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: head/bin/sh/jobs.c 361112 2020-05-16 16:29:23Z jilles $");
  40
  41 #include <sys/ioctl.h>
  42 #include <sys/param.h>
  43 #include <sys/resource.h>
  44 #include <sys/time.h>
  45 #include <sys/wait.h>
  46 #include <errno.h>
  47 #include <fcntl.h>
  48 #include <paths.h>
  49 #include <signal.h>
  50 #include <stddef.h>
  51 #include <stdlib.h>
  52 #include <unistd.h>
  53
  54 #include "shell.h"
  55 #if JOBS
  56 #include <termios.h>
  57 #undef CEOF                     /* syntax.h redefines this */
  58 #endif
  59 #include "redir.h"
  60 #include "exec.h"
  61 #include "show.h"
  62 #include "main.h"
  63 #include "parser.h"
  64 #include "nodes.h"
  65 #include "jobs.h"
  66 #include "options.h"
  67 #include "trap.h"
  68 #include "syntax.h"
  69 #include "input.h"
  70 #include "output.h"
  71 #include "memalloc.h"
  72 #include "error.h"
  73 #include "mystring.h"
  74 #include "var.h"
  75 #include "builtins.h"
  76 #include "eval.h"
  77
  78
  79 /*
  80  * A job structure contains information about a job.  A job is either a
  81  * single process or a set of processes contained in a pipeline.  In the
  82  * latter case, pidlist will be non-NULL, and will point to a -1 terminated
  83  * array of pids.
  84  */
  85
  86 struct procstat {
  87         pid_t pid;              /* process id */
  88         int status;             /* status flags (defined above) */
  89         char *cmd;              /* text of command being run */
  90 };
  91
  92
  93 /* states */
  94 #define JOBSTOPPED 1            /* all procs are stopped */
  95 #define JOBDONE 2               /* all procs are completed */
  96
  97
  98 struct job {
  99         struct procstat ps0;    /* status of process */
 100         struct procstat *ps;    /* status or processes when more than one */
 101         short nprocs;           /* number of processes */
 102         pid_t pgrp;             /* process group of this job */
 103         char state;             /* true if job is finished */
 104         char used;              /* true if this entry is in used */
 105         char changed;           /* true if status has changed */
 106         char foreground;        /* true if running in the foreground */
 107         char remembered;        /* true if $! referenced */
 108         char pipefail;          /* pass any non-zero status */
 109 #if JOBS
 110         char jobctl;            /* job running under job control */
 111         struct job *next;       /* job used after this one */
 112 #endif
 113 };
 114
 115
 116 static struct job *jobtab;      /* array of jobs */
 117 static int njobs;               /* size of array */
 118 static pid_t backgndpid = -1;   /* pid of last background process */
 119 static struct job *bgjob = NULL; /* last background process */
 120 #if JOBS
 121 static struct job *jobmru;      /* most recently used job list */
 122 static pid_t initialpgrp;       /* pgrp of shell on invocation */
 123 #endif
 124 static int ttyfd = -1;
 125
 126 /* mode flags for dowait */
 127 #define DOWAIT_BLOCK    0x1 /* wait until a child exits */
 128 #define DOWAIT_SIG      0x2 /* if DOWAIT_BLOCK, abort on signal */
 129 #define DOWAIT_SIG_TRAP 0x4 /* if DOWAIT_SIG, abort on trapped signal only */
 130
 131 #if JOBS
 132 static void restartjob(struct job *);
 133 #endif
 134 static void freejob(struct job *);
 135 static int waitcmdloop(struct job *);
 136 static struct job *getjob_nonotfound(const char *);
 137 static struct job *getjob(const char *);
 138 pid_t killjob(const char *, int);
 139 static pid_t dowait(int, struct job *);
 140 static void checkzombies(void);
 141 static void cmdtxt(union node *);
 142 static void cmdputs(const char *);
 143 #if JOBS
 144 static void setcurjob(struct job *);
 145 static void deljob(struct job *);
 146 static struct job *getcurjob(struct job *);
 147 #endif
 148 static int getjobstatus(const struct job *);
 149 static void printjobcmd(struct job *);
 150 static void showjob(struct job *, int);
 151
 152
 153 /*
 154  * Turn job control on and off.
 155  */
 156
 157 static int jobctl;
 158
 159 #if JOBS
 160 static void
 161 jobctl_notty(void)
 162 {
 163         if (ttyfd >= 0) {
 164                 close(ttyfd);
 165                 ttyfd = -1;
 166         }
 167         if (!iflag) {
 168                 setsignal(SIGTSTP);
 169                 setsignal(SIGTTOU);
 170                 setsignal(SIGTTIN);
 171                 jobctl = 1;
 172                 return;
 173         }
 174         out2fmt_flush("sh: can't access tty; job control turned off\n");
 175         mflag = 0;
 176 }
 177
 178 void
 179 setjobctl(int on)
 180 {
 181         int i;
 182
 183         if (on == jobctl || rootshell == 0)
 184                 return;
 185         if (on) {
 186                 if (ttyfd != -1)
 187                         close(ttyfd);
 188                 if ((ttyfd = open(_PATH_TTY, O_RDWR | O_CLOEXEC_MAYBE)) < 0) {
 189                         i = 0;
 190                         while (i <= 2 && !isatty(i))
 191                                 i++;
 192                         if (i > 2 ||
 193                             (ttyfd = fcntl(i, F_DUPFD_CLOEXEC_MAYBE, 10)) < 0) {
 194                                 jobctl_notty();
 195                                 return;
 196                         }
 197                 }
 198                 if (ttyfd < 10) {
 199                         /*
 200                          * Keep our TTY file descriptor out of the way of
 201                          * the user's redirections.
