contrib/nvi/ex/ex_script.c

   1 /*-
   2  * Copyright (c) 1992, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  * Copyright (c) 1992, 1993, 1994, 1995, 1996
   5  *      Keith Bostic.  All rights reserved.
   6  *
   7  * This code is derived from software contributed to Berkeley by
   8  * Brian Hirt.
   9  *
  10  * See the LICENSE file for redistribution information.
  11  */
  12
  13 #include "config.h"
  14
  15 #ifndef lint
  16 static const char sccsid[] = "@(#)ex_script.c   10.30 (Berkeley) 9/24/96";
  17 #endif /* not lint */
  18
  19 #include <sys/types.h>
  20 #include <sys/ioctl.h>
  21 #include <sys/queue.h>
  22 #ifdef HAVE_SYS_SELECT_H
  23 #include <sys/select.h>
  24 #endif
  25 #include <sys/stat.h>
  26 #ifdef HAVE_SYS5_PTY
  27 #include <sys/stropts.h>
  28 #endif
  29 #include <sys/time.h>
  30 #include <sys/wait.h>
  31
  32 #include <bitstring.h>
  33 #include <errno.h>
  34 #include <fcntl.h>
  35 #include <stdio.h>              /* XXX: OSF/1 bug: include before <grp.h> */
  36 #include <grp.h>
  37 #include <limits.h>
  38 #include <stdlib.h>
  39 #include <string.h>
  40 #include <termios.h>
  41 #include <unistd.h>
  42
  43 #include "../common/common.h"
  44 #include "../vi/vi.h"
  45 #include "script.h"
  46 #include "pathnames.h"
  47
  48 static void     sscr_check __P((SCR *));
  49 static int      sscr_getprompt __P((SCR *));
  50 static int      sscr_init __P((SCR *));
  51 static int      sscr_insert __P((SCR *));
  52 static int      sscr_matchprompt __P((SCR *, char *, size_t, size_t *));
  53 static int      sscr_pty __P((int *, int *, char *, struct termios *, void *));
  54 static int      sscr_setprompt __P((SCR *, char *, size_t));
  55
  56 /*
  57  * ex_script -- : sc[ript][!] [file]
  58  *      Switch to script mode.
  59  *
  60  * PUBLIC: int ex_script __P((SCR *, EXCMD *));
  61  */
  62 int
  63 ex_script(sp, cmdp)
  64         SCR *sp;
  65         EXCMD *cmdp;
  66 {
  67         /* Vi only command. */
  68         if (!F_ISSET(sp, SC_VI)) {
  69                 msgq(sp, M_ERR,
  70                     "150|The script command is only available in vi mode");
  71                 return (1);
  72         }
  73
  74         /* Switch to the new file. */
  75         if (cmdp->argc != 0 && ex_edit(sp, cmdp))
  76                 return (1);
  77
  78         /* Create the shell, figure out the prompt. */
  79         if (sscr_init(sp))
  80                 return (1);
  81
  82         return (0);
  83 }
  84
  85 /*
  86  * sscr_init --
  87  *      Create a pty setup for a shell.
  88  */
  89 static int
  90 sscr_init(sp)
  91         SCR *sp;
  92 {
  93         SCRIPT *sc;
  94         char *sh, *sh_path;
  95
  96         /* We're going to need a shell. */
  97         if (opts_empty(sp, O_SHELL, 0))
  98                 return (1);
  99
 100         MALLOC_RET(sp, sc, SCRIPT *, sizeof(SCRIPT));
 101         sp->script = sc;
 102         sc->sh_prompt = NULL;
 103         sc->sh_prompt_len = 0;
 104
 105         /*
 106          * There are two different processes running through this code.
 107          * They are the shell and the parent.
 108          */
 109         sc->sh_master = sc->sh_slave = -1;
 110
 111         if (tcgetattr(STDIN_FILENO, &sc->sh_term) == -1) {
 112                 msgq(sp, M_SYSERR, "tcgetattr");
 113                 goto err;
 114         }
 115
 116         /*
 117          * Turn off output postprocessing and echo.
