jobs.c revision 251429
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 251429 2013-06-05 19:08:22Z 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 78static struct job *jobtab; /* array of jobs */ 79static int njobs; /* size of array */ 80MKINIT pid_t backgndpid = -1; /* pid of last background process */ 81MKINIT struct job *bgjob = NULL; /* last background process */ 82#if JOBS 83static struct job *jobmru; /* most recently used job list */ 84static pid_t initialpgrp; /* pgrp of shell on invocation */ 85#endif 86int in_waitcmd = 0; /* are we in waitcmd()? */ 87volatile sig_atomic_t breakwaitcmd = 0; /* should wait be terminated? */ 88static int ttyfd = -1; 89 90/* mode flags for dowait */ 91#define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 92#define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on signals */ 93 94#if JOBS 95static void restartjob(struct job *); 96#endif 97static void freejob(struct job *); 98static int waitcmdloop(struct job *); 99static struct job *getjob(char *); 100pid_t getjobpgrp(char *); 101static pid_t dowait(int, struct job *); 102static void checkzombies(void); 103static void cmdtxt(union node *); 104static void cmdputs(const char *); 105#if JOBS 106static void setcurjob(struct job *); 107static void deljob(struct job *); 108static struct job *getcurjob(struct job *); 109#endif 110static void printjobcmd(struct job *); 111static void showjob(struct job *, int); 112 113 114/* 115 * Turn job control on and off. 116 */ 117 118MKINIT int jobctl; 119 120#if JOBS 121void 122setjobctl(int on) 123{ 124 int i; 125 126 if (on == jobctl || rootshell == 0) 127 return; 128 if (on) { 129 if (ttyfd != -1) 130 close(ttyfd); 131 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC)) < 0) { 132 i = 0; 133 while (i <= 2 && !isatty(i)) 134 i++; 135 if (i > 2 || 136 (ttyfd = fcntl(i, F_DUPFD_CLOEXEC, 10)) < 0) 137 goto out; 138 } 139 if (ttyfd < 10) { 140 /* 141 * Keep our TTY file descriptor out of the way of 142 * the user's redirections. 143 */ 144 if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC, 10)) < 0) { 145 close(ttyfd); 146 ttyfd = -1; 147 goto out; 148 } 149 close(ttyfd); 150 ttyfd = i; 151 } 152 do { /* while we are in the background */ 153 initialpgrp = tcgetpgrp(ttyfd); 154 if (initialpgrp < 0) { 155out: out2fmt_flush("sh: can't access tty; job control turned off\n"); 156 mflag = 0; 157 return; 158 } 159 if (initialpgrp != getpgrp()) { 160 kill(0, SIGTTIN); 161 continue; 162 } 163 } while (0); 164 setsignal(SIGTSTP); 165 setsignal(SIGTTOU); 166 setsignal(SIGTTIN); 167 setpgid(0, rootpid); 168 tcsetpgrp(ttyfd, rootpid); 169 } else { /* turning job control off */ 170 setpgid(0, initialpgrp); 171 tcsetpgrp(ttyfd, initialpgrp); 172 close(ttyfd); 173 ttyfd = -1; 174 setsignal(SIGTSTP); 175 setsignal(SIGTTOU); 176 setsignal(SIGTTIN); 177 } 178 jobctl = on; 179} 180#endif 181 182 183#if JOBS 184int 185fgcmd(int argc __unused, char **argv) 186{ 187 struct job *jp; 188 pid_t pgrp; 189 int status; 190 191 jp = getjob(argv[1]); 192 if (jp->jobctl == 0) 193 error("job not created under job control"); 194 printjobcmd(jp); 195 flushout(&output); 196 pgrp = jp->ps[0].pid; 197 tcsetpgrp(ttyfd, pgrp); 198 restartjob(jp); 199 jp->foreground = 1; 200 INTOFF; 201 status = waitforjob(jp, (int *)NULL); 202 INTON; 203 return status; 204} 205 206 207int 208bgcmd(int argc, char **argv) 209{ 210 struct job *jp; 211 212 do { 213 jp = getjob(*++argv); 214 if (jp->jobctl == 0) 215 error("job not created under job control"); 216 if (jp->state == JOBDONE) 217 continue; 218 restartjob(jp); 219 jp->foreground = 0; 220 out1fmt("[%td] ", jp - jobtab + 1); 221 printjobcmd(jp); 222 } while (--argc > 1); 223 return 0; 224} 225 226 227static void 228restartjob(struct job *jp) 229{ 230 struct procstat *ps; 231 int i; 232 233 if (jp->state == JOBDONE) 234 return; 235 setcurjob(jp); 236 INTOFF; 237 kill(-jp->ps[0].pid, SIGCONT); 238 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 239 if (WIFSTOPPED(ps->status)) { 240 ps->status = -1; 241 jp->state = 0; 242 } 243 } 244 INTON; 245} 246#endif 247 248 249int 250jobscmd(int argc __unused, char *argv[] __unused) 251{ 252 char *id; 253 int ch, mode; 254 255 mode = SHOWJOBS_DEFAULT; 256 while ((ch = nextopt("lps")) != '\0') { 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 } 268 } 269 270 if (*argptr == NULL) 271 showjobs(0, mode); 272 else 273 while ((id = *argptr++) != NULL) 274 showjob(getjob(id), mode); 275 276 return (0); 277} 278 279static void 280printjobcmd(struct job *jp) 281{ 282 struct procstat *ps; 283 int i; 284 285 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 286 out1str(ps->cmd); 287 if (i > 0) 288 out1str(" | "); 289 } 290 out1c('\n'); 291} 292 293static void 294showjob(struct job *jp, int mode) 295{ 296 char s[64]; 297 char statestr[64]; 298 const char *sigstr; 299 struct procstat *ps; 300 struct job *j; 301 int col, curr, i, jobno, prev, procno; 302 char c; 303 304 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 305 jobno = jp - jobtab + 1; 306 curr = prev = 0; 307#if JOBS 308 if ((j = getcurjob(NULL)) != NULL) { 309 curr = j - jobtab + 1; 310 if ((j = getcurjob(j)) != NULL) 311 prev = j - jobtab + 1; 312 } 313#endif 314 ps = jp->ps + jp->nprocs - 1; 315 if (jp->state == 0) { 316 strcpy(statestr, "Running"); 317#if JOBS 318 } else if (jp->state == JOBSTOPPED) { 319 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 320 ps--; 321 if (WIFSTOPPED(ps->status)) 322 i = WSTOPSIG(ps->status); 323 else 324 i = -1; 325 sigstr = strsignal(i); 326 if (sigstr != NULL) 327 strcpy(statestr, sigstr); 328 else 329 strcpy(statestr, "Suspended"); 330#endif 331 } else if (WIFEXITED(ps->status)) { 332 if (WEXITSTATUS(ps->status) == 0) 333 strcpy(statestr, "Done"); 334 else 335 fmtstr(statestr, 64, "Done(%d)", 336 WEXITSTATUS(ps->status)); 337 } else { 338 i = WTERMSIG(ps->status); 339 sigstr = strsignal(i); 340 if (sigstr != NULL) 341 strcpy(statestr, sigstr); 342 else 343 strcpy(statestr, "Unknown signal"); 344 if (WCOREDUMP(ps->status)) 345 strcat(statestr, " (core dumped)"); 346 } 347 348 for (ps = jp->ps ; ; ps++) { /* for each process */ 349 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) { 350 out1fmt("%d\n", (int)ps->pid); 351 goto skip; 352 } 353 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps) 354 goto skip; 355 if (jobno == curr && ps == jp->ps) 356 c = '+'; 357 else if (jobno == prev && ps == jp->ps) 358 c = '-'; 359 else 360 c = ' '; 361 if (ps == jp->ps) 362 fmtstr(s, 64, "[%d] %c ", jobno, c); 363 else 364 fmtstr(s, 64, " %c ", c); 365 out1str(s); 366 col = strlen(s); 367 if (mode == SHOWJOBS_VERBOSE) { 368 fmtstr(s, 64, "%d ", (int)ps->pid); 369 out1str(s); 370 col += strlen(s); 371 } 372 if (ps == jp->ps) { 373 out1str(statestr); 374 col += strlen(statestr); 375 } 376 do { 377 out1c(' '); 378 col++; 379 } while (col < 30); 380 if (mode == SHOWJOBS_VERBOSE) { 381 out1str(ps->cmd); 382 out1c('\n'); 383 } else 384 printjobcmd(jp); 385skip: if (--procno <= 0) 386 break; 387 } 388} 389 390/* 391 * Print a list of jobs. If "change" is nonzero, only print jobs whose 392 * statuses have changed since the last call to showjobs. 393 * 394 * If the shell is interrupted in the process of creating a job, the 395 * result may be a job structure containing zero processes. Such structures 396 * will be freed here. 397 */ 398 399void 400showjobs(int change, int mode) 401{ 402 int jobno; 403 struct job *jp; 404 405 TRACE(("showjobs(%d) called\n", change)); 406 checkzombies(); 407 for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { 408 if (! jp->used) 409 continue; 410 if (jp->nprocs == 0) { 411 freejob(jp); 412 continue; 413 } 414 if (change && ! jp->changed) 415 continue; 416 showjob(jp, mode); 417 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 418 jp->changed = 0; 419 /* Hack: discard jobs for which $! has not been 420 * referenced in interactive mode when they terminate. 