| 1 | /*- |
| 2 | * Copyright (c) 1991 The Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This code is derived from software contributed to Berkeley by |
| 6 | * Kenneth Almquist. |
| 7 | * |
| 8 | * Redistribution and use in source and binary forms, with or without |
| 9 | * modification, are permitted provided that the following conditions |
| 10 | * are met: |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. All advertising materials mentioning features or use of this software |
| 17 | * must display the following acknowledgement: |
| 18 | * This product includes software developed by the University of |
| 19 | * California, Berkeley and its contributors. |
| 20 | * 4. Neither the name of the University nor the names of its contributors |
| 21 | * may be used to endorse or promote products derived from this software |
| 22 | * without specific prior written permission. |
| 23 | * |
| 24 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 25 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 26 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 27 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 28 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 29 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 30 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 31 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 32 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 33 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 34 | * SUCH DAMAGE. |
| 35 | * |
| 36 | * PATCHES MAGIC LEVEL PATCH THAT GOT US HERE |
| 37 | * -------------------- ----- ---------------------- |
| 38 | * CURRENT PATCH LEVEL: 1 00168 |
| 39 | * -------------------- ----- ---------------------- |
| 40 | * |
| 41 | * 04 Jun 93 Jim Wilson Seven (7) fixes for misc bugs |
| 42 | * |
| 43 | */ |
| 44 | |
| 45 | #ifndef lint |
| 46 | static char sccsid[] = "@(#)jobs.c 5.1 (Berkeley) 3/7/91"; |
| 47 | #endif /* not lint */ |
| 48 | |
| 49 | #include "shell.h" |
| 50 | #if JOBS |
| 51 | #include "sgtty.h" |
| 52 | #undef CEOF /* syntax.h redefines this */ |
| 53 | #endif |
| 54 | #include "main.h" |
| 55 | #include "parser.h" |
| 56 | #include "nodes.h" |
| 57 | #include "jobs.h" |
| 58 | #include "options.h" |
| 59 | #include "trap.h" |
| 60 | #include "signames.h" |
| 61 | #include "syntax.h" |
| 62 | #include "input.h" |
| 63 | #include "output.h" |
| 64 | #include "memalloc.h" |
| 65 | #include "error.h" |
| 66 | #include "mystring.h" |
| 67 | #include "redir.h" |
| 68 | #include <fcntl.h> |
| 69 | #include <signal.h> |
| 70 | #include <errno.h> |
| 71 | #ifdef BSD |
| 72 | #include <sys/types.h> |
| 73 | #include <sys/wait.h> |
| 74 | #include <sys/time.h> |
| 75 | #include <sys/resource.h> |
| 76 | #endif |
| 77 | |
| 78 | |
| 79 | |
| 80 | struct job *jobtab; /* array of jobs */ |
| 81 | int njobs; /* size of array */ |
| 82 | MKINIT short backgndpid = -1; /* pid of last background process */ |
| 83 | #if JOBS |
| 84 | int initialpgrp; /* pgrp of shell on invocation */ |
| 85 | short curjob; /* current job */ |
| 86 | #endif |
| 87 | |
| 88 | #ifdef __STDC__ |
| 89 | STATIC void restartjob(struct job *); |
| 90 | STATIC struct job *getjob(char *); |
| 91 | STATIC void freejob(struct job *); |
| 92 | STATIC int procrunning(int); |
| 93 | STATIC int dowait(int, struct job *); |
| 94 | STATIC int waitproc(int, int *); |
| 95 | STATIC char *commandtext(union node *); |
| 96 | #else |
| 97 | STATIC void restartjob(); |
| 98 | STATIC struct job *getjob(); |
| 99 | STATIC void freejob(); |
| 100 | STATIC int procrunning(); |
| 101 | STATIC int dowait(); |
| 102 | STATIC int waitproc(); |
| 103 | STATIC char *commandtext(); |
| 104 | #endif |
| 105 | |
| 106 | |
| 107 | |
| 108 | #if JOBS |
| 109 | /* |
| 110 | * Turn job control on and off. |
| 111 | * |
