jobs.c revision 264168
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/10/bin/sh/jobs.c 264168 2014-04-05 20:01:08Z 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 */ 80static pid_t backgndpid = -1; /* pid of last background process */ 81static 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 86static int ttyfd = -1; 87 88/* mode flags for dowait */ 89#define DOWAIT_BLOCK 0x1 /* wait until a child exits */ 90#define DOWAIT_SIG 0x2 /* if DOWAIT_BLOCK, abort on SIGINT/SIGQUIT */ 91#define DOWAIT_SIG_ANY 0x4 /* if DOWAIT_SIG, abort on any signal */ 92 93#if JOBS 94static void restartjob(struct job *); 95#endif 96static void freejob(struct job *); 97static int waitcmdloop(struct job *); 98pid_t getjobpgrp(char *); 99static struct job *getjob_nonotfound(const char *); 100static struct job *getjob(const 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 118static 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 __unused) 186{ 187 struct job *jp; 188 pid_t pgrp; 189 int status; 190 191 nextopt(""); 192 jp = getjob(*argptr); 193 if (jp->jobctl == 0) 194 error("job not created under job control"); 195 printjobcmd(jp); 196 flushout(&output); 197 pgrp = jp->ps[0].pid; 198 tcsetpgrp(ttyfd, pgrp); 199 restartjob(jp); 200 jp->foreground = 1; 201 INTOFF; 202 status = waitforjob(jp, (int *)NULL); 203 INTON; 204 return status; 205} 206 207 208int 209bgcmd(int argc, char **argv) 210{ 211 struct job *jp; 212 213 nextopt(""); 214 do { 215 jp = getjob(*argptr); 216 if (jp->jobctl == 0) 217 error("job not created under job control"); 218 if (jp->state == JOBDONE) 219 continue; 220 restartjob(jp); 221 jp->foreground = 0; 222 out1fmt("[%td] ", jp - jobtab + 1); 223 printjobcmd(jp); 224 } while (*argptr != NULL && *++argptr != NULL); 225 return 0; 226} 227 228 229static void 230restartjob(struct job *jp) 231{ 232 struct procstat *ps; 233 int i; 234 235 if (jp->state == JOBDONE) 236 return; 237 setcurjob(jp); 238 INTOFF; 239 kill(-jp->ps[0].pid, SIGCONT); 240 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 241 if (WIFSTOPPED(ps->status)) { 242 ps->status = -1; 243 jp->state = 0; 244 } 245 } 246 INTON; 247} 248#endif 249 250 251int 252jobscmd(int argc __unused, char *argv[] __unused) 253{ 254 char *id; 255 int ch, mode; 256 257 mode = SHOWJOBS_DEFAULT; 258 while ((ch = nextopt("lps")) != '\0') { 259 switch (ch) { 260 case 'l': 261 mode = SHOWJOBS_VERBOSE; 262 break; 263 case 'p': 264 mode = SHOWJOBS_PGIDS; 265 break; 266 case 's': 267 mode = SHOWJOBS_PIDS; 268 break; 269 } 270 } 271 272 if (*argptr == NULL) 273 showjobs(0, mode); 274 else 275 while ((id = *argptr++) != NULL) 276 showjob(getjob(id), mode); 277 278 return (0); 279} 280 281static void 282printjobcmd(struct job *jp) 283{ 284 struct procstat *ps; 285 int i; 286 287 for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { 288 out1str(ps->cmd); 289 if (i > 0) 290 out1str(" | "); 291 } 292 out1c('\n'); 293} 294 295static void 296showjob(struct job *jp, int mode) 297{ 298 char s[64]; 299 char statestr[64]; 300 const char *sigstr; 301 struct procstat *ps; 302 struct job *j; 303 int col, curr, i, jobno, prev, procno; 304 char c; 305 306 procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs; 307 jobno = jp - jobtab + 1; 308 curr = prev = 0; 309#if JOBS 310 if ((j = getcurjob(NULL)) != NULL) { 311 curr = j - jobtab + 1; 312 if ((j = getcurjob(j)) != NULL) 313 prev = j - jobtab + 1; 314 } 315#endif 316 ps = jp->ps + jp->nprocs - 1; 317 if (jp->state == 0) { 318 strcpy(statestr, "Running"); 319#if JOBS 320 } else if (jp->state == JOBSTOPPED) { 321 while (!WIFSTOPPED(ps->status) && ps > jp->ps) 322 ps--; 323 if (WIFSTOPPED(ps->status)) 324 i = WSTOPSIG(ps->status); 325 else 326 i = -1; 327 sigstr = strsignal(i); 328 if (sigstr != NULL) 329 strcpy(statestr, sigstr); 330 else 331 strcpy(statestr, "Suspended"); 332#endif 333 } else if (WIFEXITED(ps->status)) { 334 if (WEXITSTATUS(ps->status) == 0) 335 strcpy(statestr, "Done"); 336 else 337 fmtstr(statestr, 64, "Done(%d)", 338 WEXITSTATUS(ps->status)); 339 } else { 340 i = WTERMSIG(ps->status); 341 sigstr = strsignal(i); 342 if (sigstr != NULL) 343 strcpy(statestr, sigstr); 344 else 345 strcpy(statestr, "Unknown signal"); 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 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) { 420 jp->changed = 0; 421 /* Hack: discard jobs for which $! has not been 422 * referenced in interactive mode when they terminate. 423 */ 424 if (jp->state == JOBDONE && !jp->remembered && 425 (iflag || jp != bgjob)) { 426 freejob(jp); 427 } 428 } 429 } 430} 431 432 433/* 434 * Mark a job structure as unused. 435 */ 436 437static void 438freejob(struct job *jp) 439{ 440 struct procstat *ps; 441 int i; 442 443 INTOFF; 444 if (bgjob == jp) 445 bgjob = NULL; 446 for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { 447 if (ps->cmd != nullstr) 448 ckfree(ps->cmd); 449 } 450 if (jp->ps != &jp->ps0) 451 ckfree(jp->ps); 452 jp->used = 0; 453#if JOBS 454 deljob(jp); 455#endif 456 INTON; 457} 458 459 460 461int 462waitcmd(int argc __unused, char **argv __unused) 463{ 464 struct job *job; 465 int retval; 466 467 nextopt(""); 468 if (*argptr == NULL) 469 return (waitcmdloop(NULL)); 470 471 do { 472 job = getjob_nonotfound(*argptr); 473 if (job == NULL) 474 retval = 127; 475 else 476 retval = waitcmdloop(job); 477 argptr++; 478 } while (*argptr != NULL); 479 480 return (retval); 481} 482 483static int 484waitcmdloop(struct job *job) 485{ 486 int status, retval, sig; 487 struct job *jp; 488 489 /* 490 * Loop until a process is terminated or stopped, or a SIGINT is 491 * received. 492 */ 493 494 do { 495 if (job != NULL) { 496 if (job->state == JOBDONE) { 497 status = job->ps[job->nprocs - 1].status; 498 if (WIFEXITED(status)) 499 retval = WEXITSTATUS(status); 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 return retval; 510 } 511 } else { 512 for (jp = jobtab ; jp < jobtab + njobs; jp++) 513 if (jp->used && jp->state == JOBDONE) { 514 if (! iflag || ! jp->changed) 515 freejob(jp); 516 else { 517 jp->remembered = 0; 518 if (jp == bgjob) 519 bgjob = NULL; 520 } 521 } 522 for (jp = jobtab ; ; jp++) { 523 if (jp >= jobtab + njobs) { /* no running procs */ 524 return 0; 525 } 526 if (jp->used && jp->state == 0) 527 break; 528 } 529 } 530 } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1); 531 532 sig = pendingsig_waitcmd; 533 pendingsig_waitcmd = 0; 534 return sig + 128; 535} 536 537 538 539int 540jobidcmd(int