bin/sh/jobs.c

   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
  35 static char sccsid[] = "@(#)jobs.c      8.5 (Berkeley) 5/4/95";
  36 #endif
  37 #endif /* not lint */
  38 #include <sys/cdefs.h>
  39 __FBSDID("$FreeBSD$");
  40
  41 #include <sys/ioctl.h>
  42 #include <sys/param.h>
  43 #include <sys/resource.h>
  44 #include <sys/time.h>
  45 #include <sys/wait.h>
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #include <paths.h>
  49 #include <signal.h>
  50 #include <stddef.h>
  51 #include <stdlib.h>
  52 #include <unistd.h>
  53
  54 #include "shell.h"
  55 #if JOBS
  56 #include <termios.h>
  57 #undef CEOF                     /* syntax.h redefines this */
  58 #endif
  59 #include "redir.h"
  60 #include "exec.h"
  61 #include "show.h"
  62 #include "main.h"
  63 #include "parser.h"
  64 #include "nodes.h"
  65 #include "jobs.h"
  66 #include "options.h"
  67 #include "trap.h"
  68 #include "syntax.h"
  69 #include "input.h"
  70 #include "output.h"
  71 #include "memalloc.h"
  72 #include "error.h"
  73 #include "mystring.h"
  74 #include "var.h"
  75 #include "builtins.h"
  76
  77
  78 static struct job *jobtab;      /* array of jobs */
  79 static int njobs;               /* size of array */
  80 static pid_t backgndpid = -1;   /* pid of last background process */
  81 static struct job *bgjob = NULL; /* last background process */
  82 #if JOBS
  83 static struct job *jobmru;      /* most recently used job list */
  84 static pid_t initialpgrp;       /* pgrp of shell on invocation */
  85 #endif
  86 static 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
  94 static void restartjob(struct job *);
  95 #endif
  96 static void freejob(struct job *);
  97 static int waitcmdloop(struct job *);
  98 pid_t getjobpgrp(char *);
  99 static struct job *getjob_nonotfound(const char *);
 100 static struct job *getjob(const char *);
 101 static pid_t dowait(int, struct job *);
 102 static void checkzombies(void);
 103 static void cmdtxt(union node *);
 104 static void cmdputs(const char *);
 105 #if JOBS
 106 static void setcurjob(struct job *);
 107 static void deljob(struct job *);
 108 static struct job *getcurjob(struct job *);
 109 #endif
 110 static void printjobcmd(struct job *);
 111 static void showjob(struct job *, int);
 112
 113
 114 /*
 115  * Turn job control on and off.
 116  */
 117
 118 static int jobctl;
 119
 120 #if JOBS
 121 void
 122 setjobctl(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) {
 155 out:                            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
 184 int
 185 fgcmd(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
 208 int
 209 bgcmd(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
 229 static void
 230 restartjob(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
 251 int
 252 jobscmd(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
 281 static void
 282 printjobcmd(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
 295 static void
 296 showjob(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 ; procno > 0 ; ps++, procno--) { /* for each process */
 351                 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) {
 352                         out1fmt("%d\n", (int)ps->pid);
 353                         continue;
 354                 }
 355                 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps)
 356                         continue;
 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);
 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
 399 void
 400 showjobs(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
 435 static void
 436 freejob(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
 459 int
 460 waitcmd(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_nonotfound(*argptr);
 471                 if (job == NULL)
 472                         retval = 127;
 473                 else
 474                         retval = waitcmdloop(job);
 475                 argptr++;
 476         } while (*argptr != NULL);
 477
 478         return (retval);
 479 }
 480
 481 static int
 482 waitcmdloop(struct job *job)
 483 {
 484         int status, retval, sig;
 485         struct job *jp;
 486
 487         /*
 488          * Loop until a process is terminated or stopped, or a SIGINT is
 489          * received.
