) { /* no running procs */ 604 return 0; 605 } 606 if (jp->used && jp->state == 0) 607 break; 608 } 609 } 610 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 611 612 sig = pendingsig_waitcmd; 613 pendingsig_waitcmd = 0; 614 return sig + 128; 615 } 616 617 618 619 int 620 jobidcmd(int argc __unused, char **argv __unused) 621 { 622 struct job *jp; 623 int i; 624 625 nextopt(""); 626 jp = getjob(*argptr); 627 for (i = 0 ; i < jp->nprocs ; ) { 628 out1fmt("%d", (int)jp->ps[i].pid); 629 out1c(++i < jp->nprocs? ' ' : '\n'); 630 } 631 return 0; 632 } 633 634 635 636 /* 637 * Convert a job name to a job structure. 638 */ 639 640 static struct job * 641 getjob_nonotfound(const char *name) 642 { 643 int jobno; 644 struct job *found, *jp; 645 size_t namelen; 646 pid_t pid; 647 int i; 648 649 if (name == NULL) { 650 #if JOBS 651 name = "%+"; 652 #else 653 error("No current job"); 654 #endif 655 } 656 if (name[0] == '%') { 657 if (is_digit(name[1])) { 658 jobno = number(name + 1); 659 if (jobno > 0 && jobno <= njobs 660 && jobtab[jobno - 1].used != 0) 661 return &jobtab[jobno - 1]; 662 #if JOBS 663 } else if ((name[1] == '%' || name[1] == '+') && 664 name[2] == '\0') { 665 if ((jp = getcurjob(NULL)) == NULL) 666 error("No current job"); 667 return (jp); 668 } else if (name[1] == '-' && name[2] == '\0') { 669 if ((jp = getcurjob(NULL)) == NULL || 670 (jp = getcurjob(jp)) == NULL) 671 error("No previous job"); 672 return (jp); 673 #endif 674 } else if (name[1] == '?') { 675 found = NULL; 676 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 677 if (jp->used && jp->nprocs > 0 678 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 679 if (found) 680 error("%s: ambiguous", name); 681 found = jp; 682 } 683 } 684 if (found != NULL) 685 return (found); 686 } else { 687 namelen = strlen(name); 688 found = NULL; 689 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 690 if (jp->used && jp->nprocs > 0 691 && strncmp(jp->ps[0].cmd, name + 1, 692 namelen - 1) == 0) { 693 if (found) 694 error("%s: ambiguous", name); 695 found = jp; 696 } 697 } 698 if (found) 699 return found; 700 } 701 } else if (is_number(name)) { 702 pid = (pid_t)number(name); 703 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 704 if (jp->used && jp->nprocs > 0 705 && jp->ps[jp->nprocs - 1].pid == pid) 706 return jp; 707 } 708 } 709 return NULL; 710 } 711 712 713 static struct job * 714 getjob(const char *name) 715 { 716 struct job *jp; 717 718 jp = getjob_nonotfound(name); 719 if (jp == NULL) 720 error("No such job: %s", name); 721 return (jp); 722 } 723 724 725 int 726 killjob(const char *name, int sig) 727 { 728 struct job *jp; 729 int i, ret; 730 731 jp = getjob(name); 732 if (jp->state == JOBDONE) 733 return 0; 734 if (jp->jobctl) 735 return kill(-jp->ps[0].pid, sig); 736 ret = -1; 737 errno = ESRCH; 738 for (i = 0; i < jp->nprocs; i++) 739 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 740 if (kill(jp->ps[i].pid, sig) == 0) 741 ret = 0; 742 } else 743 ret = 0; 744 return ret; 745 } 746 747 /* 748 * Return a new job structure, 749 */ 750 751 struct job * 752 makejob(union node *node __unused, int nprocs) 753 { 754 int i; 755 struct job *jp; 756 757 for (i = njobs, jp = jobtab ; ; jp++) { 758 if (--i < 0) { 759 INTOFF; 760 if (njobs == 0) { 761 jobtab = ckmalloc(4 * sizeof jobtab[0]); 762 #if JOBS 763 jobmru = NULL; 764 #endif 765 } else { 766 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 767 memcpy(jp, jobtab, njobs * sizeof jp[0]); 768 #if JOBS 769 /* Relocate `next' pointers and list head */ 770 if (jobmru != NULL) 771 jobmru = &jp[jobmru - jobtab]; 772 for (i = 0; i < njobs; i++) 773 if (jp[i].next != NULL) 774 jp[i].next = &jp[jp[i].next - 775 jobtab]; 776 #endif 777 if (bgjob != NULL) 778 bgjob = &jp[bgjob - jobtab]; 779 /* Relocate `ps' pointers */ 780 for (i = 0; i < njobs; i++) 781 if (jp[i].ps == &jobtab[i].ps0) 782 jp[i].ps = &jp[i].ps0; 783 ckfree(jobtab); 784 jobtab = jp; 785 } 786 jp = jobtab + njobs; 787 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 788 ; 789 INTON; 790 break; 791 } 792 if (jp->used == 0) 793 break; 794 } 795 INTOFF; 796 jp->state = 0; 797 jp->used = 1; 798 jp->changed = 0; 799 jp->nprocs = 0; 800 jp->foreground = 0; 801 jp->remembered = 0; 802 jp->pipefail = pipefailflag; 803 #if JOBS 804 jp->jobctl = jobctl; 805 jp->next = NULL; 806 #endif 807 if (nprocs > 1) { 808 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 809 } else { 810 jp->ps = &jp->ps0; 811 } 812 INTON; 813 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 814 jp - jobtab + 1)); 815 return jp; 816 } 817 818 #if JOBS 819 static void 820 setcurjob(struct job *cj) 821 { 822 struct job *jp, *prev; 823 824 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 825 if (jp == cj) { 826 if (prev != NULL) 827 prev->next = jp->next; 828 else 829 jobmru = jp->next; 830 jp->next = jobmru; 831 jobmru = cj; 832 return; 833 } 834 } 835 cj->next = jobmru; 836 jobmru = cj; 837 } 838 839 static void 840 deljob(struct job *j) 841 { 842 struct job *jp, *prev; 843 844 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 845 if (jp == j) { 846 if (prev != NULL) 847 prev->next = jp->next; 848 else 849 jobmru = jp->next; 850 return; 851 } 852 } 853 } 854 855 /* 856 * Return the most recently used job that isn't `nj', and preferably one 857 * that is stopped. 858 */ 859 static struct job * 860 getcurjob(struct job *nj) 861 { 862 struct job *jp; 863 864 /* Try to find a stopped one.. */ 865 for (jp = jobmru; jp != NULL; jp = jp->next) 866 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 867 return (jp); 868 /* Otherwise the most recently used job that isn't `nj' */ 869 for (jp = jobmru; jp != NULL; jp = jp->next) 870 if (jp->used && jp != nj) 871 return (jp); 872 873 return (NULL); 874 } 875 876 #endif 877 878 /* 879 * Fork of a subshell. If we are doing job control, give the subshell its 880 * own process group. Jp is a job structure that the job is to be added to. 881 * N is the command that will be evaluated by the child. Both jp and n may 882 * be NULL. The mode parameter can be one of the following: 883 * FORK_FG - Fork off a foreground process. 884 * FORK_BG - Fork off a background process. 885 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 886 * process group even if job control is on. 887 * 888 * When job control is turned off, background processes have their standard 889 * input redirected to /dev/null (except for the second and later processes 890 * in a pipeline). 