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 #endif /* not lint */ 35 #include <sys/cdefs.h> 36 #include <sys/ioctl.h> 37 #include <sys/param.h> 38 #include <sys/resource.h> 39 #include <sys/time.h> 40 #include <sys/wait.h> 41 #include <errno.h> 42 #include <fcntl.h> 43 #include <paths.h> 44 #include <signal.h> 45 #include <stddef.h> 46 #include <stdlib.h> 47 #include <unistd.h> 48 49 #include "shell.h" 50 #if JOBS 51 #include <termios.h> 52 #undef CEOF /* syntax.h redefines this */ 53 #endif 54 #include "redir.h" 55 #include "exec.h" 56 #include "show.h" 57 #include "main.h" 58 #include "parser.h" 59 #include "nodes.h" 60 #include "jobs.h" 61 #include "options.h" 62 #include "trap.h" 63 #include "syntax.h" 64 #include "input.h" 65 #include "output.h" 66 #include "memalloc.h" 67 #include "error.h" 68 #include "mystring.h" 69 #include "var.h" 70 #include "builtins.h" 71 #include "eval.h" 72 73 74 /* 75 * A job structure contains information about a job. A job is either a 76 * single process or a set of processes contained in a pipeline. In the 77 * latter case, pidlist will be non-NULL, and will point to a -1 terminated 78 * array of pids. 79 */ 80 81 struct procstat { 82 pid_t pid; /* process id */ 83 int status; /* status flags (defined above) */ 84 char *cmd; /* text of command being run */ 85 }; 86 87 88 /* states */ 89 #define JOBSTOPPED 1 /* all procs are stopped */ 90 #define JOBDONE 2 /* all procs are completed */ 91 92 93 struct job { 94 struct procstat ps0; /* status of process */ 95 struct procstat *ps; /* status or processes when more than one */ 96 short nprocs; /* number of processes */ 97 pid_t pgrp; /* process group of this job */ 98 char state; /* true if job is finished */ 99 char used; /* true if this entry is in used */ 100 char changed; /* true if status has changed */ 101 char foreground; /* true if running in the foreground */ 102 char remembered; /* true if $! referenced */ 103 char pipefail; /* pass any non-zero status */ 104 #if JOBS 105 char jobctl; /* job running under job control */ 106 struct job *next; /* job used after this one */ 107 #endif 108 }; 109 110 111 static struct job *jobtab; /* array of jobs */ 112 static int njobs; /* size of array */ 113 static pid_t backgndpid = -1; /* pid of last background process */ 114 static struct job *bgjob = NULL; /* last background process */ 115 #if JOBS 116 static struct job *jobmru; /* most recently used job list */ 117 static pid_t initialpgrp; /* pgrp of shell on invocation */ 118 #endif 119 static int ttyfd = -1; 120 121 /* mode flags for dowait */ 122 #define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 123 #define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signal */ 124 #define DOWAIT_SIG_TRAP 0x4 /* if DOWAIT_SIG, abort on trapped signal only */ 125 126 #if JOBS 127 static void restartjob(struct job *); 128 #endif 129 static void freejob(struct job *); 130 static int waitcmdloop(struct job *); 131 static struct job *getjob_nonotfound(const char *); 132 static struct job *getjob(const char *); 133 pid_t killjob(const char *, int); 134 static pid_t dowait(int, struct job *); 135 static void checkzombies(void); 136 static void cmdtxt(union node *); 137 static void cmdputs(const char *); 138 #if JOBS 139 static void setcurjob(struct job *); 140 static void deljob(struct job *); 141 static struct job *getcurjob(struct job *); 142 #endif 143 static int getjobstatus(const struct job *); 144 static void printjobcmd(struct job *); 145 static void showjob(struct job *, int); 146 147 148 /* 149 * Turn job control on and off. 150 */ 151 152 static int jobctl; 153 154 #if JOBS 155 static void 156 jobctl_notty(void) 157 { 158 if (ttyfd >= 0) { 159 close(ttyfd); 160 ttyfd = -1; 161 } 162 if (!iflag) { 163 setsignal(SIGTSTP); 164 setsignal(SIGTTOU); 165 setsignal(SIGTTIN); 166 jobctl = 1; 167 return; 168 } 169 out2fmt_flush("sh: can't access tty; job control turned off\n"); 170 mflag = 0; 171 } 172 173 void 174 setjobctl(int on) 175 { 176 int i; 177 178 if (on == jobctl || rootshell == 0) 179 return; 180 if (on) { 181 if (ttyfd != -1) 182 close(ttyfd); 183 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 184 i = 0; 185 while (i <= 2 && !isatty(i)) 186 i++; 187 if (i > 2 || 188 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) { 189 jobctl_notty(); 190 return; 191 } 192 } 193 if (ttyfd < 10) { 194 /* 195 * Keep our TTY file descriptor out of the way of 196 * the user's redirections. 