 490          */
 491
 492         do {
 493                 if (job != NULL) {
 494                         if (job->state == JOBDONE) {
 495                                 status = job->ps[job->nprocs - 1].status;
 496                                 if (WIFEXITED(status))
 497                                         retval = WEXITSTATUS(status);
 498                                 else
 499                                         retval = WTERMSIG(status) + 128;
 500                                 if (! iflag || ! job->changed)
 501                                         freejob(job);
 502                                 else {
 503                                         job->remembered = 0;
 504                                         if (job == bgjob)
 505                                                 bgjob = NULL;
 506                                 }
 507                                 return retval;
 508                         }
 509                 } else {
 510                         for (jp = jobtab ; jp < jobtab + njobs; jp++)
 511                                 if (jp->used && jp->state == JOBDONE) {
 512                                         if (! iflag || ! jp->changed)
 513                                                 freejob(jp);
 514                                         else {
 515                                                 jp->remembered = 0;
 516                                                 if (jp == bgjob)
 517                                                         bgjob = NULL;
 518                                         }
 519                                 }
 520                         for (jp = jobtab ; ; jp++) {
 521                                 if (jp >= jobtab + njobs) {     /* no running procs */
 522                                         return 0;
 523                                 }
 524                                 if (jp->used && jp->state == 0)
 525                                         break;
 526                         }
 527                 }
 528         } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1);
 529
 530         sig = pendingsig_waitcmd;
 531         pendingsig_waitcmd = 0;
 532         return sig + 128;
 533 }
 534
 535
 536
 537 int
 538 jobidcmd(int argc __unused, char **argv __unused)
 539 {
 540         struct job *jp;
 541         int i;
 542
 543         nextopt("");
 544         jp = getjob(*argptr);
 545         for (i = 0 ; i < jp->nprocs ; ) {
 546                 out1fmt("%d", (int)jp->ps[i].pid);
 547                 out1c(++i < jp->nprocs? ' ' : '\n');
 548         }
 549         return 0;
 550 }
 551
 552
 553
 554 /*
 555  * Convert a job name to a job structure.
 556  */
 557
 558 static struct job *
 559 getjob_nonotfound(const char *name)
 560 {
 561         int jobno;
 562         struct job *found, *jp;
 563         pid_t pid;
 564         int i;
 565
 566         if (name == NULL) {
 567 #if JOBS
 568 currentjob:     if ((jp = getcurjob(NULL)) == NULL)
 569                         error("No current job");
 570                 return (jp);
 571 #else
 572                 error("No current job");
 573 #endif
 574         } else if (name[0] == '%') {
 575                 if (is_digit(name[1])) {
 576                         jobno = number(name + 1);
 577                         if (jobno > 0 && jobno <= njobs
 578                          && jobtab[jobno - 1].used != 0)
 579                                 return &jobtab[jobno - 1];
 580 #if JOBS
 581                 } else if (name[1] == '%' && name[2] == '\0') {
 582                         goto currentjob;
 583                 } else if (name[1] == '+' && name[2] == '\0') {
 584                         goto currentjob;
 585                 } else if (name[1] == '-' && name[2] == '\0') {
 586                         if ((jp = getcurjob(NULL)) == NULL ||
 587                             (jp = getcurjob(jp)) == NULL)
 588                                 error("No previous job");
 589                         return (jp);
 590 #endif
 591                 } else if (name[1] == '?') {
 592                         found = NULL;
 593                         for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 594                                 if (jp->used && jp->nprocs > 0
 595                                  && strstr(jp->ps[0].cmd, name + 2) != NULL) {
 596                                         if (found)
 597                                                 error("%s: ambiguous", name);
 598                                         found = jp;
 599                                 }
 600                         }
 601                         if (found != NULL)
 602                                 return (found);
 603                 } else {
 604                         found = NULL;
 605                         for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 606                                 if (jp->used && jp->nprocs > 0
 607                                  && prefix(name + 1, jp->ps[0].cmd)) {
 608                                         if (found)
 609                                                 error("%s: ambiguous", name);
 610                                         found = jp;
 611                                 }
 612                         }
 613                         if (found)
 614                                 return found;
 615                 }
 616         } else if (is_number(name)) {
 617                 pid = (pid_t)number(name);
 618                 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 619                         if (jp->used && jp->nprocs > 0
 620                          && jp->ps[jp->nprocs - 1].pid == pid)
