inetutils/telnet/commands.c

/*
  Copyright (C) 1995-2023 Free Software Foundation, Inc.

  This file is part of GNU Inetutils.

  GNU Inetutils is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or (at
  your option) any later version.

  GNU Inetutils is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see `http://www.gnu.org/licenses/'. */

/*
 * Copyright (c) 1988, 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <config.h>

#ifdef HAVE_SYS_PARAM_H
# include <sys/param.h>
#endif
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/file.h>

#include <sys/socket.h>
#include <netinet/in.h>

#include <fcntl.h>

#include <signal.h>
#include <netdb.h>
#include <ctype.h>
#include <pwd.h>
#include <stdarg.h>
#include <errno.h>

#include <stdlib.h>
#include <limits.h>		/* LLONG_MAX for Solaris. */

#include <arpa/inet.h>
#include <arpa/telnet.h>

#if defined HAVE_IDN2_H && defined HAVE_IDN2
# include <idn2.h>
#elif defined HAVE_IDNA_H
# include <idna.h>
#endif

#include <attribute.h>
#include <libinetutils.h>

#include "general.h"

#include "ring.h"

#include "externs.h"
#include "defines.h"
#include "types.h"

#include "xalloc.h"
#include "xvasprintf.h"
#include "xalloc.h"

#ifdef	ENCRYPTION
# include <libtelnet/encrypt.h>
#endif
#if defined AUTHENTICATION || defined ENCRYPTION
# include <libtelnet/misc.h>
#endif

#if !defined CRAY && !defined sysV88
# ifdef HAVE_NETINET_IN_SYSTM_H
#  include <netinet/in_systm.h>
# endif
# if (defined vax || defined tahoe || defined hp300) && !defined ultrix
#  include <machine/endian.h>
# endif/* vax */
#endif /* !defined(CRAY) && !defined(sysV88) */

#ifdef HAVE_NETINET_IP_H
# include <netinet/ip.h>
#endif

char *hostname = 0;

extern char *getenv (const char *);

extern int isprefix (register const char *s1, register const char *s2);
extern char **genget (const char *, char **, int);
extern int Ambiguous (void *);

typedef int (*intrtn_t) (int, char *[]);
static int call (intrtn_t, ...);

typedef struct
{
  const char *name;		/* command name */
  const char *help;		/* help string (NULL for no help) */
  int (*handler) (int, char *[]);	/* routine which executes command */
  int needconnect;		/* Do we need to be connected to execute? */
} Command;

#define TELNET_MAX_ARGS 20

static char line[256];
static char saveline[256];
static int margc;
static char *margv[TELNET_MAX_ARGS];

static struct env_lst *env_help (const char *, char *);
static void slc_help (int);

static void
makeargv (void)
{
  register char *cp, *cp2, c;
  register char **argp = margv;

  margc = 0;
  cp = line;
  if (*cp == '!')
    {				/* Special case shell escape */
      strcpy (saveline, line);	/* save for shell command */
      *argp++ = "!";		/* No room in string to get this */
      margc++;
      cp++;
    }
  while ((c = *cp))
    {
      register int inquote = 0;
      while (isspace (c))
	c = *++cp;
      if (c == '\0')
	break;
      if (margc + 1 >= TELNET_MAX_ARGS)
	{
	  fprintf (stderr, "Ignoring excess arguments.\n");
	  break;
	}
      *argp++ = cp;
      margc += 1;
      for (cp2 = cp; c != '\0'; c = *++cp)
	{
	  if (inquote)
	    {
	      if (c == inquote)
		{
		  inquote = 0;
		  continue;
		}
	    }
	  else
	    {
	      if (c == '\\')
		{
		  if ((c = *++cp) == '\0')
		    break;
		}
	      else if (c == '"')
		{
		  inquote = '"';
		  continue;
		}
	      else if (c == '\'')
		{
		  inquote = '\'';
		  continue;
		}
	      else if (isspace (c))
		break;
	    }
	  *cp2++ = c;
	}
      *cp2 = '\0';
      if (c == '\0')
	break;
      cp++;
    }
  *argp++ = 0;
}

/*
 * Make a character string into a number.
 *
 * Todo:  1.  Could take random integers (12, 0x12, 012, 0b1).
 */

static int
special (register char *s)
{
  register char c;
  char b;

  switch (*s)
    {
    case '^':
      b = *++s;
      if (b == '?')
	{
	  c = b | 0x40;		/* DEL */
	}
      else
	{
	  c = b & 0x1f;
	}
      break;
    default:
      c = *s;
      break;
    }
  return c;
}

/*
 * Construct a control character sequence
 * for a special character.
 */
static const char *
control (register cc_t c)
{
  static char buf[5];
  /*
   * The only way I could get the Sun 3.5 compiler
   * to shut up about
   *      if ((unsigned int)c >= 0x80)
   * was to assign "c" to an unsigned int variable...
   * Arggg....
   */
  register unsigned int uic = (unsigned int) c;

  if (uic == 0x7f)
    return ("^?");
  if (c == (cc_t) _POSIX_VDISABLE)
    {
      return "off";
    }
  if (uic >= 0x80)
    {
      buf[0] = '\\';
      buf[1] = ((c >> 6) & 07) + '0';
      buf[2] = ((c >> 3) & 07) + '0';
      buf[3] = (c & 07) + '0';
      buf[4] = 0;
    }
  else if (uic >= 0x20)
    {
      buf[0] = c;
      buf[1] = 0;
    }
  else
    {
      buf[0] = '^';
      buf[1] = '@' + c;
      buf[2] = 0;
    }
  return (buf);
}