 118          */
 119         sc->sh_term.c_oflag &= ~OPOST;
 120         sc->sh_term.c_cflag &= ~(ECHO|ECHOE|ECHONL|ECHOK);
 121
 122 #ifdef TIOCGWINSZ
 123         if (ioctl(STDIN_FILENO, TIOCGWINSZ, &sc->sh_win) == -1) {
 124                 msgq(sp, M_SYSERR, "tcgetattr");
 125                 goto err;
 126         }
 127
 128         if (sscr_pty(&sc->sh_master,
 129             &sc->sh_slave, sc->sh_name, &sc->sh_term, &sc->sh_win) == -1) {
 130                 msgq(sp, M_SYSERR, "pty");
 131                 goto err;
 132         }
 133 #else
 134         if (sscr_pty(&sc->sh_master,
 135             &sc->sh_slave, sc->sh_name, &sc->sh_term, NULL) == -1) {
 136                 msgq(sp, M_SYSERR, "pty");
 137                 goto err;
 138         }
 139 #endif
 140
 141         /*
 142          * __TK__ huh?
 143          * Don't use vfork() here, because the signal semantics differ from
 144          * implementation to implementation.
 145          */
 146         switch (sc->sh_pid = fork()) {
 147         case -1:                        /* Error. */
 148                 msgq(sp, M_SYSERR, "fork");
 149 err:            if (sc->sh_master != -1)
 150                         (void)close(sc->sh_master);
 151                 if (sc->sh_slave != -1)
 152                         (void)close(sc->sh_slave);
 153                 return (1);
 154         case 0:                         /* Utility. */
 155                 /*
 156                  * XXX
 157                  * So that shells that do command line editing turn it off.
 158                  */
 159                 (void)setenv("TERM", "emacs", 1);
 160                 (void)setenv("TERMCAP", "emacs:", 1);
 161                 (void)setenv("EMACS", "t", 1);
 162
 163                 (void)setsid();
 164 #ifdef TIOCSCTTY
 165                 /*
 166                  * 4.4BSD allocates a controlling terminal using the TIOCSCTTY
 167                  * ioctl, not by opening a terminal device file.  POSIX 1003.1
 168                  * doesn't define a portable way to do this.  If TIOCSCTTY is
 169                  * not available, hope that the open does it.
 170                  */
 171                 (void)ioctl(sc->sh_slave, TIOCSCTTY, 0);
 172 #endif
 173                 (void)close(sc->sh_master);
 174                 (void)dup2(sc->sh_slave, STDIN_FILENO);
 175                 (void)dup2(sc->sh_slave, STDOUT_FILENO);
 176                 (void)dup2(sc->sh_slave, STDERR_FILENO);
 177                 (void)close(sc->sh_slave);
 178
 179                 /* Assumes that all shells have -i. */
 180                 sh_path = O_STR(sp, O_SHELL);
 181                 if ((sh = strrchr(sh_path, '/')) == NULL)
 182                         sh = sh_path;
 183                 else
 184                         ++sh;
 185                 execl(sh_path, sh, "-i", NULL);
 186                 msgq_str(sp, M_SYSERR, sh_path, "execl: %s");
 187                 _exit(127);
 188         default:                        /* Parent. */
 189                 break;
 190         }
 191
 192         if (sscr_getprompt(sp))
 193                 return (1);
 194
 195         F_SET(sp, SC_SCRIPT);
 196         F_SET(sp->gp, G_SCRWIN);
 197         return (0);
 198 }
 199
 200 /*
 201  * sscr_getprompt --
 202  *      Eat lines printed by the shell until a line with no trailing
 203  *      carriage return comes; set the prompt from that line.