197 */ 198 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 199 jobctl_notty(); 200 return; 201 } 202 close(ttyfd); 203 ttyfd = i; 204 } 205 do { /* while we are in the background */ 206 initialpgrp = tcgetpgrp(ttyfd); 207 if (initialpgrp < 0) { 208 jobctl_notty(); 209 return; 210 } 211 if (initialpgrp != getpgrp()) { 212 if (!iflag) { 213 initialpgrp = -1; 214 jobctl_notty(); 215 return; 216 } 217 kill(0, SIGTTIN); 218 continue; 219 } 220 } while (0); 221 setsignal(SIGTSTP); 222 setsignal(SIGTTOU); 223 setsignal(SIGTTIN); 224 setpgid(0, rootpid); 225 tcsetpgrp(ttyfd, rootpid); 226 } else { /* turning job control off */ 227 setpgid(0, initialpgrp); 228 if (ttyfd >= 0) { 229 tcsetpgrp(ttyfd, initialpgrp); 230 close(ttyfd); 231 ttyfd = -1; 232 } 233 setsignal(SIGTSTP); 234 setsignal(SIGTTOU); 235 setsignal(SIGTTIN); 236 } 237 jobctl = on; 238 } 239 #endif 240 241 242 #if JOBS 243 int 244 fgcmd(int argc __unused, char **argv __unused) 245 { 246 struct job *jp; 247 pid_t pgrp; 248 int status; 249 250 nextopt(""); 251 jp = getjob(*argptr); 252 if (jp->jobctl == 0) 253 error("job not created under job control"); 254 printjobcmd(jp); 255 flushout(&output); 256 pgrp = jp->ps[0].pid; 257 if (ttyfd >= 0) 258 tcsetpgrp(ttyfd, pgrp); 259 restartjob(jp); 260 jp->foreground = 1; 261 INTOFF; 262 status = waitforjob(jp, (int *)NULL); 263 INTON; 264 return status; 265 } 266 267 268 int 269 bgcmd(int argc __unused, char **argv __unused) 270 { 271 struct job *jp; 272 273 nextopt(""); 274 do { 275 jp = getjob(*argptr); 276 if (jp->jobctl == 0) 277 error("job not created under job control"); 278 if (jp->state == JOBDONE) 279 continue; 280 restartjob(jp); 281 jp->foreground = 0; 282 out1fmt("[%td] ", jp - jobtab + 1); 283 printjobcmd(jp); 284 } while (*argptr != NULL && *++argptr != NULL); 285 return 0; 286 } 287 288 289 static void 290 restartjob(struct job *jp) 291 { 292 struct procstat *ps; 293 int i; 294 295 if (jp->state == JOBDONE) 296 return; 297 setcurjob(jp); 298 INTOFF; 299 kill(-jp->ps[0].pid, SIGCONT); 300 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 301 if (WIFSTOPPED(ps->status)) { 302 ps->status = -1; 303 jp->state = 0; 304 } 305 } 306 INTON; 307 } 308 #endif 309 310 311 int 312 jobscmd(int argc __unused, char *argv[] __unused) 313 { 314 char *id; 315 int ch, mode; 316 317 mode = SHOWJOBS_DEFAULT; 318 while ((ch = nextopt("lps")) != '\0') { 319 switch (ch) { 320 case 'l': 321 mode = SHOWJOBS_VERBOSE; 322 break; 323 case 'p': 324 mode = SHOWJOBS_PGIDS; 325 break; 326 case 's': 327 mode = SHOWJOBS_PIDS; 328 break; 329 } 330 } 331 332 if (*argptr == NULL) 333 showjobs(0, mode); 334 else 335 while ((id = *argptr++) != NULL) 336 showjob(getjob(id), mode); 337 338 return (0); 339 } 340 341 static int getjobstatus(const struct job *jp) 342 { 343 int i, status; 344 345 if (!jp->pipefail) 346 return (jp->ps[jp->nprocs - 1].status); 347 for (i = jp->nprocs - 1; i >= 0; i--) { 348 status = jp->ps[i].status; 349 if (status != 0) 350 return (status); 351 } 352 return (0); 353 } 354 355 static void 356 printjobcmd(struct job *jp) 357 { 358 struct procstat *ps; 359 int i; 360 361 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 362 out1str(ps->cmd); 363 if (i > 0) 364 out1str(" | "); 365 } 366 out1c('\n'); 367 } 368 369 static void 370 showjob(struct job *jp, int mode) 371 { 372 char s[64]; 373 char statebuf[16]; 374 const char *statestr, *coredump; 375 struct procstat *ps; 376 struct job *j; 377 int col, curr, i, jobno, prev, procno, status; 378 char c; 379 380 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 381 jobno = jp - jobtab + 1; 382 curr = prev = 0; 383 #if JOBS 384 if ((j = getcurjob(NULL)) != NULL) { 385 curr = j - jobtab + 1; 386 if ((j = getcurjob(j)) != NULL) 387 prev = j - jobtab + 1; 388 } 389 #endif 390 coredump = ""; 391 status = getjobstatus(jp); 392 if (jp->state == 0) { 393 statestr = "Running"; 394 #if JOBS 395 } else if (jp->state == JOBSTOPPED) { 396 ps = jp->ps + jp->nprocs - 1; 397 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 398 ps--; 399 if (WIFSTOPPED(ps->status)) 400 i = WSTOPSIG(ps->status); 401 else 402 i = -1; 403 statestr = strsignal(i); 404 if (statestr == NULL) 405 statestr = "Suspended"; 406 #endif 407 } else if (WIFEXITED(status)) { 408 if (WEXITSTATUS(status) == 0) 409 statestr = "Done"; 410 else { 411 fmtstr(statebuf, sizeof(statebuf), "Done(%d)", 