 202                          */
 203                         if ((i = fcntl(ttyfd, F_DUPFD_CLOEXEC_MAYBE, 10)) < 0) {
 204                                 jobctl_notty();
 205                                 return;
 206                         }
 207                         close(ttyfd);
 208                         ttyfd = i;
 209                 }
 210 #if !defined(O_CLOEXEC) || !defined(F_DUPFD_CLOEXEC)
 211                 if (fcntl(ttyfd, F_SETFD, FD_CLOEXEC) < 0) {
 212                         close(ttyfd);
 213                         ttyfd = -1;
 214                         goto out;
 215                 }
 216 #endif
 217                 do { /* while we are in the background */
 218                         initialpgrp = tcgetpgrp(ttyfd);
 219                         if (initialpgrp < 0) {
 220 #if !defined(O_CLOEXEC) || !defined(F_DUPFD_CLOEXEC)
 221 out:
 222 #endif
 223                                 jobctl_notty();
 224                                 return;
 225                         }
 226                         if (initialpgrp != getpgrp()) {
 227                                 if (!iflag) {
 228                                         initialpgrp = -1;
 229                                         jobctl_notty();
 230                                         return;
 231                                 }
 232                                 kill(0, SIGTTIN);
 233                                 continue;
 234                         }
 235                 } while (0);
 236                 setsignal(SIGTSTP);
 237                 setsignal(SIGTTOU);
 238                 setsignal(SIGTTIN);
 239                 setpgid(0, rootpid);
 240                 tcsetpgrp(ttyfd, rootpid);
 241         } else { /* turning job control off */
 242                 setpgid(0, initialpgrp);
 243                 if (ttyfd >= 0) {
 244                         tcsetpgrp(ttyfd, initialpgrp);
 245                         close(ttyfd);
 246                         ttyfd = -1;
 247                 }
 248                 setsignal(SIGTSTP);
 249                 setsignal(SIGTTOU);
 250                 setsignal(SIGTTIN);
 251         }
 252         jobctl = on;
 253 }
 254 #endif
 255
 256
 257 #if JOBS
 258 int
 259 fgcmd(int argc __unused, char **argv __unused)
 260 {
 261         struct job *jp;
 262         pid_t pgrp;
 263         int status;
 264
 265         nextopt("");
 266         jp = getjob(*argptr);
 267         if (jp->jobctl == 0)
 268                 error("job not created under job control");
 269         printjobcmd(jp);
 270         flushout(&output);
 271         pgrp = jp->ps[0].pid;
 272         if (ttyfd >= 0)
 273                 tcsetpgrp(ttyfd, pgrp);
 274         restartjob(jp);
 275         jp->foreground = 1;
 276         INTOFF;
 277         status = waitforjob(jp, (int *)NULL);
 278         INTON;
 279         return status;
 280 }
 281
 282
 283 int
 284 bgcmd(int argc __unused, char **argv __unused)
 285 {
 286         struct job *jp;
 287
 288         nextopt("");
 289         do {
 290                 jp = getjob(*argptr);
 291                 if (jp->jobctl == 0)
 292                         error("job not created under job control");
 293                 if (jp->state == JOBDONE)
 294                         continue;
 295                 restartjob(jp);
 296                 jp->foreground = 0;
 297                 out1fmt("[%td] ", jp - jobtab + 1);
 298                 printjobcmd(jp);
 299         } while (*argptr != NULL && *++argptr != NULL);
 300         return 0;
 301 }
 302
 303
 304 static void
 305 restartjob(struct job *jp)
 306 {
 307         struct procstat *ps;
 308         int i;
 309
 310         if (jp->state == JOBDONE)
 311                 return;
 312         setcurjob(jp);
 313         INTOFF;
 314         kill(-jp->ps[0].pid, SIGCONT);
 315         for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
 316                 if (WIFSTOPPED(ps->status)) {
 317                         ps->status = -1;
 318                         jp->state = 0;
 319                 }
 320         }
 321         INTON;
 322 }
 323 #endif
 324
 325
 326 int
 327 jobscmd(int argc __unused, char *argv[] __unused)
 328 {
 329         char *id;
 330         int ch, mode;
 331
 332         mode = SHOWJOBS_DEFAULT;
 333         while ((ch = nextopt("lps")) != '\0') {
 334                 switch (ch) {
 335                 case 'l':
 336                         mode = SHOWJOBS_VERBOSE;
 337                         break;
 338                 case 'p':
 339                         mode = SHOWJOBS_PGIDS;
 340                         break;
 341                 case 's':
 342                         mode = SHOWJOBS_PIDS;
 343                         break;
 344                 }
 345         }
 346
 347         if (*argptr == NULL)
 348                 showjobs(0, mode);
 349         else
 350                 while ((id = *argptr++) != NULL)
 351                         showjob(getjob(id), mode);
 352
 353         return (0);
 354 }
 355
 356 static int getjobstatus(const struct job *jp)
 357 {
 358         int i, status;
 359
 360         if (!jp->pipefail)
 361                 return (jp->ps[jp->nprocs - 1].status);
 362         for (i = jp->nprocs - 1; i >= 0; i--) {
 363                 status = jp->ps[i].status;
 364                 if (status != 0)
 365                         return (status);
 366         }
 367         return (0);
 368 }
 369
 370 static void
 371 printjobcmd(struct job *jp)
 372 {
 373         struct procstat *ps;
 374         int i;
 375
 376         for (ps = jp->ps, i = jp->nprocs ; --i >= 0 ; ps++) {
 377                 out1str(ps->cmd);
 378                 if (i > 0)
 379                         out1str(" | ");
 380         }
 381         out1c('\n');
 382 }
 383
 384 static void
 385 showjob(struct job *jp, int mode)
 386 {
 387         char s[64];
 388         char statebuf[16];
 389         const char *statestr, *coredump;
 390         struct procstat *ps;
 391         struct job *j;
 392         int col, curr, i, jobno, prev, procno, status;
 393         char c;
 394
 395         procno = (mode == SHOWJOBS_PGIDS) ? 1 : jp->nprocs;
 396         jobno = jp - jobtab + 1;
 397         curr = prev = 0;
 398 #if JOBS
 399         if ((j = getcurjob(NULL)) != NULL) {
 400                 curr = j - jobtab + 1;
 401                 if ((j = getcurjob(j)) != NULL)
 402                         prev = j - jobtab + 1;
 403         }
 404 #endif
 405         coredump = "";
 406         status = getjobstatus(jp);
 407         if (jp->state == 0) {
 408                 statestr = "Running";
 409 #if JOBS
 410         } else if (jp->state == JOBSTOPPED) {
 411                 ps = jp->ps + jp->nprocs - 1;
 412                 while (!WIFSTOPPED(ps->status) && ps > jp->ps)
 413                         ps--;
 414                 if (WIFSTOPPED(ps->status))
 415                         i = WSTOPSIG(ps->status);
 416                 else
 417                         i = -1;
 418                 statestr = strsignal(i);
 419                 if (statestr == NULL)
 420                         statestr = "Suspended";
 421 #endif
 422         } else if (WIFEXITED(status)) {
 423                 if (WEXITSTATUS(status) == 0)
 424                         statestr = "Done";
 425                 else {
 426                         fmtstr(statebuf, sizeof(statebuf), "Done(%d)",
 427                             WEXITSTATUS(status));
 428                         statestr = statebuf;
 429                 }
 430         } else {
 431                 i = WTERMSIG(status);
 432                 statestr = strsignal(i);
 433                 if (statestr == NULL)