| 112 | * Note: This code assumes that the third arg to ioctl is a character |
| 113 | * pointer, which is true on Berkeley systems but not System V. Since |
| 114 | * System V doesn't have job control yet, this isn't a problem now. |
| 115 | */ |
| 116 | |
| 117 | MKINIT int jobctl; |
| 118 | |
| 119 | void |
| 120 | setjobctl(on) { |
| 121 | int ldisc; |
| 122 | |
| 123 | if (on == jobctl || rootshell == 0) |
| 124 | return; |
| 125 | if (on) { |
| 126 | do { /* while we are in the background */ |
| 127 | if (ioctl(2, TIOCGPGRP, (char *)&initialpgrp) < 0) { |
| 128 | out2str("ash: can't access tty; job control turned off\n"); |
| 129 | jflag = 0; |
| 130 | return; |
| 131 | } |
| 132 | if (initialpgrp == -1) |
| 133 | initialpgrp = getpgrp(0); |
| 134 | else if (initialpgrp != getpgrp(0)) { |
| 135 | killpg(initialpgrp, SIGTTIN); |
| 136 | continue; |
| 137 | } |
| 138 | } while (0); |
| 139 | if (ioctl(2, TIOCGETD, (char *)&ldisc) < 0 || ldisc != NTTYDISC) { |
| 140 | out2str("ash: need new tty driver to run job control; job control turned off\n"); |
| 141 | jflag = 0; |
| 142 | return; |
| 143 | } |
| 144 | setsignal(SIGTSTP); |
| 145 | setsignal(SIGTTOU); |
| 146 | setpgrp(0, rootpid); |
| 147 | ioctl(2, TIOCSPGRP, (char *)&rootpid); |
| 148 | } else { /* turning job control off */ |
| 149 | setpgrp(0, initialpgrp); |
| 150 | ioctl(2, TIOCSPGRP, (char *)&initialpgrp); |
| 151 | setsignal(SIGTSTP); |
| 152 | setsignal(SIGTTOU); |
| 153 | } |
| 154 | jobctl = on; |
| 155 | } |
| 156 | #endif |
| 157 | |
| 158 | |
| 159 | #ifdef mkinit |
| 160 | |
| 161 | SHELLPROC { |
| 162 | backgndpid = -1; |
| 163 | #if JOBS |
| 164 | jobctl = 0; |
| 165 | #endif |
| 166 | } |
| 167 | |
| 168 | #endif |
| 169 | |
| 170 | |
| 171 | |
| 172 | #if JOBS |
| 173 | fgcmd(argc, argv) char **argv; { |
| 174 | struct job *jp; |
| 175 | int pgrp; |
| 176 | int status; |
| 177 | |
| 178 | jp = getjob(argv[1]); |
| 179 | if (jp->jobctl == 0) |
| 180 | error("job not created under job control"); |
| 181 | pgrp = jp->ps[0].pid; |
| 182 | ioctl(2, TIOCSPGRP, (char *)&pgrp); |
| 183 | restartjob(jp); |
| 184 | INTOFF; |
| 185 | status = waitforjob(jp); |
| 186 | INTON; |
| 187 | return status; |
| 188 | } |
| 189 | |
| 190 | |
| 191 | bgcmd(argc, argv) char **argv; { |
| 192 | struct job *jp; |
| 193 | |
| 194 | do { |
| 195 | jp = getjob(*++argv); |
| 196 | if (jp->jobctl == 0) |
| 197 | error("job not created under job control"); |
| 198 | restartjob(jp); |
| 199 | } while (--argc > 1); |
| 200 | return 0; |
| 201 | } |
| 202 | |
| 203 | |
| 204 | STATIC void |
| 205 | restartjob(jp) |
| 206 | struct job *jp; |
| 207 | { |
| 208 | struct procstat *ps; |
| 209 | int i; |
| 210 | |
| 211 | if (jp->state == JOBDONE) |
| 212 | return; |
| 213 | INTOFF; |
| 214 | killpg(jp->ps[0].pid, SIGCONT); |
| 215 | for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) { |
| 216 | if ((ps->status & 0377) == 0177) { |
| 217 | ps->status = -1; |
| 218 | jp->state = 0; |
| 219 | } |
| 220 | } |
| 221 | INTON; |
| 222 | } |
| 223 | #endif |
| 224 | |
| 225 | |
| 226 | int |
| 227 | jobscmd(argc, argv) char **argv; { |
| 228 | showjobs(0); |
| 229 | return 0; |
| 230 | } |
| 231 | |
| 232 | |
| 233 | /* |
| 234 | * Print a list of jobs. If "change" is nonzero, only print jobs whose |
| 235 | * statuses have changed since the last call to showjobs. |
| 236 | * |
| 237 | * If the shell is interrupted in the process of creating a job, the |
| 238 | * result may be a job structure containing zero processes. Such structures |
| 239 | * will be freed here. |
| 240 | */ |
| 241 | |
| 242 | void |
| 243 | showjobs(change) { |
| 244 | int jobno; |
| 245 | int procno; |
| 246 | int i; |
| 247 | struct job *jp; |
| 248 | struct procstat *ps; |
| 249 | int col; |
| 250 | char s[64]; |
| 251 | |
