src/screen.c

   1 /* Copyright (c) 2008
   2  *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
   3  *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
   4  *      Micah Cowan (micah@cowan.name)
   5  *      Sadrul Habib Chowdhury (sadrul@users.sourceforge.net)
   6  * Copyright (c) 1993-2002, 2003, 2005, 2006, 2007
   7  *      Juergen Weigert (jnweiger@immd4.informatik.uni-erlangen.de)
   8  *      Michael Schroeder (mlschroe@immd4.informatik.uni-erlangen.de)
   9  * Copyright (c) 1987 Oliver Laumann
  10 #ifdef HAVE_BRAILLE
  11  * Modified by:
  12  *      Authors:  Hadi Bargi Rangin  bargi@dots.physics.orst.edu
  13  *                Bill Barry         barryb@dots.physics.orst.edu
  14  *                Randy Lundquist    randyl@dots.physics.orst.edu
  15  *
  16  * Modifications Copyright (c) 1995 by
  17  * Science Access Project, Oregon State University.
  18 #endif
  19  *
  20  * This program is free software; you can redistribute it and/or modify
  21  * it under the terms of the GNU General Public License as published by
  22  * the Free Software Foundation; either version 3, or (at your option)
  23  * any later version.
  24  *
  25  * This program is distributed in the hope that it will be useful,
  26  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  27  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28  * GNU General Public License for more details.
  29  *
  30  * You should have received a copy of the GNU General Public License
  31  * along with this program (see the file COPYING); if not, see
  32  * http://www.gnu.org/licenses/, or contact Free Software Foundation, Inc.,
  33  * 51 Franklin Street, Fifth Floor, Boston, MA  02111-1301  USA
  34  *
  35  ****************************************************************
  36  */
  37
  38 #include <sys/types.h>
  39 #include <ctype.h>
  40
  41 #include <fcntl.h>
  42
  43 #ifdef sgi
  44 # include <sys/sysmacros.h>
  45 #endif
  46
  47 #include <sys/stat.h>
  48 #ifndef sun
  49 # include <sys/ioctl.h>
  50 #endif
  51
  52 #ifndef SIGINT
  53 # include <signal.h>
  54 #endif
  55
  56 #include "config.h"
  57
  58 #ifdef HAVE_STROPTS_H
  59 # include <sys/stropts.h>
  60 #endif
  61
  62 #if defined(SYSV) && !defined(ISC)
  63 # include <sys/utsname.h>
  64 #endif
  65
  66 #if defined(sequent) || defined(SVR4)
  67 # include <sys/resource.h>
  68 #endif /* sequent || SVR4 */
  69
  70 #ifdef ISC
  71 # include <sys/tty.h>
  72 # include <sys/sioctl.h>
  73 # include <sys/pty.h>
  74 #endif /* ISC */
  75
  76 #if (defined(AUX) || defined(_AUX_SOURCE)) && defined(POSIX)
  77 # include <compat.h>
  78 #endif
  79 #if defined(USE_LOCALE) || defined(ENCODINGS)
  80 # include <locale.h>
  81 #endif
  82 #if defined(HAVE_NL_LANGINFO) && defined(ENCODINGS)
  83 # include <langinfo.h>
  84 #endif
  85
  86 #include "screen.h"
  87 #ifdef HAVE_BRAILLE
  88 # include "braille.h"
  89 #endif
  90
  91 #include "patchlevel.h"
  92
  93 /*
  94  *  At the moment we only need the real password if the
  95  *  builtin lock is used. Therefore disable SHADOWPW if
  96  *  we do not really need it (kind of security thing).
  97  */
  98 #ifndef LOCK
  99 # undef SHADOWPW
 100 #endif
 101
 102 #include <pwd.h>
 103 #ifdef SHADOWPW
 104 # include <shadow.h>
 105 #endif /* SHADOWPW */
 106
 107 #include "logfile.h"    /* islogfile, logfflush */
 108
 109 #ifdef DEBUG
 110 FILE *dfp;
 111 #endif
 112
 113
 114 extern char Term[], screenterm[], **environ, Termcap[];
 115 int force_vt = 1;
 116 int VBellWait, MsgWait, MsgMinWait, SilenceWait;
 117
 118 extern struct acluser *users;
 119 extern struct display *displays, *display;
 120
 121
 122 extern int visual_bell;
 123 #ifdef COPY_PASTE
 124 extern unsigned char mark_key_tab[];
 125 #endif
 126 extern char version[];
 127 extern char DefaultShell[];
 128 #ifdef ZMODEM
 129 extern char *zmodem_sendcmd;
 130 extern char *zmodem_recvcmd;
 131 #endif
 132 extern struct layout *layout_last;
 133
 134
 135 char *ShellProg;
 136 char *ShellArgs[2];
 137
 138 extern struct NewWindow nwin_undef, nwin_default, nwin_options;
 139 struct backtick;
 140
 141 static struct passwd *getpwbyname __P((char *, struct passwd *));
 142 static void  SigChldHandler __P((void));
 143 static sigret_t SigChld __P(SIGPROTOARG);
 144 static sigret_t SigInt __P(SIGPROTOARG);
 145 static sigret_t CoreDump __P(SIGPROTOARG);
 146 static sigret_t FinitHandler __P(SIGPROTOARG);
 147 static void  DoWait __P((void));
 148 static void  serv_read_fn __P((struct event *, char *));
 149 static void  serv_select_fn __P((struct event *, char *));
 150 static void  logflush_fn __P((struct event *, char *));
 151 static void  backtick_filter __P((struct backtick *));
 152 static void  backtick_fn __P((struct event *, char *));
 153 static char *runbacktick __P((struct backtick *, int *, time_t));
 154 static int   IsSymbol __P((char *, char *));
 155 static char *ParseChar __P((char *, char *));
 156 static int   ParseEscape __P((char *));
 157 static char *pad_expand __P((char *, char *, int, int));
 158 #ifdef DEBUG
 159 static void  fds __P((void));
 160 #endif
 161
 162 int nversion;   /* numerical version, used for secondary DA */
 163
 164 /* the attacher */
 165 struct passwd *ppp;
 166 char *attach_tty;
 167 int attach_fd = -1;
 168 char *attach_term;
 169 char *LoginName;
 170 struct mode attach_Mode;
 171
 172 char SockPath[MAXPATHLEN + 2 * MAXSTR];
 173 char *SockName;                 /* SockName is pointer in SockPath */
 174 char *SockMatch = NULL;         /* session id command line argument */
 175 int ServerSocket = -1;
 176 struct event serv_read;
 177 struct event serv_select;
 178 struct event logflushev;
 179
 180 char **NewEnv = NULL;
 181
 182 char *RcFileName = NULL;
 183 char *home;
 184
 185 char *screenlogfile;                    /* filename layout */
 186 int log_flush = 10;                     /* flush interval in seconds */
 187 int logtstamp_on = 0;                   /* tstamp disabled */
 188 char *logtstamp_string;                 /* stamp layout */
 189 int logtstamp_after = 120;              /* first tstamp after 120s */
 190 char *hardcopydir = NULL;
 191 char *BellString;
 192 char *VisualBellString;
 193 char *ActivityString;
 194 #ifdef COPY_PASTE
 195 char *BufferFile;
 196 #endif
 197 #ifdef POW_DETACH
 198 char *PowDetachString;
 199 #endif
 200 char *hstatusstring;
 201 char *captionstring;
 202 char *timestring;
 203 char *wliststr;
 204 char *wlisttit;
 205 int auto_detach = 1;
 206 int iflag, rflag, dflag, lsflag, quietflag, wipeflag, xflag;
 207 int cmdflag;
 208 int adaptflag;
 209
 210 #ifdef MULTIUSER
 211 char *multi;
 212 char *multi_home;
 213 int multi_uid;
 214 int own_uid;
 215 int multiattach;
 216 int tty_mode;
 217 int tty_oldmode = -1;
 218 #endif
 219
 220 char HostName[MAXSTR];
 221 int MasterPid, PanicPid;
 222 int real_uid, real_gid, eff_uid, eff_gid;
 223 int default_startup;
 224 int ZombieKey_destroy, ZombieKey_resurrect, ZombieKey_onerror;
 225 char *preselect = NULL;         /* only used in Attach() */
 226
 227 #ifdef UTF8
 228 char *screenencodings;
 229 #endif
 230
 231 #ifdef DW_CHARS
 232 int cjkwidth;
 233 #endif
 234
 235 #ifdef NETHACK
 236 int nethackflag = 0;
 237 #endif
 238 int maxwin = MAXWIN;
 239
 240
 241 struct layer *flayer;
 242 struct win *fore;
 243 struct win *windows;
 244 struct win *console_window;
 245
 246
 247
 248 /*
 249  * Do this last
 250  */
 251 #include "extern.h"
 252
 253 char strnomem[] = "Out of memory.";
 254
 255
 256 static int InterruptPlease;
 257 static int GotSigChld;
 258
 259 static int
 260 lf_secreopen(name, wantfd, l)
 261 char *name;
 262 int wantfd;
 263 struct logfile *l;
 264 {
 265   int got_fd;
 266
 267   close(wantfd);
 268   if (((got_fd = secopen(name, O_WRONLY | O_CREAT | O_APPEND, 0666)) < 0) ||
 269       lf_move_fd(got_fd, wantfd) < 0)
 270     {
 271       logfclose(l);
 272       debug1("lf_secreopen: failed for %s\n", name);
 273       return -1;
 274     }
 275   l->st->st_ino = l->st->st_dev = 0;
 276   debug2("lf_secreopen: %d = %s\n", wantfd, name);
 277   return 0;
 278 }
 279
 280 /********************************************************************/
 281 /********************************************************************/
 282 /********************************************************************/
 283
 284
 285 static struct passwd *
 286 getpwbyname(name, ppp)
 287 char *name;
 288 struct passwd *ppp;
 289 {
 290   int n;
 291 #ifdef SHADOWPW
 292   struct spwd *sss = NULL;
 293   static char *spw = NULL;
 294 #endif
 295
 296   if (!ppp && !(ppp = getpwnam(name)))
 297     return NULL;
 298
 299   /* Do password sanity check..., allow ##user for SUN_C2 security */
 300 #ifdef SHADOWPW
 301 pw_try_again:
 302 #endif
 303   n = 0;
 304   if (ppp->pw_passwd[0] == '#' && ppp->pw_passwd[1] == '#' &&
 305       strcmp(ppp->pw_passwd + 2, ppp->pw_name) == 0)
 306     n = 13;
 307   for (; n < 13; n++)
 308     {
 309       char c = ppp->pw_passwd[n];
 310       if (!(c == '.' || c == '/' || c == '$' ||
 311             (c >= '0' && c <= '9') ||
 312             (c >= 'a' && c <= 'z') ||
 313             (c >= 'A' && c <= 'Z')))
 314         break;
 315     }
 316
 317 #ifdef SHADOWPW
 318   /* try to determine real password */
 319   if (n < 13 && sss == 0)
 320     {
 321       sss = getspnam(ppp->pw_name);
 322       if (sss)
 323         {
 324           if (spw)
 325             free(spw);
 326           ppp->pw_passwd = spw = SaveStr(sss->sp_pwdp);
 327           endspent();   /* this should delete all buffers ... */
 328           goto pw_try_again;
 329         }
 330       endspent();       /* this should delete all buffers ... */
 331     }
 332 #endif
 333   if (n < 13)
 334     ppp->pw_passwd = 0;
 335 #ifdef linux
 336   if (ppp->pw_passwd && strlen(ppp->pw_passwd) == 13 + 11)
 337     ppp->pw_passwd[13] = 0;     /* beware of linux's long passwords */
 338 #endif
 339
 340   return ppp;
 341 }
 342
 343 static char *
 344 locale_name(void)
 345 {
 346   static char *s;
 347
 348   if (!s)
 349     {
 350       s = getenv("LC_ALL");
 351       if (s == NULL)
 352         s = getenv("LC_CTYPE");
 353       if (s == NULL)
 354         s = getenv("LANG");
 355     }
 356   return s;
 357 }
 358
 359 int
 360 main(ac, av)
 361 int ac;
 362 char **av;
 363 {
 364   register int n;
 365   char *ap;
 366   char *av0;
 367   char socknamebuf[2 * MAXSTR];
 368   int mflag = 0;
 369   char *myname = (ac == 0) ? "screen" : av[0];
 370   char *SockDir;
 371   struct stat st;
 372 #ifdef _MODE_T                  /* (jw) */
 373   mode_t oumask;
 374 #else
 375   int oumask;
 376 #endif
 377 #if defined(SYSV) && !defined(ISC)
 378   struct utsname utsnam;
 379 #endif
 380   struct NewWindow nwin;
 381   int detached = 0;             /* start up detached */
 382 #ifdef MULTIUSER
 383   char *sockp;
 384 #endif
 385   char *sty = 0;
 386
 387 #if (defined(AUX) || defined(_AUX_SOURCE)) && defined(POSIX)
 388   setcompat(COMPAT_POSIX|COMPAT_BSDPROT); /* turn on seteuid support */
 389 #endif
 390 #if defined(sun) && defined(SVR4)
 391   {
 392     /* Solaris' login blocks SIGHUP! This is _very bad_ */
 393     sigset_t sset;
 394     sigemptyset(&sset);
 395     sigprocmask(SIG_SETMASK, &sset, 0);
 396   }
 397 #endif
 398
 399   /*
 400    *  First, close all unused descriptors
 401    *  (otherwise, we might have problems with the select() call)
 402    */
 403   closeallfiles(0);
 404 #ifdef DEBUG
 405   opendebug(1, 0);
 406 #endif
 407   snprintf(version, 59, "%d.%.2d.%.2d%s (%s%s) %s", REV, VERS,
 408           PATCHLEVEL, STATE, ORIGIN, GIT_REV, DATE);
 409   nversion = REV * 10000 + VERS * 100 + PATCHLEVEL;
 410   debug2("-- screen debug started %s (%s)\n", *av, version);
 411 #ifdef POSIX
 412   debug("POSIX\n");
 413 #endif
 414 #ifdef TERMIO
 415   debug("TERMIO\n");
 416 #endif
 417 #ifdef SYSV
 418   debug("SYSV\n");
 419 #endif
 420 #ifdef SYSVSIGS
 421   debug("SYSVSIGS\n");
 422 #endif
 423 #ifdef NAMEDPIPE
 424   debug("NAMEDPIPE\n");
 425 #endif
 426 #if defined(SIGWINCH) && defined(TIOCGWINSZ)
 427   debug("Window size changing enabled\n");
 428 #endif
 429 #ifdef HAVE_SETREUID
 430   debug("SETREUID\n");
 431 #endif
 432 #ifdef HAVE_SETEUID
 433   debug("SETEUID\n");
 434 #endif
 435 #ifdef hpux
 436   debug("hpux\n");
 437 #endif
 438 #ifdef USEBCOPY
 439   debug("USEBCOPY\n");
 440 #endif
 441 #ifdef UTMPOK
 442   debug("UTMPOK\n");
 443 #endif
 444 #ifdef LOADAV
 445   debug("LOADAV\n");
 446 #endif
 447 #ifdef NETHACK
 448   debug("NETHACK\n");
 449 #endif
 450 #ifdef TERMINFO
 451   debug("TERMINFO\n");
 452 #endif
 453 #ifdef SHADOWPW
 454   debug("SHADOWPW\n");
 455 #endif
 456 #ifdef NAME_MAX
 457   debug1("NAME_MAX = %d\n", NAME_MAX);
 458 #endif
 459
 460   BellString = SaveStr("Bell in window %n");
 461   VisualBellString = SaveStr("   Wuff,  Wuff!!  ");
 462   ActivityString = SaveStr("Activity in window %n");
 463   screenlogfile = SaveStr("screenlog.%n");
 464   logtstamp_string = SaveStr("-- %n:%t -- time-stamp -- %M/%d/%y %c:%s --\n");
 465   hstatusstring = SaveStr("%h");
 466   captionstring = SaveStr("%3n %t");
 467   timestring = SaveStr("%c:%s %M %d %H%? %l%?");
 468   wlisttit = SaveStr("Num Name%=Flags");
 469   wliststr = SaveStr("%3n %t%=%f");
 470 #ifdef COPY_PASTE
 471   BufferFile = SaveStr(DEFAULT_BUFFERFILE);
 472 #endif
 473   ShellProg = NULL;
 474 #ifdef POW_DETACH
 475   PowDetachString = 0;
 476 #endif
 477   default_startup = (ac > 1) ? 0 : 1;
 478   adaptflag = 0;
 479   VBellWait = VBELLWAIT * 1000;