 434                         statestr = "Unknown signal";
 435                 if (WCOREDUMP(status))
 436                         coredump = " (core dumped)";
 437         }
 438
 439         for (ps = jp->ps ; procno > 0 ; ps++, procno--) { /* for each process */
 440                 if (mode == SHOWJOBS_PIDS || mode == SHOWJOBS_PGIDS) {
 441                         out1fmt("%d\n", (int)ps->pid);
 442                         continue;
 443                 }
 444                 if (mode != SHOWJOBS_VERBOSE && ps != jp->ps)
 445                         continue;
 446                 if (jobno == curr && ps == jp->ps)
 447                         c = '+';
 448                 else if (jobno == prev && ps == jp->ps)
 449                         c = '-';
 450                 else
 451                         c = ' ';
 452                 if (ps == jp->ps)
 453                         fmtstr(s, 64, "[%d] %c ", jobno, c);
 454                 else
 455                         fmtstr(s, 64, "    %c ", c);
 456                 out1str(s);
 457                 col = strlen(s);
 458                 if (mode == SHOWJOBS_VERBOSE) {
 459                         fmtstr(s, 64, "%d ", (int)ps->pid);
 460                         out1str(s);
 461                         col += strlen(s);
 462                 }
 463                 if (ps == jp->ps) {
 464                         out1str(statestr);
 465                         out1str(coredump);
 466                         col += strlen(statestr) + strlen(coredump);
 467                 }
 468                 do {
 469                         out1c(' ');
 470                         col++;
 471                 } while (col < 30);
 472                 if (mode == SHOWJOBS_VERBOSE) {
 473                         out1str(ps->cmd);
 474                         out1c('\n');
 475                 } else
 476                         printjobcmd(jp);
 477         }
 478 }
 479
 480 /*
 481  * Print a list of jobs.  If "change" is nonzero, only print jobs whose
 482  * statuses have changed since the last call to showjobs.
 483  *
 484  * If the shell is interrupted in the process of creating a job, the
 485  * result may be a job structure containing zero processes.  Such structures
 486  * will be freed here.
 487  */
 488
 489 void
 490 showjobs(int change, int mode)
 491 {
 492         int jobno;
 493         struct job *jp;
 494
 495         TRACE(("showjobs(%d) called\n", change));
 496         checkzombies();
 497         for (jobno = 1, jp = jobtab ; jobno <= njobs ; jobno++, jp++) {
 498                 if (! jp->used)
 499                         continue;
 500                 if (jp->nprocs == 0) {
 501                         freejob(jp);
 502                         continue;
 503                 }
 504                 if (change && ! jp->changed)
 505                         continue;
 506                 showjob(jp, mode);
 507                 if (mode == SHOWJOBS_DEFAULT || mode == SHOWJOBS_VERBOSE) {
 508                         jp->changed = 0;
 509                         /* Hack: discard jobs for which $! has not been
 510                          * referenced in interactive mode when they terminate.
 511                          */
 512                         if (jp->state == JOBDONE && !jp->remembered &&
 513                                         (iflag || jp != bgjob)) {
 514                                 freejob(jp);
 515                         }
 516                 }
 517         }
 518 }
 519
 520
 521 /*
 522  * Mark a job structure as unused.
 523  */
 524
 525 static void
 526 freejob(struct job *jp)
 527 {
 528         struct procstat *ps;
 529         int i;
 530
 531         INTOFF;
 532         if (bgjob == jp)
 533                 bgjob = NULL;
 534         for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
 535                 if (ps->cmd != nullstr)
 536                         ckfree(ps->cmd);
 537         }
 538         if (jp->ps != &jp->ps0)
 539                 ckfree(jp->ps);
 540         jp->used = 0;
 541 #if JOBS
 542         deljob(jp);
 543 #endif
 544         INTON;
 545 }
 546
 547
 548
 549 int
 550 waitcmd(int argc __unused, char **argv __unused)
 551 {
 552         struct job *job;
 553         int retval;
 554
 555         nextopt("");
 556         if (*argptr == NULL)
 557                 return (waitcmdloop(NULL));
 558
 559         do {
 560                 job = getjob_nonotfound(*argptr);
 561                 if (job == NULL)
 562                         retval = 127;
 563                 else
 564                         retval = waitcmdloop(job);
 565                 argptr++;
 566         } while (*argptr != NULL);
 567
 568         return (retval);
 569 }
 570
 571 static int
 572 waitcmdloop(struct job *job)
 573 {
 574         int status, retval, sig;
 575         struct job *jp;
 576
 577         /*
 578          * Loop until a process is terminated or stopped, or a SIGINT is
 579          * received.
 580          */
 581
 582         do {
 583                 if (job != NULL) {
 584                         if (job->state == JOBDONE) {
 585                                 status = getjobstatus(job);
 586                                 if (WIFEXITED(status))
 587                                         retval = WEXITSTATUS(status);
 588                                 else
 589                                         retval = WTERMSIG(status) + 128;
 590                                 if (! iflag || ! job->changed)
 591                                         freejob(job);
 592                                 else {
 593                                         job->remembered = 0;
 594                                         if (job == bgjob)
 595                                                 bgjob = NULL;
 596                                 }
 597                                 return retval;
 598                         }
 599                 } else {
 600                         for (jp = jobtab ; jp < jobtab + njobs; jp++)
 601                                 if (jp->used && jp->state == JOBDONE) {
 602                                         if (! iflag || ! jp->changed)
 603                                                 freejob(jp);
 604                                         else {
 605                                                 jp->remembered = 0;
 606                                                 if (jp == bgjob)
 607                                                         bgjob = NULL;
 608                                         }
 609                                 }
 610                         for (jp = jobtab ; ; jp++) {
 611                                 if (jp >= jobtab + njobs) {     /* no running procs */
 612                                         return 0;
 613                                 }
 614                                 if (jp->used && jp->state == 0)
 615                                         break;
 616                         }
 617                 }
 618         } while (dowait(DOWAIT_BLOCK | DOWAIT_SIG, (struct job *)NULL) != -1);
 619
 620         sig = pendingsig_waitcmd;
 621         pendingsig_waitcmd = 0;
 622         return sig + 128;
 623 }
 624
 625
 626
 627 int
 628 jobidcmd(int argc __unused, char **argv __unused)
 629 {
 630         struct job *jp;
 631         int i;
 632
 633         nextopt("");
 634         jp = getjob(*argptr);
 635         for (i = 0 ; i < jp->nprocs ; ) {
 636                 out1fmt("%d", (int)jp->ps[i].pid);
 637                 out1c(++i < jp->nprocs? ' ' : '\n');
 638         }
 639         return 0;
 640 }
 641
 642
 643
 644 /*
 645  * Convert a job name to a job structure.
