jobs.c revision 223024
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: head/bin/sh/jobs.c 223024 2011-06-12 23:06:04Z 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 "show.h" 61#include "main.h" 62#include "parser.h" 63#include "nodes.h" 64#include "jobs.h" 65#include "options.h" 66#include "trap.h" 67#include "syntax.h" 68#include "input.h" 69#include "output.h" 70#include "memalloc.h" 71#include "error.h" 72#include "mystring.h" 73#include "var.h" 74 75 76static struct job *jobtab; /* array of jobs */ 77static int njobs; /* size of array */ 78MKINIT pid_t backgndpid = -1; /* pid of last background process */ 79MKINIT struct job *bgjob = NULL; /* last background process */ 80#if JOBS 81static struct job *jobmru; /* most recently used job list */ 82static pid_t initialpgrp; /* pgrp of shell on invocation */ 83#endif 84int in_waitcmd = 0; /* are we in waitcmd()? */ 85int in_dowait = 0; /* are we in dowait()? */ 86volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 87static int ttyfd = -1; 88 89#if JOBS 90static void restartjob(struct job *); 91#endif 92static void freejob(struct job *); 93static struct job *getjob(char *); 94static pid_t dowait(int, struct job *); 95static pid_t waitproc(int, int *); 96static void checkzombies(void); 97static void cmdtxt(union node *); 98static void cmdputs(const char *); 99#if JOBS 100static void setcurjob(struct job *); 101static void deljob(struct job *); 102static struct job *getcurjob(struct job *); 103#endif 104static void printjobcmd(struct job *); 105static void showjob(struct job *, int); 106 107 108/* 109 * Turn job control on and off. 110 */ 111 112MKINIT int jobctl; 113 114#if JOBS 115void 116setjobctl(int on) 117{ 118 int i; 119 120 if (on == jobctl || rootshell == 0) 121 return; 122 if (on) { 123 if (ttyfd != -1) 124 close(ttyfd); 125 if ((ttyfd = open(_PATH_TTY, O_RDWR)) < 0) { 126 i = 0; 127 while (i <= 2 && !isatty(i)) 128 i++; 129 if (i > 2 || (ttyfd = fcntl(i, F_DUPFD, 10)) < 0) 130 goto out; 131 } 132 if (ttyfd < 10) { 133 /* 134 * Keep our TTY file descriptor out of the way of 135 * the user's redirections. 136 */ 137 if ((i = fcntl(ttyfd, F_DUPFD, 10)) < 0) { 138 close(ttyfd); 139 ttyfd = -1; 140 goto out; 141 } 142 close(ttyfd); 143 ttyfd = i; 144 } 145 if (fcntl(ttyfd, F_SETFD, FD_CLOEXEC) < 0) { 146 close(ttyfd); 147 ttyfd = -1; 148 goto out; 149 } 150 do { /* while we are in the background */ 151 initialpgrp = tcgetpgrp(ttyfd); 152 if (initialpgrp < 0) { 153out: out2fmt_flush("sh: can't access tty; job control turned off\n"); 154 mflag = 0; 155 return; 156 } 157 if (initialpgrp != getpgrp()) { 158 kill(0, SIGTTIN); 159 continue; 160 } 161 } while (0); 162 setsignal(SIGTSTP); 163 setsignal(SIGTTOU); 164 setsignal(SIGTTIN); 165 setpgid(0, rootpid); 166 tcsetpgrp(ttyfd, rootpid); 167 } else { /* turning job control off */ 168 setpgid(0, initialpgrp); 169 tcsetpgrp(ttyfd, initialpgrp); 170 close(ttyfd); 171 ttyfd = -1; 172 setsignal(SIGTSTP); 173 setsignal(SIGTTOU); 174 setsignal(SIGTTIN); 175 } 176 jobctl = on; 177} 178#endif 179 180 181#if JOBS 182int 183fgcmd(int argc __unused, char **argv) 184{ 185 struct job *jp; 186 pid_t pgrp; 187 int status; 188 189 jp = getjob(argv[1]); 190 if (jp->jobctl == 0) 191 error("job not created under job control"); 192 printjobcmd(jp); 193 flushout(&output); 194 pgrp = jp->ps[0].pid; 195 tcsetpgrp(ttyfd, pgrp); 196 restartjob(jp); 197 jp->foreground = 1; 198 INTOFF; 199 status = waitforjob(jp, (int *)NULL); 200 INTON; 201 return status; 202} 203 204 205int 206bgcmd(int argc, char **argv) 207{ 208 struct job *jp; 209 210 do { 211 jp = getjob(*++argv); 212 if (jp->jobctl == 0) 213 error("job