412 WEXITSTATUS(status)); 413 statestr = statebuf; 414 } 415 } else { 416 i = WTERMSIG(status); 417 statestr = strsignal(i); 418 if (statestr == NULL) 419 statestr = "Unknown signal"; 420 if (WCOREDUMP(status)) 421 coredump = " (core dumped)"; 422 } 423 424 for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */ 425 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 426 out1fmt("%d\n", (int)ps->pid); 427 continue; 428 } 429 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 430 continue; 431 if (jobno == curr && ps == jp->ps) 432 c = '+'; 433 else if (jobno == prev && ps == jp->ps) 434 c = '-'; 435 else 436 c = ' '; 437 if (ps == jp->ps) 438 fmtstr(s, 64, "[%d] %c ", jobno, c); 439 else 440 fmtstr(s, 64, " %c ", c); 441 out1str(s); 442 col = strlen(s); 443 if (mode == SHOWJOBS_VERBOSE) { 444 fmtstr(s, 64, "%d ", (int)ps->pid); 445 out1str(s); 446 col += strlen(s); 447 } 448 if (ps == jp->ps) { 449 out1str(statestr); 450 out1str(coredump); 451 col += strlen(statestr) + strlen(coredump); 452 } 453 do { 454 out1c(' '); 455 col++; 456 } while (col < 30); 457 if (mode == SHOWJOBS_VERBOSE) { 458 out1str(ps->cmd); 459 out1c('\n'); 460 } else 461 printjobcmd(jp); 462 } 463 } 464 465 /* 466 * Print a list of jobs. If "change" is nonzero, only print jobs whose 467 * statuses have changed since the last call to showjobs. 468 * 469 * If the shell is interrupted in the process of creating a job, the 470 * result may be a job structure containing zero processes. Such structures 471 * will be freed here. 472 */ 473 474 void 475 showjobs(int change, int mode) 476 { 477 int jobno; 478 struct job *jp; 479 480 TRACE(("showjobs(%d) called\n", change)); 481 checkzombies(); 482 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 483 if (! jp->used) 484 continue; 485 if (jp->nprocs == 0) { 486 freejob(jp); 487 continue; 488 } 489 if (change && ! jp->changed) 490 continue; 491 showjob(jp, mode); 492 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 493 jp->changed = 0; 494 /* Hack: discard jobs for which $! has not been 495 * referenced in interactive mode when they terminate. 496 */ 497 if (jp->state == JOBDONE && !jp->remembered && 498 (iflag || jp != bgjob)) { 499 freejob(jp); 500 } 501 } 502 } 503 } 504 505 506 /* 507 * Mark a job structure as unused. 508 */ 509 510 static void 511 freejob(struct job *jp) 512 { 513 struct procstat *ps; 514 int i; 515 516 INTOFF; 517 if (bgjob == jp) 518 bgjob = NULL; 519 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 520 if (ps->cmd != nullstr) 521 ckfree(ps->cmd); 522 } 523 if (jp->ps != &jp->ps0) 524 ckfree(jp->ps); 525 jp->used = 0; 526 #if JOBS 527 deljob(jp); 528 #endif 529 INTON; 530 } 531 532 533 534 int 535 waitcmd(int argc __unused, char **argv __unused) 536 { 537 struct job *job; 538 int retval; 539 540 nextopt(""); 541 if (*argptr == NULL) 542 return (waitcmdloop(NULL)); 543 544 do { 545 job = getjob_nonotfound(*argptr); 546 if (job == NULL) 547 retval = 127; 548 else 549 retval = waitcmdloop(job); 550 argptr++; 551 } while (*argptr != NULL); 552 553 return (retval); 554 } 555 556 static int 557 waitcmdloop(struct job *job) 558 { 559 int status, retval, sig; 560 struct job *jp; 561 562 /* 563 * Loop until a process is terminated or stopped, or a SIGINT is 564 * received. 565 */ 566 567 do { 568 if (job != NULL) { 569 if (job->state == JOBDONE) { 570 status = getjobstatus(job); 571 if (WIFEXITED(status)) 572 retval = WEXITSTATUS(status); 573 else 574 retval = WTERMSIG(status) + 128; 575 if (! iflag || ! job->changed) 576 freejob(job); 577 else { 578 job->remembered = 0; 579 if (job == bgjob) 580 bgjob = NULL; 581 } 582 return retval; 583 } 584 } else { 585 if (njobs == 0) 586 return 0; 587 for (jp = jobtab ; jp < jobtab + njobs; jp++) 588 if (jp->used && jp->state == JOBDONE) { 589 if (! iflag || ! jp->changed) 590 freejob(jp); 591 else { 592 jp->remembered = 0; 593 if (jp == bgjob) 594 bgjob = NULL; 595 } 596 } 597 for (jp = jobtab ; ; jp++) { 598 if (jp >= jobtab + njobs) { /* no running procs */ 599 return 0; 600 } 601 if (jp->used && jp->state == 0) 602 break; 603 } 604 } 605 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 606 607 sig = pendingsig_waitcmd; 608 pendingsig_waitcmd = 0; 609 return sig + 128; 610 } 611 612 613 614 int 615 jobidcmd(int argc __unused, char **argv __unused) 616 { 617 struct job *jp; 618 int i; 619 620 nextopt(""); 621 jp = getjob(*argptr); 622 for (i = 0 ; i < jp->nprocs ; ) { 623 out1fmt("%d", (int)jp->ps[i].pid); 624 out1c(++i < jp->nprocs? ' ' : '\n'); 625 } 626 return 0; 627 } 628 629 630 631 /* 632 * Convert a job name to a job structure. 