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 #include <sys/ioctl.h> 34 #include <sys/param.h> 35 #include <sys/resource.h> 36 #include <sys/time.h> 37 #include <sys/wait.h> 38 #include <errno.h> 39 #include <fcntl.h> 40 #include <paths.h> 41 #include <signal.h> 42 #include <stddef.h> 43 #include <stdlib.h> 44 #include <unistd.h> 45 46 #include "shell.h" 47 #if JOBS 48 #include <termios.h> 49 #undef CEOF /* syntax.h redefines this */ 50 #endif 51 #include "redir.h" 52 #include "exec.h" 53 #include "show.h" 54 #include "main.h" 55 #include "parser.h" 56 #include "nodes.h" 57 #include "jobs.h" 58 #include "options.h" 59 #include "trap.h" 60 #include "syntax.h" 61 #include "input.h" 62 #include "output.h" 63 #include "memalloc.h" 64 #include "error.h" 65 #include "mystring.h" 66 #include "var.h" 67 #include "builtins.h" 68 #include "eval.h" 69 70 71 /* 72 * A job structure contains information about a job. A job is either a 73 * single process or a set of processes contained in a pipeline. In the 74 * latter case, pidlist will be non-NULL, and will point to a -1 terminated 75 * array of pids. 76 */ 77 78 struct procstat { 79 pid_t pid; /* process id */ 80 int status; /* status flags (defined above) */ 81 char *cmd; /* text of command being run */ 82 }; 83 84 85 /* states */ 86 #define JOBSTOPPED 1 /* all procs are stopped */ 87 #define JOBDONE 2 /* all procs are completed */ 88 89 90 struct job { 91 struct procstat ps0; /* status of process */ 92 struct procstat *ps; /* status or processes when more than one */ 93 short nprocs; /* number of processes */ 94 pid_t pgrp; /* process group of this job */ 95 char state; /* true if job is finished */ 96 char used; /* true if this entry is in use */ 97 char changed; /* true if status has changed */ 98 char foreground; /* true if running in the foreground */ 99 char remembered; /* true if $! referenced */ 100 char pipefail; /* pass any non-zero status */ 101 #if JOBS 102 char jobctl; /* job running under job control */ 103 struct job *next; /* job used after this one */ 104 #endif 105 }; 106 107 108 static struct job *jobtab; /* array of jobs */ 109 static int njobs; /* size of array */ 110 static pid_t backgndpid = -1; /* pid of last background process */ 111 static struct job *bgjob = NULL; /* last background process */ 112 #if JOBS 113 static struct job *jobmru; /* most recently used job list */ 114 static pid_t initialpgrp; /* pgrp of shell on invocation */ 115 #endif 116 static int ttyfd = -1; 117 118 /* mode flags for dowait */ 119 #define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 120 #define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signal */ 121 #define DOWAIT_SIG_TRAP 0x4 /* if DOWAIT_SIG, abort on trapped signal only */ 122 123 #if JOBS 124 static void restartjob(struct job *); 125 #endif 126 static void freejob(struct job *); 127 static int waitcmdloop(struct job *); 128 static struct job *getjob_nonotfound(const char *); 129 static struct job *getjob(const char *); 130 pid_t killjob(const char *, int); 131 static pid_t dowait(int, struct job *); 132 static void checkzombies(void); 133 static void cmdtxt(union node *); 134 static void cmdputs(const char *); 135 #if JOBS 136 static void setcurjob(struct job *); 137 static void deljob(struct job *); 138 static struct job *getcurjob(struct job *); 139 #endif 140 static int getjobstatus(const struct job *); 141 static void printjobcmd(struct job *); 142 static void showjob(struct job *, int); 143 144 145 /* 146 * Turn job control on and off. 147 */ 148 149 static int jobctl; 150 151 #if JOBS 152 static void 153 jobctl_notty(void) 154 { 155 if (ttyfd >= 0) { 156 close(ttyfd); 157 ttyfd = -1; 158 } 159 if (!iflag) { 160 setsignal(SIGTSTP); 161 setsignal(SIGTTOU); 162 setsignal(SIGTTIN); 163 jobctl = 1; 164 return; 165 } 166 out2fmt_flush("sh: can't access tty; job control turned off\n"); 167 mflag = 0; 168 } 169 170 void 171 setjobctl(int on) 172 { 173 int i; 174 175 if (on == jobctl || rootshell == 0) 176 return; 177 if (on) { 178 if (ttyfd != -1) 179 close(ttyfd); 180 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 181 i = 0; 182 while (i <= 2 && !isatty(i)) 183 i++; 184 if (i > 2 || 185 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) { 186 jobctl_notty(); 187 return; 188 } 189 } 190 if (ttyfd < 10) { 191 /* 192 * Keep our TTY file descriptor out of the way of 193 * the user's redirections. 