/*
 *	The following are data structures and routines for
 *	the "send" command.
 *
 */

struct sendlist
{
  const char *name;		/* How user refers to it (case independent) */
  const char *help;		/* Help information (0 ==> no help) */
  int needconnect;		/* Need to be connected */
  int narg;			/* Number of arguments */
  int (*handler) (const char *);	/* Routine to perform (for special ops) */
  int nbyte;			/* Number of bytes to send this command */
  int what;			/* Character to be sent (<0 ==> special) */
};


static int send_esc (const char *);
static int send_docmd (const char *);
static int send_dontcmd (const char *);
static int send_willcmd (const char *);
static int send_wontcmd (const char *);
static int send_help (const char *);

static struct sendlist Sendlist[] = {
  {"ao", "Send Telnet Abort output", 1, 0, 0, 2, AO},
  {"ayt", "Send Telnet 'Are You There'", 1, 0, 0, 2, AYT},
  {"brk", "Send Telnet Break", 1, 0, 0, 2, BREAK},
  {"break", 0, 1, 0, 0, 2, BREAK},
  {"ec", "Send Telnet Erase Character", 1, 0, 0, 2, EC},
  {"el", "Send Telnet Erase Line", 1, 0, 0, 2, EL},
  {"escape", "Send current escape character", 1, 0, send_esc, 1, 0},
  {"ga", "Send Telnet 'Go Ahead' sequence", 1, 0, 0, 2, GA},
  {"ip", "Send Telnet Interrupt Process", 1, 0, 0, 2, IP},
  {"intp", 0, 1, 0, 0, 2, IP},
  {"interrupt", 0, 1, 0, 0, 2, IP},
  {"intr", 0, 1, 0, 0, 2, IP},
  {"nop", "Send Telnet 'No operation'", 1, 0, 0, 2, NOP},
  {"eor", "Send Telnet 'End of Record'", 1, 0, 0, 2, EOR},
  {"abort", "Send Telnet 'Abort Process'", 1, 0, 0, 2, ABORT},
  {"susp", "Send Telnet 'Suspend Process'", 1, 0, 0, 2, SUSP},
  {"eof", "Send Telnet End of File Character", 1, 0, 0, 2, xEOF},
  {"synch", "Perform Telnet 'Synch operation'", 1, 0, dosynch, 2, 0},
  {"getstatus", "Send request for STATUS", 1, 0, get_status, 6, 0},
  {"?", "Display send options", 0, 0, send_help, 0, 0},
  {"help", 0, 0, 0, send_help, 0, 0},
  {"do", 0, 0, 1, send_docmd, 3, 0},
  {"dont", 0, 0, 1, send_dontcmd, 3, 0},
  {"will", 0, 0, 1, send_willcmd, 3, 0},
  {"wont", 0, 0, 1, send_wontcmd, 3, 0},
  {NULL, 0, 0, 0, NULL, 0, 0}
};

#define GETSEND(name) ((struct sendlist *) genget(name, (char **) Sendlist, \
				sizeof(struct sendlist)))

static int
sendcmd (int argc, char **argv)
{
  int count;			/* how many bytes we are going to need to send */
  int i;
  struct sendlist *s;		/* pointer to current command */
  int success = 0;
  int needconnect = 0;

  if (argc < 2)
    {
      printf ("need at least one argument for 'send' command\n");
      printf ("'send ?' for help\n");
      return 0;
    }
  /*
   * First, validate all the send arguments.
   * In addition, we see how much space we are going to need, and
   * whether or not we will be doing a "SYNCH" operation (which
   * flushes the network queue).
   */
  count = 0;
  for (i = 1; i < argc; i++)
    {
      s = GETSEND (argv[i]);
      if (s == 0)
	{
	  printf ("Unknown send argument '%s'\n'send ?' for help.\n",
		  argv[i]);
	  return 0;
	}
      else if (Ambiguous (s))
	{
	  printf ("Ambiguous send argument '%s'\n'send ?' for help.\n",
		  argv[i]);
	  return 0;
	}
      if (i + s->narg >= argc)
	{
	  fprintf (stderr,
		   "Need %d argument%s to 'send %s' command.  'send %s ?' for help.\n",
		   s->narg, s->narg == 1 ? "" : "s", s->name, s->name);
	  return 0;
	}
      count += s->nbyte;
      if (s->handler == send_help)
	{
	  send_help (NULL);
	  return 0;
	}

      i += s->narg;
      needconnect += s->needconnect;
    }
  if (!connected && needconnect)
    {
      printf ("?Need to be connected first.\n");
      printf ("'send ?' for help\n");
      return 0;
    }
  /* Now, do we have enough room? */
  if (NETROOM () < count)
    {
      printf ("There is not enough room in the buffer TO the network\n");
      printf ("to process your request.  Nothing will be done.\n");
      printf ("('send synch' will throw away most data in the network\n");
      printf ("buffer, if this might help.)\n");
      return 0;
    }
  /* OK, they are all OK, now go through again and actually send */
  count = 0;
  for (i = 1; i < argc; i++)
    {
      if ((s = GETSEND (argv[i])) == 0)
	{
	  fprintf (stderr, "Telnet 'send' error - argument disappeared!\n");
	  (void) quit (0, NULL);
	 /*NOTREACHED*/}
      if (s->handler)
	{
	  count++;
	  success += (*s->handler) ((s->narg > 0) ? argv[i + 1] : 0);
	  i += s->narg;
	}
      else
	{
	  NET2ADD (IAC, s->what);
	  printoption ("SENT", IAC, s->what);
	}
    }
  return (count == success);
}

static int
send_esc (const char *name)
{
  NETADD (escape);
  return 1;
}

int
send_tncmd (void (*func) (int, int), char *cmd, const char *name)
{
  char **cpp;
#if !HAVE_DECL_TELOPTS
  extern char *telopts[];
#endif
  register int val = 0;

  if (isprefix (name, "help") || isprefix (name, "?"))
    {
      register int col, len;

      printf ("Usage: send %s <value|option>\n", cmd);
      printf ("\"value\" must be from 0 to 255\n");
      printf ("Valid options are:\n\t");

      col = 8;
      for (cpp = telopts; *cpp; cpp++)
	{
	  len = strlen (*cpp) + 3;
	  if (col + len > 65)
	    {
	      printf ("\n\t");
	      col = 8;
	    }
	  printf (" \"%s\"", *cpp);
	  col += len;
	}
      printf ("\n");
      return 0;
    }
  cpp = (char **) genget (name, telopts, sizeof (char *));
  if (Ambiguous (cpp))
    {
      fprintf (stderr, "'%s': ambiguous argument ('send %s ?' for help).\n",
	       name, cmd);
      return 0;
    }
  if (cpp)
    {
#if HAVE_DECL_TELOPTS
      val = cpp - (char **) telopts;
#else /* !HAVE_DECL_TELOPTS */
      val = cpp - telopts;
#endif
    }
  else
    {
      register const char *cp = name;