421 */ 422 if (jp->state == JOBDONE && !jp->remembered && 423 (iflag || jp != bgjob)) { 424 freejob(jp); 425 } 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 __unused, char **argv __unused) 461{ 462 struct job *job; 463 int retval; 464 465 nextopt(""); 466 if (*argptr == NULL) 467 return (waitcmdloop(NULL)); 468 469 do { 470 job = getjob(*argptr); 471 retval = waitcmdloop(job); 472 argptr++; 473 } while (*argptr != NULL); 474 475 return (retval); 476} 477 478static int 479waitcmdloop(struct job *job) 480{ 481 int status, retval; 482 struct job *jp; 483 484 /* 485 * Loop until a process is terminated or stopped, or a SIGINT is 486 * received. 487 */ 488 489 in_waitcmd++; 490 do { 491 if (job != NULL) { 492 if (job->state) { 493 status = job->ps[job->nprocs - 1].status; 494 if (WIFEXITED(status)) 495 retval = WEXITSTATUS(status); 496#if JOBS 497 else if (WIFSTOPPED(status)) 498 retval = WSTOPSIG(status) + 128; 499#endif 500 else 501 retval = WTERMSIG(status) + 128; 502 if (! iflag || ! job->changed) 503 freejob(job); 504 else { 505 job->remembered = 0; 506 if (job == bgjob) 507 bgjob = NULL; 508 } 509 in_waitcmd--; 510 return retval; 511 } 512 } else { 513 for (jp = jobtab ; jp < jobtab + njobs; jp++) 514 if (jp->used && jp->state == JOBDONE) { 515 if (! iflag || ! jp->changed) 516 freejob(jp); 517 else { 518 jp->remembered = 0; 519 if (jp == bgjob) 520 bgjob = NULL; 521 } 522 } 523 for (jp = jobtab ; ; jp++) { 524 if (jp >= jobtab + njobs) { /* no running procs */ 525 in_waitcmd--; 526 return 0; 527 } 528 if (jp->used && jp->state == 0) 529 break; 530 } 531 } 532 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 533 in_waitcmd--; 534 535 return pendingsig + 128; 536} 537 538 539 540int 541jobidcmd(int argc __unused, char **argv) 542{ 543 struct job *jp; 544 int i; 545 546 jp = getjob(argv[1]); 547 for (i = 0 ; i < jp->nprocs ; ) { 548 out1fmt("%d", (int)jp->ps[i].pid); 549 out1c(++i < jp->nprocs? ' ' : '\n'); 550 } 551 return 0; 552} 553 554 555 556/* 557 * Convert a job name to a job structure. 558 */ 559 560static struct job * 561getjob(char *name) 562{ 563 int jobno; 564 struct job *found, *jp; 565 pid_t pid; 566 int i; 567 568 if (name == NULL) { 569#if JOBS 570currentjob: if ((jp = getcurjob(NULL)) == NULL) 571 error("No current job"); 572 return (jp); 573#else 574 error("No current job"); 575#endif 576 } else if (name[0] == '%') { 577 if (is_digit(name[1])) { 578 jobno = number(name + 1); 579 if (jobno > 0 && jobno <= njobs 580 && jobtab[jobno - 1].used != 0) 581 return &jobtab[jobno - 1]; 582#if JOBS 583 } else if (name[1] == '%' && name[2] == '\0') { 584 goto currentjob; 585 } else if (name[1] == '+' && name[2] == '\0') { 586 goto currentjob; 587 } else if (name[1] == '-' && name[2] == '\0') { 588 if ((jp = getcurjob(NULL)) == NULL || 589 (jp = getcurjob(jp)) == NULL) 590 error("No previous job"); 591 return (jp); 592#endif 593 } else if (name[1] == '?') { 594 found = NULL; 595 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 596 if (jp->used && jp->nprocs > 0 597 && strstr(jp->ps[0].cmd, name + 2) != NULL) { 598 if (found) 599 error("%s: ambiguous", name); 600 found = jp; 601 } 602 } 603 if (found != NULL) 604 return (found); 605 } else { 606 found = NULL; 607 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 608 if (jp->used && jp->nprocs > 0 609 && prefix(name + 1, jp->ps[0].cmd)) { 610 if (found) 611 error("%s: ambiguous", name); 612 found = jp; 613 } 614 } 615 if (found) 616 return found; 617 } 618 } else if (is_number(name)) { 619 pid = (pid_t)number(name); 620 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { 621 if (jp->used && jp->nprocs > 0 622 && jp->ps[jp->nprocs - 1].pid == pid) 623 return jp; 624 } 625 } 626 error("No such job: %s", name); 627 /*NOTREACHED*/ 628 return NULL; 629} 630 631 632pid_t 633getjobpgrp(char *name) 634{ 635 struct job *jp; 636 637 jp = getjob(name); 638 return -jp->ps[0].pid; 639} 640 641/* 642 * Return a new job structure, 643 */ 644 645struct job * 646makejob(union node *node __unused, int nprocs) 647{ 648 int i; 649 struct job *jp; 650 651 for (i = njobs, jp = jobtab ; ; jp++) { 652 if (--i < 0) { 653 INTOFF; 654 if (njobs == 0) { 655 jobtab = ckmalloc(4 * sizeof jobtab[0]); 656#if JOBS 657 jobmru = NULL; 658#endif 659 } else { 660 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 661 memcpy(jp, jobtab, njobs * sizeof jp[0]); 662#if JOBS 663 /* Relocate `next' pointers and list head */ 664 if (jobmru != NULL) 665 jobmru = &jp[jobmru - jobtab]; 666 for (i = 0; i < njobs; i++) 667 if (jp[i].next != NULL) 668 jp[i].next = &jp[jp[i].next - 669 jobtab]; 670#endif 671 if (bgjob != NULL) 672 bgjob = &jp[bgjob - jobtab]; 673 /* Relocate `ps' pointers */ 674 for (i = 0; i < njobs; i++) 675 if (jp[i].ps == &jobtab[i].ps0) 676 jp[i].ps = &jp[i].ps0; 677 ckfree(jobtab); 678 jobtab = jp; 679 } 680 jp = jobtab + njobs; 681 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 682 ; 683 INTON; 684 break; 685 } 686 if (jp->used == 0) 687 break; 688 } 689 INTOFF; 690 jp->state = 0; 691 jp->used = 1; 692 jp->changed = 0; 693 jp->nprocs = 0; 694 jp->foreground = 0; 695 jp->remembered = 0; 696#if JOBS 697 jp->jobctl = jobctl; 698 jp->next = NULL; 699#endif 700 if (nprocs > 1) { 701 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 702 } else { 703 jp->ps = &jp->ps0; 704 } 705 INTON; 706 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 707 jp - jobtab + 1)); 708 return jp; 709} 710 711#if JOBS 712static void 713setcurjob(struct job *cj) 714{ 715 struct job *jp, *prev; 716 717 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 718 if (jp == cj) { 719 if (prev != NULL) 720 prev->next = jp->next; 721 else 722 jobmru = jp->next; 723 jp->next = jobmru; 724 jobmru = cj; 725 return; 726 } 727 } 728 cj->next = jobmru; 729 jobmru = cj; 730} 731 732static void 733deljob(struct job *j) 734{ 735 struct job *jp, *prev; 736 737 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 738 if (jp == j) { 739 if (prev != NULL) 740 prev->next = jp->next; 741 else 742 jobmru = jp->next; 743 return; 744 } 745 } 746} 747 748/* 749 * Return the most recently used job that isn't `nj', and preferably one 750 * that is stopped. 751 */ 752static struct job * 753getcurjob(struct job *nj) 754{ 755 struct job *jp; 756 757 /* Try to find a stopped one.. */ 758 for (jp = jobmru; jp != NULL; jp = jp->next) 759 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 760 return (jp); 761 /* Otherwise the most recently used job that isn't `nj' */ 762 for (jp = jobmru; jp != NULL; jp = jp->next) 763 if (jp->used && jp != nj) 764 return (jp); 765 766 return (NULL); 767} 768 769#endif 770 771/* 772 * Fork of a subshell. If we are doing job control, give the subshell its 773 * own process group. Jp is a job structure that the job is to be added to. 774 * N is the command that will be evaluated by the child. Both jp and n may 775 * be NULL. The mode parameter can be one of the following: 776 * FORK_FG - Fork off a foreground process. 777 * FORK_BG - Fork off a background process. 778 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 779 * process group even if job control is on. 780 * 781 * When job control is turned off, background processes have their standard 782 * input redirected to /dev/null (except for the second and later processes 783 * in a pipeline). 