 621                                 return jp;
 622                 }
 623         }
 624         return NULL;
 625 }
 626
 627
 628 static struct job *
 629 getjob(const char *name)
 630 {
 631         struct job *jp;
 632
 633         jp = getjob_nonotfound(name);
 634         if (jp == NULL)
 635                 error("No such job: %s", name);
 636         return (jp);
 637 }
 638
 639
 640 pid_t
 641 getjobpgrp(char *name)
 642 {
 643         struct job *jp;
 644
 645         jp = getjob(name);
 646         return -jp->ps[0].pid;
 647 }
 648
 649 /*
 650  * Return a new job structure,
 651  */
 652
 653 struct job *
 654 makejob(union node *node __unused, int nprocs)
 655 {
 656         int i;
 657         struct job *jp;
 658
 659         for (i = njobs, jp = jobtab ; ; jp++) {
 660                 if (--i < 0) {
 661                         INTOFF;
 662                         if (njobs == 0) {
 663                                 jobtab = ckmalloc(4 * sizeof jobtab[0]);
 664 #if JOBS
 665                                 jobmru = NULL;
 666 #endif
 667                         } else {
 668                                 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
 669                                 memcpy(jp, jobtab, njobs * sizeof jp[0]);
 670 #if JOBS
 671                                 /* Relocate `next' pointers and list head */
 672                                 if (jobmru != NULL)
 673                                         jobmru = &jp[jobmru - jobtab];
 674                                 for (i = 0; i < njobs; i++)
 675                                         if (jp[i].next != NULL)
 676                                                 jp[i].next = &jp[jp[i].next -
 677                                                     jobtab];
 678 #endif
 679                                 if (bgjob != NULL)
 680                                         bgjob = &jp[bgjob - jobtab];
 681                                 /* Relocate `ps' pointers */
 682                                 for (i = 0; i < njobs; i++)
 683                                         if (jp[i].ps == &jobtab[i].ps0)
 684                                                 jp[i].ps = &jp[i].ps0;
 685                                 ckfree(jobtab);
 686                                 jobtab = jp;
 687                         }
 688                         jp = jobtab + njobs;
 689                         for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0)
 690                                 ;
 691                         INTON;
 692                         break;
 693                 }
 694                 if (jp->used == 0)
 695                         break;
 696         }
 697         INTOFF;
 698         jp->state = 0;
 699         jp->used = 1;
 700         jp->changed = 0;
 701         jp->nprocs = 0;
 702         jp->foreground = 0;
 703         jp->remembered = 0;
 704 #if JOBS
 705         jp->jobctl = jobctl;
 706         jp->next = NULL;
 707 #endif
 708         if (nprocs > 1) {
 709                 jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
 710         } else {
 711                 jp->ps = &jp->ps0;
 712         }
 713         INTON;
 714         TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs,
 715             jp - jobtab + 1));
 716         return jp;
 717 }
 718
 719 #if JOBS
 720 static void
 721 setcurjob(struct job *cj)
 722 {
 723         struct job *jp, *prev;
 724
 725         for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
 726                 if (jp == cj) {
 727                         if (prev != NULL)
 728                                 prev->next = jp->next;
 729                         else
 730                                 jobmru = jp->next;
 731                         jp->next = jobmru;
 732                         jobmru = cj;
 733                         return;
 734                 }
 735         }
 736         cj->next = jobmru;
 737         jobmru = cj;
 738 }
 739
 740 static void
 741 deljob(struct job *j)
 742 {
 743         struct job *jp, *prev;
 744
 745         for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
 746                 if (jp == j) {
 747                         if (prev != NULL)
 748                                 prev->next = jp->next;
 749                         else
 750                                 jobmru = jp->next;
 751                         return;
 752                 }
 753         }
 754 }
 755
 756 /*
 757  * Return the most recently used job that isn't `nj', and preferably one
 758  * that is stopped.
 759  */
 760 static struct job *
 761 getcurjob(struct job *nj)
 762 {
 763         struct job *jp;
 764
 765         /* Try to find a stopped one.. */
 766         for (jp = jobmru; jp != NULL; jp = jp->next)
 767                 if (jp->used && jp != nj && jp->state == JOBSTOPPED)
 768                         return (jp);
 769         /* Otherwise the most recently used job that isn't `nj' */
 770         for (jp = jobmru; jp != NULL; jp = jp->next)
 771                 if (jp->used && jp != nj)
 772                         return (jp);
 773
 774         return (NULL);
 775 }
 776
 777 #endif
 778
 779 /*
 780  * Fork of a subshell.  If we are doing job control, give the subshell its
 781  * own process group.  Jp is a job structure that the job is to be added to.
 782  * N is the command that will be evaluated by the child.  Both jp and n may
 783  * be NULL.  The mode parameter can be one of the following:
 784  *      FORK_FG - Fork off a foreground process.
 785  *      FORK_BG - Fork off a background process.
 786  *      FORK_NOJOB - Like FORK_FG, but don't give the process its own
 787  *                   process group even if job control is on.