 480   MsgWait = MSGWAIT * 1000;
 481   MsgMinWait = MSGMINWAIT * 1000;
 482   SilenceWait = SILENCEWAIT;
 483 #ifdef HAVE_BRAILLE
 484   InitBraille();
 485 #endif
 486 #ifdef ZMODEM
 487   zmodem_sendcmd = SaveStr("!!! sz -vv -b ");
 488   zmodem_recvcmd = SaveStr("!!! rz -vv -b -E");
 489 #endif
 490
 491 #ifdef COPY_PASTE
 492   CompileKeys((char *)0, 0, mark_key_tab);
 493 #endif
 494 #ifdef UTF8
 495   InitBuiltinTabs();
 496   screenencodings = SaveStr(SCREENENCODINGS);
 497 #endif
 498 #ifdef DW_CHARS
 499   cjkwidth = 0;
 500 #endif
 501   nwin = nwin_undef;
 502   nwin_options = nwin_undef;
 503   strcpy(screenterm, "screen");
 504
 505   logreopen_register(lf_secreopen);
 506
 507   av0 = *av;
 508   /* if this is a login screen, assume -RR */
 509   if (*av0 == '-')
 510     {
 511       rflag = 4;
 512 #ifdef MULTI
 513       xflag = 1;
 514 #else
 515       dflag = 1;
 516 #endif
 517       ShellProg = SaveStr(DefaultShell); /* to prevent nasty circles */
 518     }
 519   while (ac > 0)
 520     {
 521       ap = *++av;
 522       if (--ac > 0 && *ap == '-')
 523         {
 524           if (ap[1] == '-' && ap[2] == 0)
 525             {
 526               av++;
 527               ac--;
 528               break;
 529             }
 530           if (ap[1] == '-' && !strcmp(ap, "--version"))
 531             Panic(0, "Screen version %s", version);
 532           if (ap[1] == '-' && !strcmp(ap, "--help"))
 533             exit_with_usage(myname, NULL, NULL);
 534           while (ap && *ap && *++ap)
 535             {
 536               switch (*ap)
 537                 {
 538                 case 'a':
 539                   nwin_options.aflag = 1;
 540                   break;
 541                 case 'A':
 542                   adaptflag = 1;
 543                   break;
 544                 case 'p': /* preselect */
 545                   if (*++ap)
 546                     preselect = ap;
 547                   else
 548                     {
 549                       if (!--ac)
 550                         exit_with_usage(myname, "Specify a window to preselect with -p", NULL);
 551                       preselect = *++av;
 552                     }
 553                   ap = NULL;
 554                   break;
 555 #ifdef HAVE_BRAILLE
 556                 case 'B':
 557                   bd.bd_start_braille = 1;
 558                   break;
 559 #endif
 560                 case 'c':
 561                   if (*++ap)
 562                     RcFileName = ap;
 563                   else
 564                     {
 565                       if (--ac == 0)
 566                         exit_with_usage(myname, "Specify an alternate rc-filename with -c", NULL);
 567                       RcFileName = *++av;
 568                     }
 569                   ap = NULL;
 570                   break;
 571                 case 'e':
 572                   if (!*++ap)
 573                     {
 574                       if (--ac == 0)
 575                         exit_with_usage(myname, "Specify command characters with -e", NULL);
 576                       ap = *++av;
 577                     }
 578                   if (ParseEscape(ap))
 579                     Panic(0, "Two characters are required with -e option, not '%s'.", ap);
 580                   ap = NULL;
 581                   break;
 582                 case 'f':
 583                   ap++;
 584                   switch (*ap++)
 585                     {
 586                     case 'n':
 587                     case '0':
 588                       nwin_options.flowflag = FLOW_NOW * 0;
 589                       break;
 590                     case '\0':
 591                       ap--;
 592                       /* FALLTHROUGH */
 593                     case 'y':
 594                     case '1':
 595                       nwin_options.flowflag = FLOW_NOW * 1;
 596                       break;
 597                     case 'a':
 598                       nwin_options.flowflag = FLOW_AUTOFLAG;
 599                       break;
 600                     default:
 601                       exit_with_usage(myname, "Unknown flow option -%s", --ap);
 602                     }
 603                   break;
 604                 case 'h':
 605                   if (--ac == 0)
 606                     exit_with_usage(myname, NULL, NULL);
 607                   nwin_options.histheight = atoi(*++av);
 608                   if (nwin_options.histheight < 0)
 609                     exit_with_usage(myname, "-h: %s: negative scrollback size?", *av);
 610                   break;
 611                 case 'i':
 612                   iflag = 1;
 613                   break;
 614                 case 't': /* title, the former AkA == -k */
 615                   if (--ac == 0)
 616                     exit_with_usage(myname, "Specify a new window-name with -t", NULL);
 617                   nwin_options.aka = *++av;
 618                   break;
 619                 case 'l':
 620                   ap++;
 621                   switch (*ap++)
 622                     {
 623                     case 'n':
 624                     case '0':
 625                       nwin_options.lflag = 0;
 626                       break;
 627                     case '\0':
 628                       ap--;
 629                       /* FALLTHROUGH */
 630                     case 'y':
 631                     case '1':
 632                       nwin_options.lflag = 1;
 633                       break;
 634                     case 'a':
 635                       nwin_options.lflag = 3;
 636                       break;
 637                     case 's':   /* -ls */
 638                     case 'i':   /* -list */
 639                       lsflag = 1;
 640                       if (ac > 1 && !SockMatch)
 641                         {
 642                           SockMatch = *++av;
 643                           ac--;
 644                         }
 645                       ap = NULL;
 646                       break;
 647                     default:
 648                       exit_with_usage(myname, "%s: Unknown suboption to -l", --ap);
 649                     }
 650                   break;
 651                 case 'w':
 652                   lsflag = 1;
 653                   wipeflag = 1;
 654                   if (ac > 1 && !SockMatch)
 655                     {
 656                       SockMatch = *++av;
 657                       ac--;
 658                     }
 659                   break;
 660                 case 'L':
 661                   nwin_options.Lflag = 1;
 662                   break;
 663                 case 'm':
 664                   mflag = 1;
 665                   break;
 666                 case 'O':               /* to be (or not to be?) deleted. jw. */
 667                   force_vt = 0;
 668                   break;
 669                 case 'T':
 670                   if (--ac == 0)
 671                     exit_with_usage(myname, "Specify terminal-type with -T", NULL);
 672                   if (strlen(*++av) < 20)
 673                     strcpy(screenterm, *av);
 674                   else
 675                     Panic(0, "-T: terminal name too long. (max. 20 char)");
 676                   nwin_options.term = screenterm;
 677                   break;
 678                 case 'q':
 679                   quietflag = 1;
 680                   break;
 681                 case 'r':
 682                 case 'R':
 683 #ifdef MULTI
 684                 case 'x':
 685 #endif
 686                   if (ac > 1 && *av[1] != '-' && !SockMatch)
 687                     {
 688                       SockMatch = *++av;
 689                       ac--;
 690                       debug2("rflag=%d, SockMatch=%s\n", dflag, SockMatch);
 691                     }
 692 #ifdef MULTI
 693                   if (*ap == 'x')
 694                     xflag = 1;
 695 #endif
 696                   if (rflag)
 697                     rflag = 2;
 698                   rflag += (*ap == 'R') ? 2 : 1;
 699                   break;
 700 #ifdef REMOTE_DETACH
 701                 case 'd':
 702                   dflag = 1;
 703                   /* FALLTHROUGH */
 704                 case 'D':
 705                   if (!dflag)
 706                     dflag = 2;
 707                   if (ac == 2)
 708                     {
 709                       if (*av[1] != '-' && !SockMatch)
 710                         {
 711                           SockMatch = *++av;
 712                           ac--;
 713                           debug2("dflag=%d, SockMatch=%s\n", dflag, SockMatch);
 714                         }
 715                     }
 716                   break;
 717 #endif
 718                 case 's':
 719                   if (--ac == 0)
 720                     exit_with_usage(myname, "Specify shell with -s", NULL);
 721                   if (ShellProg)
 722                     free(ShellProg);
 723                   ShellProg = SaveStr(*++av);
 724                   debug1("ShellProg: '%s'\n", ShellProg);
 725                   break;
 726                 case 'S':
 727                   if (!SockMatch)
 728                     {
 729                       if (--ac == 0)
 730                         exit_with_usage(myname, "Specify session-name with -S", NULL);
 731                       SockMatch = *++av;
 732                     }
 733                   if (!*SockMatch)
 734                     exit_with_usage(myname, "Empty session-name?", NULL);
 735                   break;
 736                 case 'X':
 737                   cmdflag = 1;
 738                   break;
 739                 case 'v':
 740                   Panic(0, "Screen version %s", version);
 741                   /* NOTREACHED */
 742 #ifdef UTF8
 743                 case 'U':
 744                   nwin_options.encoding = nwin_options.encoding == -1 ? UTF8 : 0;
 745                   break;
 746 #endif
 747                 default:
 748                   exit_with_usage(myname, "Unknown option %s", --ap);
 749                 }
 750             }
 751         }
 752       else
 753         break;
 754     }
 755
 756   real_uid = getuid();
 757   real_gid = getgid();
 758   eff_uid = geteuid();
 759   eff_gid = getegid();
 760   if (eff_uid != real_uid)
 761     {
 762       /* if running with s-bit, we must install a special signal
 763        * handler routine that resets the s-bit, so that we get a
 764        * core file anyway.
 765        */
 766 #ifdef SIGBUS /* OOPS, linux has no bus errors! */
 767       signal(SIGBUS, CoreDump);
 768 #endif /* SIGBUS */
 769       signal(SIGSEGV, CoreDump);
 770     }
 771
 772 #ifdef USE_LOCALE
 773   setlocale(LC_ALL, "");
 774 #endif
 775 #ifdef ENCODINGS
 776   if (nwin_options.encoding == -1)
 777     {
 778       /* ask locale if we should start in UTF-8 mode */
 779 # ifdef HAVE_NL_LANGINFO
 780 #  ifndef USE_LOCALE
 781       setlocale(LC_CTYPE, "");
 782 #  endif
 783       nwin_options.encoding = FindEncoding(nl_langinfo(CODESET));
 784       debug1("locale says encoding = %d\n", nwin_options.encoding);
 785 # else
 786 #  ifdef UTF8
 787       char *s;
 788       if ((s = locale_name()) && InStr(s, "UTF-8"))
 789         nwin_options.encoding = UTF8;
 790 #  endif
 791       debug1("environment says encoding=%d\n", nwin_options.encoding);
 792 #endif
 793     }
 794 # ifdef DW_CHARS
 795   {
 796     char *s;
 797     if ((s = locale_name()))
 798     {
 799       if(!strncmp(s, "zh_", 3) || !strncmp(s, "ja_", 3) || !strncmp(s, "ko_", 3))
 800       {
 801         cjkwidth = 1;
 802       }
 803     }
 804   }
 805 #endif
 806 #endif
 807   if (nwin_options.aka)
 808     {
 809 #ifdef ENCODINGS
 810       if (nwin_options.encoding > 0)
 811         {
 812           size_t len = strlen(nwin_options.aka);
 813           size_t newsz;
 814           char *newbuf = malloc(3 * len);
 815           if (!newbuf)
 816             Panic(0, strnomem);
 817           newsz = RecodeBuf(nwin_options.aka, len,
 818                             nwin_options.encoding, 0, newbuf);
 819           newbuf[newsz] = '\0';
 820           nwin_options.aka = newbuf;
 821         }
 822       else
 823 #endif
 824         {
 825           /* If we just use the original value from av,
 826              subsequent shelltitle invocations will attempt to free
 827              space we don't own... */
 828           nwin_options.aka = SaveStr(nwin_options.aka);
 829         }
 830     }
 831
 832   if (SockMatch && strlen(SockMatch) >= MAXSTR)
 833     Panic(0, "Ridiculously long socketname - try again.");
 834   if (cmdflag && !rflag && !dflag && !xflag)
 835     xflag = 1;
 836   if (!cmdflag && dflag && mflag && !(rflag || xflag))
 837     detached = 1;
 838   nwin = nwin_options;
 839 #ifdef ENCODINGS
 840   nwin.encoding = nwin_undef.encoding;  /* let screenrc overwrite it */
 841 #endif
 842   if (ac)
 843     nwin.args = av;
 844
 845   /* make the write() calls return -1 on all errors */
 846 #ifdef SIGXFSZ
 847   /*
 848    * Ronald F. Guilmette, Oct 29 '94, bug-gnu-utils@prep.ai.mit.edu:
 849    * It appears that in System V Release 4, UNIX, if you are writing
 850    * an output file and you exceed the currently set file size limit,
 851    * you _don't_ just get the call to `write' returning with a
 852    * failure code.  Rather, you get a signal called `SIGXFSZ' which,
 853    * if neither handled nor ignored, will cause your program to crash
 854    * with a core dump.