784 */ 785 786pid_t 787forkshell(struct job *jp, union node *n, int mode) 788{ 789 pid_t pid; 790 pid_t pgrp; 791 792 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 793 mode)); 794 INTOFF; 795 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 796 checkzombies(); 797 flushall(); 798 pid = fork(); 799 if (pid == -1) { 800 TRACE(("Fork failed, errno=%d\n", errno)); 801 INTON; 802 error("Cannot fork: %s", strerror(errno)); 803 } 804 if (pid == 0) { 805 struct job *p; 806 int wasroot; 807 int i; 808 809 TRACE(("Child shell %d\n", (int)getpid())); 810 wasroot = rootshell; 811 rootshell = 0; 812 handler = &main_handler; 813 closescript(); 814 INTON; 815 forcelocal = 0; 816 clear_traps(); 817#if JOBS 818 jobctl = 0; /* do job control only in root shell */ 819 if (wasroot && mode != FORK_NOJOB && mflag) { 820 if (jp == NULL || jp->nprocs == 0) 821 pgrp = getpid(); 822 else 823 pgrp = jp->ps[0].pid; 824 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 825 /*** this causes superfluous TIOCSPGRPS ***/ 826 if (tcsetpgrp(ttyfd, pgrp) < 0) 827 error("tcsetpgrp failed, errno=%d", errno); 828 } 829 setsignal(SIGTSTP); 830 setsignal(SIGTTOU); 831 } else if (mode == FORK_BG) { 832 ignoresig(SIGINT); 833 ignoresig(SIGQUIT); 834 if ((jp == NULL || jp->nprocs == 0) && 835 ! fd0_redirected_p ()) { 836 close(0); 837 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 838 error("cannot open %s: %s", 839 _PATH_DEVNULL, strerror(errno)); 840 } 841 } 842#else 843 if (mode == FORK_BG) { 844 ignoresig(SIGINT); 845 ignoresig(SIGQUIT); 846 if ((jp == NULL || jp->nprocs == 0) && 847 ! fd0_redirected_p ()) { 848 close(0); 849 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 850 error("cannot open %s: %s", 851 _PATH_DEVNULL, strerror(errno)); 852 } 853 } 854#endif 855 INTOFF; 856 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 857 if (p->used) 858 freejob(p); 859 INTON; 860 if (wasroot && iflag) { 861 setsignal(SIGINT); 862 setsignal(SIGQUIT); 863 setsignal(SIGTERM); 864 } 865 return pid; 866 } 867 if (rootshell && mode != FORK_NOJOB && mflag) { 868 if (jp == NULL || jp->nprocs == 0) 869 pgrp = pid; 870 else 871 pgrp = jp->ps[0].pid; 872 setpgid(pid, pgrp); 873 } 874 if (mode == FORK_BG) { 875 if (bgjob != NULL && bgjob->state == JOBDONE && 876 !bgjob->remembered && !iflag) 877 freejob(bgjob); 878 backgndpid = pid; /* set $! */ 879 bgjob = jp; 880 } 881 if (jp) { 882 struct procstat *ps = &jp->ps[jp->nprocs++]; 883 ps->pid = pid; 884 ps->status = -1; 885 ps->cmd = nullstr; 886 if (iflag && rootshell && n) 887 ps->cmd = commandtext(n); 888 jp->foreground = mode == FORK_FG; 889#if JOBS 890 setcurjob(jp); 891#endif 892 } 893 INTON; 894 TRACE(("In parent shell: child = %d\n", (int)pid)); 895 return pid; 896} 897 898 899pid_t 900vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 901{ 902 pid_t pid; 903 struct jmploc jmploc; 904 struct jmploc *savehandler; 905 906 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 907 (void *)pip)); 908 INTOFF; 909 flushall(); 910 savehandler = handler; 911 pid = vfork(); 912 if (pid == -1) { 913 TRACE(("Vfork failed, errno=%d\n", errno)); 914 INTON; 915 error("Cannot fork: %s", strerror(errno)); 916 } 917 if (pid == 0) { 918 TRACE(("Child shell %d\n", (int)getpid())); 919 if (setjmp(jmploc.loc)) 920 _exit(exception == EXEXEC ? exerrno : 2); 921 if (pip != NULL) { 922 close(pip[0]); 923 if (pip[1] != 1) { 924 dup2(pip[1], 1); 925 close(pip[1]); 926 } 927 } 928 handler = &jmploc; 929 shellexec(argv, envp, path, idx); 930 } 931 handler = savehandler; 932 if (jp) { 933 struct procstat *ps = &jp->ps[jp->nprocs++]; 934 ps->pid = pid; 935 ps->status = -1; 936 ps->cmd = nullstr; 937 jp->foreground = 1; 938#if JOBS 939 setcurjob(jp); 940#endif 941 } 942 INTON; 943 TRACE(("In parent shell: child = %d\n", (int)pid)); 944 return pid; 945} 946 947 948/* 949 * Wait for job to finish. 