argc __unused, char **argv __unused) 541{ 542 struct job *jp; 543 int i; 544 545 nextopt(""); 546 jp = getjob(*argptr); 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_nonotfound(const 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 return NULL; 627} 628 629 630static struct job * 631getjob(const char *name) 632{ 633 struct job *jp; 634 635 jp = getjob_nonotfound(name); 636 if (jp == NULL) 637 error("No such job: %s", name); 638 return (jp); 639} 640 641 642pid_t 643getjobpgrp(char *name) 644{ 645 struct job *jp; 646 647 jp = getjob(name); 648 return -jp->ps[0].pid; 649} 650 651/* 652 * Return a new job structure, 653 */ 654 655struct job * 656makejob(union node *node __unused, int nprocs) 657{ 658 int i; 659 struct job *jp; 660 661 for (i = njobs, jp = jobtab ; ; jp++) { 662 if (--i < 0) { 663 INTOFF; 664 if (njobs == 0) { 665 jobtab = ckmalloc(4 * sizeof jobtab[0]); 666#if JOBS 667 jobmru = NULL; 668#endif 669 } else { 670 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); 671 memcpy(jp, jobtab, njobs * sizeof jp[0]); 672#if JOBS 673 /* Relocate `next' pointers and list head */ 674 if (jobmru != NULL) 675 jobmru = &jp[jobmru - jobtab]; 676 for (i = 0; i < njobs; i++) 677 if (jp[i].next != NULL) 678 jp[i].next = &jp[jp[i].next - 679 jobtab]; 680#endif 681 if (bgjob != NULL) 682 bgjob = &jp[bgjob - jobtab]; 683 /* Relocate `ps' pointers */ 684 for (i = 0; i < njobs; i++) 685 if (jp[i].ps == &jobtab[i].ps0) 686 jp[i].ps = &jp[i].ps0; 687 ckfree(jobtab); 688 jobtab = jp; 689 } 690 jp = jobtab + njobs; 691 for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0) 692 ; 693 INTON; 694 break; 695 } 696 if (jp->used == 0) 697 break; 698 } 699 INTOFF; 700 jp->state = 0; 701 jp->used = 1; 702 jp->changed = 0; 703 jp->nprocs = 0; 704 jp->foreground = 0; 705 jp->remembered = 0; 706#if JOBS 707 jp->jobctl = jobctl; 708 jp->next = NULL; 709#endif 710 if (nprocs > 1) { 711 jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); 712 } else { 713 jp->ps = &jp->ps0; 714 } 715 INTON; 716 TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs, 717 jp - jobtab + 1)); 718 return jp; 719} 720 721#if JOBS 722static void 723setcurjob(struct job *cj) 724{ 725 struct job *jp, *prev; 726 727 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 728 if (jp == cj) { 729 if (prev != NULL) 730 prev->next = jp->next; 731 else 732 jobmru = jp->next; 733 jp->next = jobmru; 734 jobmru = cj; 735 return; 736 } 737 } 738 cj->next = jobmru; 739 jobmru = cj; 740} 741 742static void 743deljob(struct job *j) 744{ 745 struct job *jp, *prev; 746 747 for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) { 748 if (jp == j) { 749 if (prev != NULL) 750 prev->next = jp->next; 751 else 752 jobmru = jp->next; 753 return; 754 } 755 } 756} 757 758/* 759 * Return the most recently used job that isn't `nj', and preferably one 760 * that is stopped. 