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 for (jp = jobtab ; jp < jobtab + njobs; jp++) 591 if (jp->used && jp->state == JOBDONE) { 592 if (! iflag || ! jp->changed) 593 freejob(jp); 594 else { 595 jp->remembered = 0; 596 if (jp == bgjob) 597 bgjob = NULL; 598 } 599 } 600 for (jp = jobtab ; ; jp++) { 601 if (jp >= jobtab + njobs) { /* no running procs */ 602 return 0; 603 } 604 if (jp->used && jp->state == 0) 605 break; 606 } 607 } 608 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 609 610 sig = pendingsig_waitcmd; 611 pendingsig_waitcmd = 0; 612 return sig + 128; 613 } 614 615 616 617 int 618 jobidcmd(int argc __unused, char **argv __unused) 619 { 620 struct job *jp; 621 int i; 622 623 nextopt(""); 624 jp = getjob(*argptr); 625 for (i = 0 ; i < jp->nprocs ; ) { 626 out1fmt("%d", (int)jp->ps[i].pid); 627 out1c(++i < jp->nprocs? ' ' : '\n'); 628 } 629 return 0; 630 } 631 632 633 634 /* 635 * Convert a job name to a job structure. 636 */ 637 638 static struct job * 639 getjob_nonotfound(const char *name) 640 { 641 int jobno; 642 struct job *found, *jp; 643 size_t namelen; 644 pid_t pid; 645 int i; 646 647 if (name == NULL) { 648 #if JOBS 649 name = "%+"; 650 #else 651 error("No current job"); 652 #endif 653 } 654 if (name[0] == '%') { 655 if (is_digit(name[1])) { 656 jobno = number(name + 1); 657 if (jobno > 0 && jobno <= njobs 658 && jobtab[jobno - 1].used != 0) 659 return &jobtab[jobno - 1]; 660 #if JOBS 661 } else if ((name[1] == '%' || name[1] == '+') && 662 name[2] == '\0') { 663 if ((jp = getcurjob(NULL)) == NULL) 664 error("No current job"); 665 return (jp); 666 } else if (name[1] == '-' && name[2] == '\0') { 667 if ((jp = getcurjob(NULL)) == NULL || 668 (jp = getcurjob(jp)) == NULL) 669 error("No previous job"); 670 return (jp); 671 #endif 672 } else if (name[1] == '?') { 673 found = NULL; 674 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 675 if (jp->used && jp->nprocs > 0 676 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 677 if (found) 678 error("%s: ambiguous", name); 679 found = jp; 680 } 681 } 682 if (found != NULL) 683 return (found); 684 } else { 685 namelen = strlen(name); 686 found = NULL; 687 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 688 if (jp->used && jp->nprocs > 0 689 && strncmp(jp->ps[0].cmd, name + 1, 690 namelen - 1) == 0) { 691 if (found) 692 error("%s: ambiguous", name); 693 found = jp; 694 } 695 } 696 if (found) 697 return found; 698 } 699 } else if (is_number(name)) { 700 pid = (pid_t)number(name); 701 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 702 if (jp->used && jp->nprocs > 0 703 && jp->ps[jp->nprocs - 1].pid == pid) 704 return jp; 705 } 706 } 707 return NULL; 708 } 709 710 711 static struct job * 712 getjob(const char *name) 713 { 714 struct job *jp; 715 716 jp = getjob_nonotfound(name); 717 if (jp == NULL) 718 error("No such job: %s", name); 719 return (jp); 720 } 721 722 723 int 724 killjob(const char *name, int sig) 725 { 726 struct job *jp; 727 int i, ret; 728 729 jp = getjob(name); 730 if (jp->state == JOBDONE) 731 return 0; 732 if (jp->jobctl) 733 return kill(-jp->ps[0].pid, sig); 734 ret = -1; 735 errno = ESRCH; 736 for (i = 0; i < jp->nprocs; i++) 737 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 