 855    */
 856   signal(SIGXFSZ, SIG_IGN);
 857 #endif /* SIGXFSZ */
 858
 859 #ifdef SIGPIPE
 860   signal(SIGPIPE, SIG_IGN);
 861 #endif
 862
 863   if (!ShellProg)
 864     {
 865       register char *sh;
 866
 867       sh = getenv("SHELL");
 868       ShellProg = SaveStr(sh ? sh : DefaultShell);
 869     }
 870   ShellArgs[0] = ShellProg;
 871   home = getenv("HOME");
 872   if (!mflag && !SockMatch)
 873     {
 874       sty = getenv("STY");
 875       if (sty && *sty == 0)
 876         sty = 0;
 877     }
 878
 879 #ifdef NETHACK
 880   if (!(nethackflag = (getenv("NETHACKOPTIONS") != NULL)))
 881     {
 882       char nethackrc[MAXPATHLEN];
 883
 884       if (home && (strlen(home) < (MAXPATHLEN - 20)))
 885         {
 886           sprintf(nethackrc,"%s/.nethackrc", home);
 887           nethackflag = !access(nethackrc, F_OK);
 888         }
 889     }
 890 #endif
 891
 892 #ifdef MULTIUSER
 893   own_uid = multi_uid = real_uid;
 894   if (SockMatch && (sockp = index(SockMatch, '/')))
 895     {
 896       *sockp = 0;
 897       multi = SockMatch;
 898       SockMatch = sockp + 1;
 899       if (*multi)
 900         {
 901           struct passwd *mppp;
 902           if ((mppp = getpwnam(multi)) == (struct passwd *)0)
 903             Panic(0, "Cannot identify account '%s'.", multi);
 904           multi_uid = mppp->pw_uid;
 905           multi_home = SaveStr(mppp->pw_dir);
 906           if (strlen(multi_home) > MAXPATHLEN - 10)
 907             Panic(0, "home directory path too long");
 908 # ifdef MULTI
 909           /* always fake multi attach mode */
 910           if (rflag || lsflag)
 911             xflag = 1;
 912 # endif /* MULTI */
 913           detached = 0;
 914           multiattach = 1;
 915         }
 916       /* Special case: effective user is multiuser. */
 917       if (eff_uid && (multi_uid != eff_uid))
 918         Panic(0, "Must run suid root for multiuser support.");
 919     }
 920   if (SockMatch && *SockMatch == 0)
 921     SockMatch = 0;
 922 #endif /* MULTIUSER */
 923
 924   if ((LoginName = getlogin()) && LoginName[0] != '\0')
 925     {
 926       if ((ppp = getpwnam(LoginName)) != (struct passwd *) 0)
 927         if ((int)ppp->pw_uid != real_uid)
 928           ppp = (struct passwd *) 0;
 929     }
 930   if (ppp == 0)
 931     {
 932       if ((ppp = getpwuid(real_uid)) == 0)
 933         {
 934           Panic(0, "getpwuid() can't identify your account!");
 935           exit(1);
 936         }
 937       LoginName = ppp->pw_name;
 938     }
 939   LoginName = SaveStr(LoginName);
 940
 941   ppp = getpwbyname(LoginName, ppp);
 942
 943 #if !defined(SOCKDIR) && defined(MULTIUSER)
 944   if (multi && !multiattach)
 945     {
 946       if (home && strcmp(home, ppp->pw_dir))
 947         Panic(0, "$HOME must match passwd entry for multiuser screens.");
 948     }
 949 #endif
 950
 951 #define SET_GUID() do \
 952   { \
 953     setgid(real_gid); \
 954     setuid(real_uid); \
 955     eff_uid = real_uid; \
 956     eff_gid = real_gid; \
 957   } while (0)
 958
 959 #define SET_TTYNAME(fatal) do \
 960   { \
 961     if (!(attach_tty = ttyname(0))) \
 962       { \
 963         if (fatal) \
 964           Panic(0, "Must be connected to a terminal."); \
 965         else \
 966           attach_tty = ""; \
 967       } \
 968     else if (stat(attach_tty, &st)) \
 969       Panic(errno, "Cannot access '%s'", attach_tty); \
 970     if (strlen(attach_tty) >= MAXPATHLEN) \
 971       Panic(0, "TtyName too long - sorry."); \
 972   } while (0)
 973
 974   if (home == 0 || *home == '\0')
 975     home = ppp->pw_dir;
 976   if (strlen(LoginName) > 20)
 977     Panic(0, "LoginName too long - sorry.");
 978 #ifdef MULTIUSER
 979   if (multi && strlen(multi) > 20)
 980     Panic(0, "Screen owner name too long - sorry.");
 981 #endif
 982   if (strlen(home) > MAXPATHLEN - 25)
 983     Panic(0, "$HOME too long - sorry.");
 984
 985   attach_tty = "";
 986   if (!detached && !lsflag && !cmdflag && !(dflag && !mflag && !rflag && !xflag) && !(!mflag && !SockMatch && sty && !xflag))
 987     {
 988 #ifndef NAMEDPIPE
 989       int fl;
 990 #endif
 991
 992       /* ttyname implies isatty */
 993       SET_TTYNAME(1);
 994 #ifdef MULTIUSER
 995       tty_mode = (int)st.st_mode & 0777;
 996 #endif
 997
 998 #ifndef NAMEDPIPE
 999       fl = fcntl(0, F_GETFL, 0);
1000       if (fl != -1 && (fl & (O_RDWR|O_RDONLY|O_WRONLY)) == O_RDWR)
1001         attach_fd = 0;
1002 #endif
1003       if (attach_fd == -1)
1004         {
1005           if ((n = secopen(attach_tty, O_RDWR | O_NONBLOCK, 0)) < 0)
1006             Panic(0, "Cannot open your terminal '%s' - please check.", attach_tty);
1007           close(n);
1008         }
1009       debug2("attach_tty is %s, attach_fd is %d\n", attach_tty, attach_fd);
1010
1011       if ((attach_term = getenv("TERM")) == 0 || *attach_term == 0)
1012         Panic(0, "Please set a terminal type.");
1013       if (strlen(attach_term) > sizeof(D_termname) - 1)
1014         Panic(0, "$TERM too long - sorry.");
1015       GetTTY(0, &attach_Mode);
1016 #ifdef DEBUGGGGGGGGGGGGGGG
1017       DebugTTY(&attach_Mode);
1018 #endif /* DEBUG */
1019     }
1020
1021 #ifdef _MODE_T
1022   oumask = umask(0);            /* well, unsigned never fails? jw. */
1023 #else
1024   if ((oumask = (int)umask(0)) == -1)
1025     Panic(errno, "Cannot change umask to zero");
1026 #endif
1027   SockDir = getenv("SCREENDIR");
1028   if (SockDir)
1029     {
1030       if (strlen(SockDir) >= MAXPATHLEN - 1)
1031         Panic(0, "Ridiculously long $SCREENDIR - try again.");
1032 #ifdef MULTIUSER
1033       if (multi)
1034         Panic(0, "No $SCREENDIR with multi screens, please.");
1035 #endif
1036     }
1037 #ifdef MULTIUSER
1038   if (multiattach)
1039     {
1040 # ifndef SOCKDIR
1041       sprintf(SockPath, "%s/.screen", multi_home);
1042       SockDir = SockPath;
1043 # else
1044       SockDir = SOCKDIR;
1045       sprintf(SockPath, "%s/S-%s", SockDir, multi);
1046 # endif
1047     }
1048   else
1049 #endif
1050     {
1051 #ifndef SOCKDIR
1052       if (SockDir == 0)
1053         {
1054           sprintf(SockPath, "%s/.screen", home);
1055           SockDir = SockPath;
1056         }
1057 #endif
1058       if (SockDir)
1059         {
1060           if (access(SockDir, F_OK))
1061             {
1062               debug1("SockDir '%s' missing ...\n", SockDir);
1063               if (UserContext() > 0)
1064                 {
1065                   if (mkdir(SockDir, 0700))
1066                     UserReturn(0);
1067                   UserReturn(1);
1068                 }
1069               if (UserStatus() <= 0)
1070                 Panic(0, "Cannot make directory '%s'.", SockDir);
1071             }
1072           if (SockDir != SockPath)
1073             strcpy(SockPath, SockDir);
1074         }
1075 #ifdef SOCKDIR
1076       else
1077         {
1078           SockDir = SOCKDIR;
1079           if (lstat(SockDir, &st))
1080             {
1081               n = (eff_uid == 0 && (real_uid || eff_gid == real_gid)) ? 0755 :
1082                   (eff_gid != real_gid) ? 0775 :
1083 #ifdef S_ISVTX
1084                   0777|S_ISVTX;
1085 #else
1086                   0777;
1087 #endif
1088               if (mkdir(SockDir, n) == -1)
1089                 Panic(errno, "Cannot make directory '%s'", SockDir);
1090             }
1091           else
1092             {
1093               if (!S_ISDIR(st.st_mode))
1094                 Panic(0, "'%s' must be a directory.", SockDir);
1095               if (eff_uid == 0 && real_uid && (int)st.st_uid != eff_uid)
1096                 Panic(0, "Directory '%s' must be owned by root.", SockDir);
1097               n = (eff_uid == 0 && (real_uid || (st.st_mode & 0775) != 0775)) ? 0755 :
1098                   (eff_gid == (int)st.st_gid && eff_gid != real_gid) ? 0775 :
1099                   0777;
1100               if (((int)st.st_mode & 0777) != n)
1101                 Panic(0, "Directory '%s' must have mode %03o.", SockDir, n);
1102             }
1103           sprintf(SockPath, "%s/S-%s", SockDir, LoginName);
1104           if (access(SockPath, F_OK))
1105             {
1106               if (mkdir(SockPath, 0700) == -1)
1107                 Panic(errno, "Cannot make directory '%s'", SockPath);
1108               (void) chown(SockPath, real_uid, real_gid);
1109             }
1110         }
1111 #endif
1112     }
1113
1114   if (stat(SockPath, &st) == -1)
1115     Panic(errno, "Cannot access %s", SockPath);
1116   else
1117   if (!S_ISDIR(st.st_mode))
1118     Panic(0, "%s is not a directory.", SockPath);
1119 #ifdef MULTIUSER
1120   if (multi)
1121     {
1122       if ((int)st.st_uid != multi_uid)
1123         Panic(0, "%s is not the owner of %s.", multi, SockPath);
1124     }
1125   else
1126 #endif
1127     {
1128       if ((int)st.st_uid != real_uid)
1129         Panic(0, "You are not the owner of %s.", SockPath);
1130     }
1131   if ((st.st_mode & 0777) != 0700)
1132     Panic(0, "Directory %s must have mode 700.", SockPath);
1133   if (SockMatch && index(SockMatch, '/'))
1134     Panic(0, "Bad session name '%s'", SockMatch);
1135   SockName = SockPath + strlen(SockPath) + 1;
1136   *SockName = 0;
1137   (void) umask(oumask);
1138   debug2("SockPath: %s  SockMatch: %s\n", SockPath, SockMatch ? SockMatch : "NULL");
1139
1140 #if defined(SYSV) && !defined(ISC)
1141   if (uname(&utsnam) == -1)
1142     Panic(errno, "uname");
1143   strncpy(HostName, utsnam.nodename, sizeof(utsnam.nodename) < MAXSTR ? sizeof(utsnam.nodename) : MAXSTR - 1);
1144   HostName[sizeof(utsnam.nodename) < MAXSTR ? sizeof(utsnam.nodename) : MAXSTR - 1] = '\0';
1145 #else
1146   (void) gethostname(HostName, MAXSTR);
1147   HostName[MAXSTR - 1] = '\0';
1148 #endif
1149   if ((ap = index(HostName, '.')) != NULL)
1150     *ap = '\0';
1151
1152   if (lsflag)
1153     {
1154       int i, fo, oth;
1155
1156 #ifdef MULTIUSER
1157       if (multi)
1158         real_uid = multi_uid;
1159 #endif
1160       SET_GUID();
1161       i = FindSocket((int *)NULL, &fo, &oth, SockMatch);
1162       if (quietflag)
1163         exit(8 + (fo ? ((oth || i) ? 2 : 1) : 0) + i);
1164       if (fo == 0)
1165         Panic(0, "No Sockets found in %s.\n", SockPath);
1166       Panic(0, "%d Socket%s in %s.\n", fo, fo > 1 ? "s" : "", SockPath);
1167       /* NOTREACHED */
1168     }
1169   signal(SIG_BYE, AttacherFinit);       /* prevent races */
1170   if (cmdflag)
1171     {
1172       /* attach_tty is not mandatory */
1173       SET_TTYNAME(0);
1174       if (!*av)
1175         Panic(0, "Please specify a command.");
1176       SET_GUID();
1177       SendCmdMessage(sty, SockMatch, av);
1178       exit(0);
1179     }
1180   else if (rflag || xflag)
1181     {
1182       debug("screen -r: - is there anybody out there?\n");
1183       if (Attach(MSG_ATTACH))
1184         {
1185           Attacher();
1186           /* NOTREACHED */
1187         }
1188 #ifdef MULTIUSER
1189       if (multiattach)
1190         Panic(0, "Can't create sessions of other users.");
1191 #endif
1192       debug("screen -r: backend not responding -- still crying\n");
1193     }
1194   else if (dflag && !mflag)
1195     {
1196       SET_TTYNAME(0);
1197       Attach(MSG_DETACH);
1198       Msg(0, "[%s %sdetached.]\n", SockName, (dflag > 1 ? "power " : ""));
1199       eexit(0);
1200       /* NOTREACHED */
1201     }
1202   if (!SockMatch && !mflag && sty)
1203     {
1204       /* attach_tty is not mandatory */
1205       SET_TTYNAME(0);
1206       SET_GUID();
1207       nwin_options.args = av;
1208       SendCreateMsg(sty, &nwin);
1209       exit(0);
1210       /* NOTREACHED */
1211     }
1212   nwin_compose(&nwin_default, &nwin_options, &nwin_default);
1213
1214   if (!detached || dflag != 2)
1215     MasterPid = fork();
1216   else
1217     MasterPid = 0;
1218
1219   switch (MasterPid)
1220     {
1221     case -1:
1222       Panic(errno, "fork");
1223       /* NOTREACHED */
1224     case 0:
1225       break;
1226     default:
1227       if (detached)
1228         exit(0);
1229       if (SockMatch)
1230         sprintf(socknamebuf, "%d.%s", MasterPid, SockMatch);
1231       else
1232         sprintf(socknamebuf, "%d.%s.%s", MasterPid, stripdev(attach_tty), HostName);
1233       for (ap = socknamebuf; *ap; ap++)
1234         if (*ap == '/')
1235           *ap = '-';
1236 #ifdef NAME_MAX
1237       if (strlen(socknamebuf) > NAME_MAX)
1238         socknamebuf[NAME_MAX] = 0;
1239 #endif
1240       sprintf(SockPath + strlen(SockPath), "/%s", socknamebuf);
1241       SET_GUID();
1242       Attacher();
1243       /* NOTREACHED */
1244     }
1245
1246   if (!detached)
1247     PanicPid = getppid();
1248
1249   if (DefaultEsc == -1)
1250     DefaultEsc = Ctrl('a');
1251   if (DefaultMetaEsc == -1)
1252     DefaultMetaEsc = 'a';
1253
1254   ap = av0 + strlen(av0) - 1;
1255   while (ap >= av0)
1256     {
1257       if (!strncmp("screen", ap, 6))
1258         {
1259           strncpy(ap, "SCREEN", 6); /* name this process "SCREEN-BACKEND" */
1260           break;
1261         }
1262       ap--;
1263     }
1264   if (ap < av0)
1265     *av0 = 'S';
1266
1267 #ifdef DEBUG
1268   {
1269     char buf[256];
1270
1271     if (dfp && dfp != stderr)
1272       fclose(dfp);
1273     sprintf(buf, "%s/SCREEN.%d", DEBUGDIR, (int)getpid());
1274     if ((dfp = fopen(buf, "w")) == NULL)
1275       dfp = stderr;
1276     else
1277       (void) chmod(buf, 0666);
1278   }
1279 #endif
1280   if (!detached)
1281     {
1282       if (attach_fd == -1)
1283         {
1284           if ((n = secopen(attach_tty, O_RDWR, 0)) < 0)
1285             Panic(0, "Cannot reopen '%s' - please check.", attach_tty);
1286         }
1287       else
1288         n = dup(attach_fd);
1289     }
1290   else
1291     n = -1;
1292   freopen("/dev/null", "r", stdin);
1293   freopen("/dev/null", "w", stdout);
1294
1295 #ifdef DEBUG
1296   if (dfp != stderr)
1297 #endif
1298   freopen("/dev/null", "w", stderr);
1299   debug("-- screen.back debug started\n");
1300
1301   /*
1302    * This guarantees that the session owner is listed, even when we
1303    * start detached. From now on we should not refer to 'LoginName'
1304    * any more, use users->u_name instead.
