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 * 4. 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 35static char sccsid[] = "@(#)jobs.c 8.5 (Berkeley) 5/4/95"; 36#endif 37#endif /* not lint */ 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: stable/11/bin/sh/jobs.c 345561 2019-03-26 22:34:07Z jilles $"); 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 85struct 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 97struct 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 char pipefail; /* pass any non-zero status */ 108#if JOBS 109 char jobctl; /* job running under job control */ 110 struct job *next; /* job used after this one */ 111#endif 112}; 113 114 115static struct job *jobtab; /* array of jobs */ 116static int njobs; /* size of array */ 117static pid_t backgndpid = -1; /* pid of last background process */ 118static struct job *bgjob = NULL; /* last background process */ 119#if JOBS 120static struct job *jobmru; /* most recently used job list */ 121static pid_t initialpgrp; /* pgrp of shell on invocation */ 122#endif 123static int ttyfd = -1; 124 125/* mode flags for dowait */ 126#define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 127#define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signal */ 128#define DOWAIT_SIG_TRAP 0x4 /* if DOWAIT_SIG, abort on trapped signal only */ 129 130#if JOBS 131static void restartjob(struct job *); 132#endif 133static void freejob(struct job *); 134static int waitcmdloop(struct job *); 135static struct job *getjob_nonotfound(const char *); 136static struct job *getjob(const char *); 137pid_t killjob(const char *, int); 138static pid_t dowait(int, struct job *); 139static void checkzombies(void); 140static void cmdtxt(union node *); 141static void cmdputs(const char *); 142#if JOBS 143static void setcurjob(struct job *); 144static void deljob(struct job *); 145static struct job *getcurjob(struct job *); 146#endif 147static int getjobstatus(const struct job *); 148static void printjobcmd(struct job *); 149static void showjob(struct job *, int); 150 151 152/* 153 * Turn job control on and off. 154 */ 155 156static int jobctl; 157 158#if JOBS 159static void 160jobctl_notty(void) 161{ 162 if (ttyfd >= 0) { 163 close(ttyfd); 164 ttyfd = -1; 165 } 166 if (!iflag) { 167 setsignal(SIGTSTP); 168 setsignal(SIGTTOU); 169 setsignal(SIGTTIN); 170 jobctl = 1; 171 return; 172 } 173 out2fmt_flush("sh: can't access tty; job control turned off\n"); 174 mflag = 0; 175} 176 177void 178setjobctl(int on) 179{ 180 int i; 181 182 if (on == jobctl || rootshell == 0) 183 return; 184 if (on) { 185 if (ttyfd != -1) 186 close(ttyfd); 187 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 188 i = 0; 189 while (i <= 2 && !isatty(i)) 190 i++; 191 if (i > 2 || 192 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) { 193 jobctl_notty(); 194 return; 195 } 196 } 197 if (ttyfd < 10) { 198 /* 199 * Keep our TTY file descriptor out of the way of 200 * the user's redirections. 201 */ 202 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 203 jobctl_notty(); 204 return; 205 } 206 close(ttyfd); 207 ttyfd = i; 208 } 209 do { /* while we are in the background */ 210 initialpgrp = tcgetpgrp(ttyfd); 211 if (initialpgrp < 0) { 212 jobctl_notty(); 213 return; 214 } 215 if (initialpgrp != getpgrp()) { 216 if (!iflag) { 217 initialpgrp = -1; 218 jobctl_notty(); 219 return; 220 } 221 kill(0, SIGTTIN); 222 continue; 223 } 224 } while (0); 225 setsignal(SIGTSTP); 226 setsignal(SIGTTOU); 227 setsignal(SIGTTIN); 228 setpgid(0, rootpid); 229 tcsetpgrp(ttyfd, rootpid); 230 } else { /* turning job control off */ 231 setpgid(0, initialpgrp); 232 if (ttyfd >= 0) { 233 tcsetpgrp(ttyfd, initialpgrp); 234 close(ttyfd); 235 ttyfd = -1; 236 } 237 setsignal(SIGTSTP); 238 setsignal(SIGTTOU); 239 setsignal(SIGTTIN); 240 } 241 jobctl = on; 242} 243#endif 244 245 246#if JOBS 247int 248fgcmd(int argc __unused, char **argv __unused) 249{ 250 struct job *jp; 251 pid_t