 788  *
 789  * When job control is turned off, background processes have their standard
 790  * input redirected to /dev/null (except for the second and later processes
 791  * in a pipeline).
 792  */
 793
 794 pid_t
 795 forkshell(struct job *jp, union node *n, int mode)
 796 {
 797         pid_t pid;
 798         pid_t pgrp;
 799
 800         TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n,
 801             mode));
 802         INTOFF;
 803         if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0))
 804                 checkzombies();
 805         flushall();
 806         pid = fork();
 807         if (pid == -1) {
 808                 TRACE(("Fork failed, errno=%d\n", errno));
 809                 INTON;
 810                 error("Cannot fork: %s", strerror(errno));
 811         }
 812         if (pid == 0) {
 813                 struct job *p;
 814                 int wasroot;
 815                 int i;
 816
 817                 TRACE(("Child shell %d\n", (int)getpid()));
 818                 wasroot = rootshell;
 819                 rootshell = 0;
 820                 handler = &main_handler;
 821                 closescript();
 822                 INTON;
 823                 forcelocal = 0;
 824                 clear_traps();
 825 #if JOBS
 826                 jobctl = 0;             /* do job control only in root shell */
 827                 if (wasroot && mode != FORK_NOJOB && mflag) {
 828                         if (jp == NULL || jp->nprocs == 0)
 829                                 pgrp = getpid();
 830                         else
 831                                 pgrp = jp->ps[0].pid;
 832                         if (setpgid(0, pgrp) == 0 && mode == FORK_FG) {
 833                                 /*** this causes superfluous TIOCSPGRPS ***/
 834                                 if (tcsetpgrp(ttyfd, pgrp) < 0)
 835                                         error("tcsetpgrp failed, errno=%d", errno);
 836                         }
 837                         setsignal(SIGTSTP);
 838                         setsignal(SIGTTOU);
 839                 } else if (mode == FORK_BG) {
 840                         ignoresig(SIGINT);
 841                         ignoresig(SIGQUIT);
 842                         if ((jp == NULL || jp->nprocs == 0) &&
 843                             ! fd0_redirected_p ()) {
 844                                 close(0);
 845                                 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
 846                                         error("cannot open %s: %s",
 847                                             _PATH_DEVNULL, strerror(errno));
 848                         }
 849                 }
 850 #else
 851                 if (mode == FORK_BG) {
 852                         ignoresig(SIGINT);
 853                         ignoresig(SIGQUIT);
 854                         if ((jp == NULL || jp->nprocs == 0) &&
 855                             ! fd0_redirected_p ()) {
 856                                 close(0);
 857                                 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
 858                                         error("cannot open %s: %s",
 859                                             _PATH_DEVNULL, strerror(errno));
 860                         }
 861                 }
 862 #endif
 863                 INTOFF;
 864                 for (i = njobs, p = jobtab ; --i >= 0 ; p++)
 865                         if (p->used)
 866                                 freejob(p);
 867                 INTON;
 868                 if (wasroot && iflag) {
 869                         setsignal(SIGINT);
 870                         setsignal(SIGQUIT);
 871                         setsignal(SIGTERM);
 872                 }
 873                 return pid;
 874         }
 875         if (rootshell && mode != FORK_NOJOB && mflag) {
 876                 if (jp == NULL || jp->nprocs == 0)
 877                         pgrp = pid;
 878                 else
 879                         pgrp = jp->ps[0].pid;
 880                 setpgid(pid, pgrp);
 881         }
 882         if (mode == FORK_BG) {
 883                 if (bgjob != NULL && bgjob->state == JOBDONE &&
 884                     !bgjob->remembered && !iflag)
 885                         freejob(bgjob);
 886                 backgndpid = pid;               /* set $! */
 887                 bgjob = jp;
 888         }
 889         if (jp) {
 890                 struct procstat *ps = &jp->ps[jp->nprocs++];
 891                 ps->pid = pid;
 892                 ps->status = -1;
 893                 ps->cmd = nullstr;
 894                 if (iflag && rootshell && n)
 895                         ps->cmd = commandtext(n);
 896                 jp->foreground = mode == FORK_FG;
 897 #if JOBS