| 252 | TRACE(("showjobs(%d) called\n", change)); |
| 253 | while (dowait(0, (struct job *)NULL) > 0); |
| 254 | for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) { |
| 255 | if (! jp->used) |
| 256 | continue; |
| 257 | if (jp->nprocs == 0) { |
| 258 | freejob(jp); |
| 259 | continue; |
| 260 | } |
| 261 | if (change && ! jp->changed) |
| 262 | continue; |
| 263 | procno = jp->nprocs; |
| 264 | for (ps = jp->ps ; ; ps++) { /* for each process */ |
| 265 | if (ps == jp->ps) |
| 266 | fmtstr(s, 64, "[%d] %d ", jobno, ps->pid); |
| 267 | else |
| 268 | fmtstr(s, 64, " %d ", ps->pid); |
| 269 | out1str(s); |
| 270 | col = strlen(s); |
| 271 | s[0] = '\0'; |
| 272 | if (ps->status == -1) { |
| 273 | /* don't print anything */ |
| 274 | } else if ((ps->status & 0xFF) == 0) { |
| 275 | fmtstr(s, 64, "Exit %d", ps->status >> 8); |
| 276 | } else { |
| 277 | i = ps->status; |
| 278 | #if JOBS |
| 279 | if ((i & 0xFF) == 0177) |
| 280 | i >>= 8; |
| 281 | #endif |
| 282 | if ((i & 0x7F) <= MAXSIG && sigmesg[i & 0x7F]) |
| 283 | scopy(sigmesg[i & 0x7F], s); |
| 284 | else |
| 285 | fmtstr(s, 64, "Signal %d", i & 0x7F); |
| 286 | if (i & 0x80) |
| 287 | strcat(s, " (core dumped)"); |
| 288 | } |
| 289 | out1str(s); |
| 290 | col += strlen(s); |
| 291 | do { |
| 292 | out1c(' '); |
| 293 | col++; |
| 294 | } while (col < 30); |
| 295 | out1str(ps->cmd); |
| 296 | out1c('\n'); |
| 297 | if (--procno <= 0) |
| 298 | break; |
| 299 | } |
| 300 | jp->changed = 0; |
| 301 | if (jp->state == JOBDONE) { |
| 302 | freejob(jp); |
| 303 | } |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | |
| 308 | /* |
| 309 | * Mark a job structure as unused. |
| 310 | */ |
| 311 | |
| 312 | STATIC void |
| 313 | freejob(jp) |
| 314 | struct job *jp; |
| 315 | { |
| 316 | struct procstat *ps; |
| 317 | int i; |
| 318 | |
| 319 | INTOFF; |
| 320 | for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) { |
| 321 | if (ps->cmd != nullstr) |
| 322 | ckfree(ps->cmd); |
| 323 | } |
| 324 | if (jp->ps != &jp->ps0) |
| 325 | ckfree(jp->ps); |
| 326 | jp->used = 0; |
| 327 | #if JOBS |
| 328 | if (curjob == jp - jobtab + 1) |
| 329 | curjob = 0; |
| 330 | #endif |
| 331 | INTON; |
| 332 | } |
| 333 | |
| 334 | |
| 335 | |
| 336 | int |
| 337 | waitcmd(argc, argv) char **argv; { |
| 338 | struct job *job; |
| 339 | int status; |
| 340 | struct job *jp; |
| 341 | |
| 342 | if (argc > 1) { |
| 343 | job = getjob(argv[1]); |
| 344 | } else { |
| 345 | job = NULL; |
| 346 | } |
| 347 | for (;;) { /* loop until process terminated or stopped */ |
| 348 | if (job != NULL) { |
| 349 | if (job->state) { |
| 350 | status = job->ps[job->nprocs - 1].status; |
| 351 | if ((status & 0xFF) == 0) |
| 352 | status = status >> 8 & 0xFF; |
| 353 | #if JOBS |
| 354 | else if ((status & 0xFF) == 0177) |
| 355 | status = (status >> 8 & 0x7F) + 128; |
| 356 | #endif |
| 357 | else |
| 358 | status = (status & 0x7F) + 128; |
| 359 | if (! iflag) |
| 360 | freejob(job); |
| 361 | return status; |
| 362 | } |
| 363 | } else { |
| 364 | for (jp = jobtab ; ; jp++) { |
| 365 | if (jp >= jobtab + njobs) { /* no running procs */ |
| 366 | return 0; |
| 367 | } |
| 368 | if (jp->used && jp->state == 0) |
| 369 | break; |
| 370 | } |
| 371 | } |
| 372 | dowait(1, (struct job *)NULL); |
| 373 | } |
| 374 | } |
| 375 | |
| 376 | |
| 377 | |
| 378 | jobidcmd(argc, argv) char **argv; { |
| 379 | struct job *jp; |
| 380 | int i; |
| 381 | |
| 382 | jp = getjob(argv[1]); |
| 383 | for (i = 0 ; i < jp->nprocs ; ) { |
| 384 | out1fmt("%d", jp->ps[i].pid); |
| 385 | out1c(++i < jp->nprocs? ' ' : '\n'); |
| 386 | } |
| 387 | return 0; |
| 388 | } |
| 389 | |
| 390 | |
| 391 | |
| 392 | /* |
| 393 | * Convert a job name to a job structure. |
| 394 | */ |
| 395 | |
| 396 | STATIC struct job * |
| 397 | getjob(name) |
| 398 | char *name; |
