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  * 3. 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 signal */
  91 #define DOWAIT_SIG_TRAP 0x4 /* if DOWAIT_SIG, abort on trapped signal only */
  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 static struct job *getjob_nonotfound(const char *);
  99 static struct job *getjob(const char *);
 100 pid_t killjob(const char *, int);
 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 static void
 122 jobctl_notty(void)
 123 {
 124         if (ttyfd >= 0) {
 125                 close(ttyfd);
 126                 ttyfd = -1;
 127         }
 128         if (!iflag) {
 129                 setsignal(SIGTSTP);
 130                 setsignal(SIGTTOU);
 131                 setsignal(SIGTTIN);
 132                 jobctl = 1;
 133                 return;
 134         }
 135         out2fmt_flush("sh: can't access tty; job control turned off\n");
 136         mflag = 0;
 137 }
 138
 139 void
 140 setjobctl(int on)
 141 {
 142         int i;
 143
 144         if (on == jobctl || rootshell == 0)
 145                 return;
 146         if (on) {
 147                 if (ttyfd != -1)
 148                         close(ttyfd);
 149                 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC_MAYBE)) < 0) {
 150                         i = 0;
 151                         while (i <= 2 && !isatty(i))
 152                                 i++;
 153                         if (i > 2 ||
 154                             (ttyfd = fcntl(i, F_DUPFD_CLOEXEC_MAYBE, 10)) < 0) {
 155                                 jobctl_notty();
 156                                 return;
 157                         }
 158                 }
 159                 if (ttyfd < 10) {
 160                         /*
 161                          * Keep our TTY file descriptor out of the way of
 162                          * the user's redirections.
 163                          */
 164                         if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC_MAYBE, 10)) < 0) {
 165                                 jobctl_notty();
 166                                 return;
 167                         }
 168                         close(ttyfd);
 169                         ttyfd = i;
 170                 }
 171 #if !defined(O_CLOEXEC) || !defined(F_DUPFD_CLOEXEC)
 172                 if (fcntl(ttyfd, F_SETFD, FD_CLOEXEC) < 0) {
 173                         close(ttyfd);
 174                         ttyfd = -1;
 175                         goto out;
 176                 }
 177 #endif
 178                 do { /* while we are in the background */
 179                         initialpgrp = tcgetpgrp(ttyfd);
 180                         if (initialpgrp < 0) {
 181 #if !defined(O_CLOEXEC) || !defined(F_DUPFD_CLOEXEC)
 182 out:
 183 #endif
 184                                 jobctl_notty();
 185                                 return;
 186                         }
 187                         if (initialpgrp != getpgrp()) {
 188                                 if (!iflag) {
 189                                         initialpgrp = -1;
 190                                         jobctl_notty();
 191                                         return;
 192                                 }
 193                                 kill(0, SIGTTIN);
 194                                 continue;
 195                         }
 196                 } while (0);
 197                 setsignal(SIGTSTP);
 198                 setsignal(SIGTTOU);
 199                 setsignal(SIGTTIN);
 200                 setpgid(0, rootpid);
 201                 tcsetpgrp(ttyfd, rootpid);
 202         } else { /* turning job control off */
 203                 setpgid(0, initialpgrp);
 204                 if (ttyfd >= 0) {
 205                 tcsetpgrp(ttyfd, initialpgrp);
 206                 close(ttyfd);
 207                 ttyfd = -1;
 208                 }
 209                 setsignal(SIGTSTP);
 210                 setsignal(SIGTTOU);
 211                 setsignal(SIGTTIN);
 212         }
 213         jobctl = on;
 214 }
 215 #endif
 216
 217
 218 #if JOBS
 219 int
 220 fgcmd(int argc __unused, char **argv __unused)
 221 {
 222         struct job *jp;
 223         pid_t pgrp;
 224         int status;
 225
 226         nextopt("");
 227         jp = getjob(*argptr);
 228         if (jp->jobctl == 0)
 229                 error("job not created under job control");
 230         printjobcmd(jp);
 231         flushout(&output);
 232         pgrp = jp->ps[0].pid;
 233         if (ttyfd >= 0)
 234         tcsetpgrp(ttyfd, pgrp);
 235         restartjob(jp);
 236         jp->foreground = 1;
 237         INTOFF;
 238         status = waitforjob(jp, (int *)NULL);
 239         INTON;
 240         return status;
 241 }
 242
 243
 244 int
 245 bgcmd(int argc __unused, char **argv __unused)
 246 {
 247         struct job *jp;
 248
 249         nextopt("");
 250         do {
 251                 jp = getjob(*argptr);
 252                 if (jp->jobctl == 0)
 253                         error("job not created under job control");
 254                 if (jp->state == JOBDONE)
 255                         continue;
 256                 restartjob(jp);
 257                 jp->foreground = 0;
 258                 out1fmt("[%td] ", jp - jobtab + 1);
 259                 printjobcmd(jp);
 260         } while (*argptr != NULL && *++argptr != NULL);
 261         return 0;
 262 }
 263
 264
 265 static void
 266 restartjob(struct job *jp)
 267 {
 268         struct procstat *ps;
 269         int i;
 270
 271         if (jp->state == JOBDONE)
 272                 return;
 273         setcurjob(jp);
 274         INTOFF;
 275         kill(-jp->ps[0].pid, SIGCONT);
 276         for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
 277                 if (WIFSTOPPED(ps->status)) {
 278                         ps->status = -1;
 279                         jp->state = 0;
 280                 }
 281         }
 282         INTON;
 283 }
 284 #endif
 285
 286
 287 int
 288 jobscmd(int argc __unused, char *argv[] __unused)
 289 {
 290         char *id;
 291         int ch, mode;
 292
 293         mode = SHOWJOBS_DEFAULT;
 294         while ((ch = nextopt("lps")) != '\0') {
 295                 switch (ch) {
 296                 case 'l':