 204  */
 205 static int
 206 sscr_getprompt(sp)
 207         SCR *sp;
 208 {
 209         struct timeval tv;
 210         CHAR_T *endp, *p, *t, buf[1024];
 211         SCRIPT *sc;
 212         fd_set fdset;
 213         recno_t lline;
 214         size_t llen, len;
 215         u_int value;
 216         int nr;
 217
 218         FD_ZERO(&fdset);
 219         endp = buf;
 220         len = sizeof(buf);
 221
 222         /* Wait up to a second for characters to read. */
 223         tv.tv_sec = 5;
 224         tv.tv_usec = 0;
 225         sc = sp->script;
 226         FD_SET(sc->sh_master, &fdset);
 227         switch (select(sc->sh_master + 1, &fdset, NULL, NULL, &tv)) {
 228         case -1:                /* Error or interrupt. */
 229                 msgq(sp, M_SYSERR, "select");
 230                 goto prompterr;
 231         case  0:                /* Timeout */
 232                 msgq(sp, M_ERR, "Error: timed out");
 233                 goto prompterr;
 234         case  1:                /* Characters to read. */
 235                 break;
 236         }
 237
 238         /* Read the characters. */
 239 more:   len = sizeof(buf) - (endp - buf);
 240         switch (nr = read(sc->sh_master, endp, len)) {
 241         case  0:                        /* EOF. */
 242                 msgq(sp, M_ERR, "Error: shell: EOF");
 243                 goto prompterr;
 244         case -1:                        /* Error or interrupt. */
 245                 msgq(sp, M_SYSERR, "shell");
 246                 goto prompterr;
 247         default:
 248                 endp += nr;
 249                 break;
 250         }
 251
 252         /* If any complete lines, push them into the file. */
 253         for (p = t = buf; p < endp; ++p) {
 254                 value = KEY_VAL(sp, *p);
 255                 if (value == K_CR || value == K_NL) {
 256                         if (db_last(sp, &lline) ||
 257                             db_append(sp, 0, lline, t, p - t))
 258                                 goto prompterr;
 259                         t = p + 1;
 260                 }
 261         }
 262         if (p > buf) {
 263                 memmove(buf, t, endp - t);
 264                 endp = buf + (endp - t);
 265         }
 266         if (endp == buf)
 267                 goto more;
 268
 269         /* Wait up 1/10 of a second to make sure that we got it all. */
 270         tv.tv_sec = 0;
 271         tv.tv_usec = 100000;
 272         switch (select(sc->sh_master + 1, &fdset, NULL, NULL, &tv)) {
 273         case -1:                /* Error or interrupt. */
 274                 msgq(sp, M_SYSERR, "select");
 275                 goto prompterr;
 276         case  0:                /* Timeout */
 277                 break;
 278         case  1:                /* Characters to read. */
 279                 goto more;
 280         }
 281
 282         /* Timed out, so theoretically we have a prompt. */
 283         llen = endp - buf;
 284         endp = buf;
 285
 286         /* Append the line into the file. */
 287         if (db_last(sp, &lline) || db_append(sp, 0, lline, buf, llen)) {
 288 prompterr:      sscr_end(sp);
 289                 return (1);
 290         }
 291
 292         return (sscr_setprompt(sp, buf, llen));
 293 }
 294
 295 /*
 296  * sscr_exec --
 297  *      Take a line and hand it off to the shell.