not created under job control"); 214 if (jp->state == JOBDONE) 215 continue; 216 restartjob(jp); 217 jp->foreground = 0; 218 out1fmt("[%td] ", jp - jobtab + 1); 219 printjobcmd(jp); 220 } while (--argc > 1); 221 return 0; 222} 223 224 225static void 226restartjob(struct job *jp) 227{ 228 struct procstat *ps; 229 int i; 230 231 if (jp->state == JOBDONE) 232 return; 233 setcurjob(jp); 234 INTOFF; 235 kill(-jp->ps[0].pid, SIGCONT); 236 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 237 if (WIFSTOPPED(ps->status)) { 238 ps->status = -1; 239 jp->state = 0; 240 } 241 } 242 INTON; 243} 244#endif 245 246 247int 248jobscmd(int argc, char *argv[]) 249{ 250 char *id; 251 int ch, mode; 252 253 optind = optreset = 1; 254 opterr = 0; 255 mode = SHOWJOBS_DEFAULT; 256 while ((ch = getopt(argc, argv, "lps")) != -1) { 257 switch (ch) { 258 case 'l': 259 mode = SHOWJOBS_VERBOSE; 260 break; 261 case 'p': 262 mode = SHOWJOBS_PGIDS; 263 break; 264 case 's': 265 mode = SHOWJOBS_PIDS; 266 break; 267 case '?': 268 default: 269 error("unknown option: -%c", optopt); 270 } 271 } 272 argc -= optind; 273 argv += optind; 274 275 if (argc == 0) 276 showjobs(0, mode); 277 else 278 while ((id = *argv++) != NULL) 279 showjob(getjob(id), mode); 280 281 return (0); 282} 283 284static void 285printjobcmd(struct job *jp) 286{ 287 struct procstat *ps; 288 int i; 289 290 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 291 out1str(ps->cmd); 292 if (i > 0) 293 out1str(" | "); 294 } 295 out1c('\n'); 296} 297 298static void 299showjob(struct job *jp, int mode) 300{ 301 char s[64]; 302 char statestr[64]; 303 struct procstat *ps; 304 struct job *j; 305 int col, curr, i, jobno, prev, procno; 306 char c; 307 308 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 309 jobno = jp - jobtab + 1; 310 curr = prev = 0; 311#if JOBS 312 if ((j = getcurjob(NULL)) != NULL) { 313 curr = j - jobtab + 1; 314 if ((j = getcurjob(j)) != NULL) 315 prev = j - jobtab + 1; 316 } 317#endif 318 ps = jp->ps + jp->nprocs - 1; 319 if (jp->state == 0) { 320 strcpy(statestr, "Running"); 321#if JOBS 322 } else if (jp->state == JOBSTOPPED) { 323 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 324 ps--; 325 if (WIFSTOPPED(ps->status)) 326 i = WSTOPSIG(ps->status); 327 else 328 i = -1; 329 if (i > 0 && i < sys_nsig && sys_siglist[i]) 330 strcpy(statestr, sys_siglist[i]); 331 else 332 strcpy(statestr, "Suspended"); 333#endif 334 } else if (WIFEXITED(ps->status)) { 335 if (WEXITSTATUS(ps->status) == 0) 336 strcpy(statestr, "Done"); 337 else 338 fmtstr(statestr, 64, "Done(%d)", 339 WEXITSTATUS(ps->status)); 340 } else { 341 i = WTERMSIG(ps->status); 342 if (i > 0 && i < sys_nsig && sys_siglist[i]) 343 strcpy(statestr, sys_siglist[i]); 344 else 345 fmtstr(statestr, 64, "Signal %d", i); 346 if (WCOREDUMP(ps->status)) 347 strcat(statestr, " (core dumped)"); 348 } 349 350 for (ps = jp->ps ; ; ps++) { /* for each process */ 351 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 352 out1fmt("%d\n", (int)ps->pid); 353 goto skip; 354 } 355 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 356 goto skip; 357 if (jobno == curr && ps == jp->ps) 358 c = '+'; 359 else if (jobno == prev && ps == jp->ps) 360 c = '-'; 361 else 362 c = ' '; 363 if (ps == jp->ps) 364 fmtstr(s, 64, "[%d] %c ", jobno, c); 365 else 366 fmtstr(s, 64, " %c ", c); 367 out1str(s); 368 col = strlen(s); 369 if (mode == SHOWJOBS_VERBOSE) { 370 fmtstr(s, 64, "%d ", (int)ps->pid); 371 out1str(s); 372 col += strlen(s); 373 } 374 if (ps == jp->ps) { 375 out1str(statestr); 376 col += strlen(statestr); 377 } 378 do { 379 out1c(' '); 380 col++; 381 } while (col < 30); 382 if (mode == SHOWJOBS_VERBOSE) { 383 out1str(ps->cmd); 384 out1c('\n'); 385 } else 386 printjobcmd(jp); 387skip: if (--procno <= 0) 388 break; 389 } 390} 391 392/* 393 * Print a list of jobs. If "change" is nonzero, only print jobs whose 394 * statuses have changed since the last call to showjobs. 