      while (*cp >= '0' && *cp <= '9')
	{
	  val *= 10;
	  val += *cp - '0';
	  cp++;
	}
      if (*cp != 0)
	{
	  fprintf (stderr, "'%s': unknown argument ('send %s ?' for help).\n",
		   name, cmd);
	  return 0;
	}
      else if (val < 0 || val > 255)
	{
	  fprintf (stderr, "'%s': bad value ('send %s ?' for help).\n",
		   name, cmd);
	  return 0;
	}
    }
  if (!connected)
    {
      printf ("?Need to be connected first.\n");
      return 0;
    }
  (*func) (val, 1);
  return 1;
}

static int
send_docmd (const char *name)
{
  return (send_tncmd (send_do, "do", name));
}

static int
send_dontcmd (const char *name)
{
  return (send_tncmd (send_dont, "dont", name));
}

static int
send_willcmd (const char *name)
{
  return (send_tncmd (send_will, "will", name));
}

static int
send_wontcmd (const char *name)
{
  return (send_tncmd (send_wont, "wont", name));
}

static int
send_help (const char *name)
{
  struct sendlist *s;		/* pointer to current command */
  for (s = Sendlist; s->name; s++)
    {
      if (s->help)
	printf ("%-15s %s\n", s->name, s->help);
    }
  return (0);
}

/*
 * The following are the routines and data structures referred
 * to by the arguments to the "toggle" command.
 */

static int
lclchars (int val)
{
  donelclchars = 1;
  return 1;
}

static int
togdebug (int val)
{
#ifndef NOT43
  if (net > 0 && (SetSockOpt (net, SOL_SOCKET, SO_DEBUG, debug)) < 0)
    {
      perror ("setsockopt (SO_DEBUG)");
    }
#else /* NOT43 */
  if (debug)
    {
      if (net > 0 && SetSockOpt (net, SOL_SOCKET, SO_DEBUG, 0, 0) < 0)
	perror ("setsockopt (SO_DEBUG)");
    }
  else
    printf ("Cannot turn off socket debugging\n");
#endif /* NOT43 */
  return 1;
}


static int
togcrlf (int val)
{
  if (crlf)
    {
      printf ("Will send carriage returns as telnet <CR><LF>.\n");
    }
  else
    {
      printf ("Will send carriage returns as telnet <CR><NUL>.\n");
    }
  return 1;
}

int binmode;

static int
togbinary (int val)
{
  donebinarytoggle = 1;

  if (val >= 0)
    {
      binmode = val;
    }
  else
    {
      if (my_want_state_is_will (TELOPT_BINARY) &&
	  my_want_state_is_do (TELOPT_BINARY))
	{
	  binmode = 1;
	}
      else if (my_want_state_is_wont (TELOPT_BINARY) &&
	       my_want_state_is_dont (TELOPT_BINARY))
	{
	  binmode = 0;
	}
      val = binmode ? 0 : 1;
    }

  if (val == 1)
    {
      if (my_want_state_is_will (TELOPT_BINARY) &&
	  my_want_state_is_do (TELOPT_BINARY))
	{
	  printf ("Already operating in binary mode with remote host.\n");
	}
      else
	{
	  printf ("Negotiating binary mode with remote host.\n");
	  tel_enter_binary (3);
	}
    }
  else
    {
      if (my_want_state_is_wont (TELOPT_BINARY) &&
	  my_want_state_is_dont (TELOPT_BINARY))
	{
	  printf ("Already in network ascii mode with remote host.\n");
	}
      else
	{
	  printf ("Negotiating network ascii mode with remote host.\n");
	  tel_leave_binary (3);
	}
    }
  return 1;
}

static int
togrbinary (int val)
{
  donebinarytoggle = 1;

  if (val == -1)
    val = my_want_state_is_do (TELOPT_BINARY) ? 0 : 1;

  if (val == 1)
    {
      if (my_want_state_is_do (TELOPT_BINARY))
	{
	  printf ("Already receiving in binary mode.\n");
	}
      else
	{
	  printf ("Negotiating binary mode on input.\n");
	  tel_enter_binary (1);
	}
    }
  else
    {
      if (my_want_state_is_dont (TELOPT_BINARY))
	{
	  printf ("Already receiving in network ascii mode.\n");
	}
      else
	{
	  printf ("Negotiating network ascii mode on input.\n");
	  tel_leave_binary (1);
	}
    }
  return 1;
}

static int
togxbinary (int val)
{
  donebinarytoggle = 1;

  if (val == -1)
    val = my_want_state_is_will (TELOPT_BINARY) ? 0 : 1;

  if (val == 1)
    {
      if (my_want_state_is_will (TELOPT_BINARY))
	{
	  printf ("Already transmitting in binary mode.\n");
	}
      else
	{
	  printf ("Negotiating binary mode on output.\n");
	  tel_enter_binary (2);
	}
    }
  else
    {
      if (my_want_state_is_wont (TELOPT_BINARY))
	{
	  printf ("Already transmitting in network ascii mode.\n");
	}
      else
	{
	  printf ("Negotiating network ascii mode on output.\n");
	  tel_leave_binary (2);
	}
    }
  return 1;
}


static int togglehelp (int);
#if defined AUTHENTICATION
extern int auth_togdebug (int);
#endif
#ifdef	ENCRYPTION
extern int EncryptAutoEnc (int);
extern int EncryptAutoDec (int);
extern int EncryptDebug (int);
extern int EncryptVerbose (int);
#endif /* ENCRYPTION */

struct togglelist
{
  const char *name;		/* name of toggle */
  const char *help;		/* help message */
  int (*handler) (int);		/* routine to do actual setting */
  int *variable;
  const char *actionexplanation;
};