 646  */
 647
 648 static struct job *
 649 getjob_nonotfound(const char *name)
 650 {
 651         int jobno;
 652         struct job *found, *jp;
 653         size_t namelen;
 654         pid_t pid;
 655         int i;
 656
 657         if (name == NULL) {
 658 #if JOBS
 659                 name = "%+";
 660 #else
 661                 error("No current job");
 662 #endif
 663         }
 664         if (name[0] == '%') {
 665                 if (is_digit(name[1])) {
 666                         jobno = number(name + 1);
 667                         if (jobno > 0 && jobno <= njobs
 668                          && jobtab[jobno - 1].used != 0)
 669                                 return &jobtab[jobno - 1];
 670 #if JOBS
 671                 } else if ((name[1] == '%' || name[1] == '+') &&
 672                     name[2] == '\0') {
 673                         if ((jp = getcurjob(NULL)) == NULL)
 674                                 error("No current job");
 675                         return (jp);
 676                 } else if (name[1] == '-' && name[2] == '\0') {
 677                         if ((jp = getcurjob(NULL)) == NULL ||
 678                             (jp = getcurjob(jp)) == NULL)
 679                                 error("No previous job");
 680                         return (jp);
 681 #endif
 682                 } else if (name[1] == '?') {
 683                         found = NULL;
 684                         for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 685                                 if (jp->used && jp->nprocs > 0
 686                                  && strstr(jp->ps[0].cmd, name + 2) != NULL) {
 687                                         if (found)
 688                                                 error("%s: ambiguous", name);
 689                                         found = jp;
 690                                 }
 691                         }
 692                         if (found != NULL)
 693                                 return (found);
 694                 } else {
 695                         namelen = strlen(name);
 696                         found = NULL;
 697                         for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 698                                 if (jp->used && jp->nprocs > 0
 699                                  && strncmp(jp->ps[0].cmd, name + 1,
 700                                  namelen - 1) == 0) {
 701                                         if (found)
 702                                                 error("%s: ambiguous", name);
 703                                         found = jp;
 704                                 }
 705                         }
 706                         if (found)
 707                                 return found;
 708                 }
 709         } else if (is_number(name)) {
 710                 pid = (pid_t)number(name);
 711                 for (jp = jobtab, i = njobs ; --i >= 0 ; jp++) {
 712                         if (jp->used && jp->nprocs > 0
 713                          && jp->ps[jp->nprocs - 1].pid == pid)
 714                                 return jp;
 715                 }
 716         }
 717         return NULL;
 718 }
 719
 720
 721 static struct job *
 722 getjob(const char *name)
 723 {
 724         struct job *jp;
 725
 726         jp = getjob_nonotfound(name);
 727         if (jp == NULL)
 728                 error("No such job: %s", name);
 729         return (jp);
 730 }
 731
 732
 733 int
 734 killjob(const char *name, int sig)
 735 {
 736         struct job *jp;
 737         int i, ret;
 738
 739         jp = getjob(name);
 740         if (jp->state == JOBDONE)
 741                 return 0;
 742         if (jp->jobctl)
 743                 return kill(-jp->ps[0].pid, sig);
 744         ret = -1;
 745         errno = ESRCH;
 746         for (i = 0; i < jp->nprocs; i++)
 747                 if (jp->ps[i].status == -1 || WIFSTOPPED(jp->ps[i].status)) {
 748                         if (kill(jp->ps[i].pid, sig) == 0)
 749                                 ret = 0;
 750                 } else
 751                         ret = 0;
 752         return ret;
 753 }
 754
 755 /*
 756  * Return a new job structure,
 757  */
 758
 759 struct job *
 760 makejob(union node *node __unused, int nprocs)
 761 {
 762         int i;
 763         struct job *jp;
 764
 765         for (i = njobs, jp = jobtab ; ; jp++) {
 766                 if (--i < 0) {
 767                         INTOFF;
 768                         if (njobs == 0) {
 769                                 jobtab = ckmalloc(4 * sizeof jobtab[0]);
 770 #if JOBS
 771                                 jobmru = NULL;
 772 #endif
 773                         } else {
 774                                 jp = ckmalloc((njobs + 4) * sizeof jobtab[0]);
 775                                 memcpy(jp, jobtab, njobs * sizeof jp[0]);
 776 #if JOBS
 777                                 /* Relocate `next' pointers and list head */
 778                                 if (jobmru != NULL)
 779                                         jobmru = &jp[jobmru - jobtab];
 780                                 for (i = 0; i < njobs; i++)
 781                                         if (jp[i].next != NULL)
 782                                                 jp[i].next = &jp[jp[i].next -
 783                                                     jobtab];
 784 #endif
 785                                 if (bgjob != NULL)
 786                                         bgjob = &jp[bgjob - jobtab];
 787                                 /* Relocate `ps' pointers */
 788                                 for (i = 0; i < njobs; i++)
 789                                         if (jp[i].ps == &jobtab[i].ps0)
 790                                                 jp[i].ps = &jp[i].ps0;
 791                                 ckfree(jobtab);
 792                                 jobtab = jp;
 793                         }
 794                         jp = jobtab + njobs;
 795                         for (i = 4 ; --i >= 0 ; jobtab[njobs++].used = 0)
 796                                 ;
 797                         INTON;
 798                         break;
 799                 }
 800                 if (jp->used == 0)
 801                         break;
 802         }
 803         INTOFF;
 804         jp->state = 0;
 805         jp->used = 1;
 806         jp->changed = 0;
 807         jp->nprocs = 0;
 808         jp->foreground = 0;
 809         jp->remembered = 0;
 810         jp->pipefail = pipefailflag;
 811 #if JOBS
 812         jp->jobctl = jobctl;
 813         jp->next = NULL;
 814 #endif
 815         if (nprocs > 1) {
 816                 jp->ps = ckmalloc(nprocs * sizeof (struct procstat));
 817         } else {
 818                 jp->ps = &jp->ps0;
 819         }
 820         INTON;
 821         TRACE(("makejob(%p, %d) returns %%%td\n", (void *)node, nprocs,
 822             jp - jobtab + 1));
 823         return jp;
 824 }
 825
 826 #if JOBS
 827 static void
 828 setcurjob(struct job *cj)
 829 {
 830         struct job *jp, *prev;
 831
 832         for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
 833                 if (jp == cj) {
 834                         if (prev != NULL)
 835                                 prev->next = jp->next;
 836                         else
 837                                 jobmru = jp->next;
 838                         jp->next = jobmru;
 839                         jobmru = cj;
 840                         return;
 841                 }
 842         }
 843         cj->next = jobmru;
 844         jobmru = cj;
 845 }
 846
 847 static void
 848 deljob(struct job *j)
 849 {
 850         struct job *jp, *prev;
 851
 852         for (prev = NULL, jp = jobmru; jp != NULL; prev = jp, jp = jp->next) {
 853                 if (jp == j) {
 854                         if (prev != NULL)
 855                                 prev->next = jp->next;
 856                         else
 857                                 jobmru = jp->next;
 858                         return;
 859                 }
 860         }
 861 }
 862
 863 /*
 864  * Return the most recently used job that isn't `nj', and preferably one
 865  * that is stopped.