194 */ 195 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 196 jobctl_notty(); 197 return; 198 } 199 close(ttyfd); 200 ttyfd = i; 201 } 202 do { /* while we are in the background */ 203 initialpgrp = tcgetpgrp(ttyfd); 204 if (initialpgrp < 0) { 205 jobctl_notty(); 206 return; 207 } 208 if (initialpgrp != getpgrp()) { 209 if (!iflag) { 210 initialpgrp = -1; 211 jobctl_notty(); 212 return; 213 } 214 kill(0, SIGTTIN); 215 continue; 216 } 217 } while (0); 218 setsignal(SIGTSTP); 219 setsignal(SIGTTOU); 220 setsignal(SIGTTIN); 221 setpgid(0, rootpid); 222 tcsetpgrp(ttyfd, rootpid); 223 } else { /* turning job control off */ 224 setpgid(0, initialpgrp); 225 if (ttyfd >= 0) { 226 tcsetpgrp(ttyfd, initialpgrp); 227 close(ttyfd); 228 ttyfd = -1; 229 } 230 setsignal(SIGTSTP); 231 setsignal(SIGTTOU); 232 setsignal(SIGTTIN); 233 } 234 jobctl = on; 235 } 236 #endif 237 238 239 #if JOBS 240 int 241 fgcmd(int argc __unused, char **argv __unused) 242 { 243 struct job *jp; 244 pid_t pgrp; 245 int status; 246 247 nextopt(""); 248 jp = getjob(*argptr); 249 if (jp->jobctl == 0) 250 error("job not created under job control"); 251 printjobcmd(jp); 252 flushout(&output); 253 pgrp = jp->ps[0].pid; 254 if (ttyfd >= 0) 255 tcsetpgrp(ttyfd, pgrp); 256 restartjob(jp); 257 jp->foreground = 1; 258 INTOFF; 259 status = waitforjob(jp, (int *)NULL); 260 INTON; 261 return status; 262 } 263 264 265 int 266 bgcmd(int argc __unused, char **argv __unused) 267 { 268 struct job *jp; 269 270 nextopt(""); 271 do { 272 jp = getjob(*argptr); 273 if (jp->jobctl == 0) 274 error("job not created under job control"); 275 if (jp->state == JOBDONE) 276 continue; 277 restartjob(jp); 278 jp->foreground = 0; 279 out1fmt("[%td] ", jp - jobtab + 1); 280 printjobcmd(jp); 281 } while (*argptr != NULL && *++argptr != NULL); 282 return 0; 283 } 284 285 286 static void 287 restartjob(struct job *jp) 288 { 289 struct procstat *ps; 290 int i; 291 292 if (jp->state == JOBDONE) 293 return; 294 setcurjob(jp); 295 INTOFF; 296 kill(-jp->ps[0].pid, SIGCONT); 297 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 298 if (WIFSTOPPED(ps->status)) { 299 ps->status = -1; 300 jp->state = 0; 301 } 302 } 303 INTON; 304 } 305 #endif 306 307 308 int 309 jobscmd(int argc __unused, char *argv[] __unused) 310 { 311 char *id; 312 int ch, mode; 313 314 mode = SHOWJOBS_DEFAULT; 315 while ((ch = nextopt("lps")) != '\0') { 316 switch (ch) { 317 case 'l': 318 mode = SHOWJOBS_VERBOSE; 319 break; 320 case 'p': 321 mode = SHOWJOBS_PGIDS; 322 break; 323 case 's': 324 mode = SHOWJOBS_PIDS; 325 break; 326 } 327 } 328 329 if (*argptr == NULL) 330 showjobs(0, mode); 331 else 332 while ((id = *argptr++) != NULL) 333 showjob(getjob(id), mode); 334 335 return (0); 336 } 337 338 static int getjobstatus(const struct job *jp) 339 { 340 int i, status; 341 342 if (!jp->pipefail) 343 return (jp->ps[jp->nprocs - 1].status); 344 for (i = jp->nprocs - 1; i >= 0; i--) { 345 status = jp->ps[i].status; 346 if (status != 0) 347 return (status); 348 } 349 return (0); 350 } 351 352 static void 353 printjobcmd(struct job *jp) 354 { 355 struct procstat *ps; 356 int i; 357 358 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 359 out1str(ps->cmd); 360 if (i > 0) 361 out1str(" | "); 362 } 363 out1c('\n'); 364 } 365 366 static void 367 showjob(struct job *jp, int mode) 368 { 369 char s[64]; 370 char statebuf[16]; 371 const char *statestr, *coredump; 372 struct procstat *ps; 373 struct job *j; 374 int col, curr, i, jobno, prev, procno, status; 375 char c; 376 377 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 378 jobno = jp - jobtab + 1; 379 curr = prev = 0; 380 #if JOBS 381 if ((j = getcurjob(NULL)) != NULL) { 382 curr = j - jobtab + 1; 383 if ((j = getcurjob(j)) != NULL) 384 prev = j - jobtab + 1; 385 } 386 #endif 387 coredump = ""; 388 status = getjobstatus(jp); 389 if (jp->state == 0) { 390 statestr = "Running"; 391 #if JOBS 392 } else if (jp->state == JOBSTOPPED) { 393 ps = jp->ps + jp->nprocs - 1; 394 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 395 ps--; 396 if (WIFSTOPPED(ps->status)) 397 i = WSTOPSIG(ps->status); 398 else 399 i = -1; 400 statestr = strsignal(i); 401 if (statestr == NULL) 402 statestr = "Suspended"; 403 #endif 404 } else if (WIFEXITED(status)) { 405 if (WEXITSTATUS(status) == 0) 406 statestr = "Done"; 407 else { 408 fmtstr(statebuf, sizeof(statebuf), "Done(%d)", 409 WEXITSTATUS(status)); 410 