761 */ 762static struct job * 763getcurjob(struct job *nj) 764{ 765 struct job *jp; 766 767 /* Try to find a stopped one.. */ 768 for (jp = jobmru; jp != NULL; jp = jp->next) 769 if (jp->used && jp != nj && jp->state == JOBSTOPPED) 770 return (jp); 771 /* Otherwise the most recently used job that isn't `nj' */ 772 for (jp = jobmru; jp != NULL; jp = jp->next) 773 if (jp->used && jp != nj) 774 return (jp); 775 776 return (NULL); 777} 778 779#endif 780 781/* 782 * Fork of a subshell. If we are doing job control, give the subshell its 783 * own process group. Jp is a job structure that the job is to be added to. 784 * N is the command that will be evaluated by the child. Both jp and n may 785 * be NULL. The mode parameter can be one of the following: 786 * FORK_FG - Fork off a foreground process. 787 * FORK_BG - Fork off a background process. 788 * FORK_NOJOB - Like FORK_FG, but don't give the process its own 789 * process group even if job control is on. 790 * 791 * When job control is turned off, background processes have their standard 792 * input redirected to /dev/null (except for the second and later processes 793 * in a pipeline). 794 */ 795 796pid_t 797forkshell(struct job *jp, union node *n, int mode) 798{ 799 pid_t pid; 800 pid_t pgrp; 801 802 TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n, 803 mode)); 804 INTOFF; 805 if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0)) 806 checkzombies(); 807 flushall(); 808 pid = fork(); 809 if (pid == -1) { 810 TRACE(("Fork failed, errno=%d\n", errno)); 811 INTON; 812 error("Cannot fork: %s", strerror(errno)); 813 } 814 if (pid == 0) { 815 struct job *p; 816 int wasroot; 817 int i; 818 819 TRACE(("Child shell %d\n", (int)getpid())); 820 wasroot = rootshell; 821 rootshell = 0; 822 handler = &main_handler; 823 closescript(); 824 INTON; 825 forcelocal = 0; 826 clear_traps(); 827#if JOBS 828 jobctl = 0; /* do job control only in root shell */ 829 if (wasroot && mode != FORK_NOJOB && mflag) { 830 if (jp == NULL || jp->nprocs == 0) 831 pgrp = getpid(); 832 else 833 pgrp = jp->ps[0].pid; 834 if (setpgid(0, pgrp) == 0 && mode == FORK_FG) { 835 /*** this causes superfluous TIOCSPGRPS ***/ 836 if (tcsetpgrp(ttyfd, pgrp) < 0) 837 error("tcsetpgrp failed, errno=%d", errno); 838 } 839 setsignal(SIGTSTP); 840 setsignal(SIGTTOU); 841 } else if (mode == FORK_BG) { 842 ignoresig(SIGINT); 843 ignoresig(SIGQUIT); 844 if ((jp == NULL || jp->nprocs == 0) && 845 ! fd0_redirected_p ()) { 846 close(0); 847 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 848 error("cannot open %s: %s", 849 _PATH_DEVNULL, strerror(errno)); 850 } 851 } 852#else 853 if (mode == FORK_BG) { 854 ignoresig(SIGINT); 855 ignoresig(SIGQUIT); 856 if ((jp == NULL || jp->nprocs == 0) && 857 ! fd0_redirected_p ()) { 858 close(0); 859 if (open(_PATH_DEVNULL, O_RDONLY) != 0) 860 error("cannot open %s: %s", 861 _PATH_DEVNULL, strerror(errno)); 862 } 863 } 864#endif 865 INTOFF; 866 for (i = njobs, p = jobtab ; --i >= 0 ; p++) 867 if (p->used) 868 freejob(p); 869 INTON; 870 if (wasroot && iflag) { 871 setsignal(SIGINT); 872 setsignal(SIGQUIT); 873 setsignal(SIGTERM); 874 } 875 return pid; 876 } 877 if (rootshell && mode != FORK_NOJOB && mflag) { 878 if (jp == NULL || jp->nprocs == 0) 879 pgrp = pid; 880 else 881 pgrp = jp->ps[0].pid; 882 setpgid(pid, pgrp); 883 } 884 if (mode == FORK_BG) { 885 if (bgjob != NULL && bgjob->state == JOBDONE && 886 !bgjob->remembered && !iflag) 887 freejob(bgjob); 888 backgndpid = pid; /* set $! */ 889 bgjob = jp; 890 } 891 if (jp) { 892 struct procstat *ps = &jp->ps[jp->nprocs++]; 893 