1305    */
1306   if (UserAdd(LoginName, (char *)0, (struct acluser **)0) < 0)
1307     Panic(0, "Could not create user info");
1308   if (!detached)
1309     {
1310       if (MakeDisplay(LoginName, attach_tty, attach_term, n, getppid(), &attach_Mode) == 0)
1311         Panic(0, "Could not alloc display");
1312       PanicPid = 0;
1313 #ifdef ENCODINGS
1314       D_encoding = nwin_options.encoding > 0 ? nwin_options.encoding : 0;
1315       debug1("D_encoding = %d\n", D_encoding);
1316 #endif
1317     }
1318
1319   if (SockMatch)
1320     {
1321       /* user started us with -S option */
1322       sprintf(socknamebuf, "%d.%s", (int)getpid(), SockMatch);
1323     }
1324   else
1325     {
1326       sprintf(socknamebuf, "%d.%s.%s", (int)getpid(), stripdev(attach_tty),
1327               HostName);
1328     }
1329   for (ap = socknamebuf; *ap; ap++)
1330     if (*ap == '/')
1331       *ap = '-';
1332 #ifdef NAME_MAX
1333   if (strlen(socknamebuf) > NAME_MAX)
1334     {
1335       debug2("Socketname %s truncated to %d chars\n", socknamebuf, NAME_MAX);
1336       socknamebuf[NAME_MAX] = 0;
1337     }
1338 #endif
1339   sprintf(SockPath + strlen(SockPath), "/%s", socknamebuf);
1340
1341   ServerSocket = MakeServerSocket();
1342   InitKeytab();
1343 #ifdef ETCSCREENRC
1344 # ifdef ALLOW_SYSSCREENRC
1345   if ((ap = getenv("SYSSCREENRC")))
1346     (void)StartRc(ap, 0);
1347   else
1348 # endif
1349     (void)StartRc(ETCSCREENRC, 0);
1350 #endif
1351   (void)StartRc(RcFileName, 0);
1352 # ifdef UTMPOK
1353 #  ifndef UTNOKEEP
1354   InitUtmp();
1355 #  endif /* UTNOKEEP */
1356 # endif /* UTMPOK */
1357   if (display)
1358     {
1359       if (InitTermcap(0, 0))
1360         {
1361           debug("Could not init termcap - exiting\n");
1362           fcntl(D_userfd, F_SETFL, 0);  /* Flush sets FNBLOCK */
1363           freetty();
1364           if (D_userpid)
1365             Kill(D_userpid, SIG_BYE);
1366           eexit(1);
1367         }
1368       MakeDefaultCanvas();
1369       InitTerm(0);
1370 #ifdef UTMPOK
1371       RemoveLoginSlot();
1372 #endif
1373     }
1374   else
1375     MakeTermcap(1);
1376 #ifdef LOADAV
1377   InitLoadav();
1378 #endif /* LOADAV */
1379   MakeNewEnv();
1380   signal(SIGHUP, SigHup);
1381   signal(SIGINT, FinitHandler);
1382   signal(SIGQUIT, FinitHandler);
1383   signal(SIGTERM, FinitHandler);
1384 #ifdef BSDJOBS
1385   signal(SIGTTIN, SIG_IGN);
1386   signal(SIGTTOU, SIG_IGN);
1387 #endif
1388
1389   if (display)
1390     {
1391       brktty(D_userfd);
1392       SetMode(&D_OldMode, &D_NewMode, D_flow, iflag);
1393       /* Note: SetMode must be called _before_ FinishRc. */
1394       SetTTY(D_userfd, &D_NewMode);
1395       if (fcntl(D_userfd, F_SETFL, FNBLOCK))
1396         Msg(errno, "Warning: NBLOCK fcntl failed");
1397     }
1398   else
1399     brktty(-1);         /* just try */
1400   signal(SIGCHLD, SigChld);
1401 #ifdef ETCSCREENRC
1402 # ifdef ALLOW_SYSSCREENRC
1403   if ((ap = getenv("SYSSCREENRC")))
1404     FinishRc(ap);
1405   else
1406 # endif
1407     FinishRc(ETCSCREENRC);
1408 #endif
1409   FinishRc(RcFileName);
1410
1411   debug2("UID %d  EUID %d\n", (int)getuid(), (int)geteuid());
1412   if (windows == NULL)
1413     {
1414       debug("We open one default window, as screenrc did not specify one.\n");
1415       if (MakeWindow(&nwin) == -1)
1416         {
1417           Msg(0, "Sorry, could not find a PTY.");
1418           sleep(5);
1419           Finit(0);
1420           /* NOTREACHED */
1421         }
1422     }
1423   else if (ac) /* Screen was invoked with a command */
1424     {
1425       MakeWindow(&nwin);
1426     }
1427
1428 #ifdef HAVE_BRAILLE
1429   StartBraille();
1430 #endif
1431
1432   if (display && default_startup)
1433     display_copyright();
1434   signal(SIGINT, SigInt);
1435   if (rflag && (rflag & 1) == 0 && !quietflag)
1436     {
1437       Msg(0, "New screen...");
1438       rflag = 0;
1439     }
1440
1441   serv_read.type = EV_READ;
1442   serv_read.fd = ServerSocket;
1443   serv_read.handler = serv_read_fn;
1444   evenq(&serv_read);
1445
1446   serv_select.pri = -10;
1447   serv_select.type = EV_ALWAYS;
1448   serv_select.handler = serv_select_fn;
1449   evenq(&serv_select);
1450
1451   logflushev.type = EV_TIMEOUT;
1452   logflushev.handler = logflush_fn;
1453
1454   sched();
1455   /* NOTREACHED */
1456   return 0;
1457 }
1458
1459 void
1460 WindowDied(p, wstat, wstat_valid)
1461 struct win *p;
1462 #ifdef BSDWAIT
1463   union wait wstat;
1464 #else
1465   int wstat;
1466 #endif
1467 int wstat_valid;
1468 {
1469   int killit = 0;
1470
1471   if (ZombieKey_destroy && ZombieKey_onerror && wstat_valid &&
1472       WIFEXITED(wstat) && WEXITSTATUS(wstat) == 0)
1473         killit = 1;
1474
1475   if (ZombieKey_destroy && !killit)
1476     {
1477       char buf[100], *s, reason[100];
1478       time_t now;
1479
1480       if (wstat_valid) {
1481         if (WIFEXITED(wstat))
1482           if (WEXITSTATUS(wstat))
1483             sprintf(reason, "terminated with exit status %d", WEXITSTATUS(wstat));
1484           else
1485             sprintf(reason, "terminated normally");
1486         else if (WIFSIGNALED(wstat))
1487           sprintf(reason, "terminated with signal %d%s", WTERMSIG(wstat),
1488 #ifdef WCOREDUMP
1489                           WCOREDUMP(wstat) ? " (core file generated)" : "");
1490 #else
1491                           "");
1492 #endif
1493       } else
1494         sprintf(reason, "detached from window");
1495
1496       (void) time(&now);
1497       s = ctime(&now);
1498       if (s && *s)
1499         s[strlen(s) - 1] = '\0';
1500       debug3("window %d (%s) going into zombie state fd %d",
1501              p->w_number, p->w_title, p->w_ptyfd);
1502 #ifdef UTMPOK
1503       if (p->w_slot != (slot_t)0 && p->w_slot != (slot_t)-1)
1504         {
1505           RemoveUtmp(p);
1506           p->w_slot = 0;        /* "detached" */
1507         }
1508 #endif
1509       CloseDevice(p);
1510
1511       p->w_deadpid = p->w_pid;
1512       p->w_pid = 0;
1513       ResetWindow(p);
1514       /* p->w_y = p->w_bot; */
1515       p->w_y = MFindUsedLine(p, p->w_bot, 1);
1516       sprintf(buf, "\n\r=== Command %s (%s) ===", reason, s ? s : "?");
1517       WriteString(p, buf, strlen(buf));
1518       WindowChanged(p, 'f');
1519     }
1520   else
1521     KillWindow(p);
1522 #ifdef UTMPOK
1523   CarefulUtmp();
1524 #endif
1525 }
1526
1527 static void
1528 SigChldHandler()
1529 {
1530   struct stat st;
1531 #ifdef DEBUG
1532   fds();
1533 #endif
1534   while (GotSigChld)
1535     {
1536       GotSigChld = 0;
1537       DoWait();
1538 #ifdef SYSVSIGS
1539       signal(SIGCHLD, SigChld);
1540 #endif
1541     }
1542   if (stat(SockPath, &st) == -1)
1543     {
1544       debug1("SigChldHandler: Yuck! cannot stat '%s'\n", SockPath);
1545       if (!RecoverSocket())
1546         {
1547           debug("SCREEN cannot recover from corrupt Socket, bye\n");
1548           Finit(1);
1549         }
1550       else
1551         debug1("'%s' reconstructed\n", SockPath);
1552     }
1553   else
1554     debug2("SigChldHandler: stat '%s' o.k. (%03o)\n", SockPath, (int)st.st_mode);
1555 }
1556
1557 static sigret_t
1558 SigChld SIGDEFARG
1559 {
1560   debug("SigChld()\n");
1561   GotSigChld = 1;
1562   SIGRETURN;
1563 }
1564
1565 sigret_t
1566 SigHup SIGDEFARG
1567 {
1568   /* Hangup all displays */
1569   while ((display = displays) != 0)
1570     Hangup();
1571   SIGRETURN;
1572 }
1573
1574 /*
1575  * the backend's Interrupt handler
1576  * we cannot insert the intrc directly, as we never know
1577  * if fore is valid.