| 399 | { |
| 400 | int jobno; |
| 401 | register struct job *jp; |
| 402 | int pid; |
| 403 | int i; |
| 404 | |
| 405 | if (name == NULL) { |
| 406 | #if JOBS |
| 407 | currentjob: |
| 408 | if ((jobno = curjob) == 0 || jobtab[jobno - 1].used == 0) |
| 409 | error("No current job"); |
| 410 | return &jobtab[jobno - 1]; |
| 411 | #else |
| 412 | error("No current job"); |
| 413 | #endif |
| 414 | } else if (name[0] == '%') { |
| 415 | if (is_digit(name[1])) { |
| 416 | jobno = number(name + 1); |
| 417 | if (jobno > 0 && jobno <= njobs |
| 418 | && jobtab[jobno - 1].used != 0) |
| 419 | return &jobtab[jobno - 1]; |
| 420 | #if JOBS |
| 421 | } else if (name[1] == '%' && name[2] == '\0') { |
| 422 | goto currentjob; |
| 423 | #endif |
| 424 | } else { |
| 425 | register struct job *found = NULL; |
| 426 | for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { |
| 427 | if (jp->used && jp->nprocs > 0 |
| 428 | && prefix(name + 1, jp->ps[0].cmd)) { |
| 429 | if (found) |
| 430 | error("%s: ambiguous", name); |
| 431 | found = jp; |
| 432 | } |
| 433 | } |
| 434 | if (found) |
| 435 | return found; |
| 436 | } |
| 437 | } else if (is_number(name)) { |
| 438 | pid = number(name); |
| 439 | for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) { |
| 440 | if (jp->used && jp->nprocs > 0 |
| 441 | && jp->ps[jp->nprocs - 1].pid == pid) |
| 442 | return jp; |
| 443 | } |
| 444 | } |
| 445 | error("No such job: %s", name); |
| 446 | } |
| 447 | |
| 448 | |
| 449 | |
| 450 | /* |
| 451 | * Return a new job structure, |
| 452 | */ |
| 453 | |
| 454 | struct job * |
| 455 | makejob(node, nprocs) |
| 456 | union node *node; |
| 457 | { |
| 458 | int i; |
| 459 | struct job *jp; |
| 460 | |
| 461 | for (i = njobs, jp = jobtab ; ; jp++) { |
| 462 | if (--i < 0) { |
| 463 | INTOFF; |
| 464 | if (njobs == 0) { |
| 465 | jobtab = ckmalloc(4 * sizeof jobtab[0]); |
| 466 | } else { |
| 467 | jp = ckmalloc((njobs + 4) * sizeof jobtab[0]); |
| 468 | bcopy(jobtab, jp, njobs * sizeof jp[0]); |
| 469 | ckfree(jobtab); |
| 470 | jobtab = jp; |
| 471 | } |
| 472 | jp = jobtab + njobs; |
| 473 | for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0); |
| 474 | INTON; |
| 475 | break; |
| 476 | } |
| 477 | if (jp->used == 0) |
| 478 | break; |
| 479 | } |
| 480 | INTOFF; |
| 481 | jp->state = 0; |
| 482 | jp->used = 1; |
| 483 | jp->changed = 0; |
| 484 | jp->nprocs = 0; |
| 485 | #if JOBS |
| 486 | jp->jobctl = jobctl; |
| 487 | #endif |
| 488 | if (nprocs > 1) { |
| 489 | jp->ps = ckmalloc(nprocs * sizeof (struct procstat)); |
| 490 | } else { |
| 491 | jp->ps = &jp->ps0; |
| 492 | } |
| 493 | INTON; |
| 494 | TRACE(("makejob(0x%x, %d) returns %%%d\n", (int)node, nprocs, jp - jobtab + 1)); |
| 495 | return jp; |
| 496 | } |
| 497 | |
| 498 | |
| 499 | /* |
| 500 | * Fork of a subshell. If we are doing job control, give the subshell its |
| 501 | * own process group. Jp is a job structure that the job is to be added to. |
| 502 | * N is the command that will be evaluated by the child. Both jp and n may |
| 503 | * be NULL. The mode parameter can be one of the following: |
| 504 | * FORK_FG - Fork off a foreground process. |
| 505 | * FORK_BG - Fork off a background process. |
| 506 | * FORK_NOJOB - Like FORK_FG, but don't give the process its own |
| 507 | * process group even if job control is on. |
| 508 | * |
| 509 | * When job control is turned off, background processes have their standard |
| 510 | * input redirected to /dev/null (except for the second and later processes |
| 511 | * in a pipeline). |
| 512 | */ |
| 513 | |
| 514 | int |
| 515 | forkshell(jp, n, mode) |
| 516 | union node *n; |
| 517 | struct job *jp; |
| 518 | { |
| 519 | int pid; |
| 520 | int pgrp; |
| 521 | |
| 522 | TRACE(("forkshell(%%%d, 0x%x, %d) called\n", jp - jobtab, (int)n, mode)); |