ps->pid = pid; 894 ps->status = -1; 895 ps->cmd = nullstr; 896 if (iflag && rootshell && n) 897 ps->cmd = commandtext(n); 898 jp->foreground = mode == FORK_FG; 899#if JOBS 900 setcurjob(jp); 901#endif 902 } 903 INTON; 904 TRACE(("In parent shell: child = %d\n", (int)pid)); 905 return pid; 906} 907 908 909pid_t 910vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2]) 911{ 912 pid_t pid; 913 struct jmploc jmploc; 914 struct jmploc *savehandler; 915 916 TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0], 917 (void *)pip)); 918 INTOFF; 919 flushall(); 920 savehandler = handler; 921 pid = vfork(); 922 if (pid == -1) { 923 TRACE(("Vfork failed, errno=%d\n", errno)); 924 INTON; 925 error("Cannot fork: %s", strerror(errno)); 926 } 927 if (pid == 0) { 928 TRACE(("Child shell %d\n", (int)getpid())); 929 if (setjmp(jmploc.loc)) 930 _exit(exception == EXEXEC ? exerrno : 2); 931 if (pip != NULL) { 932 close(pip[0]); 933 if (pip[1] != 1) { 934 dup2(pip[1], 1); 935 close(pip[1]); 936 } 937 } 938 handler = &jmploc; 939 shellexec(argv, envp, path, idx); 940 } 941 handler = savehandler; 942 if (jp) { 943 struct procstat *ps = &jp->ps[jp->nprocs++]; 944 ps->pid = pid; 945 ps->status = -1; 946 ps->cmd = nullstr; 947 jp->foreground = 1; 948#if JOBS 949 setcurjob(jp); 950#endif 951 } 952 INTON; 953 TRACE(("In parent shell: child = %d\n", (int)pid)); 954 return pid; 955} 956 957 958/* 959 * Wait for job to finish. 960 * 961 * Under job control we have the problem that while a child process is 962 * running interrupts generated by the user are sent to the child but not 963 * to the shell. This means that an infinite loop started by an inter- 964 * active user may be hard to kill. With job control turned off, an 965 * interactive user may place an interactive program inside a loop. If 966 * the interactive program catches interrupts, the user doesn't want 967 * these interrupts to also abort the loop. The approach we take here 968 * is to have the shell ignore interrupt signals while waiting for a 969 * foreground process to terminate, and then send itself an interrupt 970 * signal if the child process was terminated by an interrupt signal. 971 * Unfortunately, some programs want to do a bit of cleanup and then 972 * exit on interrupt; unless these processes terminate themselves by 973 * sending a signal to themselves (instead of calling exit) they will 974 * confuse this approach. 975 */ 976 977int 978waitforjob(struct job *jp, int *origstatus) 979{ 980#if JOBS 981 int propagate_int = jp->jobctl && jp->foreground; 982#endif 983 int status; 984 int st; 985 986 INTOFF; 987 TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1)); 988 while (jp->state == 0) 989 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG | 990 DOWAIT_SIG_ANY : 0), jp) == -1) 991 dotrap(); 992#if JOBS 993 if (jp->jobctl) { 994 if (tcsetpgrp(ttyfd, rootpid) < 0) 995 error("tcsetpgrp failed, errno=%d\n", errno); 996 } 997 if (jp->state == JOBSTOPPED) 998 setcurjob(jp); 999#endif 1000 status = jp->ps[jp->nprocs - 1].status; 1001 if (origstatus != NULL) 1002 *origstatus = status; 1003 /* convert to 8 bits */ 1004 if (WIFEXITED(status)) 1005 st = WEXITSTATUS(status); 1006#if JOBS 1007 else if (WIFSTOPPED(status)) 