 298  *
 299  * PUBLIC: int sscr_exec __P((SCR *, recno_t));
 300  */
 301 int
 302 sscr_exec(sp, lno)
 303         SCR *sp;
 304         recno_t lno;
 305 {
 306         SCRIPT *sc;
 307         recno_t last_lno;
 308         size_t blen, len, last_len, tlen;
 309         int isempty, matchprompt, nw, rval;
 310         char *bp, *p;
 311
 312         /* If there's a prompt on the last line, append the command. */
 313         if (db_last(sp, &last_lno))
 314                 return (1);
 315         if (db_get(sp, last_lno, DBG_FATAL, &p, &last_len))
 316                 return (1);
 317         if (sscr_matchprompt(sp, p, last_len, &tlen) && tlen == 0) {
 318                 matchprompt = 1;
 319                 GET_SPACE_RET(sp, bp, blen, last_len + 128);
 320                 memmove(bp, p, last_len);
 321         } else
 322                 matchprompt = 0;
 323
 324         /* Get something to execute. */
 325         if (db_eget(sp, lno, &p, &len, &isempty)) {
 326                 if (isempty)
 327                         goto empty;
 328                 goto err1;
 329         }
 330
 331         /* Empty lines aren't interesting. */
 332         if (len == 0)
 333                 goto empty;
 334
 335         /* Delete any prompt. */
 336         if (sscr_matchprompt(sp, p, len, &tlen)) {
 337                 if (tlen == len) {
 338 empty:                  msgq(sp, M_BERR, "151|No command to execute");
 339                         goto err1;
 340                 }
 341                 p += (len - tlen);
 342                 len = tlen;
 343         }
 344
 345         /* Push the line to the shell. */
 346         sc = sp->script;
 347         if ((nw = write(sc->sh_master, p, len)) != len)
 348                 goto err2;
 349         rval = 0;
 350         if (write(sc->sh_master, "\n", 1) != 1) {
 351 err2:           if (nw == 0)
 352                         errno = EIO;
 353                 msgq(sp, M_SYSERR, "shell");
 354                 goto err1;
 355         }
 356
 357         if (matchprompt) {
 358                 ADD_SPACE_RET(sp, bp, blen, last_len + len);
 359                 memmove(bp + last_len, p, len);
 360                 if (db_set(sp, last_lno, bp, last_len + len))
 361 err1:                   rval = 1;
 362         }
 363         if (matchprompt)
 364                 FREE_SPACE(sp, bp, blen);
 365         return (rval);
 366 }
 367
 368 /*
 369  * sscr_input --
 370  *      Read any waiting shell input.
 371  *
 372  * PUBLIC: int sscr_input __P((SCR *));
 373  */
 374 int
 375 sscr_input(sp)
 376         SCR *sp;
 377 {
 378         GS *gp;
 379         struct timeval poll;
 380         fd_set rdfd;
 381         int maxfd;
 382
 383         gp = sp->gp;
 384
 385 loop:   maxfd = 0;
 386         FD_ZERO(&rdfd);
 387         poll.tv_sec = 0;
 388         poll.tv_usec = 0;
 389
 390         /* Set up the input mask. */
 391         for (sp = gp->dq.cqh_first; sp != (void *)&gp->dq; sp = sp->q.cqe_next)
 392                 if (F_ISSET(sp, SC_SCRIPT)) {
 393                         FD_SET(sp->script->sh_master, &rdfd);
 394                         if (sp->script->sh_master > maxfd)
 395                                 maxfd = sp->script->sh_master;
 396                 }
 397
 398         /* Check for input. */
 399         switch (select(maxfd + 1, &rdfd, NULL, NULL, &poll)) {
 400         case -1:
 401                 msgq(sp, M_SYSERR, "select");
 402                 return (1);
 403         case 0:
 404                 return (0);
 405         default:
 406                 break;
 407         }
 408
 409         /* Read the input. */
 410         for (sp = gp->dq.cqh_first; sp != (void *)&gp->dq; sp = sp->q.cqe_next)
 411                 if (F_ISSET(sp, SC_SCRIPT) &&
 412                     FD_ISSET(sp->script->sh_master, &rdfd) && sscr_insert(sp))
 413                         return (1);
 414         goto loop;
 415 }
 416
 417 /*
 418  * sscr_insert --
 419  *      Take a line from the shell and insert it into the file.