pgrp; 252 int status; 253 254 nextopt(""); 255 jp = getjob(*argptr); 256 if (jp->jobctl == 0) 257 error("job not created under job control"); 258 printjobcmd(jp); 259 flushout(&output); 260 pgrp = jp->ps[0].pid; 261 if (ttyfd >= 0) 262 tcsetpgrp(ttyfd, pgrp); 263 restartjob(jp); 264 jp->foreground = 1; 265 INTOFF; 266 status = waitforjob(jp, (int *)NULL); 267 INTON; 268 return status; 269} 270 271 272int 273bgcmd(int argc __unused, char **argv __unused) 274{ 275 struct job *jp; 276 277 nextopt(""); 278 do { 279 jp = getjob(*argptr); 280 if (jp->jobctl == 0) 281 error("job not created under job control"); 282 if (jp->state == JOBDONE) 283 continue; 284 restartjob(jp); 285 jp->foreground = 0; 286 out1fmt("[%td] ", jp - jobtab + 1); 287 printjobcmd(jp); 288 } while (*argptr != NULL && *++argptr != NULL); 289 return 0; 290} 291 292 293static void 294restartjob(struct job *jp) 295{ 296 struct procstat *ps; 297 int i; 298 299 if (jp->state == JOBDONE) 300 return; 301 setcurjob(jp); 302 INTOFF; 303 kill(-jp->ps[0].pid, SIGCONT); 304 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 305 if (WIFSTOPPED(ps->status)) { 306 ps->status = -1; 307 jp->state = 0; 308 } 309 } 310 INTON; 311} 312#endif 313 314 315int 316jobscmd(int argc __unused, char *argv[] __unused) 317{ 318 char *id; 319 int ch, mode; 320 321 mode = SHOWJOBS_DEFAULT; 322 while ((ch = nextopt("lps")) != '\0') { 323 switch (ch) { 324 case 'l': 325 mode = SHOWJOBS_VERBOSE; 326 break; 327 case 'p': 328 mode = SHOWJOBS_PGIDS; 329 break; 330 case 's': 331 mode = SHOWJOBS_PIDS; 332 break; 333 } 334 } 335 336 if (*argptr == NULL) 337 showjobs(0, mode); 338 else 339 while ((id = *argptr++) != NULL) 340 showjob(getjob(id), mode); 341 342 return (0); 343} 344 345static int getjobstatus(const struct job *jp) 346{ 347 int i, status; 348 349 if (!jp->pipefail) 350 return (jp->ps[jp->nprocs - 1].status); 351 for (i = jp->nprocs - 1; i >= 0; i--) { 352 status = jp->ps[i].status; 353 if (status != 0) 354 return (status); 355 } 356 return (0); 357} 358 359static void 360printjobcmd(struct job *jp) 361{ 362 struct procstat *ps; 363 int i; 364 365 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 366 out1str(ps->cmd); 367 if (i > 0) 368 out1str(" | "); 369 } 370 out1c('\n'); 371} 372 373static void 374showjob(struct job *jp, int mode) 375{ 376 char s[64]; 377 char statebuf[16]; 378 const char *statestr, *coredump; 379 struct procstat *ps; 380 struct job *j; 381 int col, curr, i, jobno, prev, procno, status; 382 char c; 383 384 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 385 jobno = jp - jobtab + 1; 386 curr = prev = 0; 387#if JOBS 388 if ((j = getcurjob(NULL)) != NULL) { 389 curr = j - jobtab + 1; 390 if ((j = getcurjob(j)) != NULL) 391 prev = j - jobtab + 1; 392 } 393#endif 394 coredump = ""; 395 status = getjobstatus(jp); 396 if (jp->state == 0) { 397 statestr = "Running"; 398#if JOBS 399 } else if (jp->state == JOBSTOPPED) { 400 ps = jp->ps + jp->nprocs - 1; 401 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 402 ps--; 403 if (WIFSTOPPED(ps->status)) 404 i = WSTOPSIG(ps->status); 405 else 406 i = -1; 407 statestr = strsignal(i); 408 if (statestr == NULL) 409 statestr = "Suspended"; 410#endif 411 } else if (WIFEXITED(status)) { 412 if (WEXITSTATUS(status) == 0) 413 statestr = "Done"; 414 else { 415 fmtstr(statebuf, sizeof(statebuf), "Done(%d)", 416 WEXITSTATUS(status)); 417 statestr = statebuf; 418 } 419 } else { 420 i = WTERMSIG(status); 421 statestr = strsignal(i); 422 if (statestr == NULL) 423 statestr = "Unknown signal"; 424 if (WCOREDUMP(status)) 425 coredump = " (core dumped)"; 426 } 427 428 for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */ 429 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 430 out1fmt("%d\n", (int)ps->pid); 431 continue; 432 } 433 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 434 continue; 435 if (jobno == curr && ps == jp->ps) 436 c = '+'; 437 else if (jobno == prev && ps == jp->ps) 