633 */ 634 635 static struct job * 636 getjob_nonotfound(const char *name) 637 { 638 int jobno; 639 struct job *found, *jp; 640 size_t namelen; 641 pid_t pid; 642 int i; 643 644 if (name == NULL) { 645 #if JOBS 646 name = "%+"; 647 #else 648 error("No current job"); 649 #endif 650 } 651 if (name[0] == '%') { 652 if (is_digit(name[1])) { 653 jobno = number(name + 1); 654 if (jobno > 0 && jobno <= njobs 655 && jobtab[jobno - 1].used != 0) 656 return &jobtab[jobno - 1]; 657 #if JOBS 658 } else if ((name[1] == '%' || name[1] == '+') && 659 name[2] == '\0') { 660 if ((jp = getcurjob(NULL)) == NULL) 661 error("No current job"); 662 return (jp); 663 } else if (name[1] == '-' && name[2] == '\0') { 664 if ((jp = getcurjob(NULL)) == NULL || 665 (jp = getcurjob(jp)) == NULL) 666 error("No previous job"); 667 return (jp); 668 #endif 669 } else if (name[1] == '?') { 670 found = NULL; 671 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 672 if (jp->used && jp->nprocs > 0 673 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 674 if (found) 675 error("%s: ambiguous", name); 676 found = jp; 677 } 678 } 679 if (found != NULL) 680 return (found); 681 } else { 682 namelen = strlen(name); 683 found = NULL; 684 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 685 if (jp->used && jp->nprocs > 0 686 && strncmp(jp->ps[0].cmd, name + 1, 687 namelen - 1) == 0) { 688 if (found) 689 error("%s: ambiguous", name); 690 found = jp; 691 } 692 } 693 if (found) 694 return found; 695 } 696 } else if (is_number(name)) { 697 pid = (pid_t)number(name); 698 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 699 if (jp->used && jp->nprocs > 0 700 && jp->ps[jp->nprocs - 1].pid == pid) 701 return jp; 702 } 703 } 704 return NULL; 705 } 706 707 708 static struct job * 709 getjob(const char *name) 710 { 711 struct job *jp; 712 713 jp = getjob_nonotfound(name); 714 if (jp == NULL) 715 error("No such job: %s", name); 716 return (jp); 717 } 718 719 720 int 721 killjob(const char *name, int sig) 722 { 723 struct job *jp; 724 int i, ret; 725 726 jp = getjob(name); 727 if (jp->state == JOBDONE) 728 return 0; 729 if (jp->jobctl) 730 return kill(-jp->ps[0].pid, sig); 731 ret = -1; 732 errno = ESRCH; 733 for (i = 0; i < jp->nprocs; i++) 734 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 735 if (kill(jp->ps[i].pid, sig) == 0) 736 ret = 0; 737 } else 738 ret = 0; 739 return ret; 740 } 741 742 /* 743 * Return a new job structure, 744 */ 745 746 struct job * 747 makejob(union node *node __unused, int nprocs) 748 { 749 int i; 750 struct job *jp; 751 752 for (i = njobs, jp = jobtab ; ; jp++) { 753 if (--i < 0) { 754 INTOFF; 755 if (njobs == 0) { 756 jobtab = ckmalloc(4 * sizeof jobtab[0]); 757 #if JOBS 758 jobmru = NULL; 759 #endif 760 } else { 761 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 762 memcpy(jp, jobtab, njobs * sizeof jp[0]); 763 #if JOBS 764 /* Relocate `next' pointers and list head */ 765 if (jobmru != NULL) 766 jobmru = &jp[jobmru - jobtab]; 767 for (i = 0; i < njobs; i++) 768 if (jp[i].next != NULL) 769 jp[i].next = &jp[jp[i].next - 770 jobtab]; 771 #endif 772 if (bgjob != NULL) 773 bgjob = &jp[bgjob - jobtab]; 774 /* Relocate `ps' pointers */ 775 for (i = 0; i < njobs; i++) 776 if (jp[i].ps == &jobtab[i].ps0) 777 jp[i].ps = &jp[i].ps0; 778 ckfree(jobtab); 779 jobtab = jp; 780 } 781 jp = jobtab + njobs; 782 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 783 ; 784 INTON; 785 break; 786 } 787 if (jp->used == 0) 788 break; 789 } 790 INTOFF; 791 jp->state = 0; 792 jp->used = 1; 793 jp->changed = 0; 794 jp->nprocs = 0; 795 jp->foreground = 0; 796 jp->remembered = 0; 797 jp->pipefail = pipefailflag; 798 #if JOBS 799 jp->jobctl = jobctl; 800 jp->next = NULL; 801 #endif 802 if (nprocs > 1) { 803 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 804 } else { 805 jp->ps = &jp->ps0; 806 } 807 INTON; 808 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 809 jp - jobtab + 1)); 810 return jp; 811 } 812 813 #if JOBS 814 static void 815 setcurjob(struct job *cj) 816 { 817 struct job *jp, *prev; 818 819 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 820 if (jp == cj) { 821 if (prev != NULL) 822 prev->next = jp->next; 823 else 824 jobmru = jp->next; 825 jp->next = jobmru; 826 jobmru = cj; 827 return; 828 } 829 } 830 cj->next = jobmru; 831 jobmru = cj; 832 } 833 834 static void 835 deljob(struct job *j) 836 { 837 struct job *jp, *prev; 838 839 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 840 if (jp == j) { 841 if (prev != NULL) 842 prev->next = jp->next; 843 else 844 jobmru = jp->next; 845 return; 846 } 847 } 848 } 849 850 /* 851 * Return the most recently used job that isn't `nj', and preferably one 852 * that is stopped. 