static struct togglelist Togglelist[] = {
  {"autoflush",
   "flushing of output when sending interrupt characters",
   0,
   &autoflush,
   "flush output when sending interrupt characters"},
  {"autosynch",
   "automatic sending of interrupt characters in urgent mode",
   0,
   &autosynch,
   "send interrupt characters in urgent mode"},
#if defined AUTHENTICATION
  {"autologin",
   "automatic sending of login and/or authentication info",
   0,
   &autologin,
   "send login name and/or authentication information"},
  {"authdebug",
   "Toggle authentication debugging",
   auth_togdebug,
   0,
   "print authentication debugging information"},
#endif
#ifdef	ENCRYPTION
  {"autoencrypt",
   "automatic encryption of data stream",
   EncryptAutoEnc,
   0,
   "automatically encrypt output"},
  {"autodecrypt",
   "automatic decryption of data stream",
   EncryptAutoDec,
   0,
   "automatically decrypt input"},
  {"verbose_encrypt",
   "Toggle verbose encryption output",
   EncryptVerbose,
   0,
   "print verbose encryption output"},
  {"encdebug",
   "Toggle encryption debugging",
   EncryptDebug,
   0,
   "print encryption debugging information"},
#endif /* ENCRYPTION */
  {"skiprc",
   "don't read ~/.telnetrc file",
   0,
   &skiprc,
   "skip reading of ~/.telnetrc file"},
  {"binary",
   "sending and receiving of binary data",
   togbinary,
   0,
   0},
  {"inbinary",
   "receiving of binary data",
   togrbinary,
   0,
   0},
  {"outbinary",
   "sending of binary data",
   togxbinary,
   0,
   0},
  {"crlf",
   "sending carriage returns as telnet <CR><LF>",
   togcrlf,
   &crlf,
   0},
  {"crmod",
   "mapping of received carriage returns",
   0,
   &crmod,
   "map carriage return on output"},
  {"localchars",
   "local recognition of certain control characters",
   lclchars,
   &localchars,
   "recognize certain control characters"},
  {" ", "", 0, NULL, NULL},	/* empty line */
#if (defined unix || defined __unix || defined __unix__) && defined TN3270
  {"apitrace",
   "(debugging) toggle tracing of API transactions",
   0,
   &apitrace,
   "trace API transactions"},
  {"cursesdata",
   "(debugging) toggle printing of hexadecimal curses data",
   0,
   &cursesdata,
   "print hexadecimal representation of curses data"},
#endif /* (unix || __unix || __unix__)) && TN3270 */
  {"debug",
   "debugging",
   togdebug,
   &debug,
   "turn on socket level debugging"},
  {"netdata",
   "printing of hexadecimal network data (debugging)",
   0,
   &netdata,
   "print hexadecimal representation of network traffic"},
  {"prettydump",
   "output of \"netdata\" to user readable format (debugging)",
   0,
   &prettydump,
   "print user readable output for \"netdata\""},
  {"options",
   "viewing of options processing (debugging)",
   0,
   &showoptions,
   "show option processing"},
  {"termdata",
   "(debugging) toggle printing of hexadecimal terminal data",
   0,
   &termdata,
   "print hexadecimal representation of terminal traffic"},
  {"?",
   0,
   togglehelp, NULL, NULL},
  {"help",
   0,
   togglehelp, NULL, NULL},
  {NULL, NULL, 0, NULL, NULL}
};

static int
togglehelp (int val)
{
  struct togglelist *c;

  for (c = Togglelist; c->name; c++)
    {
      if (c->help)
	{
	  if (*c->help)
	    printf ("%-15s toggle %s\n", c->name, c->help);
	  else
	    printf ("\n");
	}
    }
  printf ("\n");
  printf ("%-15s %s\n", "?", "display help information");
  return 0;
}

static void
settogglehelp (int set)
{
  struct togglelist *c;

  for (c = Togglelist; c->name; c++)
    {
      if (c->help)
	{
	  if (*c->help)
	    printf ("%-15s %s %s\n", c->name, set ? "enable" : "disable",
		    c->help);
	  else
	    printf ("\n");
	}
    }
}

#define GETTOGGLE(name) (struct togglelist *) \
		genget(name, (char **) Togglelist, sizeof(struct togglelist))

static int
toggle (int argc, char *argv[])
{
  int retval = 1;
  char *name;
  struct togglelist *c;

  if (argc < 2)
    {
      fprintf (stderr,
	       "Need an argument to 'toggle' command.  'toggle ?' for help.\n");
      return 0;
    }
  argc--;
  argv++;
  while (argc--)
    {
      name = *argv++;
      c = GETTOGGLE (name);
      if (Ambiguous (c))
	{
	  fprintf (stderr,
		   "'%s': ambiguous argument ('toggle ?' for help).\n", name);
	  return 0;
	}
      else if (c == 0)
	{
	  fprintf (stderr, "'%s': unknown argument ('toggle ?' for help).\n",
		   name);
	  return 0;
	}
      else
	{
	  if (c->variable)
	    {
	      *c->variable = !*c->variable;	/* invert it */
	      if (c->actionexplanation)
		{
		  printf ("%s %s.\n", *c->variable ? "Will" : "Won't",
			  c->actionexplanation);
		}
	    }
	  if (c->handler)
	    {
	      retval &= (*c->handler) (-1);
	    }
	}
    }
  return retval;
}

/*
 * The following perform the "set" command.
 */

#ifdef	USE_TERMIO
struct termio new_tc = { 0 };
#endif

struct setlist
{
  const char *name;		/* name */
  const char *help;		/* help information */
  void (*handler) (const char *);
  cc_t *charp;			/* where it is located at */
};