statestr = statebuf; 411 } 412 } else { 413 i = WTERMSIG(status); 414 statestr = strsignal(i); 415 if (statestr == NULL) 416 statestr = "Unknown signal"; 417 if (WCOREDUMP(status)) 418 coredump = " (core dumped)"; 419 } 420 421 for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */ 422 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 423 out1fmt("%d\n", (int)ps->pid); 424 continue; 425 } 426 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 427 continue; 428 if (jobno == curr && ps == jp->ps) 429 c = '+'; 430 else if (jobno == prev && ps == jp->ps) 431 c = '-'; 432 else 433 c = ' '; 434 if (ps == jp->ps) 435 fmtstr(s, 64, "[%d] %c ", jobno, c); 436 else 437 fmtstr(s, 64, " %c ", c); 438 out1str(s); 439 col = strlen(s); 440 if (mode == SHOWJOBS_VERBOSE) { 441 fmtstr(s, 64, "%d ", (int)ps->pid); 442 out1str(s); 443 col += strlen(s); 444 } 445 if (ps == jp->ps) { 446 out1str(statestr); 447 out1str(coredump); 448 col += strlen(statestr) + strlen(coredump); 449 } 450 do { 451 out1c(' '); 452 col++; 453 } while (col < 30); 454 if (mode == SHOWJOBS_VERBOSE) { 455 out1str(ps->cmd); 456 out1c('\n'); 457 } else 458 printjobcmd(jp); 459 } 460 } 461 462 /* 463 * Print a list of jobs. If "change" is nonzero, only print jobs whose 464 * statuses have changed since the last call to showjobs. 465 * 466 * If the shell is interrupted in the process of creating a job, the 467 * result may be a job structure containing zero processes. Such structures 468 * will be freed here. 469 */ 470 471 void 472 showjobs(int change, int mode) 473 { 474 int jobno; 475 struct job *jp; 476 477 TRACE(("showjobs(%d) called\n", change)); 478 checkzombies(); 479 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 480 if (! jp->used) 481 continue; 482 if (jp->nprocs == 0) { 483 freejob(jp); 484 continue; 485 } 486 if (change && ! jp->changed) 487 continue; 488 showjob(jp, mode); 489 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 490 jp->changed = 0; 491 /* Hack: discard jobs for which $! has not been 492 * referenced in interactive mode when they terminate. 493 */ 494 if (jp->state == JOBDONE && !jp->remembered && 495 (iflag || jp != bgjob)) { 496 freejob(jp); 497 } 498 } 499 } 500 } 501 502 503 /* 504 * Mark a job structure as unused. 505 */ 506 507 static void 508 freejob(struct job *jp) 509 { 510 struct procstat *ps; 511 int i; 512 513 INTOFF; 514 if (bgjob == jp) 515 bgjob = NULL; 516 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 517 if (ps->cmd != nullstr) 518 ckfree(ps->cmd); 519 } 520 if (jp->ps != &jp->ps0) 521 ckfree(jp->ps); 522 jp->used = 0; 523 #if JOBS 524 deljob(jp); 525 #endif 526 INTON; 527 } 528 529 530 531 int 532 waitcmd(int argc __unused, char **argv __unused) 533 { 534 struct job *job; 535 int retval; 536 537 nextopt(""); 538 if (*argptr == NULL) 539 return (waitcmdloop(NULL)); 540 541 do { 542 job = getjob_nonotfound(*argptr); 543 if (job == NULL) 544 retval = 127; 545 else 546 retval = waitcmdloop(job); 547 argptr++; 548 } while (*argptr != NULL); 549 550 return (retval); 551 } 552 553 static int 554 waitcmdloop(struct job *job) 555 { 556 int status, retval, sig; 557 struct job *jp; 558 559 /* 560 * Loop until a process is terminated or stopped, or a SIGINT is 561 * received. 562 */ 563 564 do { 565 if (job != NULL) { 566 if (job->state == JOBDONE) { 567 status = getjobstatus(job); 568 if (WIFEXITED(status)) 569 retval = WEXITSTATUS(status); 570 else 571 retval = WTERMSIG(status) + 128; 572 if (! iflag || ! job->changed) 573 freejob(job); 574 else { 575 job->remembered = 0; 576 if (job == bgjob) 577 bgjob = NULL; 578 } 579 return retval; 580 } 581 } else { 582 if (njobs == 0) 583 return 0; 584 for (jp = jobtab ; jp < jobtab + njobs; jp++) 585 if (jp->used && jp->state == JOBDONE) { 586 if (! iflag || ! jp->changed) 587 freejob(jp); 588 else { 589 jp->remembered = 0; 590 if (jp == bgjob) 591 bgjob = NULL; 592 } 593 } 594 for (jp = jobtab ; ; jp++) { 595 if (jp >= jobtab + njobs) { /* no running procs */ 596 return 0; 597 } 598 if (jp->used && jp->state == 0) 599 break; 600 } 601 } 602 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 603 604 sig = pendingsig_waitcmd; 605 pendingsig_waitcmd = 0; 606 return sig + 128; 607 } 608 609 610 611 int 612 jobidcmd(int argc __unused, char **argv __unused) 613 { 614 struct job *jp; 615 int i; 616 617 nextopt(""); 618 jp = getjob(*argptr); 619 for (i = 0 ; i < jp->nprocs ; ) { 620 out1fmt("%d", (int)jp->ps[i].pid); 621 out1c(++i < jp->nprocs? ' ' : '\n'); 622 } 623 return 0; 624 } 625 626 627 628 /* 629 * Convert a job name to a job structure. 