950 * 951 * Under job control we have the problem that while a child process is 952 * running interrupts generated by the user are sent to the child but not 953 * to the shell. This means that an infinite loop started by an inter- 954 * active user may be hard to kill. With job control turned off, an 955 * interactive user may place an interactive program inside a loop. If 956 * the interactive program catches interrupts, the user doesn't want 957 * these interrupts to also abort the loop. The approach we take here 958 * is to have the shell ignore interrupt signals while waiting for a 959 * foreground process to terminate, and then send itself an interrupt 960 * signal if the child process was terminated by an interrupt signal. 961 * Unfortunately, some programs want to do a bit of cleanup and then 962 * exit on interrupt; unless these processes terminate themselves by 963 * sending a signal to themselves (instead of calling exit) they will 964 * confuse this approach. 965 */ 966 967int 968waitforjob(struct job *jp, int *origstatus) 969{ 970#if JOBS 971 pid_t mypgrp = getpgrp(); 972 int propagate_int = jp->jobctl && jp->foreground; 973#endif 974 int status; 975 int st; 976 977 INTOFF; 978 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 979 while (jp->state == 0) 980 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG : 0), jp) == -1) 981 dotrap(); 982#if JOBS 983 if (jp->jobctl) { 984 if (tcsetpgrp(ttyfd, mypgrp) < 0) 985 error("tcsetpgrp failed, errno=%d\n", errno); 986 } 987 if (jp->state == JOBSTOPPED) 988 setcurjob(jp); 989#endif 990 status = jp->ps[jp->nprocs - 1].status; 991 if (origstatus != NULL) 992 *origstatus = status; 993 /* convert to 8 bits */ 994 if (WIFEXITED(status)) 995 st = WEXITSTATUS(status); 996#if JOBS 997 else if (WIFSTOPPED(status)) 998 st = WSTOPSIG(status) + 128; 999#endif 1000 else 1001 st = WTERMSIG(status) + 128; 1002 if (! JOBS || jp->state == JOBDONE) 1003 freejob(jp); 1004 if (int_pending()) { 1005 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1006 CLEAR_PENDING_INT; 1007 } 1008#if JOBS 1009 else if (rootshell && iflag && propagate_int && 1010 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1011 kill(getpid(), SIGINT); 1012#endif 1013 INTON; 1014 return st; 1015} 1016 1017 1018static void 1019dummy_handler(int sig __unused) 1020{ 1021} 1022 1023/* 1024 * Wait for a process to terminate. 1025 */ 1026 1027static pid_t 1028dowait(int mode, struct job *job) 1029{ 1030 struct sigaction sa, osa; 1031 sigset_t mask, omask; 1032 pid_t pid; 1033 int status; 1034 struct procstat *sp; 1035 struct job *jp; 1036 struct job *thisjob; 1037 const char *sigstr; 1038 int done; 1039 int stopped; 1040 int sig; 1041 int coredump; 1042 int wflags; 1043 int restore_sigchld; 1044 1045 TRACE(("dowait(%d, %p) called\n", mode, job)); 1046 restore_sigchld = 0; 1047 if ((mode & DOWAIT_SIG) != 0) { 1048 sigfillset(&mask); 1049 sigprocmask(SIG_BLOCK, &mask, &omask); 1050 INTOFF; 1051 if (!issigchldtrapped()) { 1052 restore_sigchld = 1; 1053 sa.sa_handler = dummy_handler; 1054 sa.sa_flags = 0; 1055 sigemptyset(&sa.sa_mask); 1056 sigaction(SIGCHLD, &sa, &osa); 1057 } 1058 } 1059 do { 1060#if JOBS 1061 if (iflag) 1062 wflags = WUNTRACED | WCONTINUED; 1063 else 1064#endif 1065 wflags = 0; 1066 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1067 wflags |= WNOHANG; 1068 pid = wait3(&status, wflags, (struct rusage *)NULL); 1069 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1070 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1071 sigsuspend(&omask); 1072 pid = -1; 1073 if (int_pending()) 1074 break; 1075 } 1076 } while (pid == -1 && errno == EINTR && breakwaitcmd == 0); 1077 if (pid == -1 && errno == ECHILD && job != NULL) 1078 job->state = JOBDONE; 1079 if ((mode & DOWAIT_SIG) != 0) { 1080 if (restore_sigchld) 