395 * 396 * If the shell is interrupted in the process of creating a job, the 397 * result may be a job structure containing zero processes. Such structures 398 * will be freed here. 399 */ 400 401void 402showjobs(int change, int mode) 403{ 404 int jobno; 405 struct job *jp; 406 407 TRACE(("showjobs(%d) called\n", change)); 408 checkzombies(); 409 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 410 if (! jp->used) 411 continue; 412 if (jp->nprocs == 0) { 413 freejob(jp); 414 continue; 415 } 416 if (change && ! jp->changed) 417 continue; 418 showjob(jp, mode); 419 jp->changed = 0; 420 /* Hack: discard jobs for which $! has not been referenced 421 * in interactive mode when they terminate. 422 */ 423 if (jp->state == JOBDONE && !jp->remembered && 424 (iflag || jp != bgjob)) { 425 freejob(jp); 426 } 427 } 428} 429 430 431/* 432 * Mark a job structure as unused. 433 */ 434 435static void 436freejob(struct job *jp) 437{ 438 struct procstat *ps; 439 int i; 440 441 INTOFF; 442 if (bgjob == jp) 443 bgjob = NULL; 444 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 445 if (ps->cmd != nullstr) 446 ckfree(ps->cmd); 447 } 448 if (jp->ps != &jp->ps0) 449 ckfree(jp->ps); 450 jp->used = 0; 451#if JOBS 452 deljob(jp); 453#endif 454 INTON; 455} 456 457 458 459int 460waitcmd(int argc, char **argv) 461{ 462 struct job *job; 463 int status, retval; 464 struct job *jp; 465 466 if (argc > 1) { 467 job = getjob(argv[1]); 468 } else { 469 job = NULL; 470 } 471 472 /* 473 * Loop until a process is terminated or stopped, or a SIGINT is 474 * received. 475 */ 476 477 in_waitcmd++; 478 do { 479 if (job != NULL) { 480 if (job->state) { 481 status = job->ps[job->nprocs - 1].status; 482 if (WIFEXITED(status)) 483 retval = WEXITSTATUS(status); 484#if JOBS 485 else if (WIFSTOPPED(status)) 486 retval = WSTOPSIG(status) + 128; 487#endif 488 else 489 retval = WTERMSIG(status) + 128; 490 if (! iflag || ! job->changed) 491 freejob(job); 492 else { 493 job->remembered = 0; 494 if (job == bgjob) 495 bgjob = NULL; 496 } 497 in_waitcmd--; 498 return retval; 499 } 500 } else { 501 for (jp = jobtab ; jp < jobtab + njobs; jp++) 502 if (jp->used && jp->state == JOBDONE) { 503 if (! iflag || ! jp->changed) 504 freejob(jp); 505 else { 506 jp->remembered = 0; 507 if (jp == bgjob) 508 bgjob = NULL; 509 } 510 } 511 for (jp = jobtab ; ; jp++) { 512 if (jp >= jobtab + njobs) { /* no running procs */ 513 in_waitcmd--; 514 return 0; 515 } 516 if (jp->used && jp->state == 0) 517 break; 518 } 519 } 520 } while (dowait(1, (struct job *)NULL) != -1); 521 in_waitcmd--; 522 523 return 0; 524} 525 526 527 528int 529jobidcmd(int argc __unused, char **argv) 530{ 531 struct job *jp; 532 int i; 533 534 jp = getjob(argv[1]); 535 for (i = 0 ; i < jp->nprocs ; ) { 536 out1fmt("%d", (int)jp->ps[i].pid); 537 out1c(++i < jp->nprocs? ' ' : '\n'); 538 } 539 return 0; 540} 541 542 543 544/* 545 * Convert a job name to a job structure. 