630 */ 631 632 static struct job * 633 getjob_nonotfound(const char *name) 634 { 635 int jobno; 636 struct job *found, *jp; 637 size_t namelen; 638 pid_t pid; 639 int i; 640 641 if (name == NULL) { 642 #if JOBS 643 name = "%+"; 644 #else 645 error("No current job"); 646 #endif 647 } 648 if (name[0] == '%') { 649 if (is_digit(name[1])) { 650 jobno = number(name + 1); 651 if (jobno > 0 && jobno <= njobs 652 && jobtab[jobno - 1].used != 0) 653 return &jobtab[jobno - 1]; 654 #if JOBS 655 } else if ((name[1] == '%' || name[1] == '+') && 656 name[2] == '\0') { 657 if ((jp = getcurjob(NULL)) == NULL) 658 error("No current job"); 659 return (jp); 660 } else if (name[1] == '-' && name[2] == '\0') { 661 if ((jp = getcurjob(NULL)) == NULL || 662 (jp = getcurjob(jp)) == NULL) 663 error("No previous job"); 664 return (jp); 665 #endif 666 } else if (name[1] == '?') { 667 found = NULL; 668 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 669 if (jp->used && jp->nprocs > 0 670 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 671 if (found) 672 error("%s: ambiguous", name); 673 found = jp; 674 } 675 } 676 if (found != NULL) 677 return (found); 678 } else { 679 namelen = strlen(name); 680 found = NULL; 681 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 682 if (jp->used && jp->nprocs > 0 683 && strncmp(jp->ps[0].cmd, name + 1, 684 namelen - 1) == 0) { 685 if (found) 686 error("%s: ambiguous", name); 687 found = jp; 688 } 689 } 690 if (found) 691 return found; 692 } 693 } else if (is_number(name)) { 694 pid = (pid_t)number(name); 695 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 696 if (jp->used && jp->nprocs > 0 697 && jp->ps[jp->nprocs - 1].pid == pid) 698 return jp; 699 } 700 } 701 return NULL; 702 } 703 704 705 static struct job * 706 getjob(const char *name) 707 { 708 struct job *jp; 709 710 jp = getjob_nonotfound(name); 711 if (jp == NULL) 712 error("No such job: %s", name); 713 return (jp); 714 } 715 716 717 int 718 killjob(const char *name, int sig) 719 { 720 struct job *jp; 721 int i, ret; 722 723 jp = getjob(name); 724 if (jp->state == JOBDONE) 725 return 0; 726 if (jp->jobctl) 727 return kill(-jp->ps[0].pid, sig); 728 ret = -1; 729 errno = ESRCH; 730 for (i = 0; i < jp->nprocs; i++) 731 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 732 if (kill(jp->ps[i].pid, sig) == 0) 733 ret = 0; 734 } else 735 ret = 0; 736 return ret; 737 } 738 739 /* 740 * Return a new job structure, 741 */ 742 743 struct job * 744 makejob(union node *node __unused, int nprocs) 745 { 746 int i; 747 struct job *jp; 748 749 for (i = njobs, jp = jobtab ; ; jp++) { 750 if (--i < 0) { 751 INTOFF; 752 if (njobs == 0) { 753 jobtab = ckmalloc(4 * sizeof jobtab[0]); 754 #if JOBS 755 jobmru = NULL; 756 #endif 757 } else { 758 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 759 memcpy(jp, jobtab, njobs * sizeof jp[0]); 760 #if JOBS 761 /* Relocate `next' pointers and list head */ 762 if (jobmru != NULL) 763 jobmru = &jp[jobmru - jobtab]; 764 for (i = 0; i < njobs; i++) 765 if (jp[i].next != NULL) 766 jp[i].next = &jp[jp[i].next - 767 jobtab]; 768 #endif 769 if (bgjob != NULL) 770 bgjob = &jp[bgjob - jobtab]; 771 /* Relocate `ps' pointers */ 772 for (i = 0; i < njobs; i++) 773 if (jp[i].ps == &jobtab[i].ps0) 774 jp[i].ps = &jp[i].ps0; 775 ckfree(jobtab); 776 jobtab = jp; 777 } 778 jp = jobtab + njobs; 779 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 780 ; 781 INTON; 782 break; 783 } 784 if (jp->used == 0) 785 break; 786 } 787 INTOFF; 788 jp->state = 0; 789 jp->used = 1; 790 jp->changed = 0; 791 jp->nprocs = 0; 792 jp->foreground = 0; 793 jp->remembered = 0; 794 jp->pipefail = pipefailflag; 795 #if JOBS 796 jp->jobctl = jobctl; 797 jp->next = NULL; 798 #endif 799 if (nprocs > 1) { 800 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 801 } else { 802 jp->ps = &jp->ps0; 803 } 804 INTON; 805 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 806 jp - jobtab + 1)); 807 return jp; 808 } 809 810 #if JOBS 811 static void 812 setcurjob(struct job *cj) 813 { 814 struct job *jp, *prev; 815 816 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 817 if (jp == cj) { 818 if (prev != NULL) 819 prev->next = jp->next; 820 else 821 jobmru = jp->next; 822 jp->next = jobmru; 823 jobmru = cj; 824 return; 825 } 826 } 827 cj->next = jobmru; 828 jobmru = cj; 829 } 830 831 static void 832 deljob(struct job *j) 833 { 834 struct job *jp, *prev; 835 836 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 837 if (jp == j) { 838 if (prev != NULL) 839 prev->next = jp->next; 840 else 841 jobmru = jp->next; 842 return; 843 } 844 } 845 } 846 847 /* 848 * Return the most recently used job that isn't `nj', and preferably one 849 * that is stopped. 