738 if (kill(jp->ps[i].pid, sig) == 0) 739 ret = 0; 740 } else 741 ret = 0; 742 return ret; 743 } 744 745 /* 746 * Return a new job structure, 747 */ 748 749 struct job * 750 makejob(union node *node __unused, int nprocs) 751 { 752 int i; 753 struct job *jp; 754 755 for (i = njobs, jp = jobtab ; ; jp++) { 756 if (--i < 0) { 757 INTOFF; 758 if (njobs == 0) { 759 jobtab = ckmalloc(4 * sizeof jobtab[0]); 760 #if JOBS 761 jobmru = NULL; 762 #endif 763 } else { 764 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 765 memcpy(jp, jobtab, njobs * sizeof jp[0]); 766 #if JOBS 767 /* Relocate `next' pointers and list head */ 768 if (jobmru != NULL) 769 jobmru = &jp[jobmru - jobtab]; 770 for (i = 0; i < njobs; i++) 771 if (jp[i].next != NULL) 772 jp[i].next = &jp[jp[i].next - 773 jobtab]; 774 #endif 775 if (bgjob != NULL) 776 bgjob = &jp[bgjob - jobtab]; 777 /* Relocate `ps' pointers */ 778 for (i = 0; i < njobs; i++) 779 if (jp[i].ps == &jobtab[i].ps0) 780 jp[i].ps = &jp[i].ps0; 781 ckfree(jobtab); 782 jobtab = jp; 783 } 784 jp = jobtab + njobs; 785 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 786 ; 787 INTON; 788 break; 789 } 790 if (jp->used == 0) 791 break; 792 } 793 INTOFF; 794 jp->state = 0; 795 jp->used = 1; 796 jp->changed = 0; 797 jp->nprocs = 0; 798 jp->foreground = 0; 799 jp->remembered = 0; 800 jp->pipefail = pipefailflag; 801 #if JOBS 802 jp->jobctl = jobctl; 803 jp->next = NULL; 804 #endif 805 if (nprocs > 1) { 806 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 807 } else { 808 jp->ps = &jp->ps0; 809 } 810 INTON; 811 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 812 jp - jobtab + 1)); 813 return jp; 814 } 815 816 #if JOBS 817 static void 818 setcurjob(struct job *cj) 819 { 820 struct job *jp, *prev; 821 822 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 823 if (jp == cj) { 824 if (prev != NULL) 825 prev->next = jp->next; 826 else 827 jobmru = jp->next; 828 jp->next = jobmru; 829 jobmru = cj; 830 return; 831 } 832 } 833 cj->next = jobmru; 834 jobmru = cj; 835 } 836 837 static void 838 deljob(struct job *j) 839 { 840 struct job *jp, *prev; 841 842 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 843 if (jp == j) { 844 if (prev != NULL) 845 prev->next = jp->next; 846 else 847 jobmru = jp->next; 848 return; 849 } 850 } 851 } 852 853 /* 854 * Return the most recently used job that isn't `nj', and preferably one 855 * that is stopped. 856 */ 857 static struct job * 858 getcurjob(struct job *nj) 859 { 860 struct job *jp; 861 862 /* Try to find a stopped one.. */ 863 for (jp = jobmru; jp != NULL; jp = jp->next) 864 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 865 return (jp); 866 /* Otherwise the most recently used job that isn't `nj' */ 867 for (jp = jobmru; jp != NULL; jp = jp->next) 868 if (jp->used && jp != nj) 869 return (jp); 870 871 return (NULL); 872 } 873 874 #endif 875 876 /* 877 * Fork of a subshell. If we are doing job control, give the subshell its 878 * own process group. Jp is a job structure that the job is to be added to. 879 * N is the command that will be evaluated by the child. Both jp and n may 880 * be NULL. The mode parameter can be one of the following: 881 * FORK_FG - Fork off a foreground process. 