1578  */
1579 static sigret_t
1580 SigInt SIGDEFARG
1581 {
1582 #if HAZARDOUS
1583   char ibuf;
1584
1585   debug("SigInt()\n");
1586   if (fore && displays)
1587     {
1588 # if defined(TERMIO) || defined(POSIX)
1589       ibuf = displays->d_OldMode.tio.c_cc[VINTR];
1590 # else
1591       ibuf = displays->d_OldMode.m_tchars.t_intrc;
1592 # endif
1593       fore->w_inlen = 0;
1594       write(fore->w_ptyfd, &ibuf, 1);
1595     }
1596 #else
1597   signal(SIGINT, SigInt);
1598   debug("SigInt() careful\n");
1599   InterruptPlease = 1;
1600 #endif
1601   SIGRETURN;
1602 }
1603
1604 static sigret_t
1605 CoreDump SIGDEFARG
1606 {
1607   struct display *disp;
1608   char buf[80];
1609
1610 #if defined(SYSVSIGS) && defined(SIGHASARG)
1611   signal(sigsig, SIG_IGN);
1612 #endif
1613   setgid(getgid());
1614   setuid(getuid());
1615   unlink("core");
1616 #ifdef SIGHASARG
1617   sprintf(buf, "\r\n[screen caught signal %d.%s]\r\n", sigsig,
1618 #else
1619   sprintf(buf, "\r\n[screen caught a fatal signal.%s]\r\n",
1620 #endif
1621 #if defined(SHADOWPW) && !defined(DEBUG) && !defined(DUMPSHADOW)
1622               ""
1623 #else /* SHADOWPW  && !DEBUG */
1624               " (core dumped)"
1625 #endif /* SHADOWPW  && !DEBUG */
1626               );
1627   for (disp = displays; disp; disp = disp->d_next)
1628     {
1629       fcntl(disp->d_userfd, F_SETFL, 0);
1630       SetTTY(disp->d_userfd, &D_OldMode);
1631       write(disp->d_userfd, buf, strlen(buf));
1632       Kill(disp->d_userpid, SIG_BYE);
1633     }
1634 #if defined(SHADOWPW) && !defined(DEBUG) && !defined(DUMPSHADOW)
1635   Kill(getpid(), SIGKILL);
1636   eexit(11);
1637 #else /* SHADOWPW && !DEBUG */
1638   abort();
1639 #endif /* SHADOWPW  && !DEBUG */
1640   SIGRETURN;
1641 }
1642
1643 static void
1644 DoWait()
1645 {
1646   register int pid;
1647   struct win *p, *next;
1648 #ifdef BSDWAIT
1649   union wait wstat;
1650 #else
1651   int wstat;
1652 #endif
1653
1654 #ifdef BSDJOBS
1655 # ifndef BSDWAIT
1656   while ((pid = waitpid(-1, &wstat, WNOHANG | WUNTRACED)) > 0)
1657 # else
1658 # ifdef USE_WAIT2
1659   /*
1660    * From: rouilj@sni-usa.com (John Rouillard)
1661    * note that WUNTRACED is not documented to work, but it is defined in
1662    * /usr/include/sys/wait.h, so it may work
1663    */
1664   while ((pid = wait2(&wstat, WNOHANG | WUNTRACED )) > 0)
1665 #  else /* USE_WAIT2 */
1666   while ((pid = wait3(&wstat, WNOHANG | WUNTRACED, (struct rusage *) 0)) > 0)
1667 #  endif /* USE_WAIT2 */
1668 # endif
1669 #else   /* BSDJOBS */
1670   while ((pid = wait(&wstat)) < 0)
1671     if (errno != EINTR)
1672       break;
1673   if (pid > 0)
1674 #endif  /* BSDJOBS */
1675     {
1676       for (p = windows; p; p = next)
1677         {
1678           next = p->w_next;
1679           if (  (p->w_pid     && pid == p->w_pid) ||
1680                 (p->w_deadpid && pid == p->w_deadpid) )
1681             {
1682               /* child has ceased to exist */
1683               p->w_pid = 0;
1684
1685 #ifdef BSDJOBS
1686               if (WIFSTOPPED(wstat))
1687                 {
1688                   debug3("Window %d pid %d: WIFSTOPPED (sig %d)\n", p->w_number, pid, WSTOPSIG(wstat));
1689 #ifdef SIGTTIN
1690                   if (WSTOPSIG(wstat) == SIGTTIN)
1691                     {
1692                       Msg(0, "Suspended (tty input)");
1693                       continue;
1694                     }
1695 #endif
1696 #ifdef SIGTTOU
1697                   if (WSTOPSIG(wstat) == SIGTTOU)
1698                     {
1699                       Msg(0, "Suspended (tty output)");
1700                       continue;
1701                     }
1702 #endif
1703                   /* Try to restart process */
1704                   Msg(0, "Child has been stopped, restarting.");
1705                   if (killpg(pid, SIGCONT))
1706                     kill(pid, SIGCONT);
1707                 }
1708               else
1709 #endif
1710                 {
1711                   WindowDied(p, wstat, 1);
1712                 }
1713               break;
1714             }
1715 #ifdef PSEUDOS
1716           if (p->w_pwin && pid == p->w_pwin->p_pid)
1717             {
1718               debug2("pseudo of win Nr %d died. pid == %d\n", p->w_number, p->w_pwin->p_pid);
1719               FreePseudowin(p);
1720               break;
1721             }
1722 #endif
1723         }
1724       if (p == 0)
1725         {
1726           debug1("pid %d not found - hope that's ok\n", pid);
1727         }
1728     }
1729 }
1730
1731
1732 static sigret_t
1733 FinitHandler SIGDEFARG
1734 {
1735 #ifdef SIGHASARG
1736   debug1("FinitHandler called, sig %d.\n", sigsig);
1737 #else
1738   debug("FinitHandler called.\n");
1739 #endif
1740   Finit(1);
1741   SIGRETURN;
1742 }
1743
1744 void
1745 Finit(i)
1746 int i;
1747 {
1748   signal(SIGCHLD, SIG_DFL);
1749   signal(SIGHUP, SIG_IGN);
1750   debug1("Finit(%d);\n", i);
1751   while (windows)
1752     {
1753       struct win *p = windows;
1754       windows = windows->w_next;
1755       FreeWindow(p);
1756     }
1757   if (ServerSocket != -1)
1758     {
1759       debug1("we unlink(%s)\n", SockPath);
1760 #ifdef USE_SETEUID
1761       xseteuid(real_uid);
1762       xsetegid(real_gid);
1763 #endif
1764       (void) unlink(SockPath);
1765 #ifdef USE_SETEUID
1766       xseteuid(eff_uid);
1767       xsetegid(eff_gid);
1768 #endif
1769     }
1770   for (display = displays; display; display = display->d_next)
1771     {
1772       if (D_status)
1773         RemoveStatus();
1774       FinitTerm();
1775 #ifdef UTMPOK
1776       RestoreLoginSlot();
1777 #endif
1778       AddStr("[screen is terminating]\r\n");
1779       Flush();
1780       SetTTY(D_userfd, &D_OldMode);
1781       fcntl(D_userfd, F_SETFL, 0);
1782       freetty();
1783       Kill(D_userpid, SIG_BYE);
1784     }
1785   /*
1786    * we _cannot_ call eexit(i) here,
1787    * instead of playing with the Socket above. Sigh.
1788    */
1789   exit(i);
1790 }
1791
1792 void
1793 eexit(e)
1794 int e;
1795 {
1796   debug("eexit\n");
1797   if (ServerSocket != -1)
1798     {
1799       debug1("we unlink(%s)\n", SockPath);
1800       setgid(real_gid);
1801       setuid(real_uid);
1802       (void) unlink(SockPath);
1803     }
1804   exit(e);
1805 }
1806
1807 void
1808 Hangup()
1809 {
1810   if (display == 0)
1811     return;
1812   debug1("Hangup %x\n", display);
1813   if (D_userfd >= 0)
1814     {
1815       close(D_userfd);
1816       D_userfd = -1;
1817     }
1818   if (auto_detach || displays->d_next)
1819     Detach(D_HANGUP);
1820   else
1821     Finit(0);
1822 }
1823
1824 /*
1825  * Detach now has the following modes:
1826  *D_DETACH       SIG_BYE        detach backend and exit attacher
1827  *D_HANGUP       SIG_BYE        detach backend and exit attacher
1828  *D_STOP         SIG_STOP       stop attacher (and detach backend)
1829  *D_REMOTE       SIG_BYE        remote detach -- reattach to new attacher
1830  *D_POWER        SIG_POWER_BYE  power detach -- attacher kills his parent
1831  *D_REMOTE_POWER SIG_POWER_BYE  remote power detach -- both
1832  *D_LOCK         SIG_LOCK       lock the attacher
1833  * (jw)
1834  * we always remove our utmp slots. (even when "lock" or "stop")
1835  * Note: Take extra care here, we may be called by interrupt!
1836  */
1837 void
1838 Detach(mode)
1839 int mode;
1840 {
1841   int sign = 0, pid;
1842   struct canvas *cv;
1843   struct win *p;
1844
1845   if (display == 0)
1846     return;
1847
1848 #define AddStrSock(msg) do { \
1849     if (SockName) \
1850       { \
1851         AddStr("[" msg " from "); \
1852         AddStr(SockName); \
1853         AddStr("]\r\n"); \
1854       } \
1855     else \
1856       AddStr("[" msg "]\r\n"); \
1857   } while (0)
1858
1859   signal(SIGHUP, SIG_IGN);
1860   debug1("Detach(%d)\n", mode);
1861   if (D_status)
1862     RemoveStatus();
1863   FinitTerm();
1864   if (!display)
1865     return;
1866   switch (mode)
1867     {
1868     case D_HANGUP:
1869       sign = SIG_BYE;
1870       break;
1871     case D_DETACH:
1872       AddStrSock("detached");
1873       sign = SIG_BYE;
1874       break;
1875 #ifdef BSDJOBS
1876     case D_STOP:
1877       sign = SIG_STOP;
1878       break;
1879 #endif
1880 #ifdef REMOTE_DETACH
1881     case D_REMOTE:
1882       AddStrSock("remote detached");
1883       sign = SIG_BYE;
1884       break;
1885 #endif
1886 #ifdef POW_DETACH
1887     case D_POWER:
1888       AddStrSock("power detached");
1889       if (PowDetachString)
1890         {
1891           AddStr(PowDetachString);
1892           AddStr("\r\n");
1893         }
1894       sign = SIG_POWER_BYE;
1895       break;
1896 #ifdef REMOTE_DETACH
1897     case D_REMOTE_POWER:
1898       AddStrSock("remote power detached");
1899       if (PowDetachString)
1900         {
1901           AddStr(PowDetachString);
1902           AddStr("\r\n");
1903         }
1904       sign = SIG_POWER_BYE;
1905       break;
1906 #endif
1907 #endif
1908     case D_LOCK:
1909       ClearAll();
1910       sign = SIG_LOCK;
1911       /* tell attacher to lock terminal with a lockprg. */
1912       break;
1913     }
1914 #ifdef UTMPOK
1915   if (displays->d_next == 0)
1916     {
1917       for (p = windows; p; p = p->w_next)
1918         {
1919           if (p->w_slot != (slot_t) -1 && !(p->w_lflag & 2))
1920             {
1921               RemoveUtmp(p);
1922               /*
1923                * Set the slot to 0 to get the window
1924                * logged in again.
1925                */
1926               p->w_slot = (slot_t) 0;
1927             }
1928         }
1929     }
1930   if (mode != D_HANGUP)
1931     RestoreLoginSlot();
1932 #endif
1933   if (displays->d_next == 0 && console_window)
1934     {
1935       if (TtyGrabConsole(console_window->w_ptyfd, 0, "detach"))
1936         {
1937           debug("could not release console - killing window\n");
1938           KillWindow(console_window);
1939           display = displays;           /* restore display */
1940         }
1941     }
1942   if (D_fore)
1943     {
1944 #ifdef MULTIUSER
1945       ReleaseAutoWritelock(display, D_fore);
1946 #endif
1947       D_user->u_detachwin = D_fore->w_number;
1948       D_user->u_detachotherwin = D_other ? D_other->w_number : -1;
1949     }
1950   AutosaveLayout(D_layout);
1951   layout_last = D_layout;
1952   for (cv = D_cvlist; cv; cv = cv->c_next)
1953     {
1954       p = Layer2Window(cv->c_layer);
1955       SetCanvasWindow(cv, 0);
1956       if (p)
1957         WindowChanged(p, 'u');
1958     }
1959
1960   pid = D_userpid;
1961   debug2("display: %#x displays: %#x\n", (unsigned int)display, (unsigned int)displays);
1962   FreeDisplay();
1963   if (displays == 0)
1964     /* Flag detached-ness */
1965     (void) chsock();
1966   /*
1967    * tell father what to do. We do that after we
1968    * freed the tty, thus getty feels more comfortable on hpux
1969    * if it was a power detach.
1970    */
1971   Kill(pid, sign);
1972   debug2("Detach: Signal %d to Attacher(%d)!\n", sign, pid);
1973   debug("Detach returns, we are successfully detached.\n");
1974   signal(SIGHUP, SigHup);
1975 #undef AddStrSock
1976 }
1977
1978 static int
1979 IsSymbol(e, s)
1980 char *e, *s;
1981 {
1982   register int l;
1983
1984   l = strlen(s);
1985   return strncmp(e, s, l) == 0 && e[l] == '=';
1986 }
1987
1988 void
1989 MakeNewEnv()
1990 {
1991   register char **op, **np;
1992   static char stybuf[MAXSTR];
1993
1994   for (op = environ; *op; ++op)
1995     ;
1996   if (NewEnv)
1997     free((char *)NewEnv);
1998   NewEnv = np = (char **) malloc((unsigned) (op - environ + 7 + 1) * sizeof(char **));
1999   if (!NewEnv)
2000     Panic(0, strnomem);
2001   sprintf(stybuf, "STY=%s", strlen(SockName) <= MAXSTR - 5 ? SockName : "?");
2002   *np++ = stybuf;                       /* NewEnv[0] */
2003   *np++ = Term;                 /* NewEnv[1] */
2004   np++;         /* room for SHELL */
2005 #ifdef TIOCSWINSZ
2006   np += 2;      /* room for TERMCAP and WINDOW */
2007 #else
2008   np += 4;      /* room for TERMCAP WINDOW LINES COLUMNS */
2009 #endif
2010
2011   for (op = environ; *op; ++op)
2012     {
2013       if (!IsSymbol(*op, "TERM") && !IsSymbol(*op, "TERMCAP")
2014           && !IsSymbol(*op, "STY") && !IsSymbol(*op, "WINDOW")
2015           && !IsSymbol(*op, "SCREENCAP") && !IsSymbol(*op, "SHELL")
2016           && !IsSymbol(*op, "LINES") && !IsSymbol(*op, "COLUMNS")
2017          )
2018         *np++ = *op;
2019     }
2020   *np = 0;
2021 }
2022
2023 void
2024 /*VARARGS2*/
2025 #if defined(USEVARARGS) && defined(__STDC__)
2026 Msg(int err, char *fmt, VA_DOTS)
2027 #else
2028 Msg(err, fmt, VA_DOTS)
2029 int err;
2030 char *fmt;
2031 VA_DECL
2032 #endif
2033 {
2034   VA_LIST(ap)
2035   char buf[MAXPATHLEN*2];
2036   char *p = buf;
2037
2038   VA_START(ap, fmt);
2039   fmt = DoNLS(fmt);
2040   (void)vsnprintf(p, sizeof(buf) - 100, fmt, VA_ARGS(ap));
2041   VA_END(ap);
2042   if (err)
2043     {
2044       p += strlen(p);
2045       *p++ = ':';
2046       *p++ = ' ';
2047       strncpy(p, strerror(err), buf + sizeof(buf) - p - 1);
2048       buf[sizeof(buf) - 1] = 0;
2049     }
2050   debug2("Msg('%s') (%#x);\n", buf, (unsigned int)display);
2051
2052   if (display && displays)
2053     MakeStatus(buf);
2054   else if (displays)
2055     {
2056       for (display = displays; display; display = display->d_next)
2057         MakeStatus(buf);
2058     }
2059   else if (display)
2060     {
2061       /* no displays but a display - must have forked.