 420  */
 421 static int
 422 sscr_insert(sp)
 423         SCR *sp;
 424 {
 425         struct timeval tv;
 426         CHAR_T *endp, *p, *t;
 427         SCRIPT *sc;
 428         fd_set rdfd;
 429         recno_t lno;
 430         size_t blen, len, tlen;
 431         u_int value;
 432         int nr, rval;
 433         char *bp;
 434
 435         /* Find out where the end of the file is. */
 436         if (db_last(sp, &lno))
 437                 return (1);
 438
 439 #define MINREAD 1024
 440         GET_SPACE_RET(sp, bp, blen, MINREAD);
 441         endp = bp;
 442
 443         /* Read the characters. */
 444         rval = 1;
 445         sc = sp->script;
 446 more:   switch (nr = read(sc->sh_master, endp, MINREAD)) {
 447         case  0:                        /* EOF; shell just exited. */
 448                 sscr_end(sp);
 449                 rval = 0;
 450                 goto ret;
 451         case -1:                        /* Error or interrupt. */
 452                 msgq(sp, M_SYSERR, "shell");
 453                 goto ret;
 454         default:
 455                 endp += nr;
 456                 break;
 457         }
 458
 459         /* Append the lines into the file. */
 460         for (p = t = bp; p < endp; ++p) {
 461                 value = KEY_VAL(sp, *p);
 462                 if (value == K_CR || value == K_NL) {
 463                         len = p - t;
 464                         if (db_append(sp, 1, lno++, t, len))
 465                                 goto ret;
 466                         t = p + 1;
 467                 }
 468         }
 469         if (p > t) {
 470                 len = p - t;
 471                 /*
 472                  * If the last thing from the shell isn't another prompt, wait
 473                  * up to 1/10 of a second for more stuff to show up, so that
 474                  * we don't break the output into two separate lines.  Don't
 475                  * want to hang indefinitely because some program is hanging,
 476                  * confused the shell, or whatever.
 477                  */
 478                 if (!sscr_matchprompt(sp, t, len, &tlen) || tlen != 0) {
 479                         tv.tv_sec = 0;
 480                         tv.tv_usec = 100000;
 481                         FD_ZERO(&rdfd);
 482                         FD_SET(sc->sh_master, &rdfd);
 483                         if (select(sc->sh_master + 1,
 484                             &rdfd, NULL, NULL, &tv) == 1) {
 485                                 memmove(bp, t, len);
 486                                 endp = bp + len;
 487                                 goto more;
 488                         }
 489                 }
 490                 if (sscr_setprompt(sp, t, len))
 491                         return (1);
 492                 if (db_append(sp, 1, lno++, t, len))
 493                         goto ret;
 494         }
 495
 496         /* The cursor moves to EOF. */
 497         sp->lno = lno;
 498         sp->cno = len ? len - 1 : 0;
 499         rval = vs_refresh(sp, 1);
 500
 501 ret:    FREE_SPACE(sp, bp, blen);
 502         return (rval);
 503 }
 504
 505 /*
 506  * sscr_setprompt --
 507  *
 508  * Set the prompt to the last line we got from the shell.
 509  *
 510  */
 511 static int
 512 sscr_setprompt(sp, buf, len)
 513         SCR *sp;
 514         char *buf;
 515         size_t len;
 516 {
 517         SCRIPT *sc;
 518
 519         sc = sp->script;
 520         if (sc->sh_prompt)
 521                 free(sc->sh_prompt);
 522         MALLOC(sp, sc->sh_prompt, char *, len + 1);
 523         if (sc->sh_prompt == NULL) {
 524                 sscr_end(sp);
 525                 return (1);
 526         }
 527         memmove(sc->sh_prompt, buf, len);
 528         sc->sh_prompt_len = len;
 529         sc->sh_prompt[len] = '\0';
 530         return (0);
 531 }
 532
 533 /*
 534  * sscr_matchprompt --
 535  *      Check to see if a line matches the prompt.  Nul's indicate
 536  *      parts that can change, in both content and size.