882 * FORK_BG - Fork off a background process. 883 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 884 * process group even if job control is on. 885 * 886 * When job control is turned off, background processes have their standard 887 * input redirected to /dev/null (except for the second and later processes 888 * in a pipeline). 889 */ 890 891 pid_t 892 forkshell(struct job *jp, union node *n, int mode) 893 { 894 pid_t pid; 895 pid_t pgrp; 896 897 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 898 mode)); 899 INTOFF; 900 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 901 checkzombies(); 902 flushall(); 903 pid = fork(); 904 if (pid == -1) { 905 TRACE(("Fork failed, errno=%d\n", errno)); 906 INTON; 907 error("Cannot fork: %s", strerror(errno)); 908 } 909 if (pid == 0) { 910 struct job *p; 911 int wasroot; 912 int i; 913 914 TRACE(("Child shell %d\n", (int)getpid())); 915 wasroot = rootshell; 916 rootshell = 0; 917 handler = &main_handler; 918 closescript(); 919 INTON; 920 forcelocal = 0; 921 clear_traps(); 922 #if JOBS 923 jobctl = 0; /* do job control only in root shell */ 924 if (wasroot && mode != FORK_NOJOB && mflag) { 925 if (jp == NULL || jp->nprocs == 0) 926 pgrp = getpid(); 927 else 928 pgrp = jp->ps[0].pid; 929 if (setpgid(0, pgrp) == 0 && mode == FORK_FG && 930 ttyfd >= 0) { 931 /*** this causes superfluous TIOCSPGRPS ***/ 932 if (tcsetpgrp(ttyfd, pgrp) < 0) 933 error("tcsetpgrp failed, errno=%d", errno); 934 } 935 setsignal(SIGTSTP); 936 setsignal(SIGTTOU); 937 } else if (mode == FORK_BG) { 938 ignoresig(SIGINT); 939 ignoresig(SIGQUIT); 940 if ((jp == NULL || jp->nprocs == 0) && 941 ! fd0_redirected_p ()) { 942 close(0); 943 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 944 error("cannot open %s: %s", 945 _PATH_DEVNULL, strerror(errno)); 946 } 947 } 948 #else 949 if (mode == FORK_BG) { 950 ignoresig(SIGINT); 951 ignoresig(SIGQUIT); 952 if ((jp == NULL || jp->nprocs == 0) && 953 ! fd0_redirected_p ()) { 954 close(0); 955 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 956 error("cannot open %s: %s", 957 _PATH_DEVNULL, strerror(errno)); 958 } 959 } 960 #endif 961 INTOFF; 962 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 963 if (p->used) 964 freejob(p); 965 INTON; 966 if (wasroot && iflag) { 967 setsignal(SIGINT); 968 setsignal(SIGQUIT); 969 setsignal(SIGTERM); 970 } 971 return pid; 972 } 973 if (rootshell && mode != FORK_NOJOB && mflag) { 974 if (jp == NULL || jp->nprocs == 0) 975 pgrp = pid; 976 else 977 pgrp = jp->ps[0].pid; 978 setpgid(pid, pgrp); 979 } 980 if (mode == FORK_BG) { 981 if (bgjob != NULL && bgjob->state == JOBDONE && 982 !bgjob->remembered && !iflag) 983 freejob(bgjob); 984 backgndpid = pid; /* set $! */ 985 bgjob = jp; 986 } 987 if (jp) { 988 struct procstat *ps = &jp->ps[jp->nprocs++]; 989 ps->pid = pid; 990 ps->status = -1; 991 ps->cmd = nullstr; 992 if (iflag && rootshell && n) 993 ps->cmd = commandtext(n); 994 jp->foreground = mode == FORK_FG; 995 #if JOBS 996 setcurjob(jp); 997 #endif 998 } 999 INTON; 1000 TRACE(("In parent shell: child = %d\n", (int)pid)); 1001 return pid; 1002 } 1003 1004 1005 pid_t 1006 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 1007 { 1008 pid_t pid; 1009 struct jmploc jmploc; 