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