850 */ 851 static struct job * 852 getcurjob(struct job *nj) 853 { 854 struct job *jp; 855 856 /* Try to find a stopped one.. */ 857 for (jp = jobmru; jp != NULL; jp = jp->next) 858 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 859 return (jp); 860 /* Otherwise the most recently used job that isn't `nj' */ 861 for (jp = jobmru; jp != NULL; jp = jp->next) 862 if (jp->used && jp != nj) 863 return (jp); 864 865 return (NULL); 866 } 867 868 #endif 869 870 /* 871 * Fork of a subshell. If we are doing job control, give the subshell its 872 * own process group. Jp is a job structure that the job is to be added to. 873 * N is the command that will be evaluated by the child. Both jp and n may 874 * be NULL. The mode parameter can be one of the following: 875 * FORK_FG - Fork off a foreground process. 876 * FORK_BG - Fork off a background process. 877 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 878 * process group even if job control is on. 879 * 880 * When job control is turned off, background processes have their standard 881 * input redirected to /dev/null (except for the second and later processes 882 * in a pipeline). 883 */ 884 885 pid_t 886 forkshell(struct job *jp, union node *n, int mode) 887 { 888 pid_t pid; 889 pid_t pgrp; 890 891 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 892 mode)); 893 INTOFF; 894 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 895 checkzombies(); 896 flushall(); 897 pid = fork(); 898 if (pid == -1) { 899 TRACE(("Fork failed, errno=%d\n", errno)); 900 INTON; 901 error("Cannot fork: %s", strerror(errno)); 902 } 903 if (pid == 0) { 904 struct job *p; 905 int wasroot; 906 int i; 907 908 TRACE(("Child shell %d\n", (int)getpid())); 909 wasroot = rootshell; 910 rootshell = 0; 911 handler = &main_handler; 912 closescript(); 913 INTON; 914 forcelocal = 0; 915 clear_traps(); 916 #if JOBS 917 jobctl = 0; /* do job control only in root shell */ 918 if (wasroot && mode != FORK_NOJOB && mflag) { 919 if (jp == NULL || jp->nprocs == 0) 920 pgrp = getpid(); 921 else 922 pgrp = jp->ps[0].pid; 923 if (setpgid(0, pgrp) == 0 && mode == FORK_FG && 924 ttyfd >= 0) { 925 /* 926 * Each process in a pipeline must have the tty 927 * pgrp set before running its code. 928 * Only for pipelines of three or more processes 929 * could this be reduced to two calls. 930 */ 931 if (tcsetpgrp(ttyfd, pgrp) < 0) 932 error("tcsetpgrp failed, errno=%d", errno); 933 } 934 setsignal(SIGTSTP); 935 setsignal(SIGTTOU); 936 } else if (mode == FORK_BG) { 937 ignoresig(SIGINT); 938 ignoresig(SIGQUIT); 939 if ((jp == NULL || jp->nprocs == 0) && 940 ! fd0_redirected_p ()) { 941 close(0); 942 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 943 error("cannot open %s: %s", 944 _PATH_DEVNULL, strerror(errno)); 945 } 946 } 947 #else 948 if (mode == FORK_BG) { 949 ignoresig(SIGINT); 950 ignoresig(SIGQUIT); 951 if ((jp == NULL || jp->nprocs == 0) && 952 ! fd0_redirected_p ()) { 953 close(0); 954 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 955 error("cannot open %s: %s", 956 _PATH_DEVNULL, strerror(errno)); 957 } 958 } 959 #endif 960 INTOFF; 961 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 962 if (p->used) 963 freejob(p); 964 INTON; 965 if (wasroot && iflag) { 966 setsignal(SIGINT); 967 setsignal(SIGQUIT); 968 setsignal(SIGTERM); 969 } 970 return pid; 971 } 972 if (rootshell && mode != FORK_NOJOB && mflag) { 973 if (jp == NULL || jp->nprocs == 0) 974 pgrp = pid; 975 else 976 pgrp = jp->ps[0].pid; 977 setpgid(pid, pgrp); 978 } 979 if (mode == FORK_BG) { 980 if (bgjob != NULL && bgjob->state == JOBDONE && 981 !bgjob->remembered && !iflag) 982 freejob(bgjob); 983 backgndpid = pid; /* set $! */ 984 bgjob = jp; 985 } 986 if (jp) { 987 struct procstat *ps = &jp->ps[jp->nprocs++]; 988 ps->pid = pid; 989 ps->status = -1; 990 ps->cmd = nullstr; 991 if (iflag && rootshell && n) 992 ps->cmd = commandtext(n); 993 jp->foreground = mode == FORK_FG; 994 #if JOBS 995 setcurjob(jp); 996 #endif 997 } 998 INTON; 999 TRACE(("In parent shell: child = %d\n", (int)pid)); 1000 return pid; 1001 } 1002 1003 1004 pid_t 1005 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 1006 { 1007 pid_t pid; 1008 struct jmploc jmploc; 1009 struct jmploc *savehandler; 1010 int inton; 1011 1012 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 1013 (void *)pip)); 1014 inton = is_int_on(); 1015 INTOFF; 1016 flushall(); 1017 savehandler = handler; 1018 pid = vfork(); 1019 if (pid == -1) { 1020 TRACE(("Vfork failed, errno=%d\n", errno)); 1021 INTON; 1022 error("Cannot fork: %s", strerror(errno)); 1023 } 1024 if (pid == 0) { 1025 TRACE(("Child shell %d\n", (int)getpid())); 1026 if (setjmp(jmploc.loc)) 1027 _exit(exitstatus); 1028 if (pip != NULL) { 1029 close(pip[0]); 1030 if (pip[1] != 1) { 1031 dup2(pip[1], 1); 1032 close(pip[1]); 1033 } 1034 } 1035 handler = &jmploc; 1036 shellexec(argv, envp, path, idx); 1037 } 1038 handler = savehandler; 1039 if (jp) { 1040 struct procstat *ps = &jp->ps[jp->nprocs++]; 1041 ps->pid = pid; 1042 ps->status = -1; 1043 ps->cmd = nullstr; 1044 jp->foreground = 1; 1045 #if JOBS 1046 setcurjob(jp); 1047 #endif 1048 } 1049 SETINTON(inton); 1050 TRACE(("In parent shell: child = %d\n", (int)pid)); 1051 return pid; 1052 } 1053 1054 1055 /* 1056 * Wait for job to finish. 1057 * 1058 * Under job control we have the problem that while a child process is 1059 * running interrupts generated by the user are sent to the child but not 1060 * to the shell. This means that an infinite loop started by an inter- 1061 * active user may be hard to kill. With job control turned off, an 1062 * interactive user may place an interactive program inside a loop. If 1063 * the interactive program catches interrupts, the user doesn't want 1064 * these interrupts to also abort the loop. The approach we take here 1065 * is to have the shell ignore interrupt signals while waiting for a 1066 * foreground process to terminate, and then send itself an interrupt 1067 * signal if the child process was terminated by an interrupt signal. 1068 * Unfortunately, some programs want to do a bit of cleanup and then 1069 * exit on interrupt; unless these processes terminate themselves by 1070 * sending a signal to themselves (instead of calling exit) they will 1071 * confuse this approach. 1072 */ 1073 1074 int 1075 waitforjob(struct job *jp, int *signaled) 1076 { 1077 #if JOBS 1078 int propagate_int = jp->jobctl && jp->foreground; 1079 #endif 1080 int status; 1081 int st; 1082 1083 INTOFF; 1084 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1085 while (jp->state == 0) 1086 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1087 DOWAIT_SIG_TRAP : 0), jp) == -1) 1088 dotrap(); 1089 #if JOBS 1090 if (jp->jobctl) { 1091 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0) 1092 error("tcsetpgrp failed, errno=%d\n", errno); 1093 } 1094 if (jp->state == JOBSTOPPED) 1095 setcurjob(jp); 1096 #endif 1097 status = getjobstatus(jp); 1098 if (signaled != NULL) 1099 *signaled = WIFSIGNALED(status); 1100 /* convert to 8 bits */ 1101 if (WIFEXITED(status)) 1102 st = WEXITSTATUS(status); 1103 #if JOBS 1104 else if (WIFSTOPPED(status)) 1105 st = WSTOPSIG(status) + 128; 1106 #endif 1107 else 1108 st = WTERMSIG(status) + 128; 1109 if (! JOBS || jp->state == JOBDONE) 1110 freejob(jp); 1111 if (int_pending()) { 1112 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1113 CLEAR_PENDING_INT; 1114 } 1115 #if JOBS 1116 else if (rootshell && propagate_int && 1117 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1118 kill(getpid(), SIGINT); 1119 #endif 1120 INTON; 1121 return st; 1122 } 1123 1124 1125 static void 1126 dummy_handler(int sig __unused) 1127 { 1128 } 1129 1130 /* 1131 * Wait for a process to terminate. 1132 */ 1133 1134 static pid_t 1135 dowait(int mode, struct job *job) 1136 { 1137 struct sigaction sa, osa; 1138 sigset_t mask, omask; 1139 pid_t pid; 1140 int status; 1141 struct procstat *sp; 1142 struct job *jp; 1143 struct job *thisjob; 1144 const char *sigstr; 1145 int done; 1146 int stopped; 1147 int sig; 1148 int coredump; 1149 int wflags; 1150 int restore_sigchld; 1151 1152 TRACE(("dowait(%d, %p) called\n", mode, job)); 1153 restore_sigchld = 0; 1154 if ((mode & DOWAIT_SIG) != 0) { 1155 sigfillset(&mask); 1156 sigprocmask(SIG_BLOCK, &mask, &omask); 1157 INTOFF; 1158 if (!issigchldtrapped()) { 1159 restore_sigchld = 1; 1160 sa.sa_handler = dummy_handler; 1161 sa.sa_flags = 0; 1162 sigemptyset(&sa.sa_mask); 1163 sigaction(SIGCHLD, &sa, &osa); 1164 } 1165 } 1166 do { 1167 #if JOBS 1168 if (iflag) 1169 wflags = WUNTRACED | WCONTINUED; 1170 else 1171 #endif 1172 wflags = 0; 1173 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1174 wflags |= WNOHANG; 1175 pid = wait3(&status, wflags, (struct rusage *)NULL); 1176 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1177 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1178 pid = -1; 1179 if (((mode & DOWAIT_SIG_TRAP) != 0 ? 