 297                         mode = SHOWJOBS_VERBOSE;
 298                         break;
 299                 case 'p':
 300                         mode = SHOWJOBS_PGIDS;
 301                         break;
 302                 case 's':
 303                         mode = SHOWJOBS_PIDS;
 304                         break;
 305                 }
 306         }
 307
 308         if (*argptr == NULL)
 309                 showjobs(0, mode);
 310         else
 311                 while ((id = *argptr++) != NULL)
 312                         showjob(getjob(id), mode);
 313
 314         return (0);
 315 }
 316
 317 static void
 318 printjobcmd(struct job *jp)
 319 {
 320         struct procstat *ps;
 321         int i;
 322
 323         for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
 324                 out1str(ps->cmd);
 325                 if (i > 0)
 326                         out1str(" | ");
 327         }
 328         out1c('\n');
 329 }
 330
 331 static void
 332 showjob(struct job *jp, int mode)
 333 {
 334         char s[64];
 335         char statestr[64];
 336         const char *sigstr;
 337         struct procstat *ps;
 338         struct job *j;
 339         int col, curr, i, jobno, prev, procno;
 340         char c;
 341
 342         procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs;
 343         jobno = jp - jobtab + 1;
 344         curr = prev = 0;
 345 #if JOBS
 346         if ((j = getcurjob(NULL)) != NULL) {
 347                 curr = j - jobtab + 1;
 348                 if ((j = getcurjob(j)) != NULL)
 349                         prev = j - jobtab + 1;
 350         }
 351 #endif
 352         ps = jp->ps + jp->nprocs - 1;
 353         if (jp->state == 0) {
 354                 strcpy(statestr, "Running");
 355 #if JOBS
 356         } else if (jp->state == JOBSTOPPED) {
 357                 while (!WIFSTOPPED(ps->status) && ps > jp->ps)
 358                         ps--;
 359                 if (WIFSTOPPED(ps->status))
 360                         i = WSTOPSIG(ps->status);
 361                 else
 362                         i = -1;
 363                 sigstr = strsignal(i);
 364                 if (sigstr != NULL)
 365                         strcpy(statestr, sigstr);
 366                 else
 367                         strcpy(statestr, "Suspended");
 368 #endif
 369         } else if (WIFEXITED(ps->status)) {
 370                 if (WEXITSTATUS(ps->status) == 0)
 371                         strcpy(statestr, "Done");
 372                 else
 373                         fmtstr(statestr, 64, "Done(%d)",
 374                             WEXITSTATUS(ps->status));
 375         } else {
 376                 i = WTERMSIG(ps->status);
 377                 sigstr = strsignal(i);
 378                 if (sigstr != NULL)
 379                         strcpy(statestr, sigstr);
 380                 else
 381                         strcpy(statestr, "Unknown signal");
 382                 if (WCOREDUMP(ps->status))
 383                         strcat(statestr, " (core dumped)");
 384         }
 385
 386         for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */
 387                 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) {
 388                         out1fmt("%d\n", (int)ps->pid);
 389                         continue;
 390                 }
 391                 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps)
 392                         continue;
 393                 if (jobno == curr && ps == jp->ps)
 394                         c = '+';
 395                 else if (jobno == prev && ps == jp->ps)
 396                         c = '-';
 397                 else
 398                         c = ' ';
 399                 if (ps == jp->ps)
 400                         fmtstr(s, 64, "[%d] %c ", jobno, c);
 401                 else
 402                         fmtstr(s, 64, "    %c ", c);
 403                 out1str(s);
 404                 col = strlen(s);
 405                 if (mode == SHOWJOBS_VERBOSE) {
 406                         fmtstr(s, 64, "%d ", (int)ps->pid);
 407                         out1str(s);
 408                         col += strlen(s);
 409                 }
 410                 if (ps == jp->ps) {
 411                         out1str(statestr);
 412                         col += strlen(statestr);
 413                 }
 414                 do {
 415                         out1c(' ');
 416                         col++;
 417                 } while (col < 30);
 418                 if (mode == SHOWJOBS_VERBOSE) {
 419                         out1str(ps->cmd);
 420                         out1c('\n');
 421                 } else
 422                         printjobcmd(jp);
 423         }
 424 }
 425
 426 /*
 427  * Print a list of jobs.  If "change" is nonzero, only print jobs whose
 428  * statuses have changed since the last call to showjobs.
 429  *
 430  * If the shell is interrupted in the process of creating a job, the
 431  * result may be a job structure containing zero processes.  Such structures
 432  * will be freed here.
 433  */
 434
 435 void
 436 showjobs(int change, int mode)
 437 {
 438         int jobno;
 439         struct job *jp;
 440
 441         TRACE(("showjobs(%d) called\n", change));
 442         checkzombies();
 443         for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) {
 444                 if (! jp->used)
 445                         continue;
 446                 if (jp->nprocs == 0) {
 447                         freejob(jp);
 448                         continue;
 449                 }
 450                 if (change && ! jp->changed)
 451                         continue;
 452                 showjob(jp, mode);
 453                 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) {
 454                         jp->changed = 0;
 455                         /* Hack: discard jobs for which $! has not been
 456                          * referenced in interactive mode when they terminate.
 457                          */
 458                         if (jp->state == JOBDONE && !jp->remembered &&
 459                                         (iflag || jp != bgjob)) {
 460                                 freejob(jp);
 461                         }
 462                 }
 463         }
 464 }
 465
 466
 467 /*
 468  * Mark a job structure as unused.