 898                 setcurjob(jp);
 899 #endif
 900         }
 901         INTON;
 902         TRACE(("In parent shell:  child = %d\n", (int)pid));
 903         return pid;
 904 }
 905
 906
 907 pid_t
 908 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2])
 909 {
 910         pid_t pid;
 911         struct jmploc jmploc;
 912         struct jmploc *savehandler;
 913
 914         TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0],
 915             (void *)pip));
 916         INTOFF;
 917         flushall();
 918         savehandler = handler;
 919         pid = vfork();
 920         if (pid == -1) {
 921                 TRACE(("Vfork failed, errno=%d\n", errno));
 922                 INTON;
 923                 error("Cannot fork: %s", strerror(errno));
 924         }
 925         if (pid == 0) {
 926                 TRACE(("Child shell %d\n", (int)getpid()));
 927                 if (setjmp(jmploc.loc))
 928                         _exit(exception == EXEXEC ? exerrno : 2);
 929                 if (pip != NULL) {
 930                         close(pip[0]);
 931                         if (pip[1] != 1) {
 932                                 dup2(pip[1], 1);
 933                                 close(pip[1]);
 934                         }
 935                 }
 936                 handler = &jmploc;
 937                 shellexec(argv, envp, path, idx);
 938         }
 939         handler = savehandler;
 940         if (jp) {
 941                 struct procstat *ps = &jp->ps[jp->nprocs++];
 942                 ps->pid = pid;
 943                 ps->status = -1;
 944                 ps->cmd = nullstr;
 945                 jp->foreground = 1;
 946 #if JOBS
 947                 setcurjob(jp);
 948 #endif
 949         }
 950         INTON;
 951         TRACE(("In parent shell:  child = %d\n", (int)pid));
 952         return pid;
 953 }
 954
 955
 956 /*
 957  * Wait for job to finish.
 958  *
 959  * Under job control we have the problem that while a child process is
 960  * running interrupts generated by the user are sent to the child but not
 961  * to the shell.  This means that an infinite loop started by an inter-
 962  * active user may be hard to kill.  With job control turned off, an
 963  * interactive user may place an interactive program inside a loop.  If
 964  * the interactive program catches interrupts, the user doesn't want
 965  * these interrupts to also abort the loop.  The approach we take here
 966  * is to have the shell ignore interrupt signals while waiting for a
 967  * foreground process to terminate, and then send itself an interrupt
 968  * signal if the child process was terminated by an interrupt signal.
 969  * Unfortunately, some programs want to do a bit of cleanup and then
 970  * exit on interrupt; unless these processes terminate themselves by
 971  * sending a signal to themselves (instead of calling exit) they will
 972  * confuse this approach.
 973  */
 974
 975 int
 976 waitforjob(struct job *jp, int *origstatus)
 977 {
 978 #if JOBS
 979         int propagate_int = jp->jobctl && jp->foreground;
 980 #endif
 981         int status;
 982         int st;
 983
 984         INTOFF;
 985         TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1));
 986         while (jp->state == 0)
 987                 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG |
 988                     DOWAIT_SIG_ANY : 0), jp) == -1)
 989                         dotrap();
 990 #if JOBS
 991         if (jp->jobctl) {
 992                 if (tcsetpgrp(ttyfd, rootpid) < 0)
 993                         error("tcsetpgrp failed, errno=%d\n", errno);
 994         }
 995         if (jp->state == JOBSTOPPED)
 996                 setcurjob(jp);
 997 #endif
 998         status = jp->ps[jp->nprocs - 1].status;
 999         if (origstatus != NULL)
1000                 *origstatus = status;
1001         /* convert to 8 bits */
1002         if (WIFEXITED(status))
1003                 st = WEXITSTATUS(status);
1004 #if JOBS
1005         else if (WIFSTOPPED(status))
1006                 st = WSTOPSIG(status) + 128;
1007 #endif
1008         else
1009                 st = WTERMSIG(status) + 128;
1010         if (! JOBS || jp->state == JOBDONE)
1011                 freejob(jp);
1012         if (int_pending()) {
1013                 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT)
1014                         CLEAR_PENDING_INT;
1015         }
1016 #if JOBS
1017         else if (rootshell && iflag && propagate_int &&
1018                         WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
1019                 kill(getpid(), SIGINT);
1020 #endif
1021         INTON;
1022         return st;
1023 }
1024
1025
1026 static void
1027 dummy_handler(int sig __unused)
1028 {
1029 }
1030
1031 /*
1032  * Wait for a process to terminate.