| 523 | INTOFF; |
| 524 | pid = fork(); |
| 525 | if (pid == -1) { |
| 526 | TRACE(("Fork failed, errno=%d\n", errno)); |
| 527 | INTON; |
| 528 | error("Cannot fork"); |
| 529 | } |
| 530 | if (pid == 0) { |
| 531 | struct job *p; |
| 532 | int wasroot; |
| 533 | int i; |
| 534 | |
| 535 | TRACE(("Child shell %d\n", getpid())); |
| 536 | wasroot = rootshell; |
| 537 | rootshell = 0; |
| 538 | for (i = njobs, p = jobtab ; --i >= 0 ; p++) |
| 539 | if (p->used) |
| 540 | freejob(p); |
| 541 | closescript(); |
| 542 | INTON; |
| 543 | clear_traps(); |
| 544 | #if JOBS |
| 545 | jobctl = 0; /* do job control only in root shell */ |
| 546 | if (wasroot && mode != FORK_NOJOB && jflag) { |
| 547 | if (jp == NULL || jp->nprocs == 0) |
| 548 | pgrp = getpid(); |
| 549 | else |
| 550 | pgrp = jp->ps[0].pid; |
| 551 | setpgrp(0, pgrp); |
| 552 | if (mode == FORK_FG) { |
| 553 | /*** this causes superfluous TIOCSPGRPS ***/ |
| 554 | if (ioctl(2, TIOCSPGRP, (char *)&pgrp) < 0) |
| 555 | error("TIOCSPGRP failed, errno=%d\n", errno); |
| 556 | } |
| 557 | setsignal(SIGTSTP); |
| 558 | setsignal(SIGTTOU); |
| 559 | } else if (mode == FORK_BG) { |
| 560 | ignoresig(SIGINT); |
| 561 | ignoresig(SIGQUIT); |
| 562 | if ((jp == NULL || jp->nprocs == 0) |
| 563 | && ! fd0_redirected_p ()) { |
| 564 | close(0); |
| 565 | if (open("/dev/null", O_RDONLY) != 0) |
| 566 | error("Can't open /dev/null"); |
| 567 | } |
| 568 | } |
| 569 | #else |
| 570 | if (mode == FORK_BG) { |
| 571 | ignoresig(SIGINT); |
| 572 | ignoresig(SIGQUIT); |
| 573 | if ((jp == NULL || jp->nprocs == 0) |
| 574 | && ! fd0_redirected_p ()) { |
| 575 | close(0); |
| 576 | if (open("/dev/null", O_RDONLY) != 0) |
| 577 | error("Can't open /dev/null"); |
| 578 | } |
| 579 | } |
| 580 | #endif |
| 581 | if (wasroot && iflag) { |
| 582 | setsignal(SIGINT); |
| 583 | setsignal(SIGQUIT); |
| 584 | setsignal(SIGTERM); |
| 585 | } |
| 586 | return pid; |
| 587 | } |
| 588 | if (rootshell && mode != FORK_NOJOB && jflag) { |
| 589 | if (jp == NULL || jp->nprocs == 0) |
| 590 | pgrp = pid; |
| 591 | else |
| 592 | pgrp = jp->ps[0].pid; |
| 593 | setpgrp(pid, pgrp); |
| 594 | } |
| 595 | if (mode == FORK_BG) |
| 596 | backgndpid = pid; /* set $! */ |
| 597 | if (jp) { |
| 598 | struct procstat *ps = &jp->ps[jp->nprocs++]; |
| 599 | ps->pid = pid; |
| 600 | ps->status = -1; |
| 601 | ps->cmd = nullstr; |
| 602 | if (iflag && rootshell && n) |
| 603 | ps->cmd = commandtext(n); |
| 604 | } |
| 605 | INTON; |
| 606 | TRACE(("In parent shell: child = %d\n", pid)); |
| 607 | return pid; |
| 608 | } |
| 609 | |
| 610 | |
| 611 | |
| 612 | /* |
| 613 | * Wait for job to finish. |
| 614 | * |
| 615 | * Under job control we have the problem that while a child process is |
| 616 | * running interrupts generated by the user are sent to the child but not |
| 617 | * to the shell. This means that an infinite loop started by an inter- |
| 618 | * active user may be hard to kill. With job control turned off, an |
| 619 | * interactive user may place an interactive program inside a loop. If |
| 620 | * the interactive program catches interrupts, the user doesn't want |
| 621 | * these interrupts to also abort the loop. The approach we take here |
| 622 | * is to have the shell ignore interrupt signals while waiting for a |
| 623 | * forground process to terminate, and then send itself an interrupt |
| 624 | * signal if the child process was terminated by an interrupt signal. |
| 625 | * Unfortunately, some programs want to do a bit of cleanup and then |
| 626 | * exit on interrupt; unless these processes terminate themselves by |
| 627 | * sending a signal to themselves (instead of calling exit) they will |
| 628 | * confuse this approach. |
| 629 | */ |
| 630 | |
| 631 | int |
| 632 | waitforjob(jp) |
| 633 | register struct job *jp; |