 469  */
 470
 471 static void
 472 freejob(struct job *jp)
 473 {
 474         struct procstat *ps;
 475         int i;
 476
 477         INTOFF;
 478         if (bgjob == jp)
 479                 bgjob = NULL;
 480         for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
 481                 if (ps->cmd != nullstr)
 482                         ckfree(ps->cmd);
 483         }
 484         if (jp->ps != &jp->ps0)
 485                 ckfree(jp->ps);
 486         jp->used = 0;
 487 #if JOBS
 488         deljob(jp);
 489 #endif
 490         INTON;
 491 }
 492
 493
 494
 495 int
 496 waitcmd(int argc __unused, char **argv __unused)
 497 {
 498         struct job *job;
 499         int retval;
 500
 501         nextopt("");
 502         if (*argptr == NULL)
 503                 return (waitcmdloop(NULL));
 504
 505         do {
 506                 job = getjob_nonotfound(*argptr);
 507                 if (job == NULL)
 508                         retval = 127;
 509                 else
 510                         retval = waitcmdloop(job);
 511                 argptr++;
 512         } while (*argptr != NULL);
 513
 514         return (retval);
 515 }
 516
 517 static int
 518 waitcmdloop(struct job *job)
 519 {
 520         int status, retval, sig;
 521         struct job *jp;
 522
 523         /*
 524          * Loop until a process is terminated or stopped, or a SIGINT is
 525          * received.
 526          */
 527
 528         do {
 529                 if (job != NULL) {
 530                         if (job->state == JOBDONE) {
 531                                 status = job->ps[job->nprocs - 1].status;
 532                                 if (WIFEXITED(status))
 533                                         retval = WEXITSTATUS(status);
 534                                 else
 535                                         retval = WTERMSIG(status) + 128;
 536                                 if (! iflag || ! job->changed)
 537                                         freejob(job);
 538                                 else {
 539                                         job->remembered = 0;
 540                                         if (job == bgjob)
 541                                                 bgjob = NULL;
 542                                 }
 543                                 return retval;
 544                         }
 545                 } else {
 546                         for (jp = jobtab ; jp < jobtab + njobs; jp++)
 547                                 if (jp->used && jp->state == JOBDONE) {
 548                                         if (! iflag || ! jp->changed)
 549                                                 freejob(jp);
 550                                         else {
 551                                                 jp->remembered = 0;
 552                                                 if (jp == bgjob)
 553                                                         bgjob = NULL;
 554                                         }
 555                                 }
 556                         for (jp = jobtab ; ; jp++) {
 557                                 if (jp >= jobtab + njobs) {     /* no running procs */
 558                                         return 0;
 559                                 }
 560                                 if (jp->used && jp->state == 0)
 561                                         break;
 562                         }
 563                 }
 564         } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1);
 565
 566         sig = pendingsig_waitcmd;
 567         pendingsig_waitcmd = 0;
 568         return sig + 128;
 569 }
 570
 571
 572
 573 int
 574 jobidcmd(int argc __unused, char **argv __unused)
 575 {
 576         struct job *jp;
 577         int i;
 578
 579         nextopt("");
 580         jp = getjob(*argptr);
 581         for (i = 0 ; i < jp->nprocs ; ) {
 582                 out1fmt("%d", (int)jp->ps[i].pid);
 583                 out1c(++i < jp->nprocs? ' ' : '\n');
 584         }
 585         return 0;
 586 }
 587
 588
 589
 590 /*
 591  * Convert a job name to a job structure.
 592  */
 593
 594 static struct job *
 595 getjob_nonotfound(const char *name)
 596 {
 597         int jobno;
 598         struct job *found, *jp;
 599         size_t namelen;
 600         pid_t pid;
 601         int i;
 602
 603         if (name == NULL) {
 604 #if JOBS
 605                 name = "%+";
 606 #else
 607                 error("No current job");
 608 #endif
 609         }
 610         if (name[0] == '%') {
 611                 if (is_digit(name[1])) {
 612                         jobno = number(name + 1);
 613                         if (jobno > 0 && jobno <= njobs
 614                          && jobtab[jobno - 1].used != 0)
 615                                 return &jobtab[jobno - 1];
 616 #if JOBS
 617                 } else if ((name[1] == '%' || name[1] == '+') &&
 618                     name[2] == '\0') {
 619                         if ((jp = getcurjob(NULL)) == NULL)
 620                                 error("No current job");
 621                         return (jp);
 622                 } else if (name[1] == '-' && name[2] == '\0') {
 623                         if ((jp = getcurjob(NULL)) == NULL ||
 624                             (jp = getcurjob(jp)) == NULL)
 625                                 error("No previous job");
 626                         return (jp);
 627 #endif
 628                 } else if (name[1] == '?') {
 629                         found = NULL;
 630                         for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 631                                 if (jp->used && jp->nprocs > 0
 632                                  && strstr(jp->ps[0].cmd, name + 2) != NULL) {
 633                                         if (found)
 634                                                 error("%s: ambiguous", name);
 635                                         found = jp;
 636                                 }
 637                         }
 638                         if (found != NULL)
 639                                 return (found);
 640                 } else {
 641                         namelen = strlen(name);
 642                         found = NULL;
 643                         for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 644                                 if (jp->used && jp->nprocs > 0
 645                                  && strncmp(jp->ps[0].cmd, name + 1,
 646                                  namelen - 1) == 0) {
 647                                         if (found)
 648                                                 error("%s: ambiguous", name);
 649                                         found = jp;