static struct setlist Setlist[] = {
#ifdef	KLUDGELINEMODE
  {"echo", "character to toggle local echoing on/off", 0, &echoc},
#endif
  {"escape", "character to escape back to telnet command mode", 0, &escape},
  {"rlogin", "rlogin escape character", 0, &rlogin},
  {"tracefile", "file to write trace information to", SetNetTrace,
   (cc_t *) NetTraceFile},
  {" ", "", 0, NULL},
  {" ", "The following need 'localchars' to be toggled true", 0, 0},
  {"flushoutput", "character to cause an Abort Output", 0, termFlushCharp},
  {"interrupt", "character to cause an Interrupt Process", 0, termIntCharp},
  {"quit", "character to cause an Abort process", 0, termQuitCharp},
  {"eof", "character to cause an EOF ", 0, termEofCharp},
  {" ", "", 0, NULL},
  {" ", "The following are for local editing in linemode", 0, 0},
  {"erase", "character to use to erase a character", 0, termEraseCharp},
  {"kill", "character to use to erase a line", 0, termKillCharp},
  {"lnext", "character to use for literal next", 0, termLiteralNextCharp},
  {"susp", "character to cause a Suspend Process", 0, termSuspCharp},
  {"reprint", "character to use for line reprint", 0, termRprntCharp},
  {"worderase", "character to use to erase a word", 0, termWerasCharp},
  {"start", "character to use for XON", 0, termStartCharp},
  {"stop", "character to use for XOFF", 0, termStopCharp},
  {"forw1", "alternate end of line character", 0, termForw1Charp},
  {"forw2", "alternate end of line character", 0, termForw2Charp},
  {"ayt", "alternate AYT character", 0, termAytCharp},
  {NULL, NULL, 0, NULL}
};

#if defined CRAY && !defined __STDC__
/* Work around compiler bug in pcc 4.1.5 */
void
_setlist_init ()
{
# ifndef KLUDGELINEMODE
#  define N 5
# else
#  define N 6
# endif
  Setlist[N + 0].charp = &termFlushChar;
  Setlist[N + 1].charp = &termIntChar;
  Setlist[N + 2].charp = &termQuitChar;
  Setlist[N + 3].charp = &termEofChar;
  Setlist[N + 6].charp = &termEraseChar;
  Setlist[N + 7].charp = &termKillChar;
  Setlist[N + 8].charp = &termLiteralNextChar;
  Setlist[N + 9].charp = &termSuspChar;
  Setlist[N + 10].charp = &termRprntChar;
  Setlist[N + 11].charp = &termWerasChar;
  Setlist[N + 12].charp = &termStartChar;
  Setlist[N + 13].charp = &termStopChar;
  Setlist[N + 14].charp = &termForw1Char;
  Setlist[N + 15].charp = &termForw2Char;
  Setlist[N + 16].charp = &termAytChar;
# undef	N
}
#endif /* defined(CRAY) && !defined(__STDC__) */

static struct setlist *
getset (char *name)
{
  return (struct setlist *)
    genget (name, (char **) Setlist, sizeof (struct setlist));
}

void
set_escape_char (char *s)
{
  if (rlogin != _POSIX_VDISABLE)
    {
      rlogin = (s && *s) ? special (s) : _POSIX_VDISABLE;
      printf ("Telnet rlogin escape character is '%s'.\n", control (rlogin));
    }
  else
    {
      escape = (s && *s) ? special (s) : _POSIX_VDISABLE;
      printf ("Telnet escape character is '%s'.\n", control (escape));
    }
}

static int
setcmd (int argc, char *argv[])
{
  int value;
  struct setlist *ct;
  struct togglelist *c;

  if (argc < 2 || argc > 3)
    {
      printf ("Format is 'set Name Value'\n'set ?' for help.\n");
      return 0;
    }
  if ((argc == 2) && (isprefix (argv[1], "?") || isprefix (argv[1], "help")))
    {
      for (ct = Setlist; ct->name; ct++)
	printf ("%-15s %s\n", ct->name, ct->help);
      printf ("\n");
      settogglehelp (1);
      printf ("%-15s %s\n", "?", "display help information");
      return 0;
    }

  ct = getset (argv[1]);
  if (ct == 0)
    {
      c = GETTOGGLE (argv[1]);
      if (c == 0)
	{
	  fprintf (stderr, "'%s': unknown argument ('set ?' for help).\n",
		   argv[1]);
	  return 0;
	}
      else if (Ambiguous (c))
	{
	  fprintf (stderr, "'%s': ambiguous argument ('set ?' for help).\n",
		   argv[1]);
	  return 0;
	}
      if (c->variable)
	{
	  if ((argc == 2) || (strcmp ("on", argv[2]) == 0))
	    *c->variable = 1;
	  else if (strcmp ("off", argv[2]) == 0)
	    *c->variable = 0;
	  else
	    {
	      printf
		("Format is 'set togglename [on|off]'\n'set ?' for help.\n");
	      return 0;
	    }
	  if (c->actionexplanation)
	    {
	      printf ("%s %s.\n", *c->variable ? "Will" : "Won't",
		      c->actionexplanation);
	    }
	}
      if (c->handler)
	(*c->handler) (1);
    }
  else if (argc != 3)
    {
      printf ("Format is 'set Name Value'\n'set ?' for help.\n");
      return 0;
    }
  else if (Ambiguous (ct))
    {
      fprintf (stderr, "'%s': ambiguous argument ('set ?' for help).\n",
	       argv[1]);
      return 0;
    }
  else if (ct->handler)
    {
      (*ct->handler) (argv[2]);
      printf ("%s set to \"%s\".\n", ct->name, (char *) ct->charp);
    }
  else if (!ct->charp)
    {
      fprintf (stderr, "'%s': invalid argument ('set ?' for help).\n",
	       argv[1]);
    }
  else
    {
      if (strcmp ("off", argv[2]))
	{
	  value = special (argv[2]);
	}
      else
	{
	  value = _POSIX_VDISABLE;
	}
      *(ct->charp) = (cc_t) value;
      printf ("%s character is '%s'.\n", ct->name, control (*(ct->charp)));
    }
  slc_check ();
  return 1;
}

static int
unsetcmd (int argc, char *argv[])
{
  struct setlist *ct;
  struct togglelist *c;
  register char *name;

  if (argc < 2)
    {
      fprintf (stderr,
	       "Need an argument to 'unset' command.  'unset ?' for help.\n");
      return 0;
    }
  if (isprefix (argv[1], "?") || isprefix (argv[1], "help"))
    {
      for (ct = Setlist; ct->name; ct++)
	printf ("%-15s %s\n", ct->name, ct->help);
      printf ("\n");
      settogglehelp (0);
      printf ("%-15s %s\n", "?", "display help information");
      return 0;
    }