853 */ 854 static struct job * 855 getcurjob(struct job *nj) 856 { 857 struct job *jp; 858 859 /* Try to find a stopped one.. */ 860 for (jp = jobmru; jp != NULL; jp = jp->next) 861 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 862 return (jp); 863 /* Otherwise the most recently used job that isn't `nj' */ 864 for (jp = jobmru; jp != NULL; jp = jp->next) 865 if (jp->used && jp != nj) 866 return (jp); 867 868 return (NULL); 869 } 870 871 #endif 872 873 /* 874 * Fork of a subshell. If we are doing job control, give the subshell its 875 * own process group. Jp is a job structure that the job is to be added to. 876 * N is the command that will be evaluated by the child. Both jp and n may 877 * be NULL. The mode parameter can be one of the following: 878 * FORK_FG - Fork off a foreground process. 879 * FORK_BG - Fork off a background process. 880 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 881 * process group even if job control is on. 882 * 883 * When job control is turned off, background processes have their standard 884 * input redirected to /dev/null (except for the second and later processes 885 * in a pipeline). 886 */ 887 888 pid_t 889 forkshell(struct job *jp, union node *n, int mode) 890 { 891 pid_t pid; 892 pid_t pgrp; 893 894 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 895 mode)); 896 INTOFF; 897 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 898 checkzombies(); 899 flushall(); 900 pid = fork(); 901 if (pid == -1) { 902 TRACE(("Fork failed, errno=%d\n", errno)); 903 INTON; 904 error("Cannot fork: %s", strerror(errno)); 905 } 906 if (pid == 0) { 907 struct job *p; 908 int wasroot; 909 int i; 910 911 TRACE(("Child shell %d\n", (int)getpid())); 912 wasroot = rootshell; 913 rootshell = 0; 914 handler = &main_handler; 915 closescript(); 916 INTON; 917 forcelocal = 0; 918 clear_traps(); 919 #if JOBS 920 jobctl = 0; /* do job control only in root shell */ 921 if (wasroot && mode != FORK_NOJOB && mflag) { 922 if (jp == NULL || jp->nprocs == 0) 923 pgrp = getpid(); 924 else 925 pgrp = jp->ps[0].pid; 926 if (setpgid(0, pgrp) == 0 && mode == FORK_FG && 927 ttyfd >= 0) { 928 /* 929 * Each process in a pipeline must have the tty 930 * pgrp set before running its code. 931 * Only for pipelines of three or more processes 932 * could this be reduced to two calls. 933 */ 934 if (tcsetpgrp(ttyfd, pgrp) < 0) 935 error("tcsetpgrp failed, errno=%d", errno); 936 } 937 setsignal(SIGTSTP); 938 setsignal(SIGTTOU); 939 } else if (mode == FORK_BG) { 940 ignoresig(SIGINT); 941 ignoresig(SIGQUIT); 942 if ((jp == NULL || jp->nprocs == 0) && 943 ! fd0_redirected_p ()) { 944 close(0); 945 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 946 error("cannot open %s: %s", 947 _PATH_DEVNULL, strerror(errno)); 948 } 949 } 950 #else 951 if (mode == FORK_BG) { 952 ignoresig(SIGINT); 953 ignoresig(SIGQUIT); 954 if ((jp == NULL || jp->nprocs == 0) && 955 ! fd0_redirected_p ()) { 956 close(0); 957 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 958 error("cannot open %s: %s", 959 _PATH_DEVNULL, strerror(errno)); 960 } 961 } 962 #endif 963 INTOFF; 964 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 965 if (p->used) 966 freejob(p); 967 INTON; 968 if (wasroot && iflag) { 969 setsignal(SIGINT); 970 setsignal(SIGQUIT); 971 setsignal(SIGTERM); 972 } 973 return pid; 974 } 975 if (rootshell && mode != FORK_NOJOB && mflag) { 976 if (jp == NULL || jp->nprocs == 0) 977 pgrp = pid; 978 else 979 pgrp = jp->ps[0].pid; 980 setpgid(pid, pgrp); 981 } 982 if (mode == FORK_BG) { 983 if (bgjob != NULL && bgjob->state == JOBDONE && 984 !bgjob->remembered && !iflag) 985 freejob(bgjob); 986 backgndpid = pid; /* set $! */ 987 bgjob = jp; 988 } 989 if (jp) { 990 struct procstat *ps = &jp->ps[jp->nprocs++]; 991 ps->pid = pid; 992 ps->status = -1; 993 ps->cmd = nullstr; 994 if (iflag && rootshell && n) 995 ps->cmd = commandtext(n); 996 jp->foreground = mode == FORK_FG; 997 #if JOBS 998 setcurjob(jp); 999 #endif 1000 } 1001 INTON; 1002 TRACE(("In parent shell: child = %d\n", (int)pid)); 1003 return pid; 1004 } 1005 1006 1007 pid_t 1008 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 1009 { 1010 pid_t pid; 1011 struct jmploc jmploc; 1012 struct jmploc *savehandler; 1013 int inton; 1014 1015 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 1016 (void *)pip)); 1017 inton = is_int_on(); 1018 INTOFF; 1019 flushall(); 1020 savehandler = handler; 1021 pid = vfork(); 1022 if (pid == -1) { 1023 TRACE(("Vfork failed, errno=%d\n", errno)); 1024 INTON; 1025 error("Cannot fork: %s", strerror(errno)); 1026 } 1027 if (pid == 0) { 1028 TRACE(("Child shell %d\n", (int)getpid())); 1029 if (setjmp(jmploc.loc)) 1030 _exit(exitstatus); 1031 if (pip != NULL) { 1032 close(pip[0]); 1033 if (pip[1] != 1) { 1034 dup2(pip[1], 1); 1035 close(pip[1]); 1036 } 1037 } 1038 handler = &jmploc; 1039 shellexec(argv, envp, path, idx); 1040 } 1041 handler = savehandler; 1042 if (jp) { 1043 struct procstat *ps = &jp->ps[jp->nprocs++]; 1044 ps->pid = pid; 1045 ps->status = -1; 1046 ps->cmd = nullstr; 1047 jp->foreground = 1; 1048 #if JOBS 1049 setcurjob(jp); 1050 #endif 1051 } 1052 SETINTON(inton); 1053 TRACE(("In parent shell: child = %d\n", (int)pid)); 1054 return pid; 1055 } 1056 1057 1058 /* 1059 * Wait for job to finish. 1060 * 1061 * Under job control we have the problem that while a child process is 1062 * running interrupts generated by the user are sent to the child but not 1063 * to the shell. This means that an infinite loop started by an inter- 1064 * active user may be hard to kill. With job control turned off, an 1065 * interactive user may place an interactive program inside a loop. If 1066 * the interactive program catches interrupts, the user doesn't want 1067 * these interrupts to also abort the loop. The approach we take here 1068 * is to have the shell ignore interrupt signals while waiting for a 1069 * foreground process to terminate, and then send itself an interrupt 1070 * signal if the child process was terminated by an interrupt signal. 1071 * Unfortunately, some programs want to do a bit of cleanup and then 1072 * exit on interrupt; unless these processes terminate themselves by 1073 * sending a signal to themselves (instead of calling exit) they will 1074 * confuse this approach. 1075 */ 1076 1077 int 1078 waitforjob(struct job *jp, int *signaled) 1079 { 1080 #if JOBS 1081 int propagate_int = jp->jobctl && jp->foreground; 1082 #endif 1083 int status; 1084 int st; 1085 1086 INTOFF; 1087 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1088 while (jp->state == 0) 1089 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1090 DOWAIT_SIG_TRAP : 0), jp) == -1) 1091 dotrap(); 1092 #if JOBS 1093 if (jp->jobctl) { 1094 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0) 1095 error("tcsetpgrp failed, errno=%d\n", errno); 1096 } 1097 if (jp->state == JOBSTOPPED) 1098 setcurjob(jp); 1099 #endif 1100 status = getjobstatus(jp); 1101 if (signaled != NULL) 1102 *signaled = WIFSIGNALED(status); 1103 /* convert to 8 bits */ 1104 if (WIFEXITED(status)) 1105 st = WEXITSTATUS(status); 1106 #if JOBS 1107 else if (WIFSTOPPED(status)) 1108 st = WSTOPSIG(status) + 128; 1109 #endif 1110 else 1111 st = WTERMSIG(status) + 128; 1112 if (! JOBS || jp->state == JOBDONE) 1113 freejob(jp); 1114 if (int_pending()) { 1115 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1116 CLEAR_PENDING_INT; 1117 } 1118 #if JOBS 1119 else if (rootshell && propagate_int && 1120 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1121 kill(getpid(), SIGINT); 1122 #endif 1123 INTON; 1124 return st; 1125 } 1126 1127 1128 static void 1129 dummy_handler(int sig __unused) 1130 { 1131 } 1132 1133 /* 1134 * Wait for a process to terminate. 1135 */ 1136 1137 static pid_t 1138 dowait(int mode, struct job *job) 1139 { 1140 struct sigaction sa, osa; 1141 sigset_t mask, omask; 1142 pid_t pid; 1143 int status; 1144 struct procstat *sp; 1145 struct job *jp; 1146 struct job *thisjob; 1147 const char *sigstr; 1148 int done; 1149 int stopped; 1150 int sig; 1151 int coredump; 1152 int wflags; 1153 int restore_sigchld; 1154 1155 TRACE(("dowait(%d, %p) called\n", mode, job)); 1156 restore_sigchld = 0; 1157 if ((mode & DOWAIT_SIG) != 0) { 1158 sigfillset(&mask); 1159 sigprocmask(SIG_BLOCK, &mask, &omask); 1160 INTOFF; 1161 if (!issigchldtrapped()) { 1162 restore_sigchld = 1; 1163 sa.sa_handler = dummy_handler; 1164 sa.sa_flags = 0; 1165 sigemptyset(&sa.sa_mask); 1166 sigaction(SIGCHLD, &sa, &osa); 1167 } 1168 } 1169 do { 1170 #if JOBS 1171 if (iflag) 1172 wflags = WUNTRACED | WCONTINUED; 1173 else 1174 #endif 1175 wflags = 0; 1176 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1177 wflags |= WNOHANG; 1178 pid = wait3(&status, wflags, (struct rusage *)NULL); 1179 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1180 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1181 pid = -1; 1182 if (((mode & DOWAIT_SIG_TRAP) != 0 ? 