 866  */
 867 static struct job *
 868 getcurjob(struct job *nj)
 869 {
 870         struct job *jp;
 871
 872         /* Try to find a stopped one.. */
 873         for (jp = jobmru; jp != NULL; jp = jp->next)
 874                 if (jp->used && jp != nj && jp->state == JOBSTOPPED)
 875                         return (jp);
 876         /* Otherwise the most recently used job that isn't `nj' */
 877         for (jp = jobmru; jp != NULL; jp = jp->next)
 878                 if (jp->used && jp != nj)
 879                         return (jp);
 880
 881         return (NULL);
 882 }
 883
 884 #endif
 885
 886 /*
 887  * Fork of a subshell.  If we are doing job control, give the subshell its
 888  * own process group.  Jp is a job structure that the job is to be added to.
 889  * N is the command that will be evaluated by the child.  Both jp and n may
 890  * be NULL.  The mode parameter can be one of the following:
 891  *      FORK_FG - Fork off a foreground process.
 892  *      FORK_BG - Fork off a background process.
 893  *      FORK_NOJOB - Like FORK_FG, but don't give the process its own
 894  *                   process group even if job control is on.
 895  *
 896  * When job control is turned off, background processes have their standard
 897  * input redirected to /dev/null (except for the second and later processes
 898  * in a pipeline).
 899  */
 900
 901 pid_t
 902 forkshell(struct job *jp, union node *n, int mode)
 903 {
 904         pid_t pid;
 905         pid_t pgrp;
 906
 907         TRACE(("forkshell(%%%td, %p, %d) called\n", jp - jobtab, (void *)n,
 908             mode));
 909         INTOFF;
 910         if (mode == FORK_BG && (jp == NULL || jp->nprocs == 0))
 911                 checkzombies();
 912         flushall();
 913         pid = fork();
 914         if (pid == -1) {
 915                 TRACE(("Fork failed, errno=%d\n", errno));
 916                 INTON;
 917                 error("Cannot fork: %s", strerror(errno));
 918         }
 919         if (pid == 0) {
 920                 struct job *p;
 921                 int wasroot;
 922                 int i;
 923
 924                 TRACE(("Child shell %d\n", (int)getpid()));
 925                 wasroot = rootshell;
 926                 rootshell = 0;
 927                 handler = &main_handler;
 928                 closescript();
 929                 INTON;
 930                 forcelocal = 0;
 931                 clear_traps();
 932 #if JOBS
 933                 jobctl = 0;             /* do job control only in root shell */
 934                 if (wasroot && mode != FORK_NOJOB && mflag) {
 935                         if (jp == NULL || jp->nprocs == 0)
 936                                 pgrp = getpid();
 937                         else
 938                                 pgrp = jp->ps[0].pid;
 939                         if (setpgid(0, pgrp) == 0 && mode == FORK_FG &&
 940                             ttyfd >= 0) {
 941                                 /*** this causes superfluous TIOCSPGRPS ***/
 942                                 if (tcsetpgrp(ttyfd, pgrp) < 0)
 943                                         error("tcsetpgrp failed, errno=%d", errno);
 944                         }
 945                         setsignal(SIGTSTP);
 946                         setsignal(SIGTTOU);
 947                 } else if (mode == FORK_BG) {
 948                         ignoresig(SIGINT);
 949                         ignoresig(SIGQUIT);
 950                         if ((jp == NULL || jp->nprocs == 0) &&
 951                             ! fd0_redirected_p ()) {
 952                                 close(0);
 953                                 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
 954                                         error("cannot open %s: %s",
 955                                             _PATH_DEVNULL, strerror(errno));
 956                         }
 957                 }
 958 #else
 959                 if (mode == FORK_BG) {
 960                         ignoresig(SIGINT);
 961                         ignoresig(SIGQUIT);
 962                         if ((jp == NULL || jp->nprocs == 0) &&
 963                             ! fd0_redirected_p ()) {
 964                                 close(0);
 965                                 if (open(_PATH_DEVNULL, O_RDONLY) != 0)
 966                                         error("cannot open %s: %s",
 967                                             _PATH_DEVNULL, strerror(errno));
 968                         }
 969                 }
 970 #endif
 971                 INTOFF;
 972                 for (i = njobs, p = jobtab ; --i >= 0 ; p++)
 973                         if (p->used)
 974                                 freejob(p);
 975                 INTON;
 976                 if (wasroot && iflag) {
 977                         setsignal(SIGINT);
 978                         setsignal(SIGQUIT);
 979                         setsignal(SIGTERM);
 980                 }
 981                 return pid;
 982         }
 983         if (rootshell && mode != FORK_NOJOB && mflag) {
 984                 if (jp == NULL || jp->nprocs == 0)
 985                         pgrp = pid;
 986                 else
 987                         pgrp = jp->ps[0].pid;
 988                 setpgid(pid, pgrp);
 989         }
 990         if (mode == FORK_BG) {
 991                 if (bgjob != NULL && bgjob->state == JOBDONE &&
 992                     !bgjob->remembered && !iflag)
 993                         freejob(bgjob);
 994                 backgndpid = pid;               /* set $! */
 995                 bgjob = jp;
 996         }
 997         if (jp) {
 998                 struct procstat *ps = &jp->ps[jp->nprocs++];
 999                 ps->pid = pid;
1000                 ps->status = -1;
1001                 ps->cmd = nullstr;
1002                 if (iflag && rootshell && n)
1003                         ps->cmd = commandtext(n);
1004                 jp->foreground = mode == FORK_FG;
1005 #if JOBS
1006                 setcurjob(jp);
1007 #endif
1008         }
1009         INTON;
1010         TRACE(("In parent shell:  child = %d\n", (int)pid));
1011         return pid;
1012 }
1013
1014
1015 pid_t
1016 vforkexecshell(struct job *jp, char **argv, char **envp, const char *path, int idx, int pip[2])
1017 {
1018         pid_t pid;
1019         struct jmploc jmploc;
1020         struct jmploc *savehandler;
1021         int inton;
1022
1023         TRACE(("vforkexecshell(%%%td, %s, %p) called\n", jp - jobtab, argv[0],
1024             (void *)pip));
1025         inton = is_int_on();
1026         INTOFF;
1027         flushall();
1028         savehandler = handler;
1029         pid = vfork();
1030         if (pid == -1) {
1031                 TRACE(("Vfork failed, errno=%d\n", errno));
1032                 INTON;
1033                 error("Cannot fork: %s", strerror(errno));
1034         }
1035         if (pid == 0) {
1036                 TRACE(("Child shell %d\n", (int)getpid()));
1037                 if (setjmp(jmploc.loc))
1038                         _exit(exitstatus);
1039                 if (pip != NULL) {
1040                         close(pip[0]);
1041                         if (pip[1] != 1) {
1042                                 dup2(pip[1], 1);
1043                                 close(pip[1]);
1044                         }
1045                 }
1046                 handler = &jmploc;
1047                 shellexec(argv, envp, path, idx);
1048         }
1049         handler = savehandler;
1050         if (jp) {
1051                 struct procstat *ps = &jp->ps[jp->nprocs++];
1052                 ps->pid = pid;
1053                 ps->status = -1;
1054                 ps->cmd = nullstr;
1055                 jp->foreground = 1;
1056 #if JOBS
1057                 setcurjob(jp);
1058 #endif
1059         }
1060         SETINTON(inton);
1061         TRACE(("In parent shell:  child = %d\n", (int)pid));
1062         return pid;
1063 }
1064
1065
1066 /*
1067  * Wait for job to finish.