1033  */
1034
1035 static pid_t
1036 dowait(int mode, struct job *job)
1037 {
1038         struct sigaction sa, osa;
1039         sigset_t mask, omask;
1040         pid_t pid;
1041         int status;
1042         struct procstat *sp;
1043         struct job *jp;
1044         struct job *thisjob;
1045         const char *sigstr;
1046         int done;
1047         int stopped;
1048         int sig;
1049         int coredump;
1050         int wflags;
1051         int restore_sigchld;
1052
1053         TRACE(("dowait(%d, %p) called\n", mode, job));
1054         restore_sigchld = 0;
1055         if ((mode & DOWAIT_SIG) != 0) {
1056                 sigfillset(&mask);
1057                 sigprocmask(SIG_BLOCK, &mask, &omask);
1058                 INTOFF;
1059                 if (!issigchldtrapped()) {
1060                         restore_sigchld = 1;
1061                         sa.sa_handler = dummy_handler;
1062                         sa.sa_flags = 0;
1063                         sigemptyset(&sa.sa_mask);
1064                         sigaction(SIGCHLD, &sa, &osa);
1065                 }
1066         }
1067         do {
1068 #if JOBS
1069                 if (iflag)
1070                         wflags = WUNTRACED | WCONTINUED;
1071                 else
1072 #endif
1073                         wflags = 0;
1074                 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK)
1075                         wflags |= WNOHANG;
1076                 pid = wait3(&status, wflags, (struct rusage *)NULL);
1077                 TRACE(("wait returns %d, status=%d\n", (int)pid, status));
1078                 if (pid == 0 && (mode & DOWAIT_SIG) != 0) {
1079                         pid = -1;
1080                         if (((mode & DOWAIT_SIG_ANY) != 0 ?
1081                             pendingsig : pendingsig_waitcmd) != 0) {
1082                                 errno = EINTR;
1083                                 break;
1084                         }
1085                         sigsuspend(&omask);
1086                         if (int_pending())
1087                                 break;
1088                 }
1089         } while (pid == -1 && errno == EINTR);
1090         if (pid == -1 && errno == ECHILD && job != NULL)
1091                 job->state = JOBDONE;
1092         if ((mode & DOWAIT_SIG) != 0) {
1093                 if (restore_sigchld)
1094                         sigaction(SIGCHLD, &osa, NULL);
1095                 sigprocmask(SIG_SETMASK, &omask, NULL);
1096                 INTON;
1097         }
1098         if (pid <= 0)
1099                 return pid;
1100         INTOFF;
1101         thisjob = NULL;
1102         for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
1103                 if (jp->used && jp->nprocs > 0) {
1104                         done = 1;
1105                         stopped = 1;
1106                         for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
1107                                 if (sp->pid == -1)
1108                                         continue;
1109                                 if (sp->pid == pid) {
1110                                         TRACE(("Changing status of proc %d from 0x%x to 0x%x\n",
1111                                                    (int)pid, sp->status,
1112                                                    status));
1113                                         if (WIFCONTINUED(status)) {
1114                                                 sp->status = -1;
1115                                                 jp->state = 0;
1116                                         } else
1117                                                 sp->status = status;
1118                                         thisjob = jp;
1119                                 }
1120                                 if (sp->status == -1)
1121                                         stopped = 0;
1122                                 else if (WIFSTOPPED(sp->status))
1123                                         done = 0;
1124                         }
1125                         if (stopped) {          /* stopped or done */
1126                                 int state = done? JOBDONE : JOBSTOPPED;
1127                                 if (jp->state != state) {
1128                                         TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
1129                                         jp->state = state;
1130                                         if (jp != job) {
1131                                                 if (done && !jp->remembered &&
1132                                                     !iflag && jp != bgjob)
1133                                                         freejob(jp);
1134 #if JOBS
1135                                                 else if (done)
1136                                                         deljob(jp);
1137 #endif
1138                                         }
1139                                 }
1140                         }
1141                 }
1142         }
1143         INTON;
1144         if (!thisjob || thisjob->state == 0)
1145                 ;
1146         else if ((!rootshell || !iflag || thisjob == job) &&