438 c = '-'; 439 else 440 c = ' '; 441 if (ps == jp->ps) 442 fmtstr(s, 64, "[%d] %c ", jobno, c); 443 else 444 fmtstr(s, 64, " %c ", c); 445 out1str(s); 446 col = strlen(s); 447 if (mode == SHOWJOBS_VERBOSE) { 448 fmtstr(s, 64, "%d ", (int)ps->pid); 449 out1str(s); 450 col += strlen(s); 451 } 452 if (ps == jp->ps) { 453 out1str(statestr); 454 out1str(coredump); 455 col += strlen(statestr) + strlen(coredump); 456 } 457 do { 458 out1c(' '); 459 col++; 460 } while (col < 30); 461 if (mode == SHOWJOBS_VERBOSE) { 462 out1str(ps->cmd); 463 out1c('\n'); 464 } else 465 printjobcmd(jp); 466 } 467} 468 469/* 470 * Print a list of jobs. If "change" is nonzero, only print jobs whose 471 * statuses have changed since the last call to showjobs. 472 * 473 * If the shell is interrupted in the process of creating a job, the 474 * result may be a job structure containing zero processes. Such structures 475 * will be freed here. 476 */ 477 478void 479showjobs(int change, int mode) 480{ 481 int jobno; 482 struct job *jp; 483 484 TRACE(("showjobs(%d) called\n", change)); 485 checkzombies(); 486 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 487 if (! jp->used) 488 continue; 489 if (jp->nprocs == 0) { 490 freejob(jp); 491 continue; 492 } 493 if (change && ! jp->changed) 494 continue; 495 showjob(jp, mode); 496 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 497 jp->changed = 0; 498 /* Hack: discard jobs for which $! has not been 499 * referenced in interactive mode when they terminate. 500 */ 501 if (jp->state == JOBDONE && !jp->remembered && 502 (iflag || jp != bgjob)) { 503 freejob(jp); 504 } 505 } 506 } 507} 508 509 510/* 511 * Mark a job structure as unused. 512 */ 513 514static void 515freejob(struct job *jp) 516{ 517 struct procstat *ps; 518 int i; 519 520 INTOFF; 521 if (bgjob == jp) 522 bgjob = NULL; 523 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 524 if (ps->cmd != nullstr) 525 ckfree(ps->cmd); 526 } 527 if (jp->ps != &jp->ps0) 528 ckfree(jp->ps); 529 jp->used = 0; 530#if JOBS 531 deljob(jp); 532#endif 533 INTON; 534} 535 536 537 538int 539waitcmd(int argc __unused, char **argv __unused) 540{ 541 struct job *job; 542 int retval; 543 544 nextopt(""); 545 if (*argptr == NULL) 546 return (waitcmdloop(NULL)); 547 548 do { 549 job = getjob_nonotfound(*argptr); 550 if (job == NULL) 551 retval = 127; 552 else 553 retval = waitcmdloop(job); 554 argptr++; 555 } while (*argptr != NULL); 556 557 return (retval); 558} 559 560static int 561waitcmdloop(struct job *job) 562{ 563 int status, retval, sig; 564 struct job *jp; 565 566 /* 567 * Loop until a process is terminated or stopped, or a SIGINT is 568 * received. 569 */ 570 571 do { 572 if (job != NULL) { 573 if (job->state == JOBDONE) { 574 status = getjobstatus(job); 575 if (WIFEXITED(status)) 576 retval = WEXITSTATUS(status); 577 else 578 retval = WTERMSIG(status) + 128; 579 if (! iflag || ! job->changed) 580 freejob(job); 581 else { 582 job->remembered = 0; 583 if (job == bgjob) 584 bgjob = NULL; 585 } 586 return retval; 587 } 588 } else { 589 for (jp = jobtab ; jp < jobtab + njobs; jp++) 590 if (jp->used && jp->state == JOBDONE) { 591 if (! iflag || ! jp->changed) 592 freejob(jp); 593 else { 594 jp->remembered = 0; 595 if (jp == bgjob) 596 bgjob = NULL; 597 } 598 } 599 for (jp = jobtab ; ; jp++) { 600 if (jp >= jobtab + njobs) { /* no running procs */ 601 return 0; 602 } 603 if (jp->used && jp->state == 0) 604 break; 605 } 606 } 607 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 608 609 sig = pendingsig_waitcmd; 610 pendingsig_waitcmd = 0; 611 return sig + 128; 612} 613 614 615 616int 617jobidcmd(int argc __unused, char **argv __unused) 618{ 619 struct job *jp; 620 int i; 621 622 nextopt(""); 623 jp = getjob(*argptr); 624 for (i = 0 ; i < jp->nprocs ; ) { 625 out1fmt("%d", (int)jp->ps[i].pid); 626 out1c(++i < jp->nprocs? ' ' : '\n'); 627 } 628 return 0; 629} 630 631 632 633/* 634 * Convert a job name to a job structure. 