| 634 | { |
| 635 | #if JOBS |
| 636 | int mypgrp = getpgrp(0); |
| 637 | #endif |
| 638 | int status; |
| 639 | int st; |
| 640 | |
| 641 | INTOFF; |
| 642 | TRACE(("waitforjob(%%%d) called\n", jp - jobtab + 1)); |
| 643 | while (jp->state == 0) { |
| 644 | dowait(1, jp); |
| 645 | } |
| 646 | #if JOBS |
| 647 | if (jp->jobctl) { |
| 648 | if (ioctl(2, TIOCSPGRP, (char *)&mypgrp) < 0) |
| 649 | error("TIOCSPGRP failed, errno=%d\n", errno); |
| 650 | } |
| 651 | if (jp->state == JOBSTOPPED) |
| 652 | curjob = jp - jobtab + 1; |
| 653 | #endif |
| 654 | status = jp->ps[jp->nprocs - 1].status; |
| 655 | /* convert to 8 bits */ |
| 656 | if ((status & 0xFF) == 0) |
| 657 | st = status >> 8 & 0xFF; |
| 658 | #if JOBS |
| 659 | else if ((status & 0xFF) == 0177) |
| 660 | st = (status >> 8 & 0x7F) + 128; |
| 661 | #endif |
| 662 | else |
| 663 | st = (status & 0x7F) + 128; |
| 664 | if (! JOBS || jp->state == JOBDONE) |
| 665 | freejob(jp); |
| 666 | CLEAR_PENDING_INT; |
| 667 | if ((status & 0x7F) == SIGINT) |
| 668 | kill(getpid(), SIGINT); |
| 669 | INTON; |
| 670 | return st; |
| 671 | } |
| 672 | |
| 673 | |
| 674 | |
| 675 | /* |
| 676 | * Wait for a process to terminate. |
| 677 | */ |
| 678 | |
| 679 | STATIC int |
| 680 | dowait(block, job) |
| 681 | struct job *job; |
| 682 | { |
| 683 | int pid; |
| 684 | int status; |
| 685 | struct procstat *sp; |
| 686 | struct job *jp; |
| 687 | struct job *thisjob; |
| 688 | int done; |
| 689 | int stopped; |
| 690 | int core; |
| 691 | |
| 692 | TRACE(("dowait(%d) called\n", block)); |
| 693 | do { |
| 694 | pid = waitproc(block, &status); |
| 695 | TRACE(("wait returns %d, status=%d\n", pid, status)); |
| 696 | } while (pid == -1 && errno == EINTR); |
| 697 | if (pid <= 0) |
| 698 | return pid; |
| 699 | INTOFF; |
| 700 | thisjob = NULL; |
| 701 | for (jp = jobtab ; jp < jobtab + njobs ; jp++) { |
| 702 | if (jp->used) { |
| 703 | done = 1; |
| 704 | stopped = 1; |
| 705 | for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) { |
| 706 | if (sp->pid == -1) |
| 707 | continue; |
| 708 | if (sp->pid == pid) { |
| 709 | TRACE(("Changin status of proc %d from 0x%x to 0x%x\n", pid, sp->status, status)); |
| 710 | sp->status = status; |
| 711 | thisjob = jp; |
| 712 | } |
| 713 | if (sp->status == -1) |
| 714 | stopped = 0; |
| 715 | else if ((sp->status & 0377) == 0177) |
| 716 | done = 0; |
| 717 | } |
| 718 | if (stopped) { /* stopped or done */ |
| 719 | int state = done? JOBDONE : JOBSTOPPED; |
| 720 | if (jp->state != state) { |
| 721 | TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state)); |
| 722 | jp->state = state; |
| 723 | #if JOBS |
| 724 | if (done && curjob == jp - jobtab + 1) |
| 725 | curjob = 0; /* no current job */ |
| 726 | #endif |
| 727 | } |
| 728 | } |
| 729 | } |
| 730 | } |
| 731 | INTON; |
| 732 | if (! rootshell || ! iflag || (job && thisjob == job)) { |
| 733 | #if JOBS |
| 734 | if ((status & 0xFF) == 0177) |
| 735 | status >>= 8; |
| 736 | #endif |
| 737 | core = status & 0x80; |
| 738 | status &= 0x7F; |
| 739 | if (status != 0 && status != SIGINT && status != SIGPIPE) { |
| 740 | if (thisjob != job) |
| 741 | outfmt(out2, "%d: ", pid); |
| 742 | #if JOBS |
| 743 | if (status == SIGTSTP && rootshell && iflag) |
| 744 | outfmt(out2, "%%%d ", job - jobtab + 1); |
| 745 | #endif |
| 746 | if (status <= MAXSIG && sigmesg[status]) |
| 747 | out2str(sigmesg[status]); |
| 748 | else |
| 749 | outfmt(out2, "Signal %d", status); |
| 750 | if (core) |
| 751 | out2str(" - core dumped"); |
| 752 | out2c('\n'); |
| 753 | flushout(&errout); |
| 754 | } else { |
| 755 | TRACE(("Not printing status: status=%d\n", status)); |
| 756 | } |
| 757 | } else { |
| 758 | TRACE(("Not printing status, rootshell=%d, job=0x%x\n", rootshell, job)); |
| 759 | if (thisjob) |
| 760 | thisjob->changed = 1; |