1081 sigaction(SIGCHLD, &osa, NULL); 1082 sigprocmask(SIG_SETMASK, &omask, NULL); 1083 INTON; 1084 } 1085 if (breakwaitcmd != 0) { 1086 breakwaitcmd = 0; 1087 if (pid <= 0) 1088 return -1; 1089 } 1090 if (pid <= 0) 1091 return pid; 1092 INTOFF; 1093 thisjob = NULL; 1094 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1095 if (jp->used && jp->nprocs > 0) { 1096 done = 1; 1097 stopped = 1; 1098 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1099 if (sp->pid == -1) 1100 continue; 1101 if (sp->pid == pid) { 1102 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1103 (int)pid, sp->status, 1104 status)); 1105 if (WIFCONTINUED(status)) { 1106 sp->status = -1; 1107 jp->state = 0; 1108 } else 1109 sp->status = status; 1110 thisjob = jp; 1111 } 1112 if (sp->status == -1) 1113 stopped = 0; 1114 else if (WIFSTOPPED(sp->status)) 1115 done = 0; 1116 } 1117 if (stopped) { /* stopped or done */ 1118 int state = done? JOBDONE : JOBSTOPPED; 1119 if (jp->state != state) { 1120 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1121 jp->state = state; 1122 if (jp != job) { 1123 if (done && !jp->remembered && 1124 !iflag && jp != bgjob) 1125 freejob(jp); 1126#if JOBS 1127 else if (done) 1128 deljob(jp); 1129#endif 1130 } 1131 } 1132 } 1133 } 1134 } 1135 INTON; 1136 if (!thisjob || thisjob->state == 0) 1137 ; 1138 else if ((!rootshell || !iflag || thisjob == job) && 1139 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1140 sig = 0; 1141 coredump = 0; 1142 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1143 if (WIFSIGNALED(sp->status)) { 1144 sig = WTERMSIG(sp->status); 1145 coredump = WCOREDUMP(sp->status); 1146 } 1147 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1148 sigstr = strsignal(sig); 1149 if (sigstr != NULL) 1150 out2str(sigstr); 1151 else 1152 out2str("Unknown signal"); 1153 if (coredump) 1154 out2str(" (core dumped)"); 1155 out2c('\n'); 1156 flushout(out2); 1157 } 1158 } else { 1159 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1160 thisjob->changed = 1; 1161 } 1162 return pid; 1163} 1164 1165 1166 1167/* 1168 * return 1 if there are stopped jobs, otherwise 0 1169 */ 1170int job_warning = 0; 1171int 1172stoppedjobs(void) 1173{ 1174 int jobno; 1175 struct job *jp; 1176 1177 if (job_warning) 1178 return (0); 1179 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1180 if (jp->used == 0) 1181 continue; 1182 if (jp->state == JOBSTOPPED) { 1183 out2fmt_flush("You have stopped jobs.\n"); 1184 job_warning = 2; 1185 return (1); 1186 } 1187 } 1188 1189 return (0); 1190} 1191 1192 1193static void 1194checkzombies(void) 1195{ 1196 while (njobs > 0 && dowait(0, NULL) > 0) 1197 ; 1198} 1199 1200 1201int 1202backgndpidset(void) 1203{ 1204 return backgndpid != -1; 1205} 1206 1207 1208pid_t 1209backgndpidval(void) 1210{ 1211 if (bgjob != NULL && !forcelocal) 1212 bgjob->remembered = 1; 1213 return backgndpid; 1214} 1215 1216/* 1217 * Return a string identifying a command (to be printed by the 1218 * jobs command. 1219 */ 1220 1221static char *cmdnextc; 1222static int cmdnleft; 1223#define MAXCMDTEXT 200 1224 1225char * 1226commandtext(union node *n) 1227{ 1228 char *name; 1229 1230 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1231 cmdnleft = MAXCMDTEXT - 4; 1232 cmdtxt(n); 1233 *cmdnextc = '\0'; 1234 return name; 1235} 1236 1237 1238static void 1239cmdtxt(union node *n) 1240{ 1241 union node *np; 1242 struct nodelist *lp; 1243 const char *p; 1244 int i; 1245 char s[2]; 1246 1247 if (n == NULL) 1248 return; 1249 switch (n->type) { 1250 case NSEMI: 1251 cmdtxt(n->nbinary.ch1); 1252 cmdputs("; "); 1253 cmdtxt(n->nbinary.ch2); 1254 break; 1255 case NAND: 1256 cmdtxt(n->nbinary.ch1); 1257 cmdputs(" && "); 1258 cmdtxt(n->nbinary.ch2); 1259 break; 1260 case NOR: 1261 cmdtxt(n->nbinary.ch1); 1262 cmdputs(" || "); 1263 