1183 pendingsig : pendingsig_waitcmd) != 0) { 1184 errno = EINTR; 1185 break; 1186 } 1187 sigsuspend(&omask); 1188 if (int_pending()) 1189 break; 1190 } 1191 } while (pid == -1 && errno == EINTR); 1192 if (pid == -1 && errno == ECHILD && job != NULL) 1193 job->state = JOBDONE; 1194 if ((mode & DOWAIT_SIG) != 0) { 1195 if (restore_sigchld) 1196 sigaction(SIGCHLD, &osa, NULL); 1197 sigprocmask(SIG_SETMASK, &omask, NULL); 1198 INTON; 1199 } 1200 if (pid <= 0) 1201 return pid; 1202 INTOFF; 1203 thisjob = NULL; 1204 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1205 if (jp->used && jp->nprocs > 0) { 1206 done = 1; 1207 stopped = 1; 1208 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1209 if (sp->pid == -1) 1210 continue; 1211 if (sp->pid == pid && (sp->status == -1 || 1212 WIFSTOPPED(sp->status))) { 1213 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1214 (int)pid, sp->status, 1215 status)); 1216 if (WIFCONTINUED(status)) { 1217 sp->status = -1; 1218 jp->state = 0; 1219 } else 1220 sp->status = status; 1221 thisjob = jp; 1222 } 1223 if (sp->status == -1) 1224 stopped = 0; 1225 else if (WIFSTOPPED(sp->status)) 1226 done = 0; 1227 } 1228 if (stopped) { /* stopped or done */ 1229 int state = done? JOBDONE : JOBSTOPPED; 1230 if (jp->state != state) { 1231 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1232 jp->state = state; 1233 if (jp != job) { 1234 if (done && !jp->remembered && 1235 !iflag && jp != bgjob) 1236 freejob(jp); 1237 #if JOBS 1238 else if (done) 1239 deljob(jp); 1240 #endif 1241 } 1242 } 1243 } 1244 } 1245 } 1246 INTON; 1247 if (!thisjob || thisjob->state == 0) 1248 ; 1249 else if ((!rootshell || !iflag || thisjob == job) && 1250 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1251 sig = 0; 1252 coredump = 0; 1253 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1254 if (WIFSIGNALED(sp->status)) { 1255 sig = WTERMSIG(sp->status); 1256 coredump = WCOREDUMP(sp->status); 1257 } 1258 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1259 sigstr = strsignal(sig); 1260 if (sigstr != NULL) 1261 out2str(sigstr); 1262 else 1263 out2str("Unknown signal"); 1264 if (coredump) 1265 out2str(" (core dumped)"); 1266 out2c('\n'); 1267 flushout(out2); 1268 } 1269 } else { 1270 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1271 thisjob->changed = 1; 1272 } 1273 return pid; 1274 } 1275 1276 1277 1278 /* 1279 * return 1 if there are stopped jobs, otherwise 0 1280 */ 1281 int job_warning = 0; 1282 int 1283 stoppedjobs(void) 1284 { 1285 int jobno; 1286 struct job *jp; 1287 1288 if (job_warning) 1289 return (0); 1290 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1291 if (jp->used == 0) 1292 continue; 1293 if (jp->state == JOBSTOPPED) { 1294 out2fmt_flush("You have stopped jobs.\n"); 1295 job_warning = 2; 1296 return (1); 1297 } 1298 } 1299 1300 return (0); 1301 } 1302 1303 1304 static void 1305 checkzombies(void) 1306 { 1307 while (njobs > 0 && dowait(0, NULL) > 0) 1308 ; 1309 } 1310 1311 1312 int 1313 backgndpidset(void) 1314 { 1315 return backgndpid != -1; 1316 } 1317 1318 1319 pid_t 1320 backgndpidval(void) 1321 { 1322 if (bgjob != NULL && !forcelocal) 1323 bgjob->remembered = 1; 1324 return backgndpid; 1325 } 1326 1327 /* 1328 * Return a string identifying a command (to be printed by the 1329 * jobs command. 