1068  *
1069  * Under job control we have the problem that while a child process is
1070  * running interrupts generated by the user are sent to the child but not
1071  * to the shell.  This means that an infinite loop started by an inter-
1072  * active user may be hard to kill.  With job control turned off, an
1073  * interactive user may place an interactive program inside a loop.  If
1074  * the interactive program catches interrupts, the user doesn't want
1075  * these interrupts to also abort the loop.  The approach we take here
1076  * is to have the shell ignore interrupt signals while waiting for a
1077  * foreground process to terminate, and then send itself an interrupt
1078  * signal if the child process was terminated by an interrupt signal.
1079  * Unfortunately, some programs want to do a bit of cleanup and then
1080  * exit on interrupt; unless these processes terminate themselves by
1081  * sending a signal to themselves (instead of calling exit) they will
1082  * confuse this approach.
1083  */
1084
1085 int
1086 waitforjob(struct job *jp, int *signaled)
1087 {
1088 #if JOBS
1089         int propagate_int = jp->jobctl && jp->foreground;
1090 #endif
1091         int status;
1092         int st;
1093
1094         INTOFF;
1095         TRACE(("waitforjob(%%%td) called\n", jp - jobtab + 1));
1096         while (jp->state == 0)
1097                 if (dowait(DOWAIT_BLOCK | (Tflag ? DOWAIT_SIG |
1098                     DOWAIT_SIG_TRAP : 0), jp) == -1)
1099                         dotrap();
1100 #if JOBS
1101         if (jp->jobctl) {
1102                 if (ttyfd >= 0 && tcsetpgrp(ttyfd, rootpid) < 0)
1103                         error("tcsetpgrp failed, errno=%d\n", errno);
1104         }
1105         if (jp->state == JOBSTOPPED)
1106                 setcurjob(jp);
1107 #endif
1108         status = getjobstatus(jp);
1109         if (signaled != NULL)
1110                 *signaled = WIFSIGNALED(status);
1111         /* convert to 8 bits */
1112         if (WIFEXITED(status))
1113                 st = WEXITSTATUS(status);
1114 #if JOBS
1115         else if (WIFSTOPPED(status))
1116                 st = WSTOPSIG(status) + 128;
1117 #endif
1118         else
1119                 st = WTERMSIG(status) + 128;
1120         if (! JOBS || jp->state == JOBDONE)
1121                 freejob(jp);
1122         if (int_pending()) {
1123                 if (!WIFSIGNALED(status) || WTERMSIG(status) != SIGINT)
1124                         CLEAR_PENDING_INT;
1125         }
1126 #if JOBS
1127         else if (rootshell && propagate_int &&
1128                         WIFSIGNALED(status) && WTERMSIG(status) == SIGINT)
1129                 kill(getpid(), SIGINT);
1130 #endif
1131         INTON;
1132         return st;
1133 }
1134
1135
1136 static void
1137 dummy_handler(int sig __unused)
1138 {
1139 }
1140
1141 /*
1142  * Wait for a process to terminate.
1143  */
1144
1145 static pid_t
1146 dowait(int mode, struct job *job)
1147 {
1148         struct sigaction sa, osa;
1149         sigset_t mask, omask;
1150         pid_t pid;
1151         int status;
1152         struct procstat *sp;
1153         struct job *jp;
1154         struct job *thisjob;
1155         const char *sigstr;
1156         int done;
1157         int stopped;
1158         int sig;
1159         int coredump;
1160         int wflags;
1161         int restore_sigchld;
1162
1163         TRACE(("dowait(%d, %p) called\n", mode, job));
1164         restore_sigchld = 0;
1165         if ((mode & DOWAIT_SIG) != 0) {
1166                 sigfillset(&mask);
1167                 sigprocmask(SIG_BLOCK, &mask, &omask);
1168                 INTOFF;
1169                 if (!issigchldtrapped()) {
1170                         restore_sigchld = 1;
1171                         sa.sa_handler = dummy_handler;
1172                         sa.sa_flags = 0;
1173                         sigemptyset(&sa.sa_mask);
1174                         sigaction(SIGCHLD, &sa, &osa);
1175                 }
1176         }
1177         do {
1178 #if JOBS
1179                 if (iflag)
1180                         wflags = WUNTRACED | WCONTINUED;
1181                 else
1182 #endif
1183                         wflags = 0;
1184                 if ((mode & (DOWAIT_BLOCK | DOWAIT_SIG)) != DOWAIT_BLOCK)
1185                         wflags |= WNOHANG;
1186                 pid = wait3(&status, wflags, (struct rusage *)NULL);
1187                 TRACE(("wait returns %d, status=%d\n", (int)pid, status));
1188                 if (pid == 0 && (mode & DOWAIT_SIG) != 0) {
1189                         pid = -1;
1190                         if (((mode & DOWAIT_SIG_TRAP) != 0 ?