635 */ 636 637static struct job * 638getjob_nonotfound(const char *name) 639{ 640 int jobno; 641 struct job *found, *jp; 642 size_t namelen; 643 pid_t pid; 644 int i; 645 646 if (name == NULL) { 647#if JOBS 648 name = "%+"; 649#else 650 error("No current job"); 651#endif 652 } 653 if (name[0] == '%') { 654 if (is_digit(name[1])) { 655 jobno = number(name + 1); 656 if (jobno > 0 && jobno <= njobs 657 && jobtab[jobno - 1].used != 0) 658 return &jobtab[jobno - 1]; 659#if JOBS 660 } else if ((name[1] == '%' || name[1] == '+') && 661 name[2] == '\0') { 662 if ((jp = getcurjob(NULL)) == NULL) 663 error("No current job"); 664 return (jp); 665 } else if (name[1] == '-' && name[2] == '\0') { 666 if ((jp = getcurjob(NULL)) == NULL || 667 (jp = getcurjob(jp)) == NULL) 668 error("No previous job"); 669 return (jp); 670#endif 671 } else if (name[1] == '?') { 672 found = NULL; 673 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 674 if (jp->used && jp->nprocs > 0 675 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 676 if (found) 677 error("%s: ambiguous", name); 678 found = jp; 679 } 680 } 681 if (found != NULL) 682 return (found); 683 } else { 684 namelen = strlen(name); 685 found = NULL; 686 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 687 if (jp->used && jp->nprocs > 0 688 && strncmp(jp->ps[0].cmd, name + 1, 689 namelen - 1) == 0) { 690 if (found) 691 error("%s: ambiguous", name); 692 found = jp; 693 } 694 } 695 if (found) 696 return found; 697 } 698 } else if (is_number(name)) { 699 pid = (pid_t)number(name); 700 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 701 if (jp->used && jp->nprocs > 0 702 && jp->ps[jp->nprocs - 1].pid == pid) 703 return jp; 704 } 705 } 706 return NULL; 707} 708 709 710static struct job * 711getjob(const char *name) 712{ 713 struct job *jp; 714 715 jp = getjob_nonotfound(name); 716 if (jp == NULL) 717 error("No such job: %s", name); 718 return (jp); 719} 720 721 722int 723killjob(const char *name, int sig) 724{ 725 struct job *jp; 726 int i, ret; 727 728 jp = getjob(name); 729 if (jp->state == JOBDONE) 730 return 0; 731 if (jp->jobctl) 732 return kill(-jp->ps[0].pid, sig); 733 ret = -1; 734 errno = ESRCH; 735 for (i = 0; i < jp->nprocs; i++) 736 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) { 737 if (kill(jp->ps[i].pid, sig) == 0) 738 ret = 0; 739 } else 740 ret = 0; 741 return ret; 742} 743 744/* 745 * Return a new job structure, 746 */ 747 748struct job * 749makejob(union node *node __unused, int nprocs) 750{ 751 int i; 752 struct job *jp; 753 754 for (i = njobs, jp = jobtab ; ; jp++) { 755 if (--i < 0) { 756 INTOFF; 757 if (njobs == 0) { 758 jobtab = ckmalloc(4 * sizeof jobtab[0]); 759#if JOBS 760 jobmru = NULL; 761#endif 762 } else { 763 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 764 memcpy(jp, jobtab, njobs * sizeof jp[0]); 765#if JOBS 766 /* Relocate `next' pointers and list head */ 767 if (jobmru != NULL) 768 jobmru = &jp[jobmru - jobtab]; 769 for (i = 0; i < njobs; i++) 770 if (jp[i].next != NULL) 771 jp[i].next = &jp[jp[i].next - 772 jobtab]; 773#endif 774 if (bgjob != NULL) 775 bgjob = &jp[bgjob - jobtab]; 776 /* Relocate `ps' pointers */ 777 for (i = 0; i < njobs; i++) 778 if (jp[i].ps == &jobtab[i].ps0) 779 jp[i].ps = &jp[i].ps0; 780 ckfree(jobtab); 781 jobtab = jp; 782 } 783 jp = jobtab + njobs; 784 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 785 ; 786 INTON; 787 break; 788 } 789 if (jp->used == 0) 790 break; 791 } 792 INTOFF; 793 jp->state = 0; 794 jp->used = 1; 795 jp->changed = 0; 796 jp->nprocs = 0; 797 jp->foreground = 0; 798 jp->remembered = 0; 799 jp->pipefail = pipefailflag; 800#if JOBS 801 jp->jobctl = jobctl; 802 jp->next = NULL; 803#endif 804 if (nprocs > 1) { 805 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 806 } else { 807 jp->ps = &jp->ps0; 808 } 809 INTON; 810 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 811 jp - jobtab + 1)); 812 return jp; 813} 814 815#if JOBS 816static