546 */ 547 548static struct job * 549getjob(char *name) 550{ 551 int jobno; 552 struct job *found, *jp; 553 pid_t pid; 554 int i; 555 556 if (name == NULL) { 557#if JOBS 558currentjob: if ((jp = getcurjob(NULL)) == NULL) 559 error("No current job"); 560 return (jp); 561#else 562 error("No current job"); 563#endif 564 } else if (name[0] == '%') { 565 if (is_digit(name[1])) { 566 jobno = number(name + 1); 567 if (jobno > 0 && jobno <= njobs 568 && jobtab[jobno - 1].used != 0) 569 return &jobtab[jobno - 1]; 570#if JOBS 571 } else if (name[1] == '%' && name[2] == '\0') { 572 goto currentjob; 573 } else if (name[1] == '+' && name[2] == '\0') { 574 goto currentjob; 575 } else if (name[1] == '-' && name[2] == '\0') { 576 if ((jp = getcurjob(NULL)) == NULL || 577 (jp = getcurjob(jp)) == NULL) 578 error("No previous job"); 579 return (jp); 580#endif 581 } else if (name[1] == '?') { 582 found = NULL; 583 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 584 if (jp->used && jp->nprocs > 0 585 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 586 if (found) 587 error("%s: ambiguous", name); 588 found = jp; 589 } 590 } 591 if (found != NULL) 592 return (found); 593 } else { 594 found = NULL; 595 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 596 if (jp->used && jp->nprocs > 0 597 && prefix(name + 1, jp->ps[0].cmd)) { 598 if (found) 599 error("%s: ambiguous", name); 600 found = jp; 601 } 602 } 603 if (found) 604 return found; 605 } 606 } else if (is_number(name)) { 607 pid = (pid_t)number(name); 608 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 609 if (jp->used && jp->nprocs > 0 610 && jp->ps[jp->nprocs - 1].pid == pid) 611 return jp; 612 } 613 } 614 error("No such job: %s", name); 615 /*NOTREACHED*/ 616 return NULL; 617} 618 619 620pid_t 621getjobpgrp(char *name) 622{ 623 struct job *jp; 624 625 jp = getjob(name); 626 return -jp->ps[0].pid; 627} 628 629/* 630 * Return a new job structure, 631 */ 632 633struct job * 634makejob(union node *node __unused, int nprocs) 635{ 636 int i; 637 struct job *jp; 638 639 for (i = njobs, jp = jobtab ; ; jp++) { 640 if (--i < 0) { 641 INTOFF; 642 if (njobs == 0) { 643 jobtab = ckmalloc(4 * sizeof jobtab[0]); 644#if JOBS 645 jobmru = NULL; 646#endif 647 } else { 648 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 649 memcpy(jp, jobtab, njobs * sizeof jp[0]); 650#if JOBS 651 /* Relocate `next' pointers and list head */ 652 if (jobmru != NULL) 653 jobmru = &jp[jobmru - jobtab]; 654 for (i = 0; i < njobs; i++) 655 if (jp[i].next != NULL) 656 jp[i].next = &jp[jp[i].next - 657 jobtab]; 658#endif 659 if (bgjob != NULL) 660 bgjob = &jp[bgjob - jobtab]; 661 /* Relocate `ps' pointers */ 662 for (i = 0; i < njobs; i++) 663 if (jp[i].ps == &jobtab[i].ps0) 664 jp[i].ps = &jp[i].ps0; 665 ckfree(jobtab); 666 jobtab = jp; 667 } 668 jp = jobtab + njobs; 669 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); 670 INTON; 671 break; 672 } 673 if (jp->used == 0) 674 break; 675 } 676 INTOFF; 677 jp->state = 0; 678 jp->used = 1; 679 jp->changed = 0; 680 jp->nprocs = 0; 681 jp->foreground = 0; 682 jp->remembered = 0; 683#if JOBS 684 jp->jobctl = jobctl; 685 jp->next = NULL; 686#endif 687 if (nprocs > 1) { 688 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 689 } else { 690 jp->ps = &jp->ps0; 691 } 692 INTON; 693 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 694 jp - jobtab + 1)); 695 return jp; 696} 697 698#if JOBS 699static void 700setcurjob(struct job *cj) 701{ 702 struct job *jp, *prev; 703 704 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 705 if (jp == cj) { 706 if (prev != NULL) 707 prev->next = jp->next; 708 else 709 jobmru = jp->next; 710 jp->next = jobmru; 711 jobmru = cj; 712 return; 713 } 714 } 715 cj->next = jobmru; 716 jobmru = cj; 717} 718 719static void 720deljob(struct job *j) 721{ 722 struct job *jp, *prev; 723 724 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 725 if (jp == j) { 726 if (prev != NULL) 727 prev->next = jp->next; 728 else 729 jobmru = jp->next; 730 return; 731 } 732 } 733} 734 735/* 736 * Return the most recently used job that isn't `nj', and preferably one 737 * that is stopped. 