2062        * send message to backend!
2063        */
2064       char *tty = D_usertty;
2065       struct display *olddisplay = display;
2066       display = 0;      /* only send once */
2067       SendErrorMsg(tty, buf);
2068       display = olddisplay;
2069     }
2070   else
2071     printf("%s\r\n", buf);
2072 }
2073
2074 /*
2075  * Call FinitTerm for all displays, write a message to each and call eexit();
2076  */
2077 void
2078 /*VARARGS2*/
2079 #if defined(USEVARARGS) && defined(__STDC__)
2080 Panic(int err, char *fmt, VA_DOTS)
2081 #else
2082 Panic(err, fmt, VA_DOTS)
2083 int err;
2084 char *fmt;
2085 VA_DECL
2086 #endif
2087 {
2088   VA_LIST(ap)
2089   char buf[MAXPATHLEN*2];
2090   char *p = buf;
2091
2092   VA_START(ap, fmt);
2093   fmt = DoNLS(fmt);
2094   (void)vsnprintf(p, sizeof(buf) - 100, fmt, VA_ARGS(ap));
2095   VA_END(ap);
2096   if (err)
2097     {
2098       p += strlen(p);
2099       *p++ = ':';
2100       *p++ = ' ';
2101       strncpy(p, strerror(err), buf + sizeof(buf) - p - 1);
2102       buf[sizeof(buf) - 1] = 0;
2103     }
2104   debug3("Panic('%s'); display=%x displays=%x\n", buf, display, displays);
2105   if (displays == 0 && display == 0)
2106     {
2107       printf("%s\r\n", buf);
2108       if (PanicPid)
2109         Kill(PanicPid, SIG_BYE);
2110     }
2111   else if (displays == 0)
2112     {
2113       /* no displays but a display - must have forked.
2114        * send message to backend!
2115        */
2116       char *tty = D_usertty;
2117       display = 0;
2118       SendErrorMsg(tty, buf);
2119       sleep(2);
2120       _exit(1);
2121     }
2122   else
2123     for (display = displays; display; display = display->d_next)
2124       {
2125         if (D_status)
2126           RemoveStatus();
2127         FinitTerm();
2128         Flush();
2129 #ifdef UTMPOK
2130         RestoreLoginSlot();
2131 #endif
2132         SetTTY(D_userfd, &D_OldMode);
2133         fcntl(D_userfd, F_SETFL, 0);
2134         write(D_userfd, buf, strlen(buf));
2135         write(D_userfd, "\n", 1);
2136         freetty();
2137         if (D_userpid)
2138           Kill(D_userpid, SIG_BYE);
2139       }
2140 #ifdef MULTIUSER
2141   if (tty_oldmode >= 0)
2142     {
2143 # ifdef USE_SETEUID
2144       if (setuid(own_uid))
2145         xseteuid(own_uid);      /* may be a loop. sigh. */
2146 # else
2147       setuid(own_uid);
2148 # endif
2149       debug1("Panic: changing back modes from %s\n", attach_tty);
2150       chmod(attach_tty, tty_oldmode);
2151     }
2152 #endif
2153   eexit(1);
2154 }
2155
2156
2157 /*
2158  * '^' is allowed as an escape mechanism for control characters. jw.
2159  *
2160  * Added time insertion using ideas/code from /\ndy Jones
2161  *   (andy@lingua.cltr.uq.OZ.AU) - thanks a lot!
2162  *
2163  */
2164
2165 #ifndef USE_LOCALE
2166 static const char days[]   = "SunMonTueWedThuFriSat";
2167 static const char months[] = "JanFebMarAprMayJunJulAugSepOctNovDec";
2168 #endif
2169
2170 static char winmsg_buf[MAXSTR];
2171 #define MAX_WINMSG_REND 16      /* rendition changes */
2172 static int winmsg_rend[MAX_WINMSG_REND];
2173 static int winmsg_rendpos[MAX_WINMSG_REND];
2174 static int winmsg_numrend;
2175
2176 static char *
2177 pad_expand(buf, p, numpad, padlen)
2178 char *buf;
2179 char *p;
2180 int numpad;
2181 int padlen;
2182 {
2183   char *pn, *pn2;
2184   int i, r;
2185
2186   padlen = padlen - (p - buf);  /* space for rent */
2187   if (padlen < 0)
2188     padlen = 0;
2189   pn2 = pn = p + padlen;
2190   r = winmsg_numrend;
2191   while (p >= buf)
2192     {
2193       if (r && *p != 127 && p - buf == winmsg_rendpos[r - 1])
2194         {
2195           winmsg_rendpos[--r] = pn - buf;
2196           continue;
2197         }
2198       *pn-- = *p;
2199       if (*p-- == 127)
2200         {
2201           pn[1] = ' ';
2202           i = numpad > 0 ? (padlen + numpad - 1) / numpad : 0;
2203           padlen -= i;
2204           while (i-- > 0)
2205             *pn-- = ' ';
2206           numpad--;
2207           if (r && p - buf == winmsg_rendpos[r - 1])
2208             winmsg_rendpos[--r] = pn - buf;
2209         }
2210     }
2211   return pn2;
2212 }
2213
2214 struct backtick {
2215   struct backtick *next;
2216   int num;
2217   int tick;
2218   int lifespan;
2219   time_t bestbefore;
2220   char result[MAXSTR];
2221   char **cmdv;
2222   struct event ev;
2223   char *buf;
2224   int bufi;
2225 };
2226
2227 struct backtick *backticks;
2228
2229 static void
2230 backtick_filter(bt)
2231 struct backtick *bt;
2232 {
2233   char *p, *q;
2234   int c;
2235
2236   for (p = q = bt->result; (c = (unsigned char)*p++) != 0;)
2237     {
2238       if (c == '\t')
2239         c = ' ';
2240       if (c >= ' ' || c == '\005')
2241         *q++ = c;
2242     }
2243   *q = 0;
2244 }
2245
2246 static void
2247 backtick_fn(ev, data)
2248 struct event *ev;
2249 char *data;
2250 {
2251   struct backtick *bt;
2252   int i, j, k, l;
2253
2254   bt = (struct backtick *)data;
2255   debug1("backtick_fn for #%d\n", bt->num);
2256   i = bt->bufi;
2257   l = read(ev->fd, bt->buf + i, MAXSTR - i);
2258   if (l <= 0)
2259     {
2260       debug1("EOF on backtick #%d\n", bt->num);
2261       evdeq(ev);
2262       close(ev->fd);
2263       ev->fd = -1;
2264       return;
2265     }
2266   debug1("read %d bytes\n", l);
2267   i += l;
2268   for (j = 0; j < l; j++)
2269     if (bt->buf[i - j - 1] == '\n')
2270       break;
2271   if (j < l)
2272     {
2273       for (k = i - j - 2; k >= 0; k--)
2274         if (bt->buf[k] == '\n')
2275           break;
2276       k++;
2277       bcopy(bt->buf + k, bt->result, i - j - k);
2278       bt->result[i - j - k - 1] = 0;
2279       backtick_filter(bt);
2280       WindowChanged(0, '`');
2281     }
2282   if (j == l && i == MAXSTR)
2283     {
2284       j = MAXSTR/2;
2285       l = j + 1;
2286     }
2287   if (j < l)
2288     {
2289       if (j)
2290         bcopy(bt->buf + i - j, bt->buf, j);
2291       i = j;
2292     }
2293   bt->bufi = i;
2294 }
2295
2296 void
2297 setbacktick(num, lifespan, tick, cmdv)
2298 int num;
2299 int lifespan;
2300 int tick;
2301 char **cmdv;
2302 {
2303   struct backtick **btp, *bt;
2304   char **v;
2305
2306   debug1("setbacktick called for backtick #%d\n", num);
2307   for (btp = &backticks; (bt = *btp) != 0; btp = &bt->next)
2308     if (bt->num == num)
2309       break;
2310   if (!bt && !cmdv)
2311     return;
2312   if (bt)
2313     {
2314       for (v = bt->cmdv; *v; v++)
2315         free(*v);
2316       free(bt->cmdv);
2317       if (bt->buf)
2318         free(bt->buf);
2319       if (bt->ev.fd >= 0)
2320         close(bt->ev.fd);
2321       evdeq(&bt->ev);
2322     }
2323   if (bt && !cmdv)
2324     {
2325       *btp = bt->next;
2326       free(bt);
2327       return;
2328     }
2329   if (!bt)
2330     {
2331       bt = (struct backtick *)malloc(sizeof *bt);
2332       if (!bt)
2333         {
2334           Msg(0, strnomem);
2335           return;
2336         }
2337       bzero(bt, sizeof(*bt));
2338       bt->next = 0;
2339       *btp = bt;
2340     }
2341   bt->num = num;
2342   bt->tick = tick;
2343   bt->lifespan = lifespan;
2344   bt->bestbefore = 0;
2345   bt->result[0] = 0;
2346   bt->buf = 0;
2347   bt->bufi = 0;
2348   bt->cmdv = cmdv;
2349   bt->ev.fd = -1;
2350   if (bt->tick == 0 && bt->lifespan == 0)
2351     {
2352       debug("setbacktick: continuous mode\n");
2353       bt->buf = (char *)malloc(MAXSTR);
2354       if (bt->buf == 0)
2355         {
2356           Msg(0, strnomem);
2357           setbacktick(num, 0, 0, (char **)0);
2358           return;
2359         }
2360       bt->ev.type = EV_READ;
2361       bt->ev.fd = readpipe(bt->cmdv);
2362       bt->ev.handler = backtick_fn;
2363       bt->ev.data = (char *)bt;
2364       if (bt->ev.fd >= 0)
2365         evenq(&bt->ev);
2366     }
2367 }
2368
2369 static char *
2370 runbacktick(bt, tickp, now)
2371 struct backtick *bt;
2372 int *tickp;
2373 time_t now;
2374 {
2375   int f, i, l, j;
2376   time_t now2;
2377
2378   debug1("runbacktick called for backtick #%d\n", bt->num);
2379   if (bt->tick && (!*tickp || bt->tick < *tickp))
2380     *tickp = bt->tick;
2381   if ((bt->lifespan == 0 && bt->tick == 0) || now < bt->bestbefore)
2382     {
2383       debug1("returning old result (%d)\n", bt->lifespan);
2384       return bt->result;
2385     }
2386   f = readpipe(bt->cmdv);
2387   if (f == -1)
2388     return bt->result;
2389   i = 0;
2390   while ((l = read(f, bt->result + i, sizeof(bt->result) - i)) > 0)
2391     {
2392       debug1("runbacktick: read %d bytes\n", l);
2393       i += l;
2394       for (j = 1; j < l; j++)
2395         if (bt->result[i - j - 1] == '\n')
2396           break;
2397       if (j == l && i == sizeof(bt->result))
2398         {
2399           j = sizeof(bt->result) / 2;
2400           l = j + 1;
2401         }
2402       if (j < l)
2403         {
2404           bcopy(bt->result + i - j, bt->result, j);
2405           i = j;
2406         }
2407     }
2408   close(f);
2409   bt->result[sizeof(bt->result) - 1] = '\n';
2410   if (i && bt->result[i - 1] == '\n')
2411     i--;
2412   debug1("runbacktick: finished, %d bytes\n", i);
2413   bt->result[i] = 0;
2414   backtick_filter(bt);
2415   (void)time(&now2);
2416   bt->bestbefore = now2 + bt->lifespan;
2417   return bt->result;
2418 }
2419
2420 char *
2421 MakeWinMsgEv(str, win, esc, padlen, ev, rec)
2422 char *str;
2423 struct win *win;
2424 int esc;
2425 int padlen;
2426 struct event *ev;
2427 int rec;
2428 {
2429   static int tick;
2430   char *s = str;
2431   register char *p = winmsg_buf;
2432   register int ctrl;
2433   struct timeval now;
2434   struct tm *tm;
2435   int l, i, r;
2436   int num;
2437   int zeroflg;
2438   int longflg;
2439   int minusflg;
2440   int plusflg;
2441   int qmflag = 0, omflag = 0, qmnumrend = 0;
2442   char *qmpos = 0;
2443   int numpad = 0;
2444   int lastpad = 0;
2445   int truncpos = -1;
2446   int truncper = 0;
2447   int trunclong = 0;
2448   struct backtick *bt;
2449
2450   if (winmsg_numrend >= 0)
2451     winmsg_numrend = 0;
2452   else
2453     winmsg_numrend = -winmsg_numrend;
2454
2455   tick = 0;
2456   tm = 0;
2457   ctrl = 0;
2458   gettimeofday(&now, NULL);
2459   for (; *s && (l = winmsg_buf + MAXSTR - 1 - p) > 0; s++, p++)
2460     {
2461       *p = *s;
2462       if (ctrl)
2463         {
2464           ctrl = 0;
2465           if (*s != '^' && *s >= 64)
2466             *p &= 0x1f;
2467           continue;
2468         }
2469       if (*s != esc)
2470         {
2471           if (esc == '%')
2472             {
2473               switch (*s)
2474                 {
2475 #if 0
2476                 case '~':
2477                   *p = BELL;
2478                   break;
2479 #endif
2480                 case '^':
2481                   ctrl = 1;
2482                   *p-- = '^';
2483                   break;
2484                 default:
2485                   break;
2486                 }
2487             }
2488           continue;
2489         }
2490       if (*++s == esc)  /* double escape ? */
2491         continue;
2492       if ((plusflg = *s == '+') != 0)
2493         s++;
2494       if ((minusflg = *s == '-') != 0)
2495         s++;
2496       if ((zeroflg = *s == '0') != 0)
2497         s++;
2498       num = 0;
2499       while(*s >= '0' && *s <= '9')
2500         num = num * 10 + (*s++ - '0');
2501       if ((longflg = *s == 'L') != 0)
2502         s++;
2503       switch (*s)
2504         {
2505         case '?':
2506           p--;
2507           if (qmpos)
2508             {
2509               if ((!qmflag && !omflag) || omflag == 1)
2510                 {
2511                   p = qmpos;
2512                   if (qmnumrend < winmsg_numrend)
2513                     winmsg_numrend = qmnumrend;
2514                 }
2515               qmpos = 0;
2516               break;
2517             }
2518           qmpos = p;
2519           qmnumrend = winmsg_numrend;
2520           qmflag = omflag = 0;
2521           break;
2522         case ':':
2523           p--;
2524           if (!qmpos)
2525             break;
2526           if (qmflag && omflag != 1)
2527             {
2528               omflag = 1;
2529               qmpos = p;
2530               qmnumrend = winmsg_numrend;
2531             }
2532           else
2533             {
2534               p = qmpos;
2535               if (qmnumrend < winmsg_numrend)
2536                 winmsg_numrend = qmnumrend;
2537               omflag = -1;
2538             }
2539           break;
2540         case 'd': case 'D': case 'm': case 'M': case 'y': case 'Y':
2541         case 'a': case 'A': case 's': case 'c': case 'C':
2542           if (l < 4)
2543             break;
2544           if (tm == 0)
2545             {
2546               time_t nowsec = now.tv_sec;
2547               tm = localtime(&nowsec);
2548             }
2549           qmflag = 1;
2550           if (!tick || tick > 3600)
2551             tick = 3600;
2552           switch (*s)
2553             {
2554             case 'd':
2555               sprintf(p, "%02d", tm->tm_mday % 100);
2556               break;
2557             case 'D':
2558 #ifdef USE_LOCALE
2559               strftime(p, l, (longflg ? "%A" : "%a"), tm);
2560 #else