1147             thisjob->foreground && thisjob->state != JOBSTOPPED) {
1148                 sig = 0;
1149                 coredump = 0;
1150                 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++)
1151                         if (WIFSIGNALED(sp->status)) {
1152                                 sig = WTERMSIG(sp->status);
1153                                 coredump = WCOREDUMP(sp->status);
1154                         }
1155                 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) {
1156                         sigstr = strsignal(sig);
1157                         if (sigstr != NULL)
1158                                 out2str(sigstr);
1159                         else
1160                                 out2str("Unknown signal");
1161                         if (coredump)
1162                                 out2str(" (core dumped)");
1163                         out2c('\n');
1164                         flushout(out2);
1165                 }
1166         } else {
1167                 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job));
1168                 thisjob->changed = 1;
1169         }
1170         return pid;
1171 }
1172
1173
1174
1175 /*
1176  * return 1 if there are stopped jobs, otherwise 0
1177  */
1178 int job_warning = 0;
1179 int
1180 stoppedjobs(void)
1181 {
1182         int jobno;
1183         struct job *jp;
1184
1185         if (job_warning)
1186                 return (0);
1187         for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
1188                 if (jp->used == 0)
1189                         continue;
1190                 if (jp->state == JOBSTOPPED) {
1191                         out2fmt_flush("You have stopped jobs.\n");
1192                         job_warning = 2;
1193                         return (1);
1194                 }
1195         }
1196
1197         return (0);
1198 }
1199
1200
1201 static void
1202 checkzombies(void)
1203 {
1204         while (njobs > 0 && dowait(0, NULL) > 0)
1205                 ;
1206 }
1207
1208
1209 int
1210 backgndpidset(void)
1211 {
1212         return backgndpid != -1;
1213 }
1214
1215
1216 pid_t
1217 backgndpidval(void)
1218 {
1219         if (bgjob != NULL && !forcelocal)
1220                 bgjob->remembered = 1;
1221         return backgndpid;
1222 }
1223
1224 /*
1225  * Return a string identifying a command (to be printed by the
1226  * jobs command.
1227  */
1228
1229 static char *cmdnextc;
1230 static int cmdnleft;
1231 #define MAXCMDTEXT      200
1232
1233 char *
1234 commandtext(union node *n)
1235 {
1236         char *name;
1237
1238         cmdnextc = name = ckmalloc(MAXCMDTEXT);
1239         cmdnleft = MAXCMDTEXT - 4;
1240         cmdtxt(n);
1241         *cmdnextc = '\0';
1242         return name;
1243 }
1244
1245
1246 static void
1247 cmdtxt(union node *n)
1248 {
1249         union node *np;
1250         struct nodelist *lp;
1251         const char *p;
1252         int i;
1253         char s[2];
1254
1255         if (n == NULL)
1256                 return;
1257         switch (n->type) {
1258         case NSEMI:
1259                 cmdtxt(n->nbinary.ch1);
1260                 cmdputs("; ");
1261                 cmdtxt(n->nbinary.ch2);
1262                 break;
1263         case NAND:
1264                 cmdtxt(n->nbinary.ch1);
1265                 cmdputs(" && ");
1266                 cmdtxt(n->nbinary.ch2);
1267                 break;
1268         case NOR:
1269                 cmdtxt(n->nbinary.ch1);
1270                 cmdputs(" || ");
1271                 cmdtxt(n->nbinary.ch2);
1272                 break;
1273         case NPIPE:
1274                 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
1275                         cmdtxt(lp->n);
1276                         if (lp->next)
1277                                 cmdputs(" | ");
1278                 }
1279                 break;
1280         case NSUBSHELL:
1281                 cmdputs("(");
1282                 cmdtxt(n->nredir.n);
1283                 cmdputs(")");
1284                 break;
1285         case NREDIR:
1286         case NBACKGND:
1287                 cmdtxt(n->nredir.n);
1288                 break;
1289         case NIF:
1290                 cmdputs("if ");
1291                 cmdtxt(n->nif.test);
1292                 cmdputs("; then ");
1293                 cmdtxt(n->nif.ifpart);
1294                 cmdputs("...");
1295                 break;
1296         case NWHILE:
1297                 cmdputs("while ");
1298                 goto until;
1299         case NUNTIL:
1300                 cmdputs("until ");
1301 until:
1302                 cmdtxt(n->nbinary.ch1);
1303                 cmdputs("; do ");
1304                 cmdtxt(n->nbinary.ch2);
1305                 cmdputs("; done");
1306                 break;
1307         case NFOR:
1308                 cmdputs("for ");
1309                 cmdputs(n->nfor.var);
1310                 cmdputs(" in ...");
1311                 break;
1312         case NCASE:
1313                 cmdputs("case ");
1314                 cmdputs(n->ncase.expr->narg.text);
1315                 cmdputs(" in ...");
1316                 break;
1317         case NDEFUN:
1318                 cmdputs(n->narg.text);
1319                 cmdputs("() ...");