738 */ 739static struct job * 740getcurjob(struct job *nj) 741{ 742 struct job *jp; 743 744 /* Try to find a stopped one.. */ 745 for (jp = jobmru; jp != NULL; jp = jp->next) 746 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 747 return (jp); 748 /* Otherwise the most recently used job that isn't `nj' */ 749 for (jp = jobmru; jp != NULL; jp = jp->next) 750 if (jp->used && jp != nj) 751 return (jp); 752 753 return (NULL); 754} 755 756#endif 757 758/* 759 * Fork of a subshell. If we are doing job control, give the subshell its 760 * own process group. Jp is a job structure that the job is to be added to. 761 * N is the command that will be evaluated by the child. Both jp and n may 762 * be NULL. The mode parameter can be one of the following: 763 * FORK_FG - Fork off a foreground process. 764 * FORK_BG - Fork off a background process. 765 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 766 * process group even if job control is on. 767 * 768 * When job control is turned off, background processes have their standard 769 * input redirected to /dev/null (except for the second and later processes 770 * in a pipeline). 771 */ 772 773pid_t 774forkshell(struct job *jp, union node *n, int mode) 775{ 776 pid_t pid; 777 pid_t pgrp; 778 779 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 780 mode)); 781 INTOFF; 782 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 783 checkzombies(); 784 flushall(); 785 pid = fork(); 786 if (pid == -1) { 787 TRACE(("Fork failed, errno=%d\n", errno)); 788 INTON; 789 error("Cannot fork: %s", strerror(errno)); 790 } 791 if (pid == 0) { 792 struct job *p; 793 int wasroot; 794 int i; 795 796 TRACE(("Child shell %d\n", (int)getpid())); 797 wasroot = rootshell; 798 rootshell = 0; 799 handler = &main_handler; 800 closescript(); 801 INTON; 802 forcelocal = 0; 803 clear_traps(); 804#if JOBS 805 jobctl = 0; /* do job control only in root shell */ 806 if (wasroot && mode != FORK_NOJOB && mflag) { 807 if (jp == NULL || jp->nprocs == 0) 808 pgrp = getpid(); 809 else 810 pgrp = jp->ps[0].pid; 811 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 812 /*** this causes superfluous TIOCSPGRPS ***/ 813 if (tcsetpgrp(ttyfd, pgrp) < 0) 814 error("tcsetpgrp failed, errno=%d", errno); 815 } 816 setsignal(SIGTSTP); 817 setsignal(SIGTTOU); 818 } else if (mode == FORK_BG) { 819 ignoresig(SIGINT); 820 ignoresig(SIGQUIT); 821 if ((jp == NULL || jp->nprocs == 0) && 822 ! fd0_redirected_p ()) { 823 close(0); 824 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 825 error("cannot open %s: %s", 826 _PATH_DEVNULL, strerror(errno)); 827 } 828 } 829#else 830 if (mode == FORK_BG) { 831 ignoresig(SIGINT); 832 ignoresig(SIGQUIT); 833 if ((jp == NULL || jp->nprocs == 0) && 834 ! fd0_redirected_p ()) { 835 close(0); 836 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 837 error("cannot open %s: %s", 838 _PATH_DEVNULL, strerror(errno)); 839 } 840 } 841#endif 842 INTOFF; 843 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 844 if (p->used) 845 freejob(p); 846 INTON; 847 if (wasroot && iflag) { 848 setsignal(SIGINT); 849 setsignal(SIGQUIT); 850 setsignal(SIGTERM); 851 } 852 return pid; 853 } 854 if (rootshell && mode != FORK_NOJOB && mflag) { 855 if (jp == NULL || jp->nprocs == 0) 856 pgrp = pid; 857 else 858 pgrp = jp->ps[0].pid; 859 setpgid(pid, pgrp); 860 } 861 if (mode == FORK_BG) { 862 if (bgjob != NULL && bgjob->state == JOBDONE && 863 !bgjob->remembered && !iflag) 864 freejob(bgjob); 865 backgndpid = pid; /* set $! */ 866 bgjob = jp; 867 } 868 if (jp) { 869 struct procstat *ps = &jp->ps[jp->nprocs++]; 870 ps->pid = pid; 871 ps->status = -1; 872 ps->cmd = nullstr; 873 if (iflag && rootshell && n) 874 ps->cmd = commandtext(n); 875 jp->foreground = mode == FORK_FG; 876#if JOBS 877 setcurjob(jp); 878#endif 879 } 880 INTON; 881 TRACE(("In parent shell: child = %d\n", (int)pid)); 882 return pid; 883} 884 885 886 887/* 888 * Wait for job to finish. 