1180 pendingsig : pendingsig_waitcmd) != 0) { 1181 errno = EINTR; 1182 break; 1183 } 1184 sigsuspend(&omask); 1185 if (int_pending()) 1186 break; 1187 } 1188 } while (pid == -1 && errno == EINTR); 1189 if (pid == -1 && errno == ECHILD && job != NULL) 1190 job->state = JOBDONE; 1191 if ((mode & DOWAIT_SIG) != 0) { 1192 if (restore_sigchld) 1193 sigaction(SIGCHLD, &osa, NULL); 1194 sigprocmask(SIG_SETMASK, &omask, NULL); 1195 INTON; 1196 } 1197 if (pid <= 0) 1198 return pid; 1199 INTOFF; 1200 thisjob = NULL; 1201 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1202 if (jp->used && jp->nprocs > 0) { 1203 done = 1; 1204 stopped = 1; 1205 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1206 if (sp->pid == -1) 1207 continue; 1208 if (sp->pid == pid && (sp->status == -1 || 1209 WIFSTOPPED(sp->status))) { 1210 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1211 (int)pid, sp->status, 1212 status)); 1213 if (WIFCONTINUED(status)) { 1214 sp->status = -1; 1215 jp->state = 0; 1216 } else 1217 sp->status = status; 1218 thisjob = jp; 1219 } 1220 if (sp->status == -1) 1221 stopped = 0; 1222 else if (WIFSTOPPED(sp->status)) 1223 done = 0; 1224 } 1225 if (stopped) { /* stopped or done */ 1226 int state = done? JOBDONE : JOBSTOPPED; 1227 if (jp->state != state) { 1228 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1229 jp->state = state; 1230 if (jp != job) { 1231 if (done && !jp->remembered && 1232 !iflag && jp != bgjob) 1233 freejob(jp); 1234 #if JOBS 1235 else if (done) 1236 deljob(jp); 1237 #endif 1238 } 1239 } 1240 } 1241 } 1242 } 1243 INTON; 1244 if (!thisjob || thisjob->state == 0) 1245 ; 1246 else if ((!rootshell || !iflag || thisjob == job) && 1247 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1248 sig = 0; 1249 coredump = 0; 1250 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1251 if (WIFSIGNALED(sp->status)) { 1252 sig = WTERMSIG(sp->status); 1253 coredump = WCOREDUMP(sp->status); 1254 } 1255 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1256 sigstr = strsignal(sig); 1257 if (sigstr != NULL) 1258 out2str(sigstr); 1259 else 1260 out2str("Unknown signal"); 1261 if (coredump) 1262 out2str(" (core dumped)"); 1263 out2c('\n'); 1264 flushout(out2); 1265 } 1266 } else { 1267 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1268 thisjob->changed = 1; 1269 } 1270 return pid; 1271 } 1272 1273 1274 1275 /* 1276 * return 1 if there are stopped jobs, otherwise 0 1277 */ 1278 int job_warning = 0; 1279 int 1280 stoppedjobs(void) 1281 { 1282 int jobno; 1283 struct job *jp; 1284 1285 if (job_warning) 1286 return (0); 1287 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1288 if (jp->used == 0) 1289 continue; 1290 if (jp->state == JOBSTOPPED) { 1291 out2fmt_flush("You have stopped jobs.\n"); 1292 job_warning = 2; 1293 return (1); 1294 } 1295 } 1296 1297 return (0); 1298 } 1299 1300 1301 static void 1302 checkzombies(void) 1303 { 1304 while (njobs > 0 && dowait(0, NULL) > 0) 1305 ; 1306 } 1307 1308 1309 int 1310 backgndpidset(void) 1311 { 1312 return backgndpid != -1; 1313 } 1314 1315 1316 pid_t 1317 backgndpidval(void) 1318 { 1319 if (bgjob != NULL && !forcelocal) 1320 bgjob->remembered = 1; 1321 return backgndpid; 1322 } 1323 1324 /* 1325 * Return a string identifying a command (to be printed by the 1326 * jobs command. 