891 */ 892 893 pid_t 894 forkshell(struct job *jp, union node *n, int mode) 895 { 896 pid_t pid; 897 pid_t pgrp; 898 899 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 900 mode)); 901 INTOFF; 902 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 903 checkzombies(); 904 flushall(); 905 pid = fork(); 906 if (pid == -1) { 907 TRACE(("Fork failed, errno=%d\n", errno)); 908 INTON; 909 error("Cannot fork: %s", strerror(errno)); 910 } 911 if (pid == 0) { 912 struct job *p; 913 int wasroot; 914 int i; 915 916 TRACE(("Child shell %d\n", (int)getpid())); 917 wasroot = rootshell; 918 rootshell = 0; 919 handler = &main_handler; 920 closescript(); 921 INTON; 922 forcelocal = 0; 923 clear_traps(); 924 #if JOBS 925 jobctl = 0; /* do job control only in root shell */ 926 if (wasroot && mode != FORK_NOJOB && mflag) { 927 if (jp == NULL || jp->nprocs == 0) 928 pgrp = getpid(); 929 else 930 pgrp = jp->ps[0].pid; 931 if (setpgid(0, pgrp) == 0 && mode == FORK_FG && 932 ttyfd >= 0) { 933 /* 934 * Each process in a pipeline must have the tty 935 * pgrp set before running its code. 936 * Only for pipelines of three or more processes 937 * could this be reduced to two calls. 938 */ 939 if (tcsetpgrp(ttyfd, pgrp) < 0) 940 error("tcsetpgrp failed, errno=%d", errno); 941 } 942 setsignal(SIGTSTP); 943 setsignal(SIGTTOU); 944 } else if (mode == FORK_BG) { 945 ignoresig(SIGINT); 946 ignoresig(SIGQUIT); 947 if ((jp == NULL || jp->nprocs == 0) && 948 ! fd0_redirected_p ()) { 949 close(0); 950 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 951 error("cannot open %s: %s", 952 _PATH_DEVNULL, strerror(errno)); 953 } 954 } 955 #else 956 if (mode == FORK_BG) { 957 ignoresig(SIGINT); 958 ignoresig(SIGQUIT); 959 if ((jp == NULL || jp->nprocs == 0) && 960 ! fd0_redirected_p ()) { 961 close(0); 962 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 963 error("cannot open %s: %s", 964 _PATH_DEVNULL, strerror(errno)); 965 } 966 } 967 #endif 968 INTOFF; 969 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 970 if (p->used) 971 freejob(p); 972 INTON; 973 if (wasroot && iflag) { 974 setsignal(SIGINT); 975 setsignal(SIGQUIT); 976 setsignal(SIGTERM); 977 } 978 return pid; 979 } 980 if (rootshell && mode != FORK_NOJOB && mflag) { 981 if (jp == NULL || jp->nprocs == 0) 982 pgrp = pid; 983 else 984 pgrp = jp->ps[0].pid; 985 setpgid(pid, pgrp); 986 } 987 if (mode == FORK_BG) { 988 if (bgjob != NULL && bgjob->state == JOBDONE && 989 !bgjob->remembered && !iflag) 990 freejob(bgjob); 991 backgndpid = pid; /* set $! */ 992 bgjob = jp; 993 } 994 if (jp) { 995 struct procstat *ps = &jp->ps[jp->nprocs++]; 996 ps->pid = pid; 997 ps->status = -1; 998 ps->cmd = nullstr; 999 if (iflag && rootshell && n) 1000 ps->cmd = commandtext(n); 1001 jp->foreground = mode == FORK_FG; 1002 #if JOBS 1003 setcurjob(jp); 1004 #endif 1005 } 1006 INTON; 1007 TRACE(("In parent shell: child = %d\n", (int)pid)); 1008 return pid; 1009 } 1010 1011 1012 pid_t 1013 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 1014 { 1015 pid_t pid; 1016 struct jmploc jmploc; 1017 struct jmploc *savehandler; 1018 int inton; 1019 1020 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 