void 817setcurjob(struct job *cj) 818{ 819 struct job *jp, *prev; 820 821 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 822 if (jp == cj) { 823 if (prev != NULL) 824 prev->next = jp->next; 825 else 826 jobmru = jp->next; 827 jp->next = jobmru; 828 jobmru = cj; 829 return; 830 } 831 } 832 cj->next = jobmru; 833 jobmru = cj; 834} 835 836static void 837deljob(struct job *j) 838{ 839 struct job *jp, *prev; 840 841 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 842 if (jp == j) { 843 if (prev != NULL) 844 prev->next = jp->next; 845 else 846 jobmru = jp->next; 847 return; 848 } 849 } 850} 851 852/* 853 * Return the most recently used job that isn't `nj', and preferably one 854 * that is stopped. 855 */ 856static struct job * 857getcurjob(struct job *nj) 858{ 859 struct job *jp; 860 861 /* Try to find a stopped one.. */ 862 for (jp = jobmru; jp != NULL; jp = jp->next) 863 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 864 return (jp); 865 /* Otherwise the most recently used job that isn't `nj' */ 866 for (jp = jobmru; jp != NULL; jp = jp->next) 867 if (jp->used && jp != nj) 868 return (jp); 869 870 return (NULL); 871} 872 873#endif 874 875/* 876 * Fork of a subshell. If we are doing job control, give the subshell its 877 * own process group. Jp is a job structure that the job is to be added to. 878 * N is the command that will be evaluated by the child. Both jp and n may 879 * be NULL. The mode parameter can be one of the following: 880 * FORK_FG - Fork off a foreground process. 881 * FORK_BG - Fork off a background process. 882 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 883 * process group even if job control is on. 884 * 885 * When job control is turned off, background processes have their standard 886 * input redirected to /dev/null (except for the second and later processes 887 * in a pipeline). 888 */ 889 890pid_t 891forkshell(struct job *jp, union node *n, int mode) 892{ 893 pid_t pid; 894 pid_t pgrp; 895 896 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 897 mode)); 898 INTOFF; 899 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 900 checkzombies(); 901 flushall(); 902 pid = fork(); 903 if (pid == -1) { 904 TRACE(("Fork failed, errno=%d\n", errno)); 905 INTON; 906 error("Cannot fork: %s", strerror(errno)); 907 } 908 if (pid == 0) { 909 struct job *p; 910 int wasroot; 911 int i; 912 913 TRACE(("Child shell %d\n", (int)getpid())); 914 wasroot = rootshell; 915 rootshell = 0; 916 handler = &main_handler; 917 closescript(); 918 INTON; 919 forcelocal = 0; 920 clear_traps(); 921#if JOBS 922 jobctl = 0; /* do job control only in root shell */ 923 if (wasroot && mode != FORK_NOJOB && mflag) { 924 if (jp == NULL || jp->nprocs == 0) 925 pgrp = getpid(); 926 else 927 pgrp = jp->ps[0].pid; 928 if (setpgid(0, pgrp) == 0 && mode == FORK_FG && 929 ttyfd >= 0) { 930 /*** this causes superfluous TIOCSPGRPS ***/ 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 1004pid_t 1005vforkexecshell(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 1011 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 1012 (void *)pip)); 1013 INTOFF; 1014 flushall(); 1015 savehandler = handler; 1016 pid = vfork(); 1017 if (pid == -1) { 1018 TRACE(("Vfork failed, errno=%d\n", errno)); 1019 INTON; 1020 error("Cannot fork: %s", strerror(errno)); 1021 } 1022 if (pid == 0) { 1023 TRACE(("Child shell %d\n", (int)getpid())); 1024 if (setjmp(jmploc.loc)) 1025 _exit(exception == EXEXEC ? exerrno : 2); 1026 if (pip != NULL) { 1027 close(pip[0]); 1028 if (pip[1] != 1) { 1029 dup2(pip[1], 1); 1030 close(pip[1]); 1031 } 1032 } 1033 handler = &jmploc; 1034 shellexec(argv, envp, path, idx); 1035 } 1036 handler = savehandler; 1037 if (jp) { 1038 struct procstat *ps = &jp->ps[jp->nprocs++]; 1039 ps->pid = pid; 1040 ps->status = -1; 1041 ps->cmd = nullstr; 1042 jp->foreground = 1; 1043#if JOBS 1044 setcurjob(jp); 1045#endif 1046 } 1047 INTON; 1048 TRACE(("In parent shell: child = %d\n", (int)pid)); 1049 return pid; 1050} 1051 1052 1053/* 1054 * Wait for job to finish. 