1191                             pendingsig : pendingsig_waitcmd) != 0) {
1192                                 errno = EINTR;
1193                                 break;
1194                         }
1195                         sigsuspend(&omask);
1196                         if (int_pending())
1197                                 break;
1198                 }
1199         } while (pid == -1 && errno == EINTR);
1200         if (pid == -1 && errno == ECHILD && job != NULL)
1201                 job->state = JOBDONE;
1202         if ((mode & DOWAIT_SIG) != 0) {
1203                 if (restore_sigchld)
1204                         sigaction(SIGCHLD, &osa, NULL);
1205                 sigprocmask(SIG_SETMASK, &omask, NULL);
1206                 INTON;
1207         }
1208         if (pid <= 0)
1209                 return pid;
1210         INTOFF;
1211         thisjob = NULL;
1212         for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
1213                 if (jp->used && jp->nprocs > 0) {
1214                         done = 1;
1215                         stopped = 1;
1216                         for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
1217                                 if (sp->pid == -1)
1218                                         continue;
1219                                 if (sp->pid == pid && (sp->status == -1 ||
1220                                     WIFSTOPPED(sp->status))) {
1221                                         TRACE(("Changing status of proc %d from 0x%x to 0x%x\n",
1222                                                    (int)pid, sp->status,
1223                                                    status));
1224                                         if (WIFCONTINUED(status)) {
1225                                                 sp->status = -1;
1226                                                 jp->state = 0;
1227                                         } else
1228                                                 sp->status = status;
1229                                         thisjob = jp;
1230                                 }
1231                                 if (sp->status == -1)
1232                                         stopped = 0;
1233                                 else if (WIFSTOPPED(sp->status))
1234                                         done = 0;
1235                         }
1236                         if (stopped) {          /* stopped or done */
1237                                 int state = done? JOBDONE : JOBSTOPPED;
1238                                 if (jp->state != state) {
1239                                         TRACE(("Job %td: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
1240                                         jp->state = state;
1241                                         if (jp != job) {
1242                                                 if (done && !jp->remembered &&
1243                                                     !iflag && jp != bgjob)
1244                                                         freejob(jp);
1245 #if JOBS
1246                                                 else if (done)
1247                                                         deljob(jp);
1248 #endif
1249                                         }
1250                                 }
1251                         }
1252                 }
1253         }
1254         INTON;
1255         if (!thisjob || thisjob->state == 0)
1256                 ;
1257         else if ((!rootshell || !iflag || thisjob == job) &&
1258             thisjob->foreground && thisjob->state != JOBSTOPPED) {
1259                 sig = 0;
1260                 coredump = 0;
1261                 for (sp = thisjob->ps; sp < thisjob->ps + thisjob->nprocs; sp++)
1262                         if (WIFSIGNALED(sp->status)) {
1263                                 sig = WTERMSIG(sp->status);
1264                                 coredump = WCOREDUMP(sp->status);
1265                         }
1266                 if (sig > 0 && sig != SIGINT && sig != SIGPIPE) {
1267                         sigstr = strsignal(sig);
1268                         if (sigstr != NULL)
1269                                 out2str(sigstr);
1270                         else
1271                                 out2str("Unknown signal");
1272                         if (coredump)
1273                                 out2str(" (core dumped)");
1274                         out2c('\n');
1275                         flushout(out2);
1276                 }
1277         } else {
1278                 TRACE(("Not printing status, rootshell=%d, job=%p\n", rootshell, job));
1279                 thisjob->changed = 1;
1280         }
1281         return pid;
1282 }
1283
1284
1285
1286 /*
1287  * return 1 if there are stopped jobs, otherwise 0
1288  */
1289 int job_warning = 0;
1290 int
1291 stoppedjobs(void)
1292 {
1293         int jobno;
1294         struct job *jp;
1295
1296         if (job_warning)
1297                 return (0);
1298         for (jobno = 1, jp = jobtab; jobno <= njobs; jobno++, jp++) {
1299                 if (jp->used == 0)
1300                         continue;
1301                 if (jp->state == JOBSTOPPED) {
1302                         out2fmt_flush("You have stopped jobs.\n");
1303                         job_warning = 2;
1304                         return (1);
1305                 }
1306         }
1307
1308         return (0);
1309 }
1310
1311
1312 static void
1313 checkzombies(void)
1314 {
1315         while (njobs > 0 && dowait(0, NULL) > 0)
1316                 ;
1317 }
1318
1319
1320 int
1321 backgndpidset(void)
1322 {
1323         return backgndpid != -1;
1324 }
1325
1326
1327 pid_t
1328 backgndpidval(void)
1329 {
1330         if (bgjob != NULL && !forcelocal)
1331                 bgjob->remembered = 1;
1332         return backgndpid;
1333 }
1334
1335 /*
1336  * Return a string identifying a command (to be printed by the
1337  * jobs command.