1330 */ 1331 1332 static char *cmdnextc; 1333 static int cmdnleft; 1334 #define MAXCMDTEXT 200 1335 1336 char * 1337 commandtext(union node *n) 1338 { 1339 char *name; 1340 1341 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1342 cmdnleft = MAXCMDTEXT - 4; 1343 cmdtxt(n); 1344 *cmdnextc = '\0'; 1345 return name; 1346 } 1347 1348 1349 static void 1350 cmdtxtdogroup(union node *n) 1351 { 1352 cmdputs("; do "); 1353 cmdtxt(n); 1354 cmdputs("; done"); 1355 } 1356 1357 1358 static void 1359 cmdtxtredir(union node *n, const char *op, int deffd) 1360 { 1361 char s[2]; 1362 1363 if (n->nfile.fd != deffd) { 1364 s[0] = n->nfile.fd + '0'; 1365 s[1] = '\0'; 1366 cmdputs(s); 1367 } 1368 cmdputs(op); 1369 if (n->type == NTOFD || n->type == NFROMFD) { 1370 if (n->ndup.dupfd >= 0) 1371 s[0] = n->ndup.dupfd + '0'; 1372 else 1373 s[0] = '-'; 1374 s[1] = '\0'; 1375 cmdputs(s); 1376 } else { 1377 cmdtxt(n->nfile.fname); 1378 } 1379 } 1380 1381 1382 static void 1383 cmdtxt(union node *n) 1384 { 1385 union node *np; 1386 struct nodelist *lp; 1387 1388 if (n == NULL) 1389 return; 1390 switch (n->type) { 1391 case NSEMI: 1392 cmdtxt(n->nbinary.ch1); 1393 cmdputs("; "); 1394 cmdtxt(n->nbinary.ch2); 1395 break; 1396 case NAND: 1397 cmdtxt(n->nbinary.ch1); 1398 cmdputs(" && "); 1399 cmdtxt(n->nbinary.ch2); 1400 break; 1401 case NOR: 1402 cmdtxt(n->nbinary.ch1); 1403 cmdputs(" || "); 1404 cmdtxt(n->nbinary.ch2); 1405 break; 1406 case NPIPE: 1407 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1408 cmdtxt(lp->n); 1409 if (lp->next) 1410 cmdputs(" | "); 1411 } 1412 break; 1413 case NSUBSHELL: 1414 cmdputs("("); 1415 cmdtxt(n->nredir.n); 1416 cmdputs(")"); 1417 break; 1418 case NREDIR: 1419 case NBACKGND: 1420 cmdtxt(n->nredir.n); 1421 break; 1422 case NIF: 1423 cmdputs("if "); 1424 cmdtxt(n->nif.test); 1425 cmdputs("; then "); 1426 cmdtxt(n->nif.ifpart); 1427 cmdputs("..."); 1428 break; 1429 case NWHILE: 1430 cmdputs("while "); 1431 cmdtxt(n->nbinary.ch1); 1432 cmdtxtdogroup(n->nbinary.ch2); 1433 break; 1434 case NUNTIL: 1435 cmdputs("until "); 1436 cmdtxt(n->nbinary.ch1); 1437 cmdtxtdogroup(n->nbinary.ch2); 1438 break; 1439 case NFOR: 1440 cmdputs("for "); 1441 cmdputs(n->nfor.var); 1442 cmdputs(" in ..."); 1443 break; 1444 case NCASE: 1445 cmdputs("case "); 1446 cmdputs(n->ncase.expr->narg.text); 1447 cmdputs(" in ..."); 1448 break; 1449 case NDEFUN: 1450 cmdputs(n->narg.text); 1451 cmdputs("() ..."); 1452 break; 1453 case NNOT: 1454 cmdputs("! "); 1455 cmdtxt(n->nnot.com); 1456 break; 1457 case NCMD: 1458 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1459 cmdtxt(np); 1460 if (np->narg.next) 1461 cmdputs(" "); 1462 } 1463 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1464 cmdputs(" "); 1465 cmdtxt(np); 1466 } 1467 break; 1468 case NARG: 1469 cmdputs(n->narg.text); 1470 break; 1471 case NTO: 1472 cmdtxtredir(n, ">", 1); 1473 break; 1474 case NAPPEND: 1475 cmdtxtredir(n, ">>", 1); 1476 break; 1477 case NTOFD: 1478 cmdtxtredir(n, ">&", 1); 1479 break; 1480 case NCLOBBER: 1481 cmdtxtredir(n, ">|", 1); 1482 break; 1483 case NFROM: 1484 cmdtxtredir(n, "<", 0); 1485 break; 1486 case NFROMTO: 1487 cmdtxtredir(n, "<>", 0); 1488 break; 1489 case NFROMFD: 1490 cmdtxtredir(n, "<&", 0); 1491 break; 1492 case NHERE: 1493 case NXHERE: 1494 cmdputs("<<..."); 1495 break; 1496 default: 1497 cmdputs("???"); 1498 break; 1499 } 1500 } 1501 1502 1503 1504 static void 1505 cmdputs(const char *s) 1506 { 1507 const char *p; 1508 char *q; 1509 char c; 1510 int subtype = 0; 1511 1512 if (cmdnleft <= 0) 1513 return; 1514 p = s; 1515 q = cmdnextc; 1516 while ((c = *p++) != '\0') { 1517 if (c == CTLESC) 1518 *q++ = *p++; 1519 else if (c == CTLVAR) { 1520 *q++ = '$'; 1521 if (--cmdnleft > 0) 1522 *q++ = '{'; 1523 subtype = *p++; 1524 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1525 *q++ = '#'; 1526 } else if (c == '=' && subtype != 0) { 1527 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1528 if (*q) 1529 q++; 1530 else 1531 cmdnleft++; 1532 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1533 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1534 --cmdnleft > 0) 1535 *q = q[-1], q++; 1536 subtype = 0; 1537 } else if (c == CTLENDVAR) { 1538 *q++ = '}'; 1539 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1540 cmdnleft -= 5; 1541 if (cmdnleft > 0) { 1542 *q++ = '$'; 1543 *q++ = '('; 1544 *q++ = '.'; 1545 *q++ = '.'; 1546 *q++ = '.'; 1547 *q++ = ')'; 1548 } 1549 } else if (c == CTLARI) { 1550 cmdnleft -= 2; 1551 if (cmdnleft > 0) { 1552 *q++ = '$'; 1553 *q++ = '('; 1554 *q++ = '('; 1555 } 1556 p++; 1557 } else if (c == CTLENDARI) { 1558 if (--cmdnleft > 0) { 1559 *q++ = ')'; 1560 *q++ = ')'; 1561 } 1562 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1563 cmdnleft++; /* ignore */ 1564 else 1565 *q++ = c; 1566 if (--cmdnleft <= 0) { 1567 *q++ = '.'; 1568 *q++ = '.'; 1569 *q++ = '.'; 1570 break; 1571 } 1572 } 1573 cmdnextc = q; 1574 } 1575