1010 struct jmploc *savehandler; 1011 int inton; 1012 1013 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 1014 (void *)pip)); 1015 inton = is_int_on(); 1016 INTOFF; 1017 flushall(); 1018 savehandler = handler; 1019 pid = vfork(); 1020 if (pid == -1) { 1021 TRACE(("Vfork failed, errno=%d\n", errno)); 1022 INTON; 1023 error("Cannot fork: %s", strerror(errno)); 1024 } 1025 if (pid == 0) { 1026 TRACE(("Child shell %d\n", (int)getpid())); 1027 if (setjmp(jmploc.loc)) 1028 _exit(exitstatus); 1029 if (pip != NULL) { 1030 close(pip[0]); 1031 if (pip[1] != 1) { 1032 dup2(pip[1], 1); 1033 close(pip[1]); 1034 } 1035 } 1036 handler = &jmploc; 1037 shellexec(argv, envp, path, idx); 1038 } 1039 handler = savehandler; 1040 if (jp) { 1041 struct procstat *ps = &jp->ps[jp->nprocs++]; 1042 ps->pid = pid; 1043 ps->status = -1; 1044 ps->cmd = nullstr; 1045 jp->foreground = 1; 1046 #if JOBS 1047 setcurjob(jp); 1048 #endif 1049 } 1050 SETINTON(inton); 1051 TRACE(("In parent shell: child = %d\n", (int)pid)); 1052 return pid; 1053 } 1054 1055 1056 /* 1057 * Wait for job to finish. 1058 * 1059 * Under job control we have the problem that while a child process is 1060 * running interrupts generated by the user are sent to the child but not 1061 * to the shell. This means that an infinite loop started by an inter- 1062 * active user may be hard to kill. With job control turned off, an 1063 * interactive user may place an interactive program inside a loop. If 1064 * the interactive program catches interrupts, the user doesn't want 1065 * these interrupts to also abort the loop. The approach we take here 1066 * is to have the shell ignore interrupt signals while waiting for a 1067 * foreground process to terminate, and then send itself an interrupt 1068 * signal if the child process was terminated by an interrupt signal. 1069 * Unfortunately, some programs want to do a bit of cleanup and then 1070 * exit on interrupt; unless these processes terminate themselves by 1071 * sending a signal to themselves (instead of calling exit) they will 1072 * confuse this approach. 1073 */ 1074 1075 int 1076 waitforjob(struct job *jp, int *signaled) 1077 { 1078 #if JOBS 1079 int propagate_int = jp->jobctl && jp->foreground; 1080 #endif 1081 int status; 1082 int st; 1083 1084 INTOFF; 1085 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1086 while (jp->state == 0) 1087 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1088 DOWAIT_SIG_TRAP : 0), jp) == -1) 1089 dotrap(); 1090 #if JOBS 1091 if (jp->jobctl) { 1092 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0) 1093 error("tcsetpgrp failed, errno=%d\n", errno); 1094 } 1095 if (jp->state == JOBSTOPPED) 1096 setcurjob(jp); 1097 #endif 1098 status = getjobstatus(jp); 1099 if (signaled != NULL) 1100 *signaled = WIFSIGNALED(status); 1101 /* convert to 8 bits */ 1102 if (WIFEXITED(status)) 1103 st = WEXITSTATUS(status); 1104 #if JOBS 1105 else if (WIFSTOPPED(status)) 1106 st = WSTOPSIG(status) + 128; 1107 #endif 1108 else 1109 st = WTERMSIG(status) + 128; 1110 if (! JOBS || jp->state == JOBDONE) 1111 freejob(jp); 1112 if (int_pending()) { 1113 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1114 CLEAR_PENDING_INT; 1115 } 1116 #if JOBS 1117 else if (rootshell && propagate_int && 1118 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1119 kill(getpid(), SIGINT); 1120 #endif 1121 INTON; 1122 return st; 1123 } 1124 1125 1126 static void 1127 dummy_handler(int sig __unused) 1128 { 1129 } 1130 1131 /* 1132 * Wait for a process to terminate. 