2561               sprintf(p, "%3.3s", days + 3 * tm->tm_wday);
2562 #endif
2563               break;
2564             case 'm':
2565               sprintf(p, "%02d", tm->tm_mon + 1);
2566               break;
2567             case 'M':
2568 #ifdef USE_LOCALE
2569               strftime(p, l, (longflg ? "%B" : "%b"), tm);
2570 #else
2571               sprintf(p, "%3.3s", months + 3 * tm->tm_mon);
2572 #endif
2573               break;
2574             case 'y':
2575               sprintf(p, "%02d", tm->tm_year % 100);
2576               break;
2577             case 'Y':
2578               sprintf(p, "%04d", tm->tm_year + 1900);
2579               break;
2580             case 'a':
2581               sprintf(p, tm->tm_hour >= 12 ? "pm" : "am");
2582               break;
2583             case 'A':
2584               sprintf(p, tm->tm_hour >= 12 ? "PM" : "AM");
2585               break;
2586             case 's':
2587               sprintf(p, "%02d", tm->tm_sec);
2588               tick = 1;
2589               break;
2590             case 'c':
2591               sprintf(p, zeroflg ? "%02d:%02d" : "%2d:%02d", tm->tm_hour, tm->tm_min);
2592               if (!tick || tick > 60)
2593                 tick = 60;
2594               break;
2595             case 'C':
2596               sprintf(p, zeroflg ? "%02d:%02d" : "%2d:%02d", (tm->tm_hour + 11) % 12 + 1, tm->tm_min);
2597               if (!tick || tick > 60)
2598                 tick = 60;
2599               break;
2600             default:
2601               break;
2602             }
2603           p += strlen(p) - 1;
2604           break;
2605         case 'l':
2606 #ifdef LOADAV
2607           *p = 0;
2608           if (l > 20)
2609             AddLoadav(p);
2610           if (*p)
2611             {
2612               qmflag = 1;
2613               p += strlen(p) - 1;
2614             }
2615           else
2616             *p = '?';
2617           if (!tick || tick > 60)
2618             tick = 60;
2619 #else
2620           *p = '?';
2621 #endif
2622           p += strlen(p) - 1;
2623           break;
2624         case '`':
2625         case 'h':
2626           if (rec >= 10 || (*s == 'h' && (win == 0 || win->w_hstatus == 0 || *win->w_hstatus == 0)))
2627             {
2628               p--;
2629               break;
2630             }
2631           if (*s == '`')
2632             {
2633               for (bt = backticks; bt; bt = bt->next)
2634                 if (bt->num == num)
2635                   break;
2636               if (bt == 0)
2637                 {
2638                   p--;
2639                   break;
2640                 }
2641             }
2642             {
2643               char savebuf[sizeof(winmsg_buf)];
2644               int oldtick = tick;
2645               int oldnumrend = winmsg_numrend;
2646
2647               *p = 0;
2648               strcpy(savebuf, winmsg_buf);
2649               winmsg_numrend = -winmsg_numrend;
2650               MakeWinMsgEv(*s == 'h' ? win->w_hstatus : runbacktick(bt, &oldtick, now.tv_sec), win, '\005', 0, (struct event *)0, rec + 1);
2651               debug2("oldtick=%d tick=%d\n", oldtick, tick);
2652               if (!tick || oldtick < tick)
2653                 tick = oldtick;
2654               if ((int)strlen(winmsg_buf) < l)
2655                 strcat(savebuf, winmsg_buf);
2656               strcpy(winmsg_buf, savebuf);
2657               while (oldnumrend < winmsg_numrend)
2658                 winmsg_rendpos[oldnumrend++] += p - winmsg_buf;
2659               if (*p)
2660                 qmflag = 1;
2661               p += strlen(p) - 1;
2662             }
2663           break;
2664         case 'w':
2665         case 'W':
2666           {
2667             struct win *oldfore = 0;
2668             char *ss;
2669
2670             if (display)
2671               {
2672                 oldfore = D_fore;
2673                 D_fore = win;
2674               }
2675             ss = AddWindows(p, l - 1, (*s == 'w' ? 0 : 1) | (longflg ? 0 : 2) | (plusflg ? 4 : 0), win ? win->w_number : -1);
2676             if (minusflg)
2677                *ss = 0;
2678             if (display)
2679               D_fore = oldfore;
2680           }
2681           if (*p)
2682             qmflag = 1;
2683           p += strlen(p) - 1;
2684           break;
2685         case 'u':
2686           *p = 0;
2687           if (win)
2688             AddOtherUsers(p, l - 1, win);
2689           if (*p)
2690             qmflag = 1;
2691           p += strlen(p) - 1;
2692           break;
2693         case 'f':
2694           *p = 0;
2695           if (win)
2696             AddWindowFlags(p, l - 1, win);
2697           if (*p)
2698             qmflag = 1;
2699           p += strlen(p) - 1;
2700           break;
2701         case 't':
2702           *p = 0;
2703           if (win && (int)strlen(win->w_title) < l)
2704             {
2705               strcpy(p, win->w_title);
2706               if (*p)
2707                 qmflag = 1;
2708             }
2709           p += strlen(p) - 1;
2710           break;
2711         case '{':
2712           {
2713             char rbuf[128];
2714             s++;
2715             for (i = 0; i < 127; i++)
2716               if (s[i] && s[i] != '}')
2717                 rbuf[i] = s[i];
2718               else
2719                 break;
2720             if (s[i] == '}' && winmsg_numrend < MAX_WINMSG_REND)
2721               {
2722                 r = -1;
2723                 rbuf[i] = 0;
2724                 debug1("MakeWinMsg attrcolor %s\n", rbuf);
2725                 if (i != 1 || rbuf[0] != '-')
2726                   r = ParseAttrColor(rbuf, (char *)0, 0);
2727                 if (r != -1 || (i == 1 && rbuf[0] == '-'))
2728                   {
2729                     winmsg_rend[winmsg_numrend] = r;
2730                     winmsg_rendpos[winmsg_numrend] = p - winmsg_buf;
2731                     winmsg_numrend++;
2732                   }
2733               }
2734             s += i;
2735             p--;
2736           }
2737           break;
2738         case 'H':
2739           *p = 0;
2740           if ((int)strlen(HostName) < l)
2741             {
2742               strcpy(p, HostName);
2743               if (*p)
2744                 qmflag = 1;
2745             }
2746           p += strlen(p) - 1;
2747           break;
2748         case 'S':
2749           {
2750             char *session_name;
2751             *p = 0;
2752             session_name = strchr(SockName, '.') + 1;
2753             if ((int)strlen(session_name) < l)
2754               {
2755                 strcpy(p, session_name);
2756                 if (*p)
2757                   qmflag = 1;
2758               }
2759             p += strlen(p) - 1;
2760           }
2761           break;
2762         case 'p':
2763           {
2764             sprintf(p, "%d", (plusflg && display) ? D_userpid : getpid());
2765             p += strlen(p) - 1;
2766           }
2767           break;
2768         case 'F':
2769           p--;
2770           /* small hack */
2771           if (display && ((ev && ev == &D_forecv->c_captev) || (!ev && win && win == D_fore)))
2772             minusflg = !minusflg;
2773           if (minusflg)
2774             qmflag = 1;
2775           break;
2776         case '>':
2777           truncpos = p - winmsg_buf;
2778           truncper = num > 100 ? 100 : num;
2779           trunclong = longflg;
2780           p--;
2781           break;
2782         case '=':
2783         case '<':
2784           *p = ' ';
2785           if (num || zeroflg || plusflg || longflg || (*s != '='))
2786             {
2787               /* expand all pads */
2788               if (minusflg)
2789                 {
2790                   num = (plusflg ? lastpad : padlen) - num;
2791                   if (!plusflg && padlen == 0)
2792                     num = p - winmsg_buf;
2793                   plusflg = 0;
2794                 }
2795               else if (!zeroflg)
2796                 {
2797                   if (*s != '=' && num == 0 && !plusflg)
2798                     num = 100;
2799                   if (num > 100)
2800                     num = 100;
2801                   if (padlen == 0)
2802                     num = p - winmsg_buf;
2803                   else
2804                     num = (padlen - (plusflg ? lastpad : 0)) * num / 100;
2805                 }
2806               if (num < 0)
2807                 num = 0;
2808               if (plusflg)
2809                 num += lastpad;
2810               if (num > MAXSTR - 1)
2811                 num = MAXSTR - 1;
2812               if (numpad)
2813                 p = pad_expand(winmsg_buf, p, numpad, num);
2814               numpad = 0;
2815               if (p - winmsg_buf > num && !longflg)
2816                 {
2817                   int left, trunc;
2818
2819                   if (truncpos == -1)
2820                     {
2821                       truncpos = lastpad;
2822                       truncper = 0;
2823                     }
2824                   trunc = lastpad + truncper * (num - lastpad) / 100;
2825                   if (trunc > num)
2826                     trunc = num;
2827                   if (trunc < lastpad)
2828                     trunc = lastpad;
2829                   left = truncpos - trunc;
2830                   if (left > p - winmsg_buf - num)
2831                     left = p - winmsg_buf - num;
2832                   debug1("lastpad = %d, ", lastpad);
2833                   debug3("truncpos = %d, trunc = %d, left = %d\n", truncpos, trunc, left);
2834                   if (left > 0)
2835                     {
2836                       if (left + lastpad > p - winmsg_buf)
2837                         left = p - winmsg_buf - lastpad;
2838                       if (p - winmsg_buf - lastpad - left > 0)
2839                         bcopy(winmsg_buf + lastpad + left, winmsg_buf + lastpad,  p - winmsg_buf - lastpad - left);
2840                       p -= left;
2841                       r = winmsg_numrend;
2842                       while (r && winmsg_rendpos[r - 1] > lastpad)
2843                         {
2844                           r--;
2845                           winmsg_rendpos[r] -= left;
2846                           if (winmsg_rendpos[r] < lastpad)
2847                             winmsg_rendpos[r] = lastpad;
2848                         }
2849                       if (trunclong)
2850                         {
2851                           if (p - winmsg_buf > lastpad)
2852                             winmsg_buf[lastpad] = '.';
2853                           if (p - winmsg_buf > lastpad + 1)
2854                             winmsg_buf[lastpad + 1] = '.';
2855                           if (p - winmsg_buf > lastpad + 2)
2856                             winmsg_buf[lastpad + 2] = '.';
2857                         }
2858                     }
2859                   if (p - winmsg_buf > num)
2860                     {
2861                       p = winmsg_buf + num;
2862                       if (trunclong)
2863                         {
2864                           if (num - 1 >= lastpad)
2865                             p[-1] = '.';
2866                           if (num - 2 >= lastpad)
2867                             p[-2] = '.';
2868                           if (num - 3 >= lastpad)
2869                             p[-3] = '.';
2870                         }
2871                       r = winmsg_numrend;
2872                       while (r && winmsg_rendpos[r - 1] > num)
2873                         winmsg_rendpos[--r] = num;
2874                     }
2875                   truncpos = -1;
2876                   trunclong = 0;
2877                   if (lastpad > p - winmsg_buf)
2878                     lastpad = p - winmsg_buf;
2879                   debug1("lastpad now %d\n", lastpad);
2880                 }
2881               if (*s == '=')
2882                 {
2883                   while (p - winmsg_buf < num)
2884                     *p++ = ' ';
2885                   lastpad = p - winmsg_buf;
2886                   truncpos = -1;
2887                   trunclong = 0;
2888                   debug1("lastpad2 now %d\n", lastpad);
2889                 }
2890               p--;
2891             }
2892           else if (padlen)
2893             {
2894               *p = 127;         /* internal pad representation */
2895               numpad++;
2896             }
2897           break;
2898         case 'n':
2899           s++;
2900           /* FALLTHROUGH */
2901         default:
2902           s--;
2903           if (l > 10 + num)
2904             {
2905               if (num == 0)
2906                 num = 1;
2907               if (!win)
2908                 sprintf(p, "%*s", num, num > 1 ? "--" : "-");
2909               else
2910                 sprintf(p, "%*d", num, win->w_number);
2911               qmflag = 1;
2912               p += strlen(p) - 1;
2913             }
2914           break;
2915         }
2916     }
2917   if (qmpos && !qmflag)
2918     p = qmpos + 1;
2919   *p = '\0';
2920   if (numpad)
2921     {
2922       if (padlen > MAXSTR - 1)
2923         padlen = MAXSTR - 1;
2924       p = pad_expand(winmsg_buf, p, numpad, padlen);