1021 (void *)pip)); 1022 inton = is_int_on(); 1023 INTOFF; 1024 flushall(); 1025 savehandler = handler; 1026 pid = vfork(); 1027 if (pid == -1) { 1028 TRACE(("Vfork failed, errno=%d\n", errno)); 1029 INTON; 1030 error("Cannot fork: %s", strerror(errno)); 1031 } 1032 if (pid == 0) { 1033 TRACE(("Child shell %d\n", (int)getpid())); 1034 if (setjmp(jmploc.loc)) 1035 _exit(exitstatus); 1036 if (pip != NULL) { 1037 close(pip[0]); 1038 if (pip[1] != 1) { 1039 dup2(pip[1], 1); 1040 close(pip[1]); 1041 } 1042 } 1043 handler = &jmploc; 1044 shellexec(argv, envp, path, idx); 1045 } 1046 handler = savehandler; 1047 if (jp) { 1048 struct procstat *ps = &jp->ps[jp->nprocs++]; 1049 ps->pid = pid; 1050 ps->status = -1; 1051 ps->cmd = nullstr; 1052 jp->foreground = 1; 1053 #if JOBS 1054 setcurjob(jp); 1055 #endif 1056 } 1057 SETINTON(inton); 1058 TRACE(("In parent shell: child = %d\n", (int)pid)); 1059 return pid; 1060 } 1061 1062 1063 /* 1064 * Wait for job to finish. 1065 * 1066 * Under job control we have the problem that while a child process is 1067 * running interrupts generated by the user are sent to the child but not 1068 * to the shell. This means that an infinite loop started by an inter- 1069 * active user may be hard to kill. With job control turned off, an 1070 * interactive user may place an interactive program inside a loop. If 1071 * the interactive program catches interrupts, the user doesn't want 1072 * these interrupts to also abort the loop. The approach we take here 1073 * is to have the shell ignore interrupt signals while waiting for a 1074 * foreground process to terminate, and then send itself an interrupt 1075 * signal if the child process was terminated by an interrupt signal. 1076 * Unfortunately, some programs want to do a bit of cleanup and then 1077 * exit on interrupt; unless these processes terminate themselves by 1078 * sending a signal to themselves (instead of calling exit) they will 1079 * confuse this approach. 1080 */ 1081 1082 int 1083 waitforjob(struct job *jp, int *signaled) 1084 { 1085 #if JOBS 1086 int propagate_int = jp->jobctl && jp->foreground; 1087 #endif 1088 int status; 1089 int st; 1090 1091 INTOFF; 1092 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1093 while (jp->state == 0) 1094 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1095 DOWAIT_SIG_TRAP : 0), jp) == -1) 1096 dotrap(); 1097 #if JOBS 1098 if (jp->jobctl) { 1099 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0) 1100 error("tcsetpgrp failed, errno=%d\n", errno); 1101 } 1102 if (jp->state == JOBSTOPPED) 1103 setcurjob(jp); 1104 #endif 1105 status = getjobstatus(jp); 1106 if (signaled != NULL) 1107 *signaled = WIFSIGNALED(status); 1108 /* convert to 8 bits */ 1109 if (WIFEXITED(status)) 1110 st = WEXITSTATUS(status); 1111 #if JOBS 1112 else if (WIFSTOPPED(status)) 1113 st = WSTOPSIG(status) + 128; 1114 #endif 1115 else 1116 st = WTERMSIG(status) + 128; 1117 if (! JOBS || jp->state == JOBDONE) 1118 freejob(jp); 1119 if (int_pending()) { 1120 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1121 CLEAR_PENDING_INT; 1122 } 1123 #if JOBS 1124 else if (rootshell && propagate_int && 1125 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1126 kill(getpid(), SIGINT); 1127 #endif 1128 INTON; 1129 return st; 1130 } 1131 1132 1133 static void 1134 dummy_handler(int sig __unused) 1135 { 1136 } 1137 1138 /* 1139 * Wait for a process to terminate. 