1133 */ 1134 1135 static pid_t 1136 dowait(int mode, struct job *job) 1137 { 1138 struct sigaction sa, osa; 1139 sigset_t mask, omask; 1140 pid_t pid; 1141 int status; 1142 struct procstat *sp; 1143 struct job *jp; 1144 struct job *thisjob; 1145 const char *sigstr; 1146 int done; 1147 int stopped; 1148 int sig; 1149 int coredump; 1150 int wflags; 1151 int restore_sigchld; 1152 1153 TRACE(("dowait(%d, %p) called\n", mode, job)); 1154 restore_sigchld = 0; 1155 if ((mode & DOWAIT_SIG) != 0) { 1156 sigfillset(&mask); 1157 sigprocmask(SIG_BLOCK, &mask, &omask); 1158 INTOFF; 1159 if (!issigchldtrapped()) { 1160 restore_sigchld = 1; 1161 sa.sa_handler = dummy_handler; 1162 sa.sa_flags = 0; 1163 sigemptyset(&sa.sa_mask); 1164 sigaction(SIGCHLD, &sa, &osa); 1165 } 1166 } 1167 do { 1168 #if JOBS 1169 if (iflag) 1170 wflags = WUNTRACED | WCONTINUED; 1171 else 1172 #endif 1173 wflags = 0; 1174 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1175 wflags |= WNOHANG; 1176 pid = wait3(&status, wflags, (struct rusage *)NULL); 1177 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1178 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1179 pid = -1; 1180 if (((mode & DOWAIT_SIG_TRAP) != 0 ? 1181 pendingsig : pendingsig_waitcmd) != 0) { 1182 errno = EINTR; 1183 break; 1184 } 1185 sigsuspend(&omask); 1186 if (int_pending()) 1187 break; 1188 } 1189 } while (pid == -1 && errno == EINTR); 1190 if (pid == -1 && errno == ECHILD && job != NULL) 1191 job->state = JOBDONE; 1192 if ((mode & DOWAIT_SIG) != 0) { 1193 if (restore_sigchld) 1194 sigaction(SIGCHLD, &osa, NULL); 1195 sigprocmask(SIG_SETMASK, &omask, NULL); 1196 INTON; 1197 } 1198 if (pid <= 0) 1199 return pid; 1200 INTOFF; 1201 thisjob = NULL; 1202 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1203 if (jp->used && jp->nprocs > 0) { 1204 done = 1; 1205 stopped = 1; 1206 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1207 if (sp->pid == -1) 1208 continue; 1209 if (sp->pid == pid && (sp->status == -1 || 1210 WIFSTOPPED(sp->status))) { 1211 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1212 (int)pid, sp->status, 1213 status)); 1214 if (WIFCONTINUED(status)) { 1215 sp->status = -1; 1216 jp->state = 0; 1217 } else 1218 sp->status = status; 1219 thisjob = jp; 1220 } 1221 if (sp->status == -1) 1222 stopped = 0; 1223 else if (WIFSTOPPED(sp->status)) 1224 done = 0; 1225 } 1226 if (stopped) { /* stopped or done */ 1227 int state = done? JOBDONE : JOBSTOPPED; 1228 if (jp->state != state) { 1229 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1230 jp->state = state; 1231 if (jp != job) { 1232 if (done && !jp->remembered && 1233 !iflag && jp != bgjob) 1234 freejob(jp); 1235 #if JOBS 1236 else if (done) 1237 deljob(jp); 1238 #endif 1239 } 1240 } 1241 } 1242 } 1243 } 1244 INTON; 1245 if (!thisjob || thisjob->state == 0) 1246 ; 1247 else if ((!rootshell || !iflag || thisjob == job) && 1248 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1249 sig = 0; 1250 coredump = 0; 1251 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1252 if (WIFSIGNALED(sp->status)) { 1253 sig = WTERMSIG(sp->status); 1254 coredump = WCOREDUMP(sp->status); 1255 } 1256 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1257 sigstr = strsignal(sig); 1258 if (sigstr != NULL) 1259 out2str(sigstr); 1260 else 1261 out2str("Unknown signal"); 1262 if (coredump) 1263 out2str(" (core dumped)"); 1264 out2c('\n'); 1265 flushout(out2); 1266 } 1267 } else { 1268 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1269 thisjob->changed = 1; 1270 } 1271 return pid; 1272 } 1273 1274 1275 1276 /* 1277 * return 1 if there are stopped jobs, otherwise 0 1278 */ 1279 int job_warning = 0; 1280 int 1281 stoppedjobs(void) 1282 { 1283 int jobno; 1284 struct job *jp; 1285 1286 if (job_warning) 1287 return (0); 1288 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1289 if (jp->used == 0) 1290 continue; 1291 if (jp->state == JOBSTOPPED) { 1292 out2fmt_flush("You have stopped jobs.\n"); 1293 job_warning = 2; 1294 return (1); 1295 } 1296 } 1297 1298 return (0); 1299 } 1300 1301 1302 static void 1303 checkzombies(void) 1304 { 1305 while (njobs > 0 && dowait(0, NULL) > 0) 1306 ; 1307 } 1308 1309 1310 int 1311 backgndpidset(void) 1312 { 1313 return backgndpid != -1; 1314 } 1315 1316 1317 pid_t 1318 backgndpidval(void) 1319 { 1320 if (bgjob != NULL && !forcelocal) 1321 bgjob->remembered = 1; 1322 return backgndpid; 1323 } 1324 1325 /* 1326 * Return a string identifying a command (to be printed by the 1327 * jobs command. 1328 */ 1329 1330 static char *cmdnextc; 1331 static int cmdnleft; 1332 #define MAXCMDTEXT 200 1333 1334 char * 1335 commandtext(union node *n) 1336 { 1337 char *name; 1338 1339 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1340 cmdnleft = MAXCMDTEXT - 4; 1341 cmdtxt(n); 1342 *cmdnextc = '\0'; 1343 return name; 1344 } 1345 1346 1347 static void 1348 cmdtxtdogroup(union node *n) 1349 { 1350 cmdputs("; do "); 1351 cmdtxt(n); 1352 cmdputs("; done"); 1353 } 1354 1355 1356 static void 1357 cmdtxtredir(union node *n, const char *op, int deffd) 1358 { 1359 char s[2]; 1360 1361 if (n->nfile.fd != deffd) { 1362 s[0] = n->nfile.fd + '0'; 1363 s[1] = '\0'; 1364 cmdputs(s); 1365 } 1366 cmdputs(op); 1367 if (n->type == NTOFD || n->type == NFROMFD) { 1368 if (n->ndup.dupfd >= 0) 1369 s[0] = n->ndup.dupfd + '0'; 1370 else 1371 s[0] = '-'; 1372 s[1] = '\0'; 1373 cmdputs(s); 1374 } else { 1375 cmdtxt(n->nfile.fname); 1376 } 1377 } 1378 1379 1380 static void 1381 cmdtxt(union node *n) 1382 { 1383 union node *np; 1384 struct nodelist *lp; 1385 1386 if (n == NULL) 1387 return; 1388 switch (n->type) { 1389 case NSEMI: 1390 cmdtxt(n->nbinary.ch1); 1391 cmdputs("; "); 1392 cmdtxt(n->nbinary.ch2); 1393 break; 1394 case NAND: 1395 cmdtxt(n->nbinary.ch1); 1396 cmdputs(" && "); 1397 cmdtxt(n->nbinary.ch2); 1398 break; 1399 case NOR: 1400 cmdtxt(n->nbinary.ch1); 1401 cmdputs(" || "); 1402 cmdtxt(n->nbinary.ch2); 1403 break; 1404 case NPIPE: 1405 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1406 cmdtxt(lp->n); 1407 if (lp->next) 1408 cmdputs(" | "); 1409 } 1410 break; 1411 case NSUBSHELL: 1412 cmdputs("("); 1413 cmdtxt(n->nredir.n); 1414 cmdputs(")"); 1415 break; 1416 case