889 * 890 * Under job control we have the problem that while a child process is 891 * running interrupts generated by the user are sent to the child but not 892 * to the shell. This means that an infinite loop started by an inter- 893 * active user may be hard to kill. With job control turned off, an 894 * interactive user may place an interactive program inside a loop. If 895 * the interactive program catches interrupts, the user doesn't want 896 * these interrupts to also abort the loop. The approach we take here 897 * is to have the shell ignore interrupt signals while waiting for a 898 * foreground process to terminate, and then send itself an interrupt 899 * signal if the child process was terminated by an interrupt signal. 900 * Unfortunately, some programs want to do a bit of cleanup and then 901 * exit on interrupt; unless these processes terminate themselves by 902 * sending a signal to themselves (instead of calling exit) they will 903 * confuse this approach. 904 */ 905 906int 907waitforjob(struct job *jp, int *origstatus) 908{ 909#if JOBS 910 pid_t mypgrp = getpgrp(); 911 int propagate_int = jp->jobctl && jp->foreground; 912#endif 913 int status; 914 int st; 915 916 INTOFF; 917 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 918 while (jp->state == 0) 919 if (dowait(1, jp) == -1) 920 dotrap(); 921#if JOBS 922 if (jp->jobctl) { 923 if (tcsetpgrp(ttyfd, mypgrp) < 0) 924 error("tcsetpgrp failed, errno=%d\n", errno); 925 } 926 if (jp->state == JOBSTOPPED) 927 setcurjob(jp); 928#endif 929 status = jp->ps[jp->nprocs - 1].status; 930 if (origstatus != NULL) 931 *origstatus = status; 932 /* convert to 8 bits */ 933 if (WIFEXITED(status)) 934 st = WEXITSTATUS(status); 935#if JOBS 936 else if (WIFSTOPPED(status)) 937 st = WSTOPSIG(status) + 128; 938#endif 939 else 940 st = WTERMSIG(status) + 128; 941 if (! JOBS || jp->state == JOBDONE) 942 freejob(jp); 943 if (int_pending()) { 944 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 945 CLEAR_PENDING_INT; 946 } 947#if JOBS 948 else if (rootshell && iflag && propagate_int && 949 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 950 kill(getpid(), SIGINT); 951#endif 952 INTON; 953 return st; 954} 955 956 957 958/* 959 * Wait for a process to terminate. 960 */ 961 962static pid_t 963dowait(int block, struct job *job) 964{ 965 pid_t pid; 966 int status; 967 struct procstat *sp; 968 struct job *jp; 969 struct job *thisjob; 970 int done; 971 int stopped; 972 int sig; 973 int coredump; 974 975 in_dowait++; 976 TRACE(("dowait(%d) called\n", block)); 977 do { 978 pid = waitproc(block, &status); 979 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 980 } while ((pid == -1 && errno == EINTR && breakwaitcmd == 0) || 981 (pid > 0 && WIFSTOPPED(status) && !iflag)); 982 in_dowait--; 983 if (pid == -1 && errno == ECHILD && job != NULL) 984 job->state = JOBDONE; 985 if (breakwaitcmd != 0) { 986 breakwaitcmd = 0; 987 if (pid <= 0) 988 return -1; 989 } 990 if (pid <= 0) 991 return pid; 992 INTOFF; 993 thisjob = NULL; 994 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 995 if (jp->used && jp->nprocs > 0) { 996 done = 1; 997 stopped = 1; 998 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 999 if (sp->pid == -1) 1000 continue; 1001 if (sp->pid == pid) { 1002 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1003 (int)pid, sp->status, 1004 