 650                                 }
 651                         }
 652                         if (found)
 653                                 return found;
 654                 }
 655         } else if (is_number(name)) {
 656                 pid = (pid_t)number(name);
 657                 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 658                         if (jp->used && jp->nprocs > 0
 659                          && jp->ps[jp->nprocs - 1].pid == pid)
 660                                 return jp;
 661                 }
 662         }
 663         return NULL;
 664 }
 665
 666
 667 static struct job *
 668 getjob(const char *name)
 669 {
 670         struct job *jp;
 671
 672         jp = getjob_nonotfound(name);
 673         if (jp == NULL)
 674                 error("No such job: %s", name);
 675         return (jp);
 676 }
 677
 678
 679 int
 680 killjob(const char *name, int sig)
 681 {
 682         struct job *jp;
 683         int i, ret;
 684
 685         jp = getjob(name);
 686         if (jp->state == JOBDONE)
 687                 return 0;
 688         if (jp->jobctl)
 689                 return kill(-jp->ps[0].pid, sig);
 690         ret = -1;
 691         errno = ESRCH;
 692         for (i = 0; i < jp->nprocs; i++)
 693                 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) {
 694                         if (kill(jp->ps[i].pid, sig) == 0)
 695                                 ret = 0;
 696                 } else
 697                         ret = 0;
 698         return ret;
 699 }
 700
 701 /*
 702  * Return a new job structure,
 703  */
 704
 705 struct job *
 706 makejob(union node *node __unused, int nprocs)
 707 {
 708         int i;
 709         struct job *jp;
 710
 711         for (i = njobs, jp = jobtab ; ; jp++) {
 712                 if (--i < 0) {
 713                         INTOFF;
 714                         if (njobs == 0) {
 715                                 jobtab = ckmalloc(4 * sizeof jobtab[0]);
 716 #if JOBS
 717                                 jobmru = NULL;
 718 #endif
 719                         } else {
 720                                 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
 721                                 memcpy(jp, jobtab, njobs * sizeof jp[0]);
 722 #if JOBS
 723                                 /* Relocate `next' pointers and list head */
 724                                 if (jobmru != NULL)
 725                                         jobmru = &jp[jobmru - jobtab];
 726                                 for (i = 0; i < njobs; i++)
 727                                         if (jp[i].next != NULL)
 728                                                 jp[i].next = &jp[jp[i].next -
 729                                                     jobtab];
 730 #endif
 731                                 if (bgjob != NULL)
 732                                         bgjob = &jp[bgjob - jobtab];
 733                                 /* Relocate `ps' pointers */
 734                                 for (i = 0; i < njobs; i++)
 735                                         if (jp[i].ps == &jobtab[i].ps0)
 736                                                 jp[i].ps = &jp[i].ps0;
 737                                 ckfree(jobtab);
 738                                 jobtab = jp;
 739                         }
 740                         jp = jobtab + njobs;
 741                         for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0)
 742                                 ;
 743                         INTON;
 744                         break;
 745                 }
 746                 if (jp->used == 0)
 747                         break;
 748         }
 749         INTOFF;
 750         jp->state = 0;
 751         jp->used = 1;
 752         jp->changed = 0;
 753         jp->nprocs = 0;
 754         jp->foreground = 0;
 755         jp->remembered = 0;
 756 #if JOBS
 757         jp->jobctl = jobctl;
 758         jp->next = NULL;
 759 #endif
 760         if (nprocs > 1) {
 761                 jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
 762         } else {
 763                 jp->ps = &jp->ps0;
 764         }
 765         INTON;
 766         TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs,
 767             jp - jobtab + 1));
 768         return jp;
 769 }
 770
 771 #if JOBS
 772 static void
 773 setcurjob(struct job *cj)
 774 {
 775         struct job *jp, *prev;
 776
 777         for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
 778                 if (jp == cj) {
 779                         if (prev != NULL)
 780                                 prev->next = jp->next;
 781                         else
 782                                 jobmru = jp->next;
 783                         jp->next = jobmru;
 784                         jobmru = cj;
 785                         return;
 786                 }
 787         }
 788         cj->next = jobmru;
 789         jobmru = cj;
 790 }
 791
 792 static void
 793 deljob(struct job *j)
 794 {
 795         struct job *jp, *prev;
 796
 797         for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
 798                 if (jp == j) {
 799                         if (prev != NULL)
 800                                 prev->next = jp->next;
 801                         else
 802                                 jobmru = jp->next;
 803                         return;
 804                 }
 805         }
 806 }
 807
 808 /*
 809  * Return the most recently used job that isn't `nj', and preferably one
 810  * that is stopped.
 811  */
 812 static struct job *
 813 getcurjob(struct job *nj)
 814 {
 815         struct job *jp;
 816
 817         /* Try to find a stopped one.. */
 818         for (jp = jobmru; jp != NULL; jp = jp->next)
 819                 if (jp->used && jp != nj && jp->state == JOBSTOPPED)
 820                         return (jp);
 821         /* Otherwise the most recently used job that isn't `nj' */
 822         for (jp = jobmru; jp != NULL; jp = jp->next)
 823                 if (jp->used && jp != nj)
 824                         return (jp);
 825
 826         return (NULL);
 827 }
 828
 829 #endif
 830
 831 /*
 832  * Fork of a subshell.  If we are doing job control, give the subshell its
 833  * own process group.  Jp is a job structure that the job is to be added to.
 834  * N is the command that will be evaluated by the child.  Both jp and n may
 835  * be NULL.  The mode parameter can be one of the following:
 836  *      FORK_FG - Fork off a foreground process.
 837  *      FORK_BG - Fork off a background process.
 838  *      FORK_NOJOB - Like FORK_FG, but don't give the process its own
 839  *                   process group even if job control is on.