 537  */
 538 static int
 539 sscr_matchprompt(sp, lp, line_len, lenp)
 540         SCR *sp;
 541         char *lp;
 542         size_t line_len, *lenp;
 543 {
 544         SCRIPT *sc;
 545         size_t prompt_len;
 546         char *pp;
 547
 548         sc = sp->script;
 549         if (line_len < (prompt_len = sc->sh_prompt_len))
 550                 return (0);
 551
 552         for (pp = sc->sh_prompt;
 553             prompt_len && line_len; --prompt_len, --line_len) {
 554                 if (*pp == '\0') {
 555                         for (; prompt_len && *pp == '\0'; --prompt_len, ++pp);
 556                         if (!prompt_len)
 557                                 return (0);
 558                         for (; line_len && *lp != *pp; --line_len, ++lp);
 559                         if (!line_len)
 560                                 return (0);
 561                 }
 562                 if (*pp++ != *lp++)
 563                         break;
 564         }
 565
 566         if (prompt_len)
 567                 return (0);
 568         if (lenp != NULL)
 569                 *lenp = line_len;
 570         return (1);
 571 }
 572
 573 /*
 574  * sscr_end --
 575  *      End the pipe to a shell.
 576  *
 577  * PUBLIC: int sscr_end __P((SCR *));
 578  */
 579 int
 580 sscr_end(sp)
 581         SCR *sp;
 582 {
 583         SCRIPT *sc;
 584
 585         if ((sc = sp->script) == NULL)
 586                 return (0);
 587
 588         /* Turn off the script flags. */
 589         F_CLR(sp, SC_SCRIPT);
 590         sscr_check(sp);
 591
 592         /* Close down the parent's file descriptors. */
 593         if (sc->sh_master != -1)
 594             (void)close(sc->sh_master);
 595         if (sc->sh_slave != -1)
 596             (void)close(sc->sh_slave);
 597
 598         /* This should have killed the child. */
 599         (void)proc_wait(sp, (long)sc->sh_pid, "script-shell", 0, 0);
 600
 601         /* Free memory. */
 602         free(sc->sh_prompt);
 603         free(sc);
 604         sp->script = NULL;
 605
 606         return (0);
 607 }
 608
 609 /*
 610  * sscr_check --
 611  *      Set/clear the global scripting bit.
 612  */
 613 static void
 614 sscr_check(sp)
 615         SCR *sp;
 616 {
 617         GS *gp;
 618
 619         gp = sp->gp;
 620         for (sp = gp->dq.cqh_first; sp != (void *)&gp->dq; sp = sp->q.cqe_next)
 621                 if (F_ISSET(sp, SC_SCRIPT)) {
 622                         F_SET(gp, G_SCRWIN);
 623                         return;
 624                 }
 625         F_CLR(gp, G_SCRWIN);
 626 }
 627
 628 #ifdef HAVE_SYS5_PTY
 629 static int ptys_open __P((int, char *));
 630 static int ptym_open __P((char *));
 631
 632 static int
 633 sscr_pty(amaster, aslave, name, termp, winp)
 634         int *amaster, *aslave;
 635         char *name;
 636         struct termios *termp;
 637         void *winp;
 638 {
 639         int master, slave, ttygid;
 640
 641         /* open master terminal */
 642         if ((master = ptym_open(name)) < 0)  {
 643                 errno = ENOENT; /* out of ptys */
 644                 return (-1);
 645         }
 646
 647         /* open slave terminal */
 648         if ((slave = ptys_open(master, name)) >= 0) {
 649                 *amaster = master;
 650                 *aslave = slave;
 651         } else {
 652                 errno = ENOENT; /* out of ptys */
 653                 return (-1);
 654         }
 655
 656         if (termp)
 657                 (void) tcsetattr(slave, TCSAFLUSH, termp);
 658 #ifdef TIOCSWINSZ
 659         if (winp != NULL)
 660                 (void) ioctl(slave, TIOCSWINSZ, (struct winsize *)winp);
 661 #endif
 662         return (0);
 663 }
 664
 665 /*
 666  * ptym_open --
 667  *      This function opens a master pty and returns the file descriptor
 668  *      to it.  pts_name is also returned which is the name of the slave.