status)); 1005 sp->status = status; 1006 thisjob = jp; 1007 } 1008 if (sp->status == -1) 1009 stopped = 0; 1010 else if (WIFSTOPPED(sp->status)) 1011 done = 0; 1012 } 1013 if (stopped) { /* stopped or done */ 1014 int state = done? JOBDONE : JOBSTOPPED; 1015 if (jp->state != state) { 1016 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1017 jp->state = state; 1018 if (jp != job) { 1019 if (done && !jp->remembered && 1020 !iflag && jp != bgjob) 1021 freejob(jp); 1022#if JOBS 1023 else if (done) 1024 deljob(jp); 1025#endif 1026 } 1027 } 1028 } 1029 } 1030 } 1031 INTON; 1032 if (!thisjob || thisjob->state == 0) 1033 ; 1034 else if ((!rootshell || !iflag || thisjob == job) && 1035 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1036 sig = 0; 1037 coredump = 0; 1038 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1039 if (WIFSIGNALED(sp->status)) { 1040 sig = WTERMSIG(sp->status); 1041 coredump = WCOREDUMP(sp->status); 1042 } 1043 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1044 if (sig < sys_nsig && sys_siglist[sig]) 1045 out2str(sys_siglist[sig]); 1046 else 1047 outfmt(out2, "Signal %d", sig); 1048 if (coredump) 1049 out2str(" (core dumped)"); 1050 out2c('\n'); 1051 flushout(out2); 1052 } 1053 } else { 1054 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1055 thisjob->changed = 1; 1056 } 1057 return pid; 1058} 1059 1060 1061 1062/* 1063 * Do a wait system call. If job control is compiled in, we accept 1064 * stopped processes. If block is zero, we return a value of zero 1065 * rather than blocking. 1066 */ 1067static pid_t 1068waitproc(int block, int *status) 1069{ 1070 int flags; 1071 1072#if JOBS 1073 flags = WUNTRACED; 1074#else 1075 flags = 0; 1076#endif 1077 if (block == 0) 1078 flags |= WNOHANG; 1079 return wait3(status, flags, (struct rusage *)NULL); 1080} 1081 1082/* 1083 * return 1 if there are stopped jobs, otherwise 0 1084 */ 1085int job_warning = 0; 1086int 1087stoppedjobs(void) 1088{ 1089 int jobno; 1090 struct job *jp; 1091 1092 if (job_warning) 1093 return (0); 1094 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1095 if (jp->used == 0) 1096 continue; 1097 if (jp->state == JOBSTOPPED) { 1098 out2fmt_flush("You have stopped jobs.\n"); 1099 job_warning = 2; 1100 return (1); 1101 } 1102 } 1103 1104 return (0); 1105} 1106 1107 1108static void 1109checkzombies(void) 1110{ 1111 while (njobs > 0 && dowait(0, NULL) > 0) 1112 ; 1113} 1114 1115 1116int 1117backgndpidset(void) 1118{ 1119 return backgndpid != -1; 1120} 1121 1122 1123pid_t 1124backgndpidval(void) 1125{ 1126 if (bgjob != NULL && !forcelocal) 1127 bgjob->remembered = 1; 1128 return backgndpid; 1129} 1130 1131/* 1132 * Return a string identifying a command (to be printed by the 1133 * jobs command. 1134 */ 1135 1136static char *cmdnextc; 1137static int cmdnleft; 1138#define MAXCMDTEXT 200 1139 1140char * 1141commandtext(union node *n) 1142{ 1143 char *name; 1144 1145 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1146 cmdnleft = MAXCMDTEXT - 4; 1147 cmdtxt(n); 1148 *cmdnextc = '\0'; 1149 return name; 1150} 1151 1152 1153static void 1154cmdtxt(union node *n) 1155{ 1156 union node *np; 1157 struct nodelist *lp; 1158 const char *p; 1159 int i; 1160 char s[2]; 1161 1162 if (n == NULL) 1163 return; 1164 switch (n->type) { 1165 case NSEMI: 1166 cmdtxt(n->nbinary.ch1); 1167 cmdputs("; "); 1168 cmdtxt(n->nbinary.ch2); 1169 break; 1170 case NAND: 1171 cmdtxt(n->nbinary.ch1); 1172 cmdputs(" && "); 1173 cmdtxt(n->nbinary.ch2); 1174 break; 1175 case NOR: 1176 cmdtxt(n->nbinary.ch1); 1177 cmdputs(" || "); 1178 cmdtxt(n->nbinary.ch2); 1179 break; 1180 case NPIPE: 1181 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1182 