  argc--;
  argv++;
  while (argc--)
    {
      name = *argv++;
      ct = getset (name);
      if (ct == 0)
	{
	  c = GETTOGGLE (name);
	  if (c == 0)
	    {
	      fprintf (stderr,
		       "'%s': unknown argument ('unset ?' for help).\n",
		       name);
	      return 0;
	    }
	  else if (Ambiguous (c))
	    {
	      fprintf (stderr,
		       "'%s': ambiguous argument ('unset ?' for help).\n",
		       name);
	      return 0;
	    }
	  if (c->variable)
	    {
	      *c->variable = 0;
	      if (c->actionexplanation)
		{
		  printf ("%s %s.\n", *c->variable ? "Will" : "Won't",
			  c->actionexplanation);
		}
	    }
	  if (c->handler)
	    (*c->handler) (0);
	}
      else if (Ambiguous (ct))
	{
	  fprintf (stderr, "'%s': ambiguous argument ('unset ?' for help).\n",
		   name);
	  return 0;
	}
      else if (ct->handler)
	{
	  (*ct->handler) (0);
	  printf ("%s reset to \"%s\".\n", ct->name, (char *) ct->charp);
	}
      else if (!ct->charp)
	{
	  fprintf (stderr, "'%s': invalid argument ('unset ?' for help).\n",
		   name);
	  return 0;
	}
      else
	{
	  *(ct->charp) = _POSIX_VDISABLE;
	  printf ("%s character is '%s'.\n", ct->name,
		  control (*(ct->charp)));
	}
    }
  return 1;
}

/*
 * The following are the data structures and routines for the
 * 'mode' command.
 */
#ifdef	KLUDGELINEMODE
extern int kludgelinemode;

static int
dokludgemode (int val)
{
  kludgelinemode = 1;
  send_wont (TELOPT_LINEMODE, 1);
  send_dont (TELOPT_SGA, 1);
  send_dont (TELOPT_ECHO, 1);
  return 0;
}
#endif

static int
dolinemode (int val)
{
#ifdef	KLUDGELINEMODE
  if (kludgelinemode)
    send_dont (TELOPT_SGA, 1);
#endif
  send_will (TELOPT_LINEMODE, 1);
  send_dont (TELOPT_ECHO, 1);
  return 1;
}

static int
docharmode (int val)
{
#ifdef	KLUDGELINEMODE
  if (kludgelinemode)
    send_do (TELOPT_SGA, 1);
  else
#endif
    send_wont (TELOPT_LINEMODE, 1);
  send_do (TELOPT_ECHO, 1);
  return 1;
}

static int
dolmmode (int bit, int on)
{
  unsigned char c;
  extern int linemode;

  if (my_want_state_is_wont (TELOPT_LINEMODE))
    {
      printf ("?Need to have LINEMODE option enabled first.\n");
      printf ("'mode ?' for help.\n");
      return 0;
    }

  if (on)
    c = (linemode | bit);
  else
    c = (linemode & ~bit);
  lm_mode (&c, 1, 1);
  return 1;
}

int
set_mode (int bit)
{
  return dolmmode (bit, 1);
}

int
clear_mode (int bit)
{
  return dolmmode (bit, 0);
}

struct modelist
{
  const char *name;		/* command name */
  const char *help;		/* help string */
  int (*handler) (int);		/* routine which executes command */
  int needconnect;		/* Do we need to be connected to execute? */
  int arg1;
};

extern int modehelp (int val);

static struct modelist ModeList[] = {
  {"character", "Disable LINEMODE option", docharmode, 1, 0},
#ifdef	KLUDGELINEMODE
  {"", "(or disable obsolete line-by-line mode)", NULL, 0, 0},
#endif
  {"line", "Enable LINEMODE option", dolinemode, 1, 0},
#ifdef	KLUDGELINEMODE
  {"", "(or enable obsolete line-by-line mode)", NULL, 0, 0},
#endif
  {"", "", NULL, 0, 0},
  {"", "These require the LINEMODE option to be enabled", NULL, 0, 0},
  {"isig", "Enable signal trapping", set_mode, 1, MODE_TRAPSIG},
  {"+isig", 0, set_mode, 1, MODE_TRAPSIG},
  {"-isig", "Disable signal trapping", clear_mode, 1, MODE_TRAPSIG},
  {"edit", "Enable character editing", set_mode, 1, MODE_EDIT},
  {"+edit", 0, set_mode, 1, MODE_EDIT},
  {"-edit", "Disable character editing", clear_mode, 1, MODE_EDIT},
  {"softtabs", "Enable tab expansion", set_mode, 1, MODE_SOFT_TAB},
  {"+softtabs", 0, set_mode, 1, MODE_SOFT_TAB},
  {"-softtabs", "Disable character editing", clear_mode, 1, MODE_SOFT_TAB},
  {"litecho", "Enable literal character echo", set_mode, 1, MODE_LIT_ECHO},
  {"+litecho", 0, set_mode, 1, MODE_LIT_ECHO},
  {"-litecho", "Disable literal character echo", clear_mode, 1,
   MODE_LIT_ECHO},
  {"help", 0, modehelp, 0, 0},
#ifdef	KLUDGELINEMODE
  {"kludgeline", 0, dokludgemode, 1, 0},
#endif
  {"", "", NULL, 0, 0},
  {"?", "Print help information", modehelp, 0, 0},
  {NULL, NULL, NULL, 0, 0},
};


int
modehelp (int val)
{
  struct modelist *mt;

  printf ("format is:  'mode Mode', where 'Mode' is one of:\n\n");
  for (mt = ModeList; mt->name; mt++)
    {
      if (mt->help)
	{
	  if (*mt->help)
	    printf ("%-15s %s\n", mt->name, mt->help);
	  else
	    printf ("\n");
	}
    }
  return 0;
}