 840  *
 841  * When job control is turned off, background processes have their standard
 842  * input redirected to /dev/null (except for the second and later processes
 843  * in a pipeline).
 844  */
 845
 846 pid_t
 847 forkshell(struct job *jp, union node *n, int mode)
 848 {
 849         pid_t pid;
 850         pid_t pgrp;
 851
 852         TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n,
 853             mode));
 854         INTOFF;
 855         if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0))
 856                 checkzombies();
 857         flushall();
 858         pid = fork();
 859         if (pid == -1) {
 860                 TRACE(("Fork failed, errno=%d\n", errno));
 861                 INTON;
 862                 error("Cannot fork: %s", strerror(errno));
 863         }
 864         if (pid == 0) {
 865                 struct job *p;
 866                 int wasroot;
 867                 int i;
 868
 869                 TRACE(("Child shell %d\n", (int)getpid()));
 870                 wasroot = rootshell;
 871                 rootshell = 0;
 872                 handler = &main_handler;
 873                 closescript();
 874                 INTON;
 875                 forcelocal = 0;
 876                 clear_traps();
 877 #if JOBS
 878                 jobctl = 0;             /* do job control only in root shell */
 879                 if (wasroot && mode != FORK_NOJOB && mflag) {
 880                         if (jp == NULL || jp->nprocs == 0)
 881                                 pgrp = getpid();
 882                         else
 883                                 pgrp = jp->ps[0].pid;
 884                         if (setpgid(0, pgrp) == 0 && mode == FORK_FG &&
 885                             ttyfd >= 0) {
 886                                 /*** this causes superfluous TIOCSPGRPS ***/
 887                                 if (tcsetpgrp(ttyfd, pgrp) < 0)
 888                                         error("tcsetpgrp failed, errno=%d", errno);
 889                         }
 890                         setsignal(SIGTSTP);
 891                         setsignal(SIGTTOU);
 892                 } else if (mode == FORK_BG) {
 893                         ignoresig(SIGINT);
 894                         ignoresig(SIGQUIT);
 895                         if ((jp == NULL || jp->nprocs == 0) &&
 896                             ! fd0_redirected_p ()) {
 897                                 close(0);
 898                                 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
 899                                         error("cannot open %s: %s",
 900                                             _PATH_DEVNULL, strerror(errno));
 901                         }
 902                 }
 903 #else
 904                 if (mode == FORK_BG) {
 905                         ignoresig(SIGINT);
 906                         ignoresig(SIGQUIT);
 907                         if ((jp == NULL || jp->nprocs == 0) &&
 908                             ! fd0_redirected_p ()) {
 909                                 close(0);
 910                                 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
 911                                         error("cannot open %s: %s",
 912                                             _PATH_DEVNULL, strerror(errno));
 913                         }
 914                 }
 915 #endif
 916                 INTOFF;
 917                 for (i = njobs, p = jobtab ; --i >= 0 ; p++)
 918                         if (p->used)
 919                                 freejob(p);
 920                 INTON;
 921                 if (wasroot && iflag) {
 922                         setsignal(SIGINT);
 923                         setsignal(SIGQUIT);
 924                         setsignal(SIGTERM);
 925                 }
 926                 return pid;
 927         }
 928         if (rootshell && mode != FORK_NOJOB && mflag) {
 929                 if (jp == NULL || jp->nprocs == 0)
 930                         pgrp = pid;
 931                 else
 932                         pgrp = jp->ps[0].pid;
 933                 setpgid(pid, pgrp);
 934         }
 935         if (mode == FORK_BG) {
 936                 if (bgjob != NULL && bgjob->state == JOBDONE &&
 937                     !bgjob->remembered && !iflag)
 938                         freejob(bgjob);
 939                 backgndpid = pid;               /* set $! */
 940                 bgjob = jp;
 941         }
 942         if (jp) {
 943                 struct procstat *ps = &jp->ps[jp->nprocs++];
 944                 ps->pid = pid;
 945                 ps->status = -1;
 946                 ps->cmd = nullstr;
 947                 if (iflag && rootshell && n)
 948                         ps->cmd = commandtext(n);
 949                 jp->foreground = mode == FORK_FG;
 950 #if JOBS
 951                 setcurjob(jp);
 952 #endif
 953         }
 954         INTON;
 955         TRACE(("In parent shell:  child = %d\n", (int)pid));
 956         return pid;
 957 }
 958
 959
 960 pid_t
 961 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2])
 962 {
 963         pid_t pid;
 964         struct jmploc jmploc;
 965         struct jmploc *savehandler;
 966
 967         TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0],
 968             (void *)pip));
 969         INTOFF;
 970         flushall();
 971         savehandler = handler;
 972         pid = vfork();
 973         if (pid == -1) {
 974                 TRACE(("Vfork failed, errno=%d\n", errno));
 975                 INTON;
 976                 error("Cannot fork: %s", strerror(errno));
 977         }
 978         if (pid == 0) {
 979                 TRACE(("Child shell %d\n", (int)getpid()));
 980                 if (setjmp(jmploc.loc))
 981                         _exit(exception == EXEXEC ? exerrno : 2);
 982                 if (pip != NULL) {
 983                         close(pip[0]);
 984                         if (pip[1] != 1) {
 985                                 dup2(pip[1], 1);
 986                                 close(pip[1]);
 987                         }
 988                 }
 989                 handler = &jmploc;
 990                 shellexec(argv, envp, path, idx);
 991         }
 992         handler = savehandler;
 993         if (jp) {
 994                 struct procstat *ps = &jp->ps[jp->nprocs++];
 995                 ps->pid = pid;
 996                 ps->status = -1;
 997                 ps->cmd = nullstr;
 998                 jp->foreground = 1;
 999 #if JOBS
1000                 setcurjob(jp);
1001 #endif
1002         }
1003         INTON;
1004         TRACE(("In parent shell:  child = %d\n", (int)pid));
1005         return pid;
1006 }
1007
1008
1009 /*
1010  * Wait for job to finish.