cmdtxt(lp->n); 1183 if (lp->next) 1184 cmdputs(" | "); 1185 } 1186 break; 1187 case NSUBSHELL: 1188 cmdputs("("); 1189 cmdtxt(n->nredir.n); 1190 cmdputs(")"); 1191 break; 1192 case NREDIR: 1193 case NBACKGND: 1194 cmdtxt(n->nredir.n); 1195 break; 1196 case NIF: 1197 cmdputs("if "); 1198 cmdtxt(n->nif.test); 1199 cmdputs("; then "); 1200 cmdtxt(n->nif.ifpart); 1201 cmdputs("..."); 1202 break; 1203 case NWHILE: 1204 cmdputs("while "); 1205 goto until; 1206 case NUNTIL: 1207 cmdputs("until "); 1208until: 1209 cmdtxt(n->nbinary.ch1); 1210 cmdputs("; do "); 1211 cmdtxt(n->nbinary.ch2); 1212 cmdputs("; done"); 1213 break; 1214 case NFOR: 1215 cmdputs("for "); 1216 cmdputs(n->nfor.var); 1217 cmdputs(" in ..."); 1218 break; 1219 case NCASE: 1220 cmdputs("case "); 1221 cmdputs(n->ncase.expr->narg.text); 1222 cmdputs(" in ..."); 1223 break; 1224 case NDEFUN: 1225 cmdputs(n->narg.text); 1226 cmdputs("() ..."); 1227 break; 1228 case NCMD: 1229 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1230 cmdtxt(np); 1231 if (np->narg.next) 1232 cmdputs(" "); 1233 } 1234 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1235 cmdputs(" "); 1236 cmdtxt(np); 1237 } 1238 break; 1239 case NARG: 1240 cmdputs(n->narg.text); 1241 break; 1242 case NTO: 1243 p = ">"; i = 1; goto redir; 1244 case NAPPEND: 1245 p = ">>"; i = 1; goto redir; 1246 case NTOFD: 1247 p = ">&"; i = 1; goto redir; 1248 case NCLOBBER: 1249 p = ">|"; i = 1; goto redir; 1250 case NFROM: 1251 p = "<"; i = 0; goto redir; 1252 case NFROMTO: 1253 p = "<>"; i = 0; goto redir; 1254 case NFROMFD: 1255 p = "<&"; i = 0; goto redir; 1256redir: 1257 if (n->nfile.fd != i) { 1258 s[0] = n->nfile.fd + '0'; 1259 s[1] = '\0'; 1260 cmdputs(s); 1261 } 1262 cmdputs(p); 1263 if (n->type == NTOFD || n->type == NFROMFD) { 1264 if (n->ndup.dupfd >= 0) 1265 s[0] = n->ndup.dupfd + '0'; 1266 else 1267 s[0] = '-'; 1268 s[1] = '\0'; 1269 cmdputs(s); 1270 } else { 1271 cmdtxt(n->nfile.fname); 1272 } 1273 break; 1274 case NHERE: 1275 case NXHERE: 1276 cmdputs("<<..."); 1277 break; 1278 default: 1279 cmdputs("???"); 1280 break; 1281 } 1282} 1283 1284 1285 1286static void 1287cmdputs(const char *s) 1288{ 1289 const char *p; 1290 char *q; 1291 char c; 1292 int subtype = 0; 1293 1294 if (cmdnleft <= 0) 1295 return; 1296 p = s; 1297 q = cmdnextc; 1298 while ((c = *p++) != '\0') { 1299 if (c == CTLESC) 1300 *q++ = *p++; 1301 else if (c == CTLVAR) { 1302 *q++ = '$'; 1303 if (--cmdnleft > 0) 1304 *q++ = '{'; 1305 subtype = *p++; 1306 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1307 *q++ = '#'; 1308 } else if (c == '=' && subtype != 0) { 1309 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1310 if (*q) 1311 q++; 1312 else 1313 cmdnleft++; 1314 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1315 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1316 --cmdnleft > 0) 1317 *q = q[-1], q++; 1318 subtype = 0; 1319 } else if (c == CTLENDVAR) { 1320 *q++ = '}'; 1321 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1322 cmdnleft -= 5; 1323 if (cmdnleft > 0) { 1324 *q++ = '$'; 1325 *q++ = '('; 1326 *q++ = '.'; 1327 *q++ = '.'; 1328 *q++ = '.'; 1329 *q++ = ')'; 1330 } 1331 } else if (c == CTLARI) { 1332 cmdnleft -= 2; 1333 if (cmdnleft > 0) { 1334 *q++ = '$'; 1335 *q++ = '('; 1336 *q++ = '('; 1337 } 1338 p++; 1339 } else if (c == CTLENDARI) { 1340 if (--cmdnleft > 0) { 1341 *q++ = ')'; 1342 *q++ = ')'; 1343 } 1344 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1345 cmdnleft++; /* ignore */ 1346 else 1347 *q++ = c; 1348 if (--cmdnleft <= 0) { 1349 *q++ = '.'; 1350 *q++ = '.'; 1351 *q++ = '.'; 1352 break; 1353 } 1354 } 1355 cmdnextc = q; 1356} 1357