 669  */
 670 static int
 671 ptym_open(pts_name)
 672         char *pts_name;
 673 {
 674         int fdm;
 675         char *ptr, *ptsname();
 676
 677         strcpy(pts_name, _PATH_SYSV_PTY);
 678         if ((fdm = open(pts_name, O_RDWR)) < 0 )
 679                 return (-1);
 680
 681         if (grantpt(fdm) < 0) {
 682                 close(fdm);
 683                 return (-2);
 684         }
 685
 686         if (unlockpt(fdm) < 0) {
 687                 close(fdm);
 688                 return (-3);
 689         }
 690
 691         if (unlockpt(fdm) < 0) {
 692                 close(fdm);
 693                 return (-3);
 694         }
 695
 696         /* get slave's name */
 697         if ((ptr = ptsname(fdm)) == NULL) {
 698                 close(fdm);
 699                 return (-3);
 700         }
 701         strcpy(pts_name, ptr);
 702         return (fdm);
 703 }
 704
 705 /*
 706  * ptys_open --
 707  *      This function opens the slave pty.
 708  */
 709 static int
 710 ptys_open(fdm, pts_name)
 711         int fdm;
 712         char *pts_name;
 713 {
 714         int fds;
 715
 716         if ((fds = open(pts_name, O_RDWR)) < 0) {
 717                 close(fdm);
 718                 return (-5);
 719         }
 720
 721         if (ioctl(fds, I_PUSH, "ptem") < 0) {
 722                 close(fds);
 723                 close(fdm);
 724                 return (-6);
 725         }
 726
 727         if (ioctl(fds, I_PUSH, "ldterm") < 0) {
 728                 close(fds);
 729                 close(fdm);
 730                 return (-7);
 731         }
 732
 733         if (ioctl(fds, I_PUSH, "ttcompat") < 0) {
 734                 close(fds);
 735                 close(fdm);
 736                 return (-8);
 737         }
 738
 739         return (fds);
 740 }
 741
 742 #else /* !HAVE_SYS5_PTY */
 743
 744 static int
 745 sscr_pty(amaster, aslave, name, termp, winp)
 746         int *amaster, *aslave;
 747         char *name;
 748         struct termios *termp;
 749         void *winp;
 750 {
 751         static char line[] = "/dev/ptyXX";
 752         register char *cp1, *cp2;
 753         register int master, slave, ttygid;
 754         struct group *gr;
 755
 756         if ((gr = getgrnam("tty")) != NULL)
 757                 ttygid = gr->gr_gid;
 758         else
 759                 ttygid = -1;
 760
 761         for (cp1 = "pqrs"; *cp1; cp1++) {
 762                 line[8] = *cp1;
 763                 for (cp2 = "0123456789abcdef"; *cp2; cp2++) {
 764                         line[5] = 'p';
 765                         line[9] = *cp2;
 766                         if ((master = open(line, O_RDWR, 0)) == -1) {
 767                                 if (errno == ENOENT)
 768                                         return (-1);    /* out of ptys */
 769                         } else {
 770                                 line[5] = 't';
 771                                 (void) chown(line, getuid(), ttygid);
 772                                 (void) chmod(line, S_IRUSR|S_IWUSR|S_IWGRP);
 773 #ifdef HAVE_REVOKE
 774                                 (void) revoke(line);
 775 #endif
 776                                 if ((slave = open(line, O_RDWR, 0)) != -1) {
 777                                         *amaster = master;
 778                                         *aslave = slave;
 779                                         if (name)
 780                                                 strcpy(name, line);
 781                                         if (termp)
 782                                                 (void) tcsetattr(slave,
 783                                                         TCSAFLUSH, termp);
 784 #ifdef TIOCSWINSZ
 785                                         if (winp)
 786                                                 (void) ioctl(slave, TIOCSWINSZ,
 787                                                         (char *)winp);
 788 #endif
 789                                         return (0);
 790                                 }
 791                                 (void) close(master);
 792                         }
 793                 }
 794         }
 795         errno = ENOENT; /* out of ptys */
 796         return (-1);
 797 }
 798 #endif /* HAVE_SYS5_PTY */