1140 */ 1141 1142 static pid_t 1143 dowait(int mode, struct job *job) 1144 { 1145 struct sigaction sa, osa; 1146 sigset_t mask, omask; 1147 pid_t pid; 1148 int status; 1149 struct procstat *sp; 1150 struct job *jp; 1151 struct job *thisjob; 1152 const char *sigstr; 1153 int done; 1154 int stopped; 1155 int sig; 1156 int coredump; 1157 int wflags; 1158 int restore_sigchld; 1159 1160 TRACE(("dowait(%d, %p) called\n", mode, job)); 1161 restore_sigchld = 0; 1162 if ((mode & DOWAIT_SIG) != 0) { 1163 sigfillset(&mask); 1164 sigprocmask(SIG_BLOCK, &mask, &omask); 1165 INTOFF; 1166 if (!issigchldtrapped()) { 1167 restore_sigchld = 1; 1168 sa.sa_handler = dummy_handler; 1169 sa.sa_flags = 0; 1170 sigemptyset(&sa.sa_mask); 1171 sigaction(SIGCHLD, &sa, &osa); 1172 } 1173 } 1174 do { 1175 #if JOBS 1176 if (iflag) 1177 wflags = WUNTRACED | WCONTINUED; 1178 else 1179 #endif 1180 wflags = 0; 1181 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1182 wflags |= WNOHANG; 1183 pid = wait3(&status, wflags, (struct rusage *)NULL); 1184 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1185 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1186 pid = -1; 1187 if (((mode & DOWAIT_SIG_TRAP) != 0 ? 1188 pendingsig : pendingsig_waitcmd) != 0) { 1189 errno = EINTR; 1190 break; 1191 } 1192 sigsuspend(&omask); 1193 if (int_pending()) 1194 break; 1195 } 1196 } while (pid == -1 && errno == EINTR); 1197 if (pid == -1 && errno == ECHILD && job != NULL) 1198 job->state = JOBDONE; 1199 if ((mode & DOWAIT_SIG) != 0) { 1200 if (restore_sigchld) 1201 sigaction(SIGCHLD, &osa, NULL); 1202 sigprocmask(SIG_SETMASK, &omask, NULL); 1203 INTON; 1204 } 1205 if (pid <= 0) 1206 return pid; 1207 INTOFF; 1208 thisjob = NULL; 1209 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1210 if (jp->used && jp->nprocs > 0) { 1211 done = 1; 1212 stopped = 1; 1213 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1214 if (sp->pid == -1) 1215 continue; 1216 if (sp->pid == pid && (sp->status == -1 || 1217 WIFSTOPPED(sp->status))) { 1218 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1219 (int)pid, sp->status, 1220 status)); 1221 if (WIFCONTINUED(status)) { 1222 sp->status = -1; 1223 jp->state = 0; 1224 } else 1225 sp->status = status; 1226 thisjob = jp; 1227 } 1228 if (sp->status == -1) 1229 stopped = 0; 1230 else if (WIFSTOPPED(sp->status)) 1231 done = 0; 1232 } 1233 if (stopped) { /* stopped or done */ 1234 int state = done? JOBDONE : JOBSTOPPED; 1235 if (jp->state != state) { 1236 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1237 jp->state = state; 1238 if (jp != job) { 1239 if (done && !jp->remembered && 1240 !iflag && jp != bgjob) 1241 freejob(jp); 1242 #if JOBS 1243 else if (done) 1244 deljob(jp); 1245 #endif 1246 } 1247 } 1248 } 1249 } 1250 } 1251 INTON; 1252 if (!thisjob || thisjob->state == 0) 1253 ; 1254 else if ((!rootshell || !iflag || thisjob == job) && 1255 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1256 sig = 0; 1257 coredump = 0; 1258 