1320                 break;
1321         case NNOT:
1322                 cmdputs("! ");
1323                 cmdtxt(n->nnot.com);
1324                 break;
1325         case NCMD:
1326                 for (np = n->ncmd.args ; np ; np = np->narg.next) {
1327                         cmdtxt(np);
1328                         if (np->narg.next)
1329                                 cmdputs(" ");
1330                 }
1331                 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) {
1332                         cmdputs(" ");
1333                         cmdtxt(np);
1334                 }
1335                 break;
1336         case NARG:
1337                 cmdputs(n->narg.text);
1338                 break;
1339         case NTO:
1340                 p = ">";  i = 1;  goto redir;
1341         case NAPPEND:
1342                 p = ">>";  i = 1;  goto redir;
1343         case NTOFD:
1344                 p = ">&";  i = 1;  goto redir;
1345         case NCLOBBER:
1346                 p = ">|"; i = 1; goto redir;
1347         case NFROM:
1348                 p = "<";  i = 0;  goto redir;
1349         case NFROMTO:
1350                 p = "<>";  i = 0;  goto redir;
1351         case NFROMFD:
1352                 p = "<&";  i = 0;  goto redir;
1353 redir:
1354                 if (n->nfile.fd != i) {
1355                         s[0] = n->nfile.fd + '0';
1356                         s[1] = '\0';
1357                         cmdputs(s);
1358                 }
1359                 cmdputs(p);
1360                 if (n->type == NTOFD || n->type == NFROMFD) {
1361                         if (n->ndup.dupfd >= 0)
1362                                 s[0] = n->ndup.dupfd + '0';
1363                         else
1364                                 s[0] = '-';
1365                         s[1] = '\0';
1366                         cmdputs(s);
1367                 } else {
1368                         cmdtxt(n->nfile.fname);
1369                 }
1370                 break;
1371         case NHERE:
1372         case NXHERE:
1373                 cmdputs("<<...");
1374                 break;
1375         default:
1376                 cmdputs("???");
1377                 break;
1378         }
1379 }
1380
1381
1382
1383 static void
1384 cmdputs(const char *s)
1385 {
1386         const char *p;
1387         char *q;
1388         char c;
1389         int subtype = 0;
1390
1391         if (cmdnleft <= 0)
1392                 return;
1393         p = s;
1394         q = cmdnextc;
1395         while ((c = *p++) != '\0') {
1396                 if (c == CTLESC)
1397                         *q++ = *p++;
1398                 else if (c == CTLVAR) {
1399                         *q++ = '$';
1400                         if (--cmdnleft > 0)
1401                                 *q++ = '{';
1402                         subtype = *p++;
1403                         if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0)
1404                                 *q++ = '#';
1405                 } else if (c == '=' && subtype != 0) {
1406                         *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL];
1407                         if (*q)
1408                                 q++;
1409                         else
1410                                 cmdnleft++;
1411                         if (((subtype & VSTYPE) == VSTRIMLEFTMAX ||
1412                             (subtype & VSTYPE) == VSTRIMRIGHTMAX) &&
1413                             --cmdnleft > 0)
1414                                 *q = q[-1], q++;
1415                         subtype = 0;
1416                 } else if (c == CTLENDVAR) {
1417                         *q++ = '}';
1418                 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) {
1419                         cmdnleft -= 5;
1420                         if (cmdnleft > 0) {
1421                                 *q++ = '$';
1422                                 *q++ = '(';
1423                                 *q++ = '.';
1424                                 *q++ = '.';
1425                                 *q++ = '.';
1426                                 *q++ = ')';
1427                         }
1428                 } else if (c == CTLARI) {
1429                         cmdnleft -= 2;
1430                         if (cmdnleft > 0) {
1431                                 *q++ = '$';
1432                                 *q++ = '(';
1433                                 *q++ = '(';
1434                         }
1435                         p++;
1436                 } else if (c == CTLENDARI) {
1437                         if (--cmdnleft > 0) {
1438                                 *q++ = ')';
1439                                 *q++ = ')';
1440                         }
1441                 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND)
1442                         cmdnleft++; /* ignore */
1443                 else
1444                         *q++ = c;
1445                 if (--cmdnleft <= 0) {
1446                         *q++ = '.';
1447                         *q++ = '.';
1448                         *q++ = '.';
1449                         break;
1450                 }
1451         }
1452         cmdnextc = q;
1453 }