1008 st = WSTOPSIG(status) + 128; 1009#endif 1010 else 1011 st = WTERMSIG(status) + 128; 1012 if (! JOBS || jp->state == JOBDONE) 1013 freejob(jp); 1014 if (int_pending()) { 1015 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT) 1016 CLEAR_PENDING_INT; 1017 } 1018#if JOBS 1019 else if (rootshell && iflag && propagate_int && 1020 WIFSIGNALED(status) && WTERMSIG(status) == SIGINT) 1021 kill(getpid(), SIGINT); 1022#endif 1023 INTON; 1024 return st; 1025} 1026 1027 1028static void 1029dummy_handler(int sig __unused) 1030{ 1031} 1032 1033/* 1034 * Wait for a process to terminate. 1035 */ 1036 1037static pid_t 1038dowait(int mode, struct job *job) 1039{ 1040 struct sigaction sa, osa; 1041 sigset_t mask, omask; 1042 pid_t pid; 1043 int status; 1044 struct procstat *sp; 1045 struct job *jp; 1046 struct job *thisjob; 1047 const char *sigstr; 1048 int done; 1049 int stopped; 1050 int sig; 1051 int coredump; 1052 int wflags; 1053 int restore_sigchld; 1054 1055 TRACE(("dowait(%d, %p) called\n", mode, job)); 1056 restore_sigchld = 0; 1057 if ((mode & DOWAIT_SIG) != 0) { 1058 sigfillset(&mask); 1059 sigprocmask(SIG_BLOCK, &mask, &omask); 1060 INTOFF; 1061 if (!issigchldtrapped()) { 1062 restore_sigchld = 1; 1063 sa.sa_handler = dummy_handler; 1064 sa.sa_flags = 0; 1065 sigemptyset(&sa.sa_mask); 1066 sigaction(SIGCHLD, &sa, &osa); 1067 } 1068 } 1069 do { 1070#if JOBS 1071 if (iflag) 1072 wflags = WUNTRACED | WCONTINUED; 1073 else 1074#endif 1075 wflags = 0; 1076 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK) 1077 wflags |= WNOHANG; 1078 pid = wait3(&status, wflags, (struct rusage *)NULL); 1079 TRACE(("wait returns %d, status=%d\n", (int)pid, status)); 1080 if (pid == 0 && (mode & DOWAIT_SIG) != 0) { 1081 pid = -1; 1082 if (((mode & DOWAIT_SIG_ANY) != 0 ? 1083 pendingsig : pendingsig_waitcmd) != 0) { 1084 errno = EINTR; 1085 break; 1086 } 1087 sigsuspend(&omask); 1088 if (int_pending()) 1089 break; 1090 } 1091 } while (pid == -1 && errno == EINTR); 1092 if (pid == -1 && errno == ECHILD && job != NULL) 1093 job->state = JOBDONE; 1094 if ((mode & DOWAIT_SIG) != 0) { 1095 if (restore_sigchld) 1096 sigaction(SIGCHLD, &osa, NULL); 1097 sigprocmask(SIG_SETMASK, &omask, NULL); 1098 INTON; 1099 } 1100 if (pid <= 0) 1101 return pid; 1102 INTOFF; 1103 thisjob = NULL; 1104 for (jp = jobtab ; jp < jobtab + njobs ; jp++) { 1105 if (jp->used && jp->nprocs > 0) { 1106 done = 1; 1107 stopped = 1; 1108 for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { 1109 if (sp->pid == -1) 1110 continue; 1111 if (sp->pid == pid) { 1112 TRACE(("Changing status of proc %d from 0x%x to 0x%x\n", 1113 (int)pid, sp->status, 1114 status)); 1115 if (WIFCONTINUED(status)) { 1116 sp->status = -1; 1117 jp->state = 0; 1118 } else 1119 sp->status = status; 1120 thisjob = jp; 1121 } 1122 if (sp->status == -1) 1123 stopped = 0; 1124 else if (WIFSTOPPED(sp->status)) 1125 done = 0; 1126 } 1127 if (stopped) { /* stopped or done */ 1128 int state = done? JOBDONE : JOBSTOPPED; 1129 if (jp->state != state) { 1130 TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); 1131 jp->state = state; 1132 if (jp != job) { 1133 if (done && !jp->remembered && 1134 !iflag && jp != bgjob) 1135 freejob(jp); 1136#if JOBS 1137 else