2925     }
2926   if (ev)
2927     {
2928       evdeq(ev);                /* just in case */
2929       ev->timeout.tv_sec = 0;
2930       ev->timeout.tv_usec = 0;
2931     }
2932   if (ev && tick)
2933     {
2934       now.tv_usec = 100000;
2935       if (tick == 1)
2936         now.tv_sec++;
2937       else
2938         now.tv_sec += tick - (now.tv_sec % tick);
2939       ev->timeout = now;
2940       debug2("NEW timeout %d %d\n", ev->timeout.tv_sec, tick);
2941     }
2942   return winmsg_buf;
2943 }
2944
2945 char *
2946 MakeWinMsg(s, win, esc)
2947 char *s;
2948 struct win *win;
2949 int esc;
2950 {
2951   return MakeWinMsgEv(s, win, esc, 0, (struct event *)0, 0);
2952 }
2953
2954 void
2955 PutWinMsg(s, start, max)
2956 char *s;
2957 int start, max;
2958 {
2959   int i, p, l, r, n;
2960   struct mchar rend;
2961   struct mchar rendstack[MAX_WINMSG_REND];
2962   int rendstackn = 0;
2963
2964   if (s != winmsg_buf)
2965     {
2966       /* sorry, no fancy coloring available */
2967       debug1("PutWinMsg %s plain\n", s);
2968       l = strlen(s);
2969       if (l > max)
2970         l = max;
2971       l -= start;
2972       s += start;
2973       while (l-- > 0)
2974         PUTCHARLP(*s++);
2975       return;
2976     }
2977   rend = D_rend;
2978   p = 0;
2979   l = strlen(s);
2980   debug2("PutWinMsg %s start attr %x\n", s, rend.attr);
2981   for (i = 0; i < winmsg_numrend && max > 0; i++)
2982     {
2983       if (p > winmsg_rendpos[i] || winmsg_rendpos[i] > l)
2984         break;
2985       if (p < winmsg_rendpos[i])
2986         {
2987           n = winmsg_rendpos[i] - p;
2988           if (n > max)
2989             n = max;
2990           max -= n;
2991           p += n;
2992           while(n-- > 0)
2993             {
2994               if (start-- > 0)
2995                 s++;
2996               else
2997                 PUTCHARLP(*s++);
2998             }
2999         }
3000       r = winmsg_rend[i];
3001       if (r == -1)
3002         {
3003           if (rendstackn > 0)
3004             rend = rendstack[--rendstackn];
3005         }
3006       else
3007         {
3008           rendstack[rendstackn++] = rend;
3009           ApplyAttrColor(r, &rend);
3010         }
3011       SetRendition(&rend);
3012     }
3013   if (p < l)
3014     {
3015       n = l - p;
3016       if (n > max)
3017         n = max;
3018       while(n-- > 0)
3019         {
3020           if (start-- > 0)
3021             s++;
3022           else
3023             PUTCHARLP(*s++);
3024         }
3025     }
3026 }
3027
3028
3029 #ifdef DEBUG
3030 static void
3031 fds1(i, j)
3032 int i, j;
3033 {
3034   while (i < j)
3035     {
3036       debug1("%d ", i);
3037       i++;
3038     }
3039   if ((j = open("/dev/null", 0)) >= 0)
3040     {
3041       fds1(i + 1, j);
3042       close(j);
3043     }
3044   else
3045     {
3046       while (dup(++i) < 0 && errno != EBADF)
3047         debug1("%d ", i);
3048       debug1(" [%d]\n", i);
3049     }
3050 }
3051
3052 static void
3053 fds()
3054 {
3055   debug("fds: ");
3056   fds1(-1, -1);
3057 }
3058 #endif
3059
3060 static void
3061 serv_read_fn(ev, data)
3062 struct event *ev;
3063 char *data;
3064 {
3065   debug("Knock - knock!\n");
3066   ReceiveMsg();
3067 }
3068
3069 static void
3070 serv_select_fn(ev, data)
3071 struct event *ev;
3072 char *data;
3073 {
3074   struct win *p;
3075
3076   debug("serv_select_fn called\n");
3077   /* XXX: messages?? */
3078   if (GotSigChld)
3079     {
3080       SigChldHandler();
3081     }
3082   if (InterruptPlease)
3083     {
3084       debug("Backend received interrupt\n");
3085       /* This approach is rather questionable in a multi-display
3086        * environment */
3087       if (fore && displays)
3088         {
3089 #if defined(TERMIO) || defined(POSIX)
3090           char ibuf = displays->d_OldMode.tio.c_cc[VINTR];
3091 #else
3092           char ibuf = displays->d_OldMode.m_tchars.t_intrc;
3093 #endif
3094 #ifdef PSEUDOS
3095           write(W_UWP(fore) ? fore->w_pwin->p_ptyfd : fore->w_ptyfd,
3096                 &ibuf, 1);
3097           debug1("Backend wrote interrupt to %d", fore->w_number);
3098           debug1("%s\n", W_UWP(fore) ? " (pseudowin)" : "");
3099 #else
3100           write(fore->w_ptyfd, &ibuf, 1);
3101           debug1("Backend wrote interrupt to %d\n", fore->w_number);
3102 #endif
3103         }
3104       InterruptPlease = 0;
3105     }
3106
3107   for (p = windows; p; p = p->w_next)
3108     {
3109       if (p->w_bell == BELL_FOUND || p->w_bell == BELL_VISUAL)
3110         {
3111           struct canvas *cv;
3112           int visual = p->w_bell == BELL_VISUAL || visual_bell;
3113           p->w_bell = BELL_ON;
3114           for (display = displays; display; display = display->d_next)
3115             {
3116               for (cv = D_cvlist; cv; cv = cv->c_next)
3117                 if (cv->c_layer->l_bottom == &p->w_layer)
3118                   break;
3119               if (cv == 0)
3120                 {
3121                   p->w_bell = BELL_DONE;
3122                   Msg(0, "%s", MakeWinMsg(BellString, p, '%'));
3123                 }
3124               else if (visual && !D_VB && (!D_status || !D_status_bell))
3125                 {
3126                   Msg(0, "%s", VisualBellString);
3127                   if (D_status)
3128                     {
3129                       D_status_bell = 1;
3130                       debug1("using vbell timeout %d\n", VBellWait);
3131                       SetTimeout(&D_statusev, VBellWait );
3132                     }
3133                 }
3134             }
3135           /* don't annoy the user with two messages */
3136           if (p->w_monitor == MON_FOUND)
3137             p->w_monitor = MON_DONE;
3138           WindowChanged(p, 'f');
3139         }
3140       if (p->w_monitor == MON_FOUND)
3141         {
3142           struct canvas *cv;
3143           p->w_monitor = MON_ON;
3144           for (display = displays; display; display = display->d_next)
3145             {
3146               for (cv = D_cvlist; cv; cv = cv->c_next)
3147                 if (cv->c_layer->l_bottom == &p->w_layer)
3148                   break;
3149               if (cv)
3150                 continue;       /* user already sees window */
3151 #ifdef MULTIUSER
3152               if (!(ACLBYTE(p->w_mon_notify, D_user->u_id) & ACLBIT(D_user->u_id)))
3153                 continue;       /* user doesn't care */
3154 #endif
3155               Msg(0, "%s", MakeWinMsg(ActivityString, p, '%'));
3156               p->w_monitor = MON_DONE;
3157             }
3158           WindowChanged(p, 'f');
3159         }
3160     }
3161
3162   for (display = displays; display; display = display->d_next)
3163     {
3164       struct canvas *cv;
3165       if (D_status == STATUS_ON_WIN)
3166         continue;
3167       /* XXX: should use display functions! */
3168       for (cv = D_cvlist; cv; cv = cv->c_next)
3169         {
3170           int lx, ly;
3171
3172           /* normalize window, see resize.c */
3173           lx = cv->c_layer->l_x;
3174           ly = cv->c_layer->l_y;
3175           if (lx == cv->c_layer->l_width)
3176             lx--;
3177           if (ly + cv->c_yoff < cv->c_ys)
3178             {
3179               int i, n = cv->c_ys - (ly + cv->c_yoff);
3180               cv->c_yoff = cv->c_ys - ly;
3181               RethinkViewportOffsets(cv);
3182               if (n > cv->c_layer->l_height)
3183                 n = cv->c_layer->l_height;
3184               CV_CALL(cv,
3185                 LScrollV(flayer, -n, 0, flayer->l_height - 1, 0);
3186                 LayRedisplayLine(-1, -1, -1, 1);
3187                 for (i = 0; i < n; i++)
3188                   LayRedisplayLine(i, 0, flayer->l_width - 1, 1);
3189                 if (cv == cv->c_display->d_forecv)
3190                   LaySetCursor();
3191               );
3192             }
3193           else if (ly + cv->c_yoff > cv->c_ye)
3194             {
3195               int i, n = ly + cv->c_yoff - cv->c_ye;
3196               cv->c_yoff = cv->c_ye - ly;
3197               RethinkViewportOffsets(cv);
3198               if (n > cv->c_layer->l_height)
3199                 n = cv->c_layer->l_height;
3200               CV_CALL(cv,
3201                 LScrollV(flayer, n, 0, cv->c_layer->l_height - 1, 0);
3202                 LayRedisplayLine(-1, -1, -1, 1);
3203                 for (i = 0; i < n; i++)
3204                   LayRedisplayLine(i + flayer->l_height - n, 0, flayer->l_width - 1, 1);
3205                 if (cv == cv->c_display->d_forecv)
3206                   LaySetCursor();
3207               );
3208             }
3209           if (lx + cv->c_xoff < cv->c_xs)
3210             {
3211               int i, n = cv->c_xs - (lx + cv->c_xoff);
3212               if (n < (cv->c_xe - cv->c_xs + 1) / 2)
3213                 n = (cv->c_xe - cv->c_xs + 1) / 2;
3214               if (cv->c_xoff + n > cv->c_xs)
3215                 n = cv->c_xs - cv->c_xoff;
3216               cv->c_xoff += n;
3217               RethinkViewportOffsets(cv);
3218               if (n > cv->c_layer->l_width)
3219                 n = cv->c_layer->l_width;
3220               CV_CALL(cv,
3221                 LayRedisplayLine(-1, -1, -1, 1);
3222                 for (i = 0; i < flayer->l_height; i++)
3223                   {
3224                     LScrollH(flayer, -n, i, 0, flayer->l_width - 1, 0, 0);
3225                     LayRedisplayLine(i, 0, n - 1, 1);
3226                   }
3227                 if (cv == cv->c_display->d_forecv)
3228                   LaySetCursor();
3229               );
3230             }
3231           else if (lx + cv->c_xoff > cv->c_xe)
3232             {
3233               int i, n = lx + cv->c_xoff - cv->c_xe;
3234               if (n < (cv->c_xe - cv->c_xs + 1) / 2)
3235                 n = (cv->c_xe - cv->c_xs + 1) / 2;
3236               if (cv->c_xoff - n + cv->c_layer->l_width - 1 < cv->c_xe)
3237                 n = cv->c_xoff + cv->c_layer->l_width - 1 - cv->c_xe;
3238               cv->c_xoff -= n;
3239               RethinkViewportOffsets(cv);
3240               if (n > cv->c_layer->l_width)
3241                 n = cv->c_layer->l_width;
3242               CV_CALL(cv,
3243                 LayRedisplayLine(-1, -1, -1, 1);
3244                 for (i = 0; i < flayer->l_height; i++)
3245                   {
3246                     LScrollH(flayer, n, i, 0, flayer->l_width - 1, 0, 0);
3247                     LayRedisplayLine(i, flayer->l_width - n, flayer->l_width - 1, 1);
3248                   }
3249                 if (cv == cv->c_display->d_forecv)
3250                   LaySetCursor();
3251               );
3252             }
3253         }
3254     }
3255
3256   for (display = displays; display; display = display->d_next)
3257     {
3258       if (D_status == STATUS_ON_WIN || D_cvlist == 0 || D_cvlist->c_next == 0)
3259         continue;
3260       debug1("serv_select_fn: Restore on cv %#x\n", (int)D_forecv);
3261       CV_CALL(D_forecv, LayRestore();LaySetCursor());
3262     }
3263 }
3264
3265 static void
3266 logflush_fn(ev, data)
3267 struct event *ev;
3268 char *data;
3269 {
3270   struct win *p;
3271   char *buf;
3272   int n;
3273
3274   if (!islogfile(NULL))
3275     return;             /* no more logfiles */
3276   logfflush(NULL);
3277   n = log_flush ? log_flush : (logtstamp_after + 4) / 5;
3278   if (n)
3279     {
3280       SetTimeout(ev, n * 1000);
3281       evenq(ev);        /* re-enqueue ourself */
3282     }
3283   if (!logtstamp_on)
3284     return;
3285   /* write fancy time-stamp */
3286   for (p = windows; p; p = p->w_next)
3287     {
3288       if (!p->w_log)
3289         continue;
3290       p->w_logsilence += n;
3291       if (p->w_logsilence < logtstamp_after)
3292         continue;
3293       if (p->w_logsilence - n >= logtstamp_after)
3294         continue;
3295       buf = MakeWinMsg(logtstamp_string, p, '%');
3296       logfwrite(p->w_log, buf, strlen(buf));
3297     }
3298 }
3299
3300 /*
3301  * Interprets ^?, ^@ and other ^-control-char notation.
3302  * Interprets \ddd octal notation
3303  *
3304  * The result is placed in *cp, p is advanced behind the parsed expression and
3305  * returned.
3306  */
3307 static char *
3308 ParseChar(p, cp)
3309 char *p, *cp;
3310 {
3311   if (*p == 0)
3312     return 0;
3313   if (*p == '^' && p[1])
3314     {
3315       if (*++p == '?')
3316         *cp = '\177';
3317       else if (*p >= '@')
3318         *cp = Ctrl(*p);
3319       else
3320         return 0;
3321       ++p;
3322     }
3323   else if (*p == '\\' && *++p <= '7' && *p >= '0')
3324     {
3325       *cp = 0;
3326       do
3327         *cp = *cp * 8 + *p - '0';
3328       while (*++p <= '7' && *p >= '0');
3329     }
3330   else
3331     *cp = *p++;
3332   return p;
3333 }
3334
3335 static int
3336 ParseEscape(p)
3337 char *p;
3338 {
3339   unsigned char buf[2];
3340
3341   if (*p == 0)
3342     SetEscape((struct acluser *)0, -1, -1);
3343   else
3344     {
3345       if ((p = ParseChar(p, (char *)buf)) == NULL ||
3346           (p = ParseChar(p, (char *)buf+1)) == NULL || *p)
3347         return -1;
3348       SetEscape((struct acluser *)0, buf[0], buf[1]);
3349     }
3350   return 0;
3351 }
3352