1011  *
1012  * Under job control we have the problem that while a child process is
1013  * running interrupts generated by the user are sent to the child but not
1014  * to the shell.  This means that an infinite loop started by an inter-
1015  * active user may be hard to kill.  With job control turned off, an
1016  * interactive user may place an interactive program inside a loop.  If
1017  * the interactive program catches interrupts, the user doesn't want
1018  * these interrupts to also abort the loop.  The approach we take here
1019  * is to have the shell ignore interrupt signals while waiting for a
1020  * foreground process to terminate, and then send itself an interrupt
1021  * signal if the child process was terminated by an interrupt signal.
1022  * Unfortunately, some programs want to do a bit of cleanup and then
1023  * exit on interrupt; unless these processes terminate themselves by
1024  * sending a signal to themselves (instead of calling exit) they will
1025  * confuse this approach.
1026  */
1027
1028 int
1029 waitforjob(struct job *jp, int *origstatus)
1030 {
1031 #if JOBS
1032         int propagate_int = jp->jobctl && jp->foreground;
1033 #endif
1034         int status;
1035         int st;
1036
1037         INTOFF;
1038         TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1));
1039         while (jp->state == 0)
1040                 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG |
1041                     DOWAIT_SIG_TRAP : 0), jp) == -1)
1042                         dotrap();
1043 #if JOBS
1044         if (jp->jobctl) {
1045                 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0)
1046                         error("tcsetpgrp failed, errno=%d\n", errno);
1047         }
1048         if (jp->state == JOBSTOPPED)
1049                 setcurjob(jp);
1050 #endif
1051         status = jp->ps[jp->nprocs - 1].status;
1052         if (origstatus != NULL)
1053                 *origstatus = status;
1054         /* convert to 8 bits */
1055         if (WIFEXITED(status))
1056                 st = WEXITSTATUS(status);
1057 #if JOBS
1058         else if (WIFSTOPPED(status))
1059                 st = WSTOPSIG(status) + 128;
1060 #endif
1061         else
1062                 st = WTERMSIG(status) + 128;
1063         if (! JOBS || jp->state == JOBDONE)
1064                 freejob(jp);
1065         if (int_pending()) {
1066                 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT)
1067                         CLEAR_PENDING_INT;
1068         }
1069 #if JOBS
1070         else if (rootshell && propagate_int &&
1071                         WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
1072                 kill(getpid(), SIGINT);
1073 #endif
1074         INTON;
1075         return st;
1076 }
1077
1078
1079 static void
1080 dummy_handler(int sig __unused)
1081 {
1082 }
1083
1084 /*
1085  * Wait for a process to terminate.
1086  */
1087
1088 static pid_t
1089 dowait(int mode, struct job *job)
1090 {
1091         struct sigaction sa, osa;
1092         sigset_t mask, omask;
1093         pid_t pid;
1094         int status;
1095         struct procstat *sp;
1096         struct job *jp;
1097         struct job *thisjob;
1098         const char *sigstr;
1099         int done;
1100         int stopped;
1101         int sig;
1102         int coredump;
1103         int wflags;
1104         int restore_sigchld;
1105
1106         TRACE(("dowait(%d, %p) called\n", mode, job));
1107         restore_sigchld = 0;
1108         if ((mode & DOWAIT_SIG) != 0) {
1109                 sigfillset(&mask);
1110                 sigprocmask(SIG_BLOCK, &mask, &omask);
1111                 INTOFF;
1112                 if (!issigchldtrapped()) {
1113                         restore_sigchld = 1;
1114                         sa.sa_handler = dummy_handler;
1115                         sa.sa_flags = 0;
1116                         sigemptyset(&sa.sa_mask);
1117                         sigaction(SIGCHLD, &sa, &osa);
1118                 }
1119         }
1120         do {
1121 #if JOBS
1122                 if (iflag)
1123                         wflags = WUNTRACED | WCONTINUED;
1124                 else
1125 #endif
1126                         wflags = 0;
1127                 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK)
1128                         wflags |= WNOHANG;
1129                 pid = wait3(&status, wflags, (struct rusage *)NULL);
1130                 TRACE(("wait returns %d, status=%d\n", (int)pid, status));
1131                 if (pid == 0 && (mode & DOWAIT_SIG) != 0) {
1132                         pid = -1;
1133                         if (((mode & DOWAIT_SIG_TRAP) != 0 ?