#define GETMODECMD(name) (struct modelist *) \
		genget(name, (char **) ModeList, sizeof(struct modelist))

static int
modecmd (int argc, char *argv[])
{
  struct modelist *mt;

  if (argc != 2)
    {
      printf ("'mode' command requires an argument\n");
      printf ("'mode ?' for help.\n");
    }
  else if ((mt = GETMODECMD (argv[1])) == 0)
    {
      fprintf (stderr, "Unknown mode '%s' ('mode ?' for help).\n", argv[1]);
    }
  else if (Ambiguous (mt))
    {
      fprintf (stderr, "Ambiguous mode '%s' ('mode ?' for help).\n", argv[1]);
    }
  else if (mt->needconnect && !connected)
    {
      printf ("?Need to be connected first.\n");
      printf ("'mode ?' for help.\n");
    }
  else if (mt->handler)
    {
      return (*mt->handler) (mt->arg1);
    }
  return 0;
}

/*
 * The following data structures and routines implement the
 * "display" command.
 */

static int
display (int argc, char *argv[])
{
  struct togglelist *tl;
  struct setlist *sl;

#define dotog(tl)	if (tl->variable && tl->actionexplanation) { \
			    if (*tl->variable) { \
				printf("will"); \
			    } else { \
				printf("won't"); \
			    } \
			    printf(" %s.\n", tl->actionexplanation); \
			}

#define doset(sl)   if (sl->name && *sl->name != ' ') { \
			if (sl->handler == 0) \
			    printf("%-15s [%s]\n", sl->name, control(*sl->charp)); \
			else \
			    printf("%-15s \"%s\"\n", sl->name, (char *)sl->charp); \
		    }

  if (argc == 1)
    {
      for (tl = Togglelist; tl->name; tl++)
	{
	  dotog (tl);
	}
      printf ("\n");
      for (sl = Setlist; sl->name; sl++)
	{
	  doset (sl);
	}
    }
  else
    {
      int i;

      for (i = 1; i < argc; i++)
	{
	  sl = getset (argv[i]);
	  tl = GETTOGGLE (argv[i]);
	  if (Ambiguous (sl) || Ambiguous (tl))
	    {
	      printf ("?Ambiguous argument '%s'.\n", argv[i]);
	      return 0;
	    }
	  else if (!sl && !tl)
	    {
	      printf ("?Unknown argument '%s'.\n", argv[i]);
	      return 0;
	    }
	  else
	    {
	      if (tl)
		{
		  dotog (tl);
		}
	      if (sl)
		{
		  doset (sl);
		}
	    }
	}
    }
/*@*/ optionstatus ();
#ifdef	ENCRYPTION
  EncryptStatus ();
#endif /* ENCRYPTION */
  return 1;
#undef	doset
#undef	dotog
}

/*
 * The following are the data structures, and many of the routines,
 * relating to command processing.
 */

/*
 * Set the escape character.
 */
static int
setescape (int argc, char *argv[])
{
  register char *arg;
  char buf[50];

  printf ("Deprecated usage - please use 'set escape%s%s' in the future.\n",
	  (argc > 2) ? " " : "", (argc > 2) ? argv[1] : "");
  if (argc > 2)
    arg = argv[1];
  else
    {
      printf ("new escape character: ");
      if (fgets (buf, sizeof (buf), stdin) == NULL)
	{
	  buf[0] = '\0';
	  printf ("\n");
	}
      arg = buf;
    }
  if (arg[0] != '\0')
    escape = arg[0];
  if (!In3270)
    {
      printf ("Escape character is '%s'.\n", control (escape));
    }
  fflush (stdout);
  return 1;
}

static int
togcrmod (int argc, char *argv[])
{
  crmod = !crmod;
  printf ("Deprecated usage - please use 'toggle crmod' in the future.\n");
  printf ("%s map carriage return on output.\n", crmod ? "Will" : "Won't");
  fflush (stdout);
  return 1;
}

int
suspend (int argc, char *argv[])
{
#ifdef	SIGTSTP
  setcommandmode ();
  {
    long oldrows, oldcols, newrows, newcols, err;

    err = (TerminalWindowSize (&oldrows, &oldcols) == 0) ? 1 : 0;
    kill (0, SIGTSTP);
    /*
     * If we didn't get the window size before the SUSPEND, but we
     * can get them now (?), then send the NAWS to make sure that
     * we are set up for the right window size.
     */
    if (TerminalWindowSize (&newrows, &newcols) && connected &&
	(err || ((oldrows != newrows) || (oldcols != newcols))))
      {
	sendnaws ();
      }
  }
  /* reget parameters in case they were changed */
  TerminalSaveState ();
  setconnmode (0);
#else
  printf ("Suspend is not supported.  Try the '!' command instead\n");
#endif
  return 1;
}

#if !defined TN3270
int
shell (int argc, MAYBE_UNUSED char *argv[])
{
  long oldrows, oldcols, newrows, newcols, err;

  setcommandmode ();

  err = (TerminalWindowSize (&oldrows, &oldcols) == 0) ? 1 : 0;
  switch (vfork ())
    {
    case -1:
      perror ("Fork failed\n");
      break;

    case 0:
      {
	/*
	 * Fire up the shell in the child.
	 */
	register char *shellp, *shellname;
# ifndef strrchr
	extern char *strrchr (const char *, int);
# endif

	shellp = getenv ("SHELL");
	if (shellp == NULL)
	  shellp = PATH_BSHELL;
	shellname = strrchr (shellp, '/');
	if (shellname == NULL)
	  shellname = shellp;
	else
	  shellname++;
	if (argc > 1)
	  execl (shellp, shellname, "-c", &saveline[1], NULL);
	else
	  execl (shellp, shellname, NULL);
	perror ("Execl");
	_exit (EXIT_FAILURE);
      }
    default:
      wait ((int *) 0);		/* Wait for the shell to complete */

      if (TerminalWindowSize (&newrows, &newcols) && connected &&
	  (err || ((oldrows != newrows) || (oldcols != newcols))))
	{
	  sendnaws ();
	}
      break;
    }
  return 1;
}
#else /* !defined(TN3270) */
extern int shell ();
#endif /* !defined(TN3270) */