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1259 if (WIFSIGNALED(sp->status)) { 1260 sig = WTERMSIG(sp->status); 1261 coredump = WCOREDUMP(sp->status); 1262 } 1263 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1264 sigstr = strsignal(sig); 1265 if (sigstr != NULL) 1266 out2str(sigstr); 1267 else 1268 out2str("Unknown signal"); 1269 if (coredump) 1270 out2str(" (core dumped)"); 1271 out2c('\n'); 1272 flushout(out2); 1273 } 1274 } else { 1275 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1276 thisjob->changed = 1; 1277 } 1278 return pid; 1279 } 1280 1281 1282 1283 /* 1284 * return 1 if there are stopped jobs, otherwise 0 1285 */ 1286 int job_warning = 0; 1287 int 1288 stoppedjobs(void) 1289 { 1290 int jobno; 1291 struct job *jp; 1292 1293 if (job_warning) 1294 return (0); 1295 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1296 if (jp->used == 0) 1297 continue; 1298 if (jp->state == JOBSTOPPED) { 1299 out2fmt_flush("You have stopped jobs.\n"); 1300 job_warning = 2; 1301 return (1); 1302 } 1303 } 1304 1305 return (0); 1306 } 1307 1308 1309 static void 1310 checkzombies(void) 1311 { 1312 while (njobs > 0 && dowait(0, NULL) > 0) 1313 ; 1314 } 1315 1316 1317 int 1318 backgndpidset(void) 1319 { 1320 return backgndpid != -1; 1321 } 1322 1323 1324 pid_t 1325 backgndpidval(void) 1326 { 1327 if (bgjob != NULL && !forcelocal) 1328 bgjob->remembered = 1; 1329 return backgndpid; 1330 } 1331 1332 /* 1333 * Return a string identifying a command (to be printed by the 1334 * jobs command. 1335 */ 1336 1337 static char *cmdnextc; 1338 static int cmdnleft; 1339 #define MAXCMDTEXT 200 1340 1341 char * 1342 commandtext(union node *n) 1343 { 1344 char *name; 1345 1346 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1347 cmdnleft = MAXCMDTEXT - 4; 1348 cmdtxt(n); 1349 *cmdnextc = '\0'; 1350 return name; 1351 } 1352 1353 1354 static void 1355 cmdtxtdogroup(union node *n) 1356 { 1357 cmdputs("; do "); 1358 cmdtxt(n); 1359 cmdputs("; done"); 1360 } 1361 1362 1363 static void 1364 cmdtxtredir(union node *n, const char *op, int deffd) 1365 { 1366 char s[2]; 1367 1368 if (n->nfile.fd != deffd) { 1369 s[0] = n->nfile.fd + '0'; 1370 s[1] = '\0'; 1371 cmdputs(s); 1372 } 1373 cmdputs(op); 1374 if (n->type == NTOFD || n->type == NFROMFD) { 1375 if (n->ndup.dupfd >= 0) 1376 s[0] = n->ndup.dupfd + '0'; 1377 else 1378 s[0] = '-'; 1379 s[1] = '\0'; 1380 cmdputs(s); 1381 } else { 1382 cmdtxt(n->nfile.fname); 1383 } 1384 } 1385 1386 1387 static void 1388 cmdtxt(union node *n) 1389 { 1390 union node *np; 1391 struct nodelist *lp; 1392 1393 if (n == NULL) 1394 return; 1395 switch (n->type) { 1396 case NSEMI: 1397 cmdtxt(n->nbinary.ch1); 1398 cmdputs("; "); 1399 cmdtxt(n->nbinary.ch2); 1400 break; 1401 case NAND: 1402 cmdtxt(n->nbinary.ch1); 1403 cmdputs(" && "); 1404 cmdtxt(n->nbinary.ch2); 1405 break; 1406 case NOR: 1407 cmdtxt(n->nbinary.ch1); 1408 cmdputs(" || "); 1409 cmdtxt(n->nbinary.ch2); 1410 break; 1411 case NPIPE: 1412 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1413 cmdtxt(lp->n); 1414 if (lp->next) 1415 cmdputs(" | "); 1416 } 1417 break; 1418 case NSUBSHELL: 1419 cmdputs("("); 1420 cmdtxt(n->nredir.n); 1421 cmdputs(")"); 1422 break; 1423 case NREDIR: 1424 case NBACKGND: 