1338  */
1339
1340 static char *cmdnextc;
1341 static int cmdnleft;
1342 #define MAXCMDTEXT      200
1343
1344 char *
1345 commandtext(union node *n)
1346 {
1347         char *name;
1348
1349         cmdnextc = name = ckmalloc(MAXCMDTEXT);
1350         cmdnleft = MAXCMDTEXT - 4;
1351         cmdtxt(n);
1352         *cmdnextc = '\0';
1353         return name;
1354 }
1355
1356
1357 static void
1358 cmdtxtdogroup(union node *n)
1359 {
1360         cmdputs("; do ");
1361         cmdtxt(n);
1362         cmdputs("; done");
1363 }
1364
1365
1366 static void
1367 cmdtxtredir(union node *n, const char *op, int deffd)
1368 {
1369         char s[2];
1370
1371         if (n->nfile.fd != deffd) {
1372                 s[0] = n->nfile.fd + '0';
1373                 s[1] = '\0';
1374                 cmdputs(s);
1375         }
1376         cmdputs(op);
1377         if (n->type == NTOFD || n->type == NFROMFD) {
1378                 if (n->ndup.dupfd >= 0)
1379                         s[0] = n->ndup.dupfd + '0';
1380                 else
1381                         s[0] = '-';
1382                 s[1] = '\0';
1383                 cmdputs(s);
1384         } else {
1385                 cmdtxt(n->nfile.fname);
1386         }
1387 }
1388
1389
1390 static void
1391 cmdtxt(union node *n)
1392 {
1393         union node *np;
1394         struct nodelist *lp;
1395
1396         if (n == NULL)
1397                 return;
1398         switch (n->type) {
1399         case NSEMI:
1400                 cmdtxt(n->nbinary.ch1);
1401                 cmdputs("; ");
1402                 cmdtxt(n->nbinary.ch2);
1403                 break;
1404         case NAND:
1405                 cmdtxt(n->nbinary.ch1);
1406                 cmdputs(" && ");
1407                 cmdtxt(n->nbinary.ch2);
1408                 break;
1409         case NOR:
1410                 cmdtxt(n->nbinary.ch1);
1411                 cmdputs(" || ");
1412                 cmdtxt(n->nbinary.ch2);
1413                 break;
1414         case NPIPE:
1415                 for (lp = n->npipe.cmdlist ; lp ; lp = lp->next) {
1416                         cmdtxt(lp->n);
1417                         if (lp->next)
1418                                 cmdputs(" | ");
1419                 }
1420                 break;
1421         case NSUBSHELL:
1422                 cmdputs("(");
1423                 cmdtxt(n->nredir.n);
1424                 cmdputs(")");
1425                 break;
1426         case NREDIR:
1427         case NBACKGND:
1428                 cmdtxt(n->nredir.n);
1429                 break;
1430         case NIF:
1431                 cmdputs("if ");
1432                 cmdtxt(n->nif.test);
1433                 cmdputs("; then ");
1434                 cmdtxt(n->nif.ifpart);
1435                 cmdputs("...");
1436                 break;
1437         case NWHILE:
1438                 cmdputs("while ");
1439                 cmdtxt(n->nbinary.ch1);
1440                 cmdtxtdogroup(n->nbinary.ch2);
1441                 break;
1442         case NUNTIL:
1443                 cmdputs("until ");
1444                 cmdtxt(n->nbinary.ch1);
1445                 cmdtxtdogroup(n->nbinary.ch2);
1446                 break;
1447         case NFOR:
1448                 cmdputs("for ");
1449                 cmdputs(n->nfor.var);
1450                 cmdputs(" in ...");
1451                 break;
1452         case NCASE:
1453                 cmdputs("case ");
1454                 cmdputs(n->ncase.expr->narg.text);
1455                 cmdputs(" in ...");
1456                 break;
1457         case NDEFUN:
1458                 cmdputs(n->narg.text);
1459                 cmdputs("() ...");
1460                 break;
1461         case NNOT:
1462                 cmdputs("! ");
1463                 cmdtxt(n->nnot.com);
1464                 break;
1465         case NCMD:
1466                 for (np = n->ncmd.args ; np ; np = np->narg.next) {
1467                         cmdtxt(np);
1468                         if (np->narg.next)
1469                                 cmdputs(" ");
1470                 }
1471                 for (np = n->ncmd.redirect ; np ; np = np->nfile.next) {
1472                         cmdputs(" ");
1473                         cmdtxt(np);
1474                 }
1475                 break;
1476         case NARG:
1477                 cmdputs(n->narg.text);
1478                 break;
1479         case NTO:
1480                 cmdtxtredir(n, ">", 1);
1481                 break;
1482         case NAPPEND:
1483                 cmdtxtredir(n, ">>", 1);
1484                 break;
1485         case NTOFD:
1486                 cmdtxtredir(n, ">&", 1);
1487                 break;
1488         case NCLOBBER:
1489                 cmdtxtredir(n, ">|", 1);
1490                 break;
1491         case NFROM:
1492                 cmdtxtredir(n, "<", 0);
1493                 break;
1494         case NFROMTO:
1495                 cmdtxtredir(n, "<>", 0);
1496                 break;
1497         case NFROMFD:
1498                 cmdtxtredir(n, "<&", 0);
1499                 break;
1500         case NHERE:
1501         case NXHERE:
1502                 cmdputs("<<...");
1503                 break;
1504         default:
1505                 cmdputs("???");
1506                 break;
1507         }
1508 }
1509
1510
1511
1512 static void
1513 cmdputs(const char *s)
1514 {
1515         const char *p;
1516         char *q;
1517         char c;
1518         int subtype = 0;
1519
1520         if (cmdnleft <= 0)
1521                 return;
1522         p = s;
1523         q = cmdnextc;
1524         while ((c = *p++) != '\0') {
1525                 if (c == CTLESC)
1526                         *q++ = *p++;
1527                 else if (c == CTLVAR) {
1528                         *q++ = '$';
1529                         if (--cmdnleft > 0)
1530                                 *q++ = '{';
1531                         subtype = *p++;
1532                         if ((subtype & VSTYPE) == VSLENGTH && --cmdnleft > 0)
1533                                 *q++ = '#';
1534                 } else if (c == '=' && subtype != 0) {
1535                         *q = "}-+?=##%%\0X"[(subtype & VSTYPE) - VSNORMAL];
1536                         if (*q)
1537                                 q++;
1538                         else
1539                                 cmdnleft++;
1540                         if (((subtype & VSTYPE) == VSTRIMLEFTMAX ||
1541                             (subtype & VSTYPE) == VSTRIMRIGHTMAX) &&
1542                             --cmdnleft > 0)
1543                                 *q = q[-1], q++;
1544                         subtype = 0;
1545                 } else if (c == CTLENDVAR) {
1546                         *q++ = '}';
1547                 } else if (c == CTLBACKQ || c == CTLBACKQ+CTLQUOTE) {
1548                         cmdnleft -= 5;
1549                         if (cmdnleft > 0) {
1550                                 *q++ = '$';
1551                                 *q++ = '(';
1552                                 *q++ = '.';
1553                                 *q++ = '.';
1554                                 *q++ = '.';
1555                                 *q++ = ')';
1556                         }
1557                 } else if (c == CTLARI) {
1558                         cmdnleft -= 2;
1559                         if (cmdnleft > 0) {
1560                                 *q++ = '$';
1561                                 *q++ = '(';
1562                                 *q++ = '(';
1563                         }
1564                         p++;
1565                 } else if (c == CTLENDARI) {
1566                         if (--cmdnleft > 0) {
1567                                 *q++ = ')';
1568                                 *q++ = ')';
1569                         }
1570                 } else if (c == CTLQUOTEMARK || c == CTLQUOTEEND)
1571                         cmdnleft++; /* ignore */
1572                 else
1573                         *q++ = c;
1574                 if (--cmdnleft <= 0) {
1575                         *q++ = '.';
1576                         *q++ = '.';
1577                         *q++ = '.';
1578                         break;
1579                 }
1580         }
1581         cmdnextc = q;
1582 }