1134                             pendingsig : pendingsig_waitcmd) != 0) {
1135                                 errno = EINTR;
1136                                 break;
1137                         }
1138                         sigsuspend(&omask);
1139                         if (int_pending())
1140                                 break;
1141                 }
1142         } while (pid == -1 && errno == EINTR);
1143         if (pid == -1 && errno == ECHILD && job != NULL)
1144                 job->state = JOBDONE;
1145         if ((mode & DOWAIT_SIG) != 0) {
1146                 if (restore_sigchld)
1147                         sigaction(SIGCHLD, &osa, NULL);
1148                 sigprocmask(SIG_SETMASK, &omask, NULL);
1149                 INTON;
1150         }
1151         if (pid <= 0)
1152                 return pid;
1153         INTOFF;
1154         thisjob = NULL;
1155         for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
1156                 if (jp->used && jp->nprocs > 0) {
1157                         done = 1;
1158                         stopped = 1;
1159                         for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
1160                                 if (sp->pid == -1)
1161                                         continue;
1162                                 if (sp->pid == pid && (sp->status == -1 ||
1163                                     WIFSTOPPED(sp->status))) {
1164                                         TRACE(("Changing status of proc %d from 0x%x to 0x%x\n",
1165                                                    (int)pid, sp->status,
1166                                                    status));
1167                                         if (WIFCONTINUED(status)) {
1168                                                 sp->status = -1;
1169                                                 jp->state = 0;
1170                                         } else
1171                                                 sp->status = status;
1172                                         thisjob = jp;
1173                                 }
1174                                 if (sp->status == -1)
1175                                         stopped = 0;
1176                                 else if (WIFSTOPPED(sp->status))
1177                                         done = 0;
1178                         }
1179                         if (stopped) {          /* stopped or done */
1180                                 int state = done? JOBDONE : JOBSTOPPED;
1181                                 if (jp->state != state) {
1182                                         TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
1183                                         jp->state = state;
1184                                         if (jp != job) {
1185                                                 if (done && !jp->remembered &&
1186                                                     !iflag && jp != bgjob)
1187                                                         freejob(jp);
1188 #if JOBS
1189                                                 else if (done)
1190                                                         deljob(jp);
1191 #endif
1192                                         }
1193                                 }
1194                         }
1195                 }
1196         }
1197         INTON;
1198         if (!thisjob || thisjob->state == 0)
1199                 ;
1200         else if ((!rootshell || !iflag || thisjob == job) &&
1201             thisjob->foreground && thisjob->state != JOBSTOPPED) {
1202                 sig = 0;
1203                 coredump = 0;
1204                 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++)
1205                         if (WIFSIGNALED(sp->status)) {
1206                                 sig = WTERMSIG(sp->status);
1207                                 coredump = WCOREDUMP(sp->status);
1208                         }
1209                 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) {
1210                         sigstr = strsignal(sig);
1211                         if (sigstr != NULL)
1212                                 out2str(sigstr);
1213                         else
1214                                 out2str("Unknown signal");
1215                         if (coredump)
1216                                 out2str(" (core dumped)");
1217                         out2c('\n');
1218                         flushout(out2);
1219                 }
1220         } else {
1221                 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job));
1222                 thisjob->changed = 1;
1223         }
1224         return pid;
1225 }
1226
1227
1228
1229 /*
1230  * return 1 if there are stopped jobs, otherwise 0
1231  */
1232 int job_warning = 0;
1233 int
1234 stoppedjobs(void)
1235 {
1236         int jobno;
1237         struct job *jp;
1238
1239         if (job_warning)
1240                 return (0);
1241         for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
1242                 if (jp->used == 0)
1243                         continue;
1244                 if (jp->state == JOBSTOPPED) {
1245                         out2fmt_flush("You have stopped jobs.\n");
1246                         job_warning = 2;
1247                         return (1);
1248                 }
1249         }
1250
1251         return (0);
1252 }
1253
1254
1255 static void
1256 checkzombies(void)
1257 {
1258         while (njobs > 0 && dowait(0, NULL) > 0)
1259                 ;
1260 }
1261
1262
1263 int
1264 backgndpidset(void)
1265 {
1266         return backgndpid != -1;
1267 }
1268
1269
1270 pid_t
1271 backgndpidval(void)
1272 {
1273         if (bgjob != NULL && !forcelocal)
1274                 bgjob->remembered = 1;
1275         return backgndpid;
1276 }
1277
1278 /*
1279  * Return a string identifying a command (to be printed by the
1280  * jobs command.
1281  */
1282
1283 static char *cmdnextc;
1284 static int cmdnleft;
1285 #define MAXCMDTEXT      200
1286
1287 char *
1288 commandtext(union node *n)
1289 {
1290         char *name;
1291
1292         cmdnextc = name = ckmalloc(MAXCMDTEXT);
1293         cmdnleft = MAXCMDTEXT - 4;
1294         cmdtxt(n);
1295         *cmdnextc = '\0';
1296         return name;
1297 }
1298
1299
1300 static void
1301 cmdtxtdogroup(union node *n)
1302 {
1303         cmdputs("; do ");
1304         cmdtxt(n);
1305         cmdputs("; done");
1306 }
1307
1308
1309 static void
1310 cmdtxtredir(union node *n, const char *op, int deffd)
1311 {
1312         char s[2];
1313
1314         if (n->nfile.fd != deffd) {
1315                 s[0] = n->nfile.fd + '0';
1316                 s[1] = '\0';
1317                 cmdputs(s);
1318         }
1319         cmdputs(op);
1320         if (n->type == NTOFD || n->type == NFROMFD) {
1321                 if (n->ndup.dupfd >= 0)
1322                         s[0] = n->ndup.dupfd + '0';
1323                 else
1324                         s[0] = '-';
1325                 s[1] = '\0';
1326                 cmdputs(s);
1327         } else {