NREDIR: 1417 case NBACKGND: 1418 cmdtxt(n->nredir.n); 1419 break; 1420 case NIF: 1421 cmdputs("if "); 1422 cmdtxt(n->nif.test); 1423 cmdputs("; then "); 1424 cmdtxt(n->nif.ifpart); 1425 cmdputs("..."); 1426 break; 1427 case NWHILE: 1428 cmdputs("while "); 1429 cmdtxt(n->nbinary.ch1); 1430 cmdtxtdogroup(n->nbinary.ch2); 1431 break; 1432 case NUNTIL: 1433 cmdputs("until "); 1434 cmdtxt(n->nbinary.ch1); 1435 cmdtxtdogroup(n->nbinary.ch2); 1436 break; 1437 case NFOR: 1438 cmdputs("for "); 1439 cmdputs(n->nfor.var); 1440 cmdputs(" in ..."); 1441 break; 1442 case NCASE: 1443 cmdputs("case "); 1444 cmdputs(n->ncase.expr->narg.text); 1445 cmdputs(" in ..."); 1446 break; 1447 case NDEFUN: 1448 cmdputs(n->narg.text); 1449 cmdputs("() ..."); 1450 break; 1451 case NNOT: 1452 cmdputs("! "); 1453 cmdtxt(n->nnot.com); 1454 break; 1455 case NCMD: 1456 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1457 cmdtxt(np); 1458 if (np->narg.next) 1459 cmdputs(" "); 1460 } 1461 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1462 cmdputs(" "); 1463 cmdtxt(np); 1464 } 1465 break; 1466 case NARG: 1467 cmdputs(n->narg.text); 1468 break; 1469 case NTO: 1470 cmdtxtredir(n, ">", 1); 1471 break; 1472 case NAPPEND: 1473 cmdtxtredir(n, ">>", 1); 1474 break; 1475 case NTOFD: 1476 cmdtxtredir(n, ">&", 1); 1477 break; 1478 case NCLOBBER: 1479 cmdtxtredir(n, ">|", 1); 1480 break; 1481 case NFROM: 1482 cmdtxtredir(n, "<", 0); 1483 break; 1484 case NFROMTO: 1485 cmdtxtredir(n, "<>", 0); 1486 break; 1487 case NFROMFD: 1488 cmdtxtredir(n, "<&", 0); 1489 break; 1490 case NHERE: 1491 case NXHERE: 1492 cmdputs("<<..."); 1493 break; 1494 default: 1495 cmdputs("???"); 1496 break; 1497 } 1498 } 1499 1500 1501 1502 static void 1503 cmdputs(const char *s) 1504 { 1505 const char *p; 1506 char *q; 1507 char c; 1508 int subtype = 0; 1509 1510 if (cmdnleft <= 0) 1511 return; 1512 p = s; 1513 q = cmdnextc; 1514 while ((c = *p++) != '\0') { 1515 if (c == CTLESC) 1516 *q++ = *p++; 1517 else if (c == CTLVAR) { 1518 *q++ = '$'; 1519 if (--cmdnleft > 0) 1520 *q++ = '{'; 1521 subtype = *p++; 1522 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1523 *q++ = '#'; 1524 } else if (c == '=' && subtype != 0) { 1525 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1526 if (*q) 1527 q++; 1528 else 1529 cmdnleft++; 1530 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1531 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1532 --cmdnleft > 0) 1533 *q = q[-1], q++; 1534 subtype = 0; 1535 } else if (c == CTLENDVAR) { 1536 *q++ = '}'; 1537 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1538 cmdnleft -= 5; 1539 if (cmdnleft > 0) { 1540 *q++ = '$'; 1541 *q++ = '('; 1542 *q++ = '.'; 1543 *q++ = '.'; 1544 *q++ = '.'; 1545 *q++ = ')'; 1546 } 1547 } else if (c == CTLARI) { 1548 cmdnleft -= 2; 1549 if (cmdnleft > 0) { 1550 *q++ = '$'; 1551 *q++ = '('; 1552 *q++ = '('; 1553 } 1554 p++; 1555 } else if (c == CTLENDARI) { 1556 if (--cmdnleft > 0) { 1557 *q++ = ')'; 1558 *q++ = ')'; 1559 } 1560 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1561 cmdnleft++; /* ignore */ 1562 else 1563 *q++ = c; 1564 if (--cmdnleft <= 0) { 1565 *q++ = '.'; 1566 *q++ = '.'; 1567 *q++ = '.'; 1568 break; 1569 } 1570 } 1571 cmdnextc = q; 1572 } 1573