1055 * 1056 * Under job control we have the problem that while a child process is 1057 * running interrupts generated by the user are sent to the child but not 1058 * to the shell. This means that an infinite loop started by an inter- 1059 * active user may be hard to kill. With job control turned off, an 1060 * interactive user may place an interactive program inside a loop. If 1061 * the interactive program catches interrupts, the user doesn't want 1062 * these interrupts to also abort the loop. The approach we take here 1063 * is to have the shell ignore interrupt signals while waiting for a 1064 * foreground process to terminate, and then send itself an interrupt 1065 * signal if the child process was terminated by an interrupt signal. 1066 * Unfortunately, some programs want to do a bit of cleanup and then 1067 * exit on interrupt; unless these processes terminate themselves by 1068 * sending a signal to themselves (instead of calling exit) they will 1069 * confuse this approach. 1070 */ 1071 1072int 1073waitforjob(struct job *jp, int *origstatus) 1074{ 1075#if JOBS 1076 int propagate_int = jp->jobctl && jp->foreground; 1077#endif 1078 int status; 1079 int st; 1080 1081 INTOFF; 1082 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 1083 while (jp->state == 0) 1084 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 1085 DOWAIT_SIG_TRAP : 0), jp) == -1) 1086 dotrap(); 1087#if JOBS 1088 if (jp->jobctl) { 1089 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0) 1090 error("tcsetpgrp failed, errno=%d\n", errno); 1091 } 1092 if (jp->state == JOBSTOPPED) 1093 setcurjob(jp); 1094#endif 1095 status = getjobstatus(jp); 1096 if (origstatus != NULL) 1097 *origstatus = status; 1098 /* convert to 8 bits */ 1099 if (WIFEXITED(status)) 1100 st = WEXITSTATUS(status); 1101#if JOBS 1102 else if (WIFSTOPPED(status)) 1103 st = WSTOPSIG(status) + 128; 1104#endif 1105 else 1106 st = WTERMSIG(status) + 128; 1107 if (! JOBS || jp->state == JOBDONE) 1108 freejob(jp); 1109 if (int_pending()) { 1110 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1111 CLEAR_PENDING_INT; 1112 } 1113#if JOBS 1114 else if (rootshell && propagate_int && 1115 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1116 kill(getpid(), SIGINT); 1117#endif 1118 INTON; 1119 return st; 1120} 1121 1122 1123static void 1124dummy_handler(int sig __unused) 1125{ 1126} 1127 1128/* 1129 * Wait for a process to terminate. 1130 */ 1131 1132static pid_t 1133dowait(int mode, struct job *job) 1134{ 1135 struct sigaction sa, osa; 1136 sigset_t mask, omask; 1137 pid_t pid; 1138 int status; 1139 struct procstat *sp; 1140 struct job *jp; 1141 struct job *thisjob; 1142 const char *sigstr; 1143 int done; 1144 int stopped; 1145 int sig; 1146 int coredump; 1147 int wflags; 1148 int restore_sigchld; 1149 1150 TRACE(("dowait(%d, %p) called\n", mode, job)); 1151 restore_sigchld = 0; 1152 if ((mode & DOWAIT_SIG) != 0) { 1153 sigfillset(&mask); 1154 sigprocmask(SIG_BLOCK, &mask, &omask); 1155 INTOFF; 1156 if (!issigchldtrapped()) { 1157 restore_sigchld = 1; 1158 sa.sa_handler = dummy_handler; 1159 sa.sa_flags = 0; 1160 sigemptyset(&sa.sa_mask); 1161 sigaction(SIGCHLD, &sa, &osa); 1162 } 1163 } 1164 do { 1165#if JOBS 1166 if (iflag) 1167 wflags = WUNTRACED | WCONTINUED; 1168 else 1169#endif 1170 wflags = 0; 1171 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1172 wflags |= WNOHANG; 1173 pid = wait3(&status, wflags, (struct rusage *)NULL); 1174 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1175 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1176 pid = -1; 1177 if (((mode & DOWAIT_SIG_TRAP) != 0 ? 