| 761 | } |
| 762 | return pid; |
| 763 | } |
| 764 | |
| 765 | |
| 766 | |
| 767 | /* |
| 768 | * Do a wait system call. If job control is compiled in, we accept |
| 769 | * stopped processes. If block is zero, we return a value of zero |
| 770 | * rather than blocking. |
| 771 | * |
| 772 | * System V doesn't have a non-blocking wait system call. It does |
| 773 | * have a SIGCLD signal that is sent to a process when one of it's |
| 774 | * children dies. The obvious way to use SIGCLD would be to install |
| 775 | * a handler for SIGCLD which simply bumped a counter when a SIGCLD |
| 776 | * was received, and have waitproc bump another counter when it got |
| 777 | * the status of a process. Waitproc would then know that a wait |
| 778 | * system call would not block if the two counters were different. |
| 779 | * This approach doesn't work because if a process has children that |
| 780 | * have not been waited for, System V will send it a SIGCLD when it |
| 781 | * installs a signal handler for SIGCLD. What this means is that when |
| 782 | * a child exits, the shell will be sent SIGCLD signals continuously |
| 783 | * until is runs out of stack space, unless it does a wait call before |
| 784 | * restoring the signal handler. The code below takes advantage of |
| 785 | * this (mis)feature by installing a signal handler for SIGCLD and |
| 786 | * then checking to see whether it was called. If there are any |
| 787 | * children to be waited for, it will be. |
| 788 | * |
| 789 | * If neither SYSV nor BSD is defined, we don't implement nonblocking |
| 790 | * waits at all. In this case, the user will not be informed when |
| 791 | * a background process until the next time she runs a real program |
| 792 | * (as opposed to running a builtin command or just typing return), |
| 793 | * and the jobs command may give out of date information. |
| 794 | */ |
| 795 | |
| 796 | #ifdef SYSV |
| 797 | STATIC int gotsigchild; |
| 798 | |
| 799 | STATIC int onsigchild() { |
| 800 | gotsigchild = 1; |
| 801 | } |
| 802 | #endif |
| 803 | |
| 804 | |
| 805 | STATIC int |
| 806 | waitproc(block, status) |
| 807 | int *status; |
| 808 | { |
| 809 | #ifdef BSD |
| 810 | int flags; |
| 811 | |
| 812 | #if JOBS |
| 813 | flags = WUNTRACED; |
| 814 | #else |
| 815 | flags = 0; |
| 816 | #endif |
| 817 | if (block == 0) |
| 818 | flags |= WNOHANG; |
| 819 | return wait3((union wait *)status, flags, (struct rusage *)NULL); |
| 820 | #else |
| 821 | #ifdef SYSV |
| 822 | int (*save)(); |
| 823 | |
| 824 | if (block == 0) { |
| 825 | gotsigchild = 0; |
| 826 | save = signal(SIGCLD, onsigchild); |
| 827 | signal(SIGCLD, save); |
| 828 | if (gotsigchild == 0) |
| 829 | return 0; |
| 830 | } |
| 831 | return wait(status); |
| 832 | #else |
| 833 | if (block == 0) |
| 834 | return 0; |
| 835 | return wait(status); |
| 836 | #endif |
| 837 | #endif |
| 838 | } |
| 839 | |
| 840 | |
| 841 | |
| 842 | /* |
| 843 | * Return a string identifying a command (to be printed by the |
| 844 | * jobs command. |
| 845 | */ |
| 846 | |
| 847 | STATIC char *cmdnextc; |
| 848 | STATIC int cmdnleft; |
| 849 | STATIC void cmdtxt(), cmdputs(); |
| 850 | |
| 851 | STATIC char * |
| 852 | commandtext(n) |
| 853 | union node *n; |
| 854 | { |
| 855 | char *name; |
| 856 | |
| 857 | cmdnextc = name = ckmalloc(50); |
| 858 | cmdnleft = 50 - 4; |
| 859 | cmdtxt(n); |
| 860 | *cmdnextc = '\0'; |
| 861 | return name; |
| 862 | } |
| 863 | |
| 864 | |
| 865 | STATIC void |
| 866 | cmdtxt(n) |
| 867 | union node *n; |
| 868 | { |
| 869 | union node *np; |
| 870 | struct nodelist *lp; |
| 871 | char *p; |
| 872 | int i; |
| 873 | char s[2]; |
| 874 | |
| 875 | switch (n->type) { |
| 876 | case NSEMI: |
| 877 | cmdtxt(n->nbinary.ch1); |
| 878 | cmdputs("; "); |
| 879 | cmdtxt(n->nbinary.ch2); |