if (done) 1138 deljob(jp); 1139#endif 1140 } 1141 } 1142 } 1143 } 1144 } 1145 INTON; 1146 if (!thisjob || thisjob->state == 0) 1147 ; 1148 else if ((!rootshell || !iflag || thisjob == job) && 1149 thisjob->foreground && thisjob->state != JOBSTOPPED) { 1150 sig = 0; 1151 coredump = 0; 1152 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++) 1153 if (WIFSIGNALED(sp->status)) { 1154 sig = WTERMSIG(sp->status); 1155 coredump = WCOREDUMP(sp->status); 1156 } 1157 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) { 1158 sigstr = strsignal(sig); 1159 if (sigstr != NULL) 1160 out2str(sigstr); 1161 else 1162 out2str("Unknown signal"); 1163 if (coredump) 1164 out2str(" (core dumped)"); 1165 out2c('\n'); 1166 flushout(out2); 1167 } 1168 } else { 1169 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job)); 1170 thisjob->changed = 1; 1171 } 1172 return pid; 1173} 1174 1175 1176 1177/* 1178 * return 1 if there are stopped jobs, otherwise 0 1179 */ 1180int job_warning = 0; 1181int 1182stoppedjobs(void) 1183{ 1184 int jobno; 1185 struct job *jp; 1186 1187 if (job_warning) 1188 return (0); 1189 for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) { 1190 if (jp->used == 0) 1191 continue; 1192 if (jp->state == JOBSTOPPED) { 1193 out2fmt_flush("You have stopped jobs.\n"); 1194 job_warning = 2; 1195 return (1); 1196 } 1197 } 1198 1199 return (0); 1200} 1201 1202 1203static void 1204checkzombies(void) 1205{ 1206 while (njobs > 0 && dowait(0, NULL) > 0) 1207 ; 1208} 1209 1210 1211int 1212backgndpidset(void) 1213{ 1214 return backgndpid != -1; 1215} 1216 1217 1218pid_t 1219backgndpidval(void) 1220{ 1221 if (bgjob != NULL && !forcelocal) 1222 bgjob->remembered = 1; 1223 return backgndpid; 1224} 1225 1226/* 1227 * Return a string identifying a command (to be printed by the 1228 * jobs command. 1229 */ 1230 1231static char *cmdnextc; 1232static int cmdnleft; 1233#define MAXCMDTEXT 200 1234 1235char * 1236commandtext(union node *n) 1237{ 1238 char *name; 1239 1240 cmdnextc = name = ckmalloc(MAXCMDTEXT); 1241 cmdnleft = MAXCMDTEXT - 4; 1242 cmdtxt(n); 1243 *cmdnextc = '\0'; 1244 return name; 1245} 1246 1247 1248static void 1249cmdtxt(union node *n) 1250{ 1251 union node *np; 1252 struct nodelist *lp; 1253 const char *p; 1254 int i; 1255 char s[2]; 1256 1257 if (n == NULL) 1258 return; 1259 switch (n->type) { 1260 case NSEMI: 1261 cmdtxt(n->nbinary.ch1); 1262 cmdputs("; "); 1263 cmdtxt(n->nbinary.ch2); 1264 break; 1265 case NAND: 1266 cmdtxt(n->nbinary.ch1); 1267 cmdputs(" && "); 1268 cmdtxt(n->nbinary.ch2); 1269 break; 1270 case NOR: 1271 cmdtxt(n->nbinary.ch1); 1272 cmdputs(" || "); 1273 cmdtxt(n->nbinary.ch2); 1274 break; 1275 case NPIPE: 1276 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { 1277 cmdtxt(lp->n); 1278 if (lp->next) 1279 cmdputs(" | "); 1280 } 1281 break; 1282 case NSUBSHELL: 1283 cmdputs("("); 1284 cmdtxt(n->nredir.n); 1285 cmdputs(")"); 1286 break; 1287 case NREDIR: 1288 case NBACKGND: 1289 cmdtxt(n->nredir.n); 1290 break; 1291 case NIF: 1292 cmdputs("if "); 1293 cmdtxt(n->nif.test); 1294 cmdputs("; then "); 1295 cmdtxt(n->nif.ifpart); 1296 cmdputs("..."); 1297 break; 1298 case NWHILE: 1299 cmdputs("while "); 1300 goto until; 1301 case NUNTIL: 1302 cmdputs("until "); 1303until: 1304 cmdtxt(n->nbinary.ch1); 1305 cmdputs("; do "); 1306 cmdtxt(n->nbinary.ch2); 1307 cmdputs("; done"); 1308 break; 1309 case NFOR: 1310 cmdputs("for "); 1311 cmdputs(n->nfor.var); 1312 cmdputs(" in ..."); 1313 break; 1314 case NCASE: 1315 cmdputs("case "); 1316 cmdputs(n->ncase.expr->narg.text); 1317 cmdputs(" in ..."); 1318 break; 1319 case NDEFUN: 1320 cmdputs(n->narg.text); 1321 cmdputs("() ..."); 1322 break; 1323 case NNOT: 1324 cmdputs("! "); 1325 cmdtxt(n->nnot.com); 1326 break; 1327 case NCMD: 1328 for (np = n->ncmd.args ; np ; np = np->narg.next) { 1329 cmdtxt(np); 1330 if (np->narg.next) 1331 cmdputs(" "); 1332 } 1333 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { 1334 cmdputs(" "); 1335 cmdtxt(np); 1336 } 1337 break; 1338 case NARG: 1339 cmdputs(n->narg.text); 1340 break; 1341 case NTO: 1342 p = ">"; i = 1; goto redir; 1343 case NAPPEND: 1344 p = ">>"; i = 1; goto redir; 1345 case NTOFD: 1346 p = ">&"; i = 1; goto redir; 1347 case NCLOBBER: 1348 p = ">|"; i = 1; goto redir; 1349 case NFROM: 1350 p = "<"; i = 0; goto redir; 1351 case NFROMTO: 1352 p = "<>"; i = 0; goto redir; 1353 case NFROMFD: 1354 p = "<&"; i = 0; goto redir; 1355redir: 1356 if (n->nfile.fd != i) { 1357 s[0] = n->nfile.fd + '0'; 1358 s[1] = '\0'; 1359 cmdputs(s); 1360 } 1361 cmdputs(p); 1362 if (n->type == NTOFD || n->type == NFROMFD) { 1363 if (n->ndup.dupfd >= 0) 1364 s[0] = n->ndup.dupfd + '0'; 1365 else 1366 s[0] = '-'; 1367 s[1] = '\0'; 1368 cmdputs(s); 1369 } else { 1370 cmdtxt(n->nfile.fname); 1371 } 1372 break; 1373 case NHERE: 1374 case NXHERE: 1375 cmdputs("<<..."); 1376 break; 1377 default: 1378 cmdputs("???"); 1379 break; 1380 } 1381} 1382 1383 1384 1385static void 1386cmdputs(const char *s) 1387{ 1388 const char *p; 1389 char *q; 1390 char c; 1391 int subtype = 0; 1392 1393 if (cmdnleft <= 0) 1394 return; 1395 p = s; 1396 q = cmdnextc; 1397 while ((c = *p++) != '\0') { 1398 if (c == CTLESC) 1399 *q++ = *p++; 1400 else if (c == CTLVAR) { 1401 *q++ = '$'; 1402 if (--cmdnleft > 0) 1403 *q++ = '{'; 1404 subtype = *p++; 1405 if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0) 1406 *q++ = '#'; 1407 } else if (c == '=' && subtype != 0) { 1408 *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL]; 1409 if (*q) 1410 q++; 1411 else 1412 cmdnleft++; 1413 if (((subtype & VSTYPE) == VSTRIMLEFTMAX || 1414 (subtype & VSTYPE) == VSTRIMRIGHTMAX) && 1415 --cmdnleft > 0) 1416 *q = q[-1], q++; 1417 subtype = 0; 1418 } else if (c == CTLENDVAR) { 1419 *q++ = '}'; 1420 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) { 1421 cmdnleft -= 5; 1422 if (cmdnleft > 0) { 1423 *q++ = '$'; 1424 *q++ = '('; 1425 *q++ = '.'; 1426 *q++ = '.'; 1427 *q++ = '.'; 1428 *q++ = ')'; 1429 } 1430 } else if (c == CTLARI) { 1431 cmdnleft -= 2; 1432 if (cmdnleft > 0) { 1433 *q++ = '$'; 1434 *q++ = '('; 1435 *q++ = '('; 1436 } 1437 p++; 1438 } else if (c == CTLENDARI) { 1439 if (--cmdnleft > 0) { 1440 *q++ = ')'; 1441 *q++ = ')'; 1442 } 1443 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND) 1444 cmdnleft++; /* ignore */ 1445 else 1446 *q++ = c; 1447 if (--cmdnleft <= 0) { 1448 *q++ = '.'; 1449 *q++ = '.'; 1450 *q++ = '.'; 1451 break; 1452 } 1453 } 1454 cmdnextc = q; 1455} 1456