1328                 cmdtxt(n->nfile.fname);
1329         }
1330 }
1331
1332
1333 static void
1334 cmdtxt(union node *n)
1335 {
1336         union node *np;
1337         struct nodelist *lp;
1338
1339         if (n == NULL)
1340                 return;
1341         switch (n->type) {
1342         case NSEMI:
1343                 cmdtxt(n->nbinary.ch1);
1344                 cmdputs("; ");
1345                 cmdtxt(n->nbinary.ch2);
1346                 break;
1347         case NAND:
1348                 cmdtxt(n->nbinary.ch1);
1349                 cmdputs(" && ");
1350                 cmdtxt(n->nbinary.ch2);
1351                 break;
1352         case NOR:
1353                 cmdtxt(n->nbinary.ch1);
1354                 cmdputs(" || ");
1355                 cmdtxt(n->nbinary.ch2);
1356                 break;
1357         case NPIPE:
1358                 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
1359                         cmdtxt(lp->n);
1360                         if (lp->next)
1361                                 cmdputs(" | ");
1362                 }
1363                 break;
1364         case NSUBSHELL:
1365                 cmdputs("(");
1366                 cmdtxt(n->nredir.n);
1367                 cmdputs(")");
1368                 break;
1369         case NREDIR:
1370         case NBACKGND:
1371                 cmdtxt(n->nredir.n);
1372                 break;
1373         case NIF:
1374                 cmdputs("if ");
1375                 cmdtxt(n->nif.test);
1376                 cmdputs("; then ");
1377                 cmdtxt(n->nif.ifpart);
1378                 cmdputs("...");
1379                 break;
1380         case NWHILE:
1381                 cmdputs("while ");
1382                 cmdtxt(n->nbinary.ch1);
1383                 cmdtxtdogroup(n->nbinary.ch2);
1384                 break;
1385         case NUNTIL:
1386                 cmdputs("until ");
1387                 cmdtxt(n->nbinary.ch1);
1388                 cmdtxtdogroup(n->nbinary.ch2);
1389                 break;
1390         case NFOR:
1391                 cmdputs("for ");
1392                 cmdputs(n->nfor.var);
1393                 cmdputs(" in ...");
1394                 break;
1395         case NCASE:
1396                 cmdputs("case ");
1397                 cmdputs(n->ncase.expr->narg.text);
1398                 cmdputs(" in ...");
1399                 break;
1400         case NDEFUN:
1401                 cmdputs(n->narg.text);
1402                 cmdputs("() ...");
1403                 break;
1404         case NNOT:
1405                 cmdputs("! ");
1406                 cmdtxt(n->nnot.com);
1407                 break;
1408         case NCMD:
1409                 for (np = n->ncmd.args ; np ; np = np->narg.next) {
1410                         cmdtxt(np);
1411                         if (np->narg.next)
1412                                 cmdputs(" ");
1413                 }
1414                 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) {
1415                         cmdputs(" ");
1416                         cmdtxt(np);
1417                 }
1418                 break;
1419         case NARG:
1420                 cmdputs(n->narg.text);
1421                 break;
1422         case NTO:
1423                 cmdtxtredir(n, ">", 1);
1424                 break;
1425         case NAPPEND:
1426                 cmdtxtredir(n, ">>", 1);
1427                 break;
1428         case NTOFD:
1429                 cmdtxtredir(n, ">&", 1);
1430                 break;
1431         case NCLOBBER:
1432                 cmdtxtredir(n, ">|", 1);
1433                 break;
1434         case NFROM:
1435                 cmdtxtredir(n, "<", 0);
1436                 break;
1437         case NFROMTO:
1438                 cmdtxtredir(n, "<>", 0);
1439                 break;
1440         case NFROMFD:
1441                 cmdtxtredir(n, "<&", 0);
1442                 break;
1443         case NHERE:
1444         case NXHERE:
1445                 cmdputs("<<...");
1446                 break;
1447         default:
1448                 cmdputs("???");
1449                 break;
1450         }
1451 }
1452
1453
1454
1455 static void
1456 cmdputs(const char *s)
1457 {
1458         const char *p;
1459         char *q;
1460         char c;
1461         int subtype = 0;
1462
1463         if (cmdnleft <= 0)
1464                 return;
1465         p = s;
1466         q = cmdnextc;
1467         while ((c = *p++) != '\0') {
1468                 if (c == CTLESC)
1469                         *q++ = *p++;
1470                 else if (c == CTLVAR) {
1471                         *q++ = '$';
1472                         if (--cmdnleft > 0)
1473                                 *q++ = '{';
1474                         subtype = *p++;
1475                         if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0)
1476                                 *q++ = '#';
1477                 } else if (c == '=' && subtype != 0) {
1478                         *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL];
1479                         if (*q)
1480                                 q++;
1481                         else
1482                                 cmdnleft++;
1483                         if (((subtype & VSTYPE) == VSTRIMLEFTMAX ||
1484                             (subtype & VSTYPE) == VSTRIMRIGHTMAX) &&
1485                             --cmdnleft > 0)
1486                                 *q = q[-1], q++;
1487                         subtype = 0;
1488                 } else if (c == CTLENDVAR) {
1489                         *q++ = '}';
1490                 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) {
1491                         cmdnleft -= 5;
1492                         if (cmdnleft > 0) {
1493                                 *q++ = '$';
1494                                 *q++ = '(';
1495                                 *q++ = '.';
1496                                 *q++ = '.';
1497                                 *q++ = '.';
1498                                 *q++ = ')';
1499                         }
1500                 } else if (c == CTLARI) {
1501                         cmdnleft -= 2;
1502                         if (cmdnleft > 0) {
1503                                 *q++ = '$';
1504                                 *q++ = '(';
1505                                 *q++ = '(';
1506                         }
1507                         p++;
1508                 } else if (c == CTLENDARI) {
1509                         if (--cmdnleft > 0) {
1510                                 *q++ = ')';
1511                                 *q++ = ')';
1512                         }
1513                 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND)
1514                         cmdnleft++; /* ignore */
1515                 else
1516                         *q++ = c;
1517                 if (--cmdnleft <= 0) {
1518                         *q++ = '.';
1519                         *q++ = '.';
1520                         *q++ = '.';
1521                         break;
1522                 }
1523         }
1524         cmdnextc = q;
1525 }