1327 */ 1328 1329 static char *cmdnextc; 1330 static int cmdnleft; 1331 #define MAXCMDTEXT 200 1332 1333 char * 1334 commandtext(union node *n) 1335 { 1336 char *name; 1337 1338 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1339 cmdnleft = MAXCMDTEXT - 4; 1340 cmdtxt(n); 1341 *cmdnextc = '\0'; 1342 return name; 1343 } 1344 1345 1346 static void 1347 cmdtxtdogroup(union node *n) 1348 { 1349 cmdputs("; do "); 1350 cmdtxt(n); 1351 cmdputs("; done"); 1352 } 1353 1354 1355 static void 1356 cmdtxtredir(union node *n, const char *op, int deffd) 1357 { 1358 char s[2]; 1359 1360 if (n->nfile.fd != deffd) { 1361 s[0] = n->nfile.fd + '0'; 1362 s[1] = '\0'; 1363 cmdputs(s); 1364 } 1365 cmdputs(op); 1366 if (n->type == NTOFD || n->type == NFROMFD) { 1367 if (n->ndup.dupfd >= 0) 1368 s[0] = n->ndup.dupfd + '0'; 1369 else 1370 s[0] = '-'; 1371 s[1] = '\0'; 1372 cmdputs(s); 1373 } else { 1374 cmdtxt(n->nfile.fname); 1375 } 1376 } 1377 1378 1379 static void 1380 cmdtxt(union node *n) 1381 { 1382 union node *np; 1383 struct nodelist *lp; 1384 1385 if (n == NULL) 1386 return; 1387 switch (n->type) { 1388 case NSEMI: 1389 cmdtxt(n->nbinary.ch1); 1390 cmdputs("; "); 1391 cmdtxt(n->nbinary.ch2); 1392 break; 1393 case NAND: 1394 cmdtxt(n->nbinary.ch1); 1395 cmdputs(" && "); 1396 cmdtxt(n->nbinary.ch2); 1397 break; 1398 case NOR: 1399 cmdtxt(n->nbinary.ch1); 1400 cmdputs(" || "); 1401 cmdtxt(n->nbinary.ch2); 1402 break; 1403 case NPIPE: 1404 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1405 cmdtxt(lp->n); 1406 if (lp->next) 1407 cmdputs(" | "); 1408 } 1409 break; 1410 case NSUBSHELL: 1411 cmdputs("("); 1412 cmdtxt(n->nredir.n); 1413 cmdputs(")"); 1414 break; 1415 case NREDIR: 1416 case NBACKGND: 1417 cmdtxt(n->nredir.n); 1418 break; 1419 case NIF: 1420 cmdputs("if "); 1421 cmdtxt(n->nif.test); 1422 cmdputs("; then "); 1423 cmdtxt(n->nif.ifpart); 1424 cmdputs("..."); 1425 break; 1426 case NWHILE: 1427 cmdputs("while "); 1428 cmdtxt(n->nbinary.ch1); 1429 cmdtxtdogroup(n->nbinary.ch2); 1430 break; 1431 case NUNTIL: 1432 cmdputs("until "); 1433 cmdtxt(n->nbinary.ch1); 1434 cmdtxtdogroup(n->nbinary.ch2); 1435 break; 1436 case NFOR: 1437 cmdputs("for "); 1438 cmdputs(n->nfor.var); 1439 cmdputs(" in ..."); 1440 break; 1441 case NCASE: 1442 cmdputs("case "); 1443 cmdputs(n->ncase.expr->narg.text); 1444 cmdputs(" in ..."); 1445 break; 1446 case NDEFUN: 1447 cmdputs(n->narg.text); 1448 cmdputs("() ..."); 1449 break; 1450 case NNOT: 1451 cmdputs("! "); 1452 cmdtxt(n->nnot.com); 1453 break; 1454 case NCMD: 1455 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1456 cmdtxt(np); 1457 if (np->narg.next) 1458 cmdputs(" "); 1459 } 1460 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1461 cmdputs(" "); 1462 cmdtxt(np); 1463 } 1464 break; 1465 case NARG: 1466 cmdputs(n->narg.text); 1467 break; 1468 case NTO: 1469 cmdtxtredir(n, ">", 1); 1470 break; 1471 case NAPPEND: 1472 cmdtxtredir(n, ">>", 1); 1473 break; 1474 case NTOFD: 1475 cmdtxtredir(n, ">&", 1); 1476 break; 1477 case NCLOBBER: 1478 cmdtxtredir(n, ">|", 1); 1479 break; 1480 case NFROM: 1481 cmdtxtredir(n, "<", 0); 1482 break; 1483 case NFROMTO: 1484 cmdtxtredir(n, "<>", 0); 1485 break; 1486 case NFROMFD: 1487 cmdtxtredir(n, "<&", 0); 1488 break; 1489 case NHERE: 1490 case NXHERE: 1491 cmdputs("<<..."); 1492 break; 1493 default: 1494 cmdputs("???"); 1495 break; 1496 } 1497 } 1498 1499 1500 1501 static void 1502 cmdputs(const char *s) 1503 { 1504 const char *p; 1505 char *q; 1506 char c; 1507 int subtype = 0; 1508 1509 if (cmdnleft <= 0) 1510 return; 1511 p = s; 1512 q = cmdnextc; 1513 while ((c = *p++) != '\0') { 1514 if (c == CTLESC) 1515 *q++ = *p++; 1516 else if (c == CTLVAR) { 1517 *q++ = '$'; 1518 if (--cmdnleft > 0) 1519 *q++ = '{'; 1520 subtype = *p++; 1521 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1522 *q++ = '#'; 1523 } else if (c == '=' && subtype != 0) { 1524 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1525 if (*q) 1526 q++; 1527 else 1528 cmdnleft++; 1529 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1530 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1531 --cmdnleft > 0) 1532 *q = q[-1], q++; 1533 subtype = 0; 1534 } else if (c == CTLENDVAR) { 1535 *q++ = '}'; 1536 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1537 cmdnleft -= 5; 1538 if (cmdnleft > 0) { 1539 *q++ = '$'; 1540 *q++ = '('; 1541 *q++ = '.'; 1542 *q++ = '.'; 1543 *q++ = '.'; 1544 *q++ = ')'; 1545 } 1546 } else if (c == CTLARI) { 1547 cmdnleft -= 2; 1548 if (cmdnleft > 0) { 1549 *q++ = '$'; 1550 *q++ = '('; 1551 *q++ = '('; 1552 } 1553 p++; 1554 } else if (c == CTLENDARI) { 1555 if (--cmdnleft > 0) { 1556 *q++ = ')'; 1557 *q++ = ')'; 1558 } 1559 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1560 cmdnleft++; /* ignore */ 1561 else 1562 *q++ = c; 1563 if (--cmdnleft <= 0) { 1564 *q++ = '.'; 1565 *q++ = '.'; 1566 *q++ = '.'; 1567 break; 1568 } 1569 } 1570 cmdnextc = q; 1571 } 1572