| 880 | break; |
| 881 | case NAND: |
| 882 | cmdtxt(n->nbinary.ch1); |
| 883 | cmdputs(" && "); |
| 884 | cmdtxt(n->nbinary.ch2); |
| 885 | break; |
| 886 | case NOR: |
| 887 | cmdtxt(n->nbinary.ch1); |
| 888 | cmdputs(" || "); |
| 889 | cmdtxt(n->nbinary.ch2); |
| 890 | break; |
| 891 | case NPIPE: |
| 892 | for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) { |
| 893 | cmdtxt(lp->n); |
| 894 | if (lp->next) |
| 895 | cmdputs(" | "); |
| 896 | } |
| 897 | break; |
| 898 | case NSUBSHELL: |
| 899 | cmdputs("("); |
| 900 | cmdtxt(n->nredir.n); |
| 901 | cmdputs(")"); |
| 902 | break; |
| 903 | case NREDIR: |
| 904 | case NBACKGND: |
| 905 | cmdtxt(n->nredir.n); |
| 906 | break; |
| 907 | case NIF: |
| 908 | cmdputs("if "); |
| 909 | cmdtxt(n->nif.test); |
| 910 | cmdputs("; then "); |
| 911 | cmdtxt(n->nif.ifpart); |
| 912 | cmdputs("..."); |
| 913 | break; |
| 914 | case NWHILE: |
| 915 | cmdputs("while "); |
| 916 | goto until; |
| 917 | case NUNTIL: |
| 918 | cmdputs("until "); |
| 919 | until: |
| 920 | cmdtxt(n->nbinary.ch1); |
| 921 | cmdputs("; do "); |
| 922 | cmdtxt(n->nbinary.ch2); |
| 923 | cmdputs("; done"); |
| 924 | break; |
| 925 | case NFOR: |
| 926 | cmdputs("for "); |
| 927 | cmdputs(n->nfor.var); |
| 928 | cmdputs(" in ..."); |
| 929 | break; |
| 930 | case NCASE: |
| 931 | cmdputs("case "); |
| 932 | cmdputs(n->ncase.expr->narg.text); |
| 933 | cmdputs(" in ..."); |
| 934 | break; |
| 935 | case NDEFUN: |
| 936 | cmdputs(n->narg.text); |
| 937 | cmdputs("() ..."); |
| 938 | break; |
| 939 | case NCMD: |
| 940 | for (np = n->ncmd.args ; np ; np = np->narg.next) { |
| 941 | cmdtxt(np); |
| 942 | if (np->narg.next) |
| 943 | cmdputs(" "); |
| 944 | } |
| 945 | for (np = n->ncmd.redirect ; np ; np = np->nfile.next) { |
| 946 | cmdputs(" "); |
| 947 | cmdtxt(np); |
| 948 | } |
| 949 | break; |
| 950 | case NARG: |
| 951 | cmdputs(n->narg.text); |
| 952 | break; |
| 953 | case NTO: |
| 954 | p = ">"; i = 1; goto redir; |
| 955 | case NAPPEND: |
| 956 | p = ">>"; i = 1; goto redir; |
| 957 | case NTOFD: |
| 958 | p = ">&"; i = 1; goto redir; |
| 959 | case NFROM: |
| 960 | p = "<"; i = 0; goto redir; |
| 961 | case NFROMFD: |
| 962 | p = "<&"; i = 0; goto redir; |
| 963 | redir: |
| 964 | if (n->nfile.fd != i) { |
| 965 | s[0] = n->nfile.fd + '0'; |
| 966 | s[1] = '\0'; |
| 967 | cmdputs(s); |
| 968 | } |
| 969 | cmdputs(p); |
| 970 | if (n->type == NTOFD || n->type == NFROMFD) { |
| 971 | s[0] = n->ndup.dupfd + '0'; |
| 972 | s[1] = '\0'; |
| 973 | cmdputs(s); |
| 974 | } else { |
| 975 | cmdtxt(n->nfile.fname); |
| 976 | } |
| 977 | break; |
| 978 | case NHERE: |
| 979 | case NXHERE: |
| 980 | cmdputs("<<..."); |
| 981 | break; |
| 982 | default: |
| 983 | cmdputs("???"); |
| 984 | break; |
| 985 | } |
| 986 | } |
| 987 | |
| 988 | |
| 989 | |
| 990 | STATIC void |
| 991 | cmdputs(s) |
| 992 | char *s; |
| 993 | { |
| 994 | register char *p, *q; |
| 995 | register char c; |
| 996 | int subtype = 0; |
| 997 | |
| 998 | if (cmdnleft <= 0) |
| 999 | return; |
| 1000 | p = s; |
| 1001 | q = cmdnextc; |
| 1002 | while ((c = *p++) != '\0') { |
| 1003 | if (c == CTLESC) |
| 1004 | *q++ = *p++; |
| 1005 | else if (c == CTLVAR) { |
| 1006 | *q++ = '$'; |
| 1007 | if (--cmdnleft > 0) |
| 1008 | *q++ = '{'; |
| 1009 | subtype = *p++; |
| 1010 | } else if (c == '=' && subtype != 0) { |
| 1011 | *q++ = "}-+?="[(subtype & VSTYPE) - VSNORMAL]; |
| 1012 | subtype = 0; |
| 1013 | } else if (c == CTLENDVAR) { |
| 1014 | *q++ = '}'; |
| 1015 | } else if (c == CTLBACKQ | c == CTLBACKQ+CTLQUOTE) |
| 1016 | cmdnleft++; /* ignore it */ |
| 1017 | else |
| 1018 | *q++ = c; |
| 1019 | if (--cmdnleft <= 0) { |
| 1020 | *q++ = '.'; |
| 1021 | *q++ = '.'; |
| 1022 | *q++ = '.'; |
| 1023 | break; |
| 1024 | } |
| 1025 | } |
| 1026 | cmdnextc = q; |
| 1027 | } |