1178 pendingsig : pendingsig_waitcmd) != 0) { 1179 errno = EINTR; 1180 break; 1181 } 1182 sigsuspend(&omask); 1183 if (int_pending()) 1184 break; 1185 } 1186 } while (pid == -1 && errno == EINTR); 1187 if (pid == -1 && errno == ECHILD && job != NULL) 1188 job->state = JOBDONE; 1189 if ((mode & DOWAIT_SIG) != 0) { 1190 if (restore_sigchld) 1191 sigaction(SIGCHLD, &osa, NULL); 1192 sigprocmask(SIG_SETMASK, &omask, NULL); 1193 INTON; 1194 } 1195 if (pid <= 0) 1196 return pid; 1197 INTOFF; 1198 thisjob = NULL; 1199 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1200 if (jp->used && jp->nprocs > 0) { 1201 done = 1; 1202 stopped = 1; 1203 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1204 if (sp->pid == -1) 1205 continue; 1206 if (sp->pid == pid && (sp->status == -1 || 1207 WIFSTOPPED(sp->status))) { 1208 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1209 (int)pid, sp->status, 1210 status)); 1211 if (WIFCONTINUED(status)) { 1212 sp->status = -1; 1213 jp->state = 0; 1214 } else 1215 sp->status = status; 1216 thisjob = jp; 1217 } 1218 if (sp->status == -1) 1219 stopped = 0; 1220 else if (WIFSTOPPED(sp->status)) 1221 done = 0; 1222 } 1223 if (stopped) { /* stopped or done */ 1224 int state = done? JOBDONE : JOBSTOPPED; 1225 if (jp->state != state) { 1226 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1227 jp->state = state; 1228 if (jp != job) { 1229 if (done && !jp->remembered && 1230 !iflag && jp != bgjob) 1231 freejob(jp); 1232#if JOBS 1233 else if (done) 1234 deljob(jp); 1235#endif 1236 } 1237 } 1238 } 1239 } 1240 } 1241 INTON; 1242 if (!thisjob || thisjob->state == 0) 1243 ; 1244 else if ((!rootshell || !iflag || thisjob == job) && 1245 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1246 sig = 0; 1247 coredump = 0; 1248 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1249 if (WIFSIGNALED(sp->status)) { 1250 sig = WTERMSIG(sp->status); 1251 coredump = WCOREDUMP(sp->status); 1252 } 1253 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1254 sigstr = strsignal(sig); 1255 if (sigstr != NULL) 1256 out2str(sigstr); 1257 else 1258 out2str("Unknown signal"); 1259 if (coredump) 1260 out2str(" (core dumped)"); 1261 out2c('\n'); 1262 flushout(out2); 1263 } 1264 } else { 1265 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1266 thisjob->changed = 1; 1267 } 1268 return pid; 1269} 1270 1271 1272 1273/* 1274 * return 1 if there are stopped jobs, otherwise 0 1275 */ 1276int job_warning = 0; 1277int 1278stoppedjobs(void) 1279{ 1280 int jobno; 1281 struct job *jp; 1282 1283 if (job_warning) 1284 return (0); 1285 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1286 if (jp->used == 0) 1287 continue; 1288 if (jp->state == JOBSTOPPED) { 1289 out2fmt_flush("You have stopped jobs.\n"); 1290 job_warning = 2; 1291 return (1); 1292 } 1293 } 1294 1295 return (0); 1296} 1297 1298 1299static void 1300checkzombies(void) 1301{ 1302 while (njobs > 0 && dowait(0, NULL) > 0) 1303 ; 1304} 1305 1306 1307int 1308backgndpidset(void) 1309{ 1310 return backgndpid != -1; 1311} 1312 1313 1314pid_t 1315backgndpidval(void) 1316{ 1317 if (bgjob != NULL && !forcelocal) 1318 bgjob->remembered = 1; 1319 return backgndpid; 1320} 1321 1322/* 1323 * Return a string identifying a command (to be printed by the 1324 * jobs command. 1325 */ 1326 1327static char *cmdnextc; 1328static int cmdnleft; 1329#define MAXCMDTEXT 200 1330 1331char * 1332commandtext(union node *n) 1333{ 1334 char *name; 1335 1336 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1337 cmdnleft = MAXCMDTEXT - 4; 1338 cmdtxt(n); 1339 *cmdnextc = '\0'; 1340 return name; 1341} 1342 1343 1344static void 1345cmdtxtdogroup(union node *n) 1346{ 1347 cmdputs("; do "); 1348 cmdtxt(n); 1349 cmdputs("; done"); 1350} 1351 1352 1353static void 1354cmdtxtredir(union node *n, const char *op, int deffd) 1355{ 1356 char s[2]; 1357 1358 if (n->nfile.fd != deffd) { 1359 s[0] = n->nfile.fd + '0'; 1360 s[1] = '\0'; 1361 cmdputs(s); 1362 } 1363 cmdputs(op); 1364 if (n->type == NTOFD || n->type == NFROMFD) { 1365 if (n->ndup.dupfd >= 0) 1366 s[0] = n->ndup.dupfd + '0'; 1367 else 1368 s[0] = '-'; 1369 s[1] = '\0'; 1370 cmdputs(s); 1371 } else { 1372 cmdtxt(n->nfile.fname); 1373 } 1374} 1375 1376 1377static void 