cmdtxt(n->nbinary.ch2); 1264 break; 1265 case NPIPE: 1266 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1267 cmdtxt(lp->n); 1268 if (lp->next) 1269 cmdputs(" | "); 1270 } 1271 break; 1272 case NSUBSHELL: 1273 cmdputs("("); 1274 cmdtxt(n->nredir.n); 1275 cmdputs(")"); 1276 break; 1277 case NREDIR: 1278 case NBACKGND: 1279 cmdtxt(n->nredir.n); 1280 break; 1281 case NIF: 1282 cmdputs("if "); 1283 cmdtxt(n->nif.test); 1284 cmdputs("; then "); 1285 cmdtxt(n->nif.ifpart); 1286 cmdputs("..."); 1287 break; 1288 case NWHILE: 1289 cmdputs("while "); 1290 goto until; 1291 case NUNTIL: 1292 cmdputs("until "); 1293until: 1294 cmdtxt(n->nbinary.ch1); 1295 cmdputs("; do "); 1296 cmdtxt(n->nbinary.ch2); 1297 cmdputs("; done"); 1298 break; 1299 case NFOR: 1300 cmdputs("for "); 1301 cmdputs(n->nfor.var); 1302 cmdputs(" in ..."); 1303 break; 1304 case NCASE: 1305 cmdputs("case "); 1306 cmdputs(n->ncase.expr->narg.text); 1307 cmdputs(" in ..."); 1308 break; 1309 case NDEFUN: 1310 cmdputs(n->narg.text); 1311 cmdputs("() ..."); 1312 break; 1313 case NNOT: 1314 cmdputs("! "); 1315 cmdtxt(n->nnot.com); 1316 break; 1317 case NCMD: 1318 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1319 cmdtxt(np); 1320 if (np->narg.next) 1321 cmdputs(" "); 1322 } 1323 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1324 cmdputs(" "); 1325 cmdtxt(np); 1326 } 1327 break; 1328 case NARG: 1329 cmdputs(n->narg.text); 1330 break; 1331 case NTO: 1332 p = ">"; i = 1; goto redir; 1333 case NAPPEND: 1334 p = ">>"; i = 1; goto redir; 1335 case NTOFD: 1336 p = ">&"; i = 1; goto redir; 1337 case NCLOBBER: 1338 p = ">|"; i = 1; goto redir; 1339 case NFROM: 1340 p = "<"; i = 0; goto redir; 1341 case NFROMTO: 1342 p = "<>"; i = 0; goto redir; 1343 case NFROMFD: 1344 p = "<&"; i = 0; goto redir; 1345redir: 1346 if (n->nfile.fd != i) { 1347 s[0] = n->nfile.fd + '0'; 1348 s[1] = '\0'; 1349 cmdputs(s); 1350 } 1351 cmdputs(p); 1352 if (n->type == NTOFD || n->type == NFROMFD) { 1353 if (n->ndup.dupfd >= 0) 1354 s[0] = n->ndup.dupfd + '0'; 1355 else 1356 s[0] = '-'; 1357 s[1] = '\0'; 1358 cmdputs(s); 1359 } else { 1360 cmdtxt(n->nfile.fname); 1361 } 1362 break; 1363 case NHERE: 1364 case NXHERE: 1365 cmdputs("<<..."); 1366 break; 1367 default: 1368 cmdputs("???"); 1369 break; 1370 } 1371} 1372 1373 1374 1375static void 1376cmdputs(const char *s) 1377{ 1378 const char *p; 1379 char *q; 1380 char c; 1381 int subtype = 0; 1382 1383 if (cmdnleft <= 0) 1384 return; 1385 p = s; 1386 q = cmdnextc; 1387 while ((c = *p++) != '\0') { 1388 if (c == CTLESC) 1389 *q++ = *p++; 1390 else if (c == CTLVAR) { 1391 *q++ = '$'; 1392 if (--cmdnleft > 0) 1393 *q++ = '{'; 1394 subtype = *p++; 1395 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1396 *q++ = '#'; 1397 } else if (c == '=' && subtype != 0) { 1398 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1399 if (*q) 1400 q++; 1401 else 1402 cmdnleft++; 1403 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1404 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1405 --cmdnleft > 0) 1406 *q = q[-1], q++; 1407 subtype = 0; 1408 } else if (c == CTLENDVAR) { 1409 *q++ = '}'; 1410 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1411 cmdnleft -= 5; 1412 if (cmdnleft > 0) { 1413 *q++ = '$'; 1414 *q++ = '('; 1415 *q++ = '.'; 1416 *q++ = '.'; 1417 *q++ = '.'; 1418 *q++ = ')'; 1419 } 1420 } else if (c == CTLARI) { 1421 cmdnleft -= 2; 1422 if (cmdnleft > 0) { 1423 *q++ = '$'; 1424 *q++ = '('; 1425 *q++ = '('; 1426 } 1427 p++; 1428 } else if (c == CTLENDARI) { 1429 if (--cmdnleft > 0) { 1430 *q++ = ')'; 1431 *q++ = ')'; 1432 } 1433 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1434 cmdnleft++; /* ignore */ 1435 else 1436 *q++ = c; 1437 if (--cmdnleft <= 0) { 1438 *q++ = '.'; 1439 *q++ = '.'; 1440 *q++ = '.'; 1441 break; 1442 } 1443 } 1444 cmdnextc = q; 1445} 1446