1425 cmdtxt(n->nredir.n); 1426 break; 1427 case NIF: 1428 cmdputs("if "); 1429 cmdtxt(n->nif.test); 1430 cmdputs("; then "); 1431 cmdtxt(n->nif.ifpart); 1432 cmdputs("..."); 1433 break; 1434 case NWHILE: 1435 cmdputs("while "); 1436 cmdtxt(n->nbinary.ch1); 1437 cmdtxtdogroup(n->nbinary.ch2); 1438 break; 1439 case NUNTIL: 1440 cmdputs("until "); 1441 cmdtxt(n->nbinary.ch1); 1442 cmdtxtdogroup(n->nbinary.ch2); 1443 break; 1444 case NFOR: 1445 cmdputs("for "); 1446 cmdputs(n->nfor.var); 1447 cmdputs(" in ..."); 1448 break; 1449 case NCASE: 1450 cmdputs("case "); 1451 cmdputs(n->ncase.expr->narg.text); 1452 cmdputs(" in ..."); 1453 break; 1454 case NDEFUN: 1455 cmdputs(n->narg.text); 1456 cmdputs("() ..."); 1457 break; 1458 case NNOT: 1459 cmdputs("! "); 1460 cmdtxt(n->nnot.com); 1461 break; 1462 case NCMD: 1463 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1464 cmdtxt(np); 1465 if (np->narg.next) 1466 cmdputs(" "); 1467 } 1468 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1469 cmdputs(" "); 1470 cmdtxt(np); 1471 } 1472 break; 1473 case NARG: 1474 cmdputs(n->narg.text); 1475 break; 1476 case NTO: 1477 cmdtxtredir(n, ">", 1); 1478 break; 1479 case NAPPEND: 1480 cmdtxtredir(n, ">>", 1); 1481 break; 1482 case NTOFD: 1483 cmdtxtredir(n, ">&", 1); 1484 break; 1485 case NCLOBBER: 1486 cmdtxtredir(n, ">|", 1); 1487 break; 1488 case NFROM: 1489 cmdtxtredir(n, "<", 0); 1490 break; 1491 case NFROMTO: 1492 cmdtxtredir(n, "<>", 0); 1493 break; 1494 case NFROMFD: 1495 cmdtxtredir(n, "<&", 0); 1496 break; 1497 case NHERE: 1498 case NXHERE: 1499 cmdputs("<<..."); 1500 break; 1501 default: 1502 cmdputs("???"); 1503 break; 1504 } 1505 } 1506 1507 1508 1509 static void 1510 cmdputs(const char *s) 1511 { 1512 const char *p; 1513 char *q; 1514 char c; 1515 int subtype = 0; 1516 1517 if (cmdnleft <= 0) 1518 return; 1519 p = s; 1520 q = cmdnextc; 1521 while ((c = *p++) != '\0') { 1522 if (c == CTLESC) 1523 *q++ = *p++; 1524 else if (c == CTLVAR) { 1525 *q++ = '$'; 1526 if (--cmdnleft > 0) 1527 *q++ = '{'; 1528 subtype = *p++; 1529 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1530 *q++ = '#'; 1531 } else if (c == '=' && subtype != 0) { 1532 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1533 if (*q) 1534 q++; 1535 else 1536 cmdnleft++; 1537 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1538 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1539 --cmdnleft > 0) 1540 *q = q[-1], q++; 1541 subtype = 0; 1542 } else if (c == CTLENDVAR) { 1543 *q++ = '}'; 1544 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1545 cmdnleft -= 5; 1546 if (cmdnleft > 0) { 1547 *q++ = '$'; 1548 *q++ = '('; 1549 *q++ = '.'; 1550 *q++ = '.'; 1551 *q++ = '.'; 1552 *q++ = ')'; 1553 } 1554 } else if (c == CTLARI) { 1555 cmdnleft -= 2; 1556 if (cmdnleft > 0) { 1557 *q++ = '$'; 1558 *q++ = '('; 1559 *q++ = '('; 1560 } 1561 p++; 1562 } else if (c == CTLENDARI) { 1563 if (--cmdnleft > 0) { 1564 *q++ = ')'; 1565 *q++ = ')'; 1566 } 1567 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1568 cmdnleft++; /* ignore */ 1569 else 1570 *q++ = c; 1571 if (--cmdnleft <= 0) { 1572 *q++ = '.'; 1573 *q++ = '.'; 1574 *q++ = '.'; 1575 break; 1576 } 1577 } 1578 cmdnextc = q; 1579 } 1580