1378cmdtxt(union node *n) 1379{ 1380 union node *np; 1381 struct nodelist *lp; 1382 1383 if (n == NULL) 1384 return; 1385 switch (n->type) { 1386 case NSEMI: 1387 cmdtxt(n->nbinary.ch1); 1388 cmdputs("; "); 1389 cmdtxt(n->nbinary.ch2); 1390 break; 1391 case NAND: 1392 cmdtxt(n->nbinary.ch1); 1393 cmdputs(" && "); 1394 cmdtxt(n->nbinary.ch2); 1395 break; 1396 case NOR: 1397 cmdtxt(n->nbinary.ch1); 1398 cmdputs(" || "); 1399 cmdtxt(n->nbinary.ch2); 1400 break; 1401 case NPIPE: 1402 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1403 cmdtxt(lp->n); 1404 if (lp->next) 1405 cmdputs(" | "); 1406 } 1407 break; 1408 case NSUBSHELL: 1409 cmdputs("("); 1410 cmdtxt(n->nredir.n); 1411 cmdputs(")"); 1412 break; 1413 case NREDIR: 1414 case NBACKGND: 1415 cmdtxt(n->nredir.n); 1416 break; 1417 case NIF: 1418 cmdputs("if "); 1419 cmdtxt(n->nif.test); 1420 cmdputs("; then "); 1421 cmdtxt(n->nif.ifpart); 1422 cmdputs("..."); 1423 break; 1424 case NWHILE: 1425 cmdputs("while "); 1426 cmdtxt(n->nbinary.ch1); 1427 cmdtxtdogroup(n->nbinary.ch2); 1428 break; 1429 case NUNTIL: 1430 cmdputs("until "); 1431 cmdtxt(n->nbinary.ch1); 1432 cmdtxtdogroup(n->nbinary.ch2); 1433 break; 1434 case NFOR: 1435 cmdputs("for "); 1436 cmdputs(n->nfor.var); 1437 cmdputs(" in ..."); 1438 break; 1439 case NCASE: 1440 cmdputs("case "); 1441 cmdputs(n->ncase.expr->narg.text); 1442 cmdputs(" in ..."); 1443 break; 1444 case NDEFUN: 1445 cmdputs(n->narg.text); 1446 cmdputs("() ..."); 1447 break; 1448 case NNOT: 1449 cmdputs("! "); 1450 cmdtxt(n->nnot.com); 1451 break; 1452 case NCMD: 1453 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1454 cmdtxt(np); 1455 if (np->narg.next) 1456 cmdputs(" "); 1457 } 1458 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1459 cmdputs(" "); 1460 cmdtxt(np); 1461 } 1462 break; 1463 case NARG: 1464 cmdputs(n->narg.text); 1465 break; 1466 case NTO: 1467 cmdtxtredir(n, ">", 1); 1468 break; 1469 case NAPPEND: 1470 cmdtxtredir(n, ">>", 1); 1471 break; 1472 case NTOFD: 1473 cmdtxtredir(n, ">&", 1); 1474 break; 1475 case NCLOBBER: 1476 cmdtxtredir(n, ">|", 1); 1477 break; 1478 case NFROM: 1479 cmdtxtredir(n, "<", 0); 1480 break; 1481 case NFROMTO: 1482 cmdtxtredir(n, "<>", 0); 1483 break; 1484 case NFROMFD: 1485 cmdtxtredir(n, "<&", 0); 1486 break; 1487 case NHERE: 1488 case NXHERE: 1489 cmdputs("<<..."); 1490 break; 1491 default: 1492 cmdputs("???"); 1493 break; 1494 } 1495} 1496 1497 1498 1499static void 1500cmdputs(const char *s) 1501{ 1502 const char *p; 1503 char *q; 1504 char c; 1505 int subtype = 0; 1506 1507 if (cmdnleft <= 0) 1508 return; 1509 p = s; 1510 q = cmdnextc; 1511 while ((c = *p++) != '\0') { 1512 if (c == CTLESC) 1513 *q++ = *p++; 1514 else if (c == CTLVAR) { 1515 *q++ = '$'; 1516 if (--cmdnleft > 0) 1517 *q++ = '{'; 1518 subtype = *p++; 1519 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1520 *q++ = '#'; 1521 } else if (c == '=' && subtype != 0) { 1522 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1523 if (*q) 1524 q++; 1525 else 1526 cmdnleft++; 1527 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1528 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1529 --cmdnleft > 0) 1530 *q = q[-1], q++; 1531 subtype = 0; 1532 } else if (c == CTLENDVAR) { 1533 *q++ = '}'; 1534 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1535 cmdnleft -= 5; 1536 if (cmdnleft > 0) { 1537 *q++ = '$'; 1538 *q++ = '('; 1539 *q++ = '.'; 1540 *q++ = '.'; 1541 *q++ = '.'; 1542 *q++ = ')'; 1543 } 1544 } else if (c == CTLARI) { 1545 cmdnleft -= 2; 1546 if (cmdnleft > 0) { 1547 *q++ = '$'; 1548 *q++ = '('; 1549 *q++ = '('; 1550 } 1551 p++; 1552 } else if (c == CTLENDARI) { 1553 if (--cmdnleft > 0) { 1554 *q++ = ')'; 1555 *q++ = ')'; 1556 } 1557 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1558 cmdnleft++; /* ignore */ 1559 else 1560 *q++ = c; 1561 if (--cmdnleft <= 0) { 1562 *q++ = '.'; 1563 *q++ = '.'; 1564 *q++ = '.'; 1565 break; 1566 } 1567 } 1568 cmdnextc = q; 1569} 1570