/* int  argc;	 Number of arguments */
/* char *argv[]; arguments */
static int
bye (int argc, char *argv[])
{
  extern int resettermname;

  if (connected)
    {
      shutdown (net, 2);
      printf ("Connection closed.\n");
      NetClose (net);
      connected = 0;
      resettermname = 1;
#if defined AUTHENTICATION || defined ENCRYPTION
      auth_encrypt_connect (connected);
#endif /* defined(AUTHENTICATION) || defined(ENCRYPTION) */
      /* reset options */
      tninit ();
#if defined TN3270
      SetIn3270 ();		/* Get out of 3270 mode */
#endif /* defined(TN3270) */
    }
  if ((argc != 2) || (strcmp (argv[1], "fromquit") != 0))
    {
      longjmp (toplevel, 1);
    }
  return 1;
}

int
quit (int argc, char *argv[])
{
  call (bye, "bye", "fromquit", 0);
  Exit (0);
  return 0;
}

int
logoutcmd (int argc, char *argv[])
{
  send_do (TELOPT_LOGOUT, 1);
  netflush ();
  return 1;
}


/*
 * The SLC command.
 */

struct slclist
{
  const char *name;
  const char *help;
  void (*handler) (int);
  int arg;
};

struct slclist SlcList[] = {
  {"export", "Use local special character definitions",
   slc_mode_export, 0},
  {"import", "Use remote special character definitions",
   slc_mode_import, 1},
  {"check", "Verify remote special character definitions",
   slc_mode_import, 0},
  {"help", 0, slc_help, 0},
  {"?", "Print help information", slc_help, 0},
  {NULL, NULL, NULL, 0},
};

static void
slc_help (int n)
{
  struct slclist *c;

  for (c = SlcList; c->name; c++)
    {
      if (c->help)
	{
	  if (*c->help)
	    printf ("%-15s %s\n", c->name, c->help);
	  else
	    printf ("\n");
	}
    }
}

static struct slclist *
getslc (char *name)
{
  return (struct slclist *)
    genget (name, (char **) SlcList, sizeof (struct slclist));
}

static int
slccmd (int argc, char **argv)
{
  struct slclist *c;

  if (argc != 2)
    {
      fprintf (stderr,
	       "Need an argument to 'slc' command.  'slc ?' for help.\n");
      return 0;
    }
  c = getslc (argv[1]);
  if (c == 0)
    {
      fprintf (stderr, "'%s': unknown argument ('slc ?' for help).\n",
	       argv[1]);
      return 0;
    }
  if (Ambiguous (c))
    {
      fprintf (stderr, "'%s': ambiguous argument ('slc ?' for help).\n",
	       argv[1]);
      return 0;
    }
  (*c->handler) (c->arg);
  slcstate ();
  return 1;
}

/*
 * The ENVIRON command.
 */

struct envlist
{
  const char *name;
  const char *help;
  struct env_lst *(*handler) (const char *, char *);
  int narg;
};

struct envlist EnvList[] = {
  {"define", "Define an environment variable",
   env_define, 2},
  {"undefine", "Undefine an environment variable",
   env_undefine, 1},
  {"export", "Mark an environment variable for automatic export",
   env_export, 1},
  {"unexport", "Don't mark an environment variable for automatic export",
   env_unexport, 1},
  {"send", "Send an environment variable", env_send, 1},
  {"list", "List the current environment variables",
   env_list, 0},
#if defined OLD_ENVIRON && defined ENV_HACK
  {"varval", "Reverse VAR and VALUE (auto, right, wrong, status)",
   env_varval, 1},
#endif
  {"help", 0, env_help, 0},
  {"?", "Print help information", env_help, 0},
  {NULL, NULL, NULL, 0},
};

static struct env_lst *
env_help (const char *us1, char *us2)
{
  struct envlist *c;

  for (c = EnvList; c->name; c++)
    {
      if (c->help)
	{
	  if (*c->help)
	    printf ("%-15s %s\n", c->name, c->help);
	  else
	    printf ("\n");
	}
    }
  return NULL;
}

static struct envlist *
getenvcmd (char *name)
{
  return (struct envlist *)
    genget (name, (char **) EnvList, sizeof (struct envlist));
}

int
env_cmd (int argc, char *argv[])
{
  struct envlist *c;

  if (argc < 2)
    {
      fprintf (stderr,
	       "Need an argument to 'environ' command.  'environ ?' for help.\n");
      return 0;
    }
  c = getenvcmd (argv[1]);
  if (c == 0)
    {
      fprintf (stderr, "'%s': unknown argument ('environ ?' for help).\n",
	       argv[1]);
      return 0;
    }
  if (Ambiguous (c))
    {
      fprintf (stderr, "'%s': ambiguous argument ('environ ?' for help).\n",
	       argv[1]);
      return 0;
    }
  if (c->narg + 2 != argc)
    {
      fprintf (stderr,
	       "Need %s%d argument%s to 'environ %s' command.  'environ ?' for help.\n",
	       c->narg < argc + 2 ? "only " : "",
	       c->narg, c->narg == 1 ? "" : "s", c->name);
      return 0;
    }
  (*c->handler) (argv[2], argv[3]);
  return 1;
}

struct env_lst
{
  struct env_lst *next;		/* pointer to next structure */
  struct env_lst *prev;		/* pointer to previous structure */
  unsigned char *var;		/* pointer to variable name */
  unsigned char *value;		/* pointer to variable value */
  int export;			/* 1 -> export with default list of variables */
  int welldefined;		/* A well defined variable */
};

struct env_lst envlisthead;

struct env_lst *
env_find (const char *var)
{
  register struct env_lst *ep;

  for (ep = envlisthead.next; ep; ep = ep->next)
    {
      if (strcmp ((char *) ep->var, var) == 0)
	return (ep);
    }
  return (NULL);
}

void
env_init (void)
{
  extern char **environ;
  register char **epp, *cp;
  register struct env_lst *ep;
#ifndef strchr
  extern char *strchr (const char *, int);
#endif

  for (epp = environ; *epp; epp++)
    {
      cp = strchr (*epp, '=');
      if (cp)
	{
	  *cp = '\0';
	  ep = env_define (*epp, cp + 1);
	  ep->export = 0;
	  *cp = '=';
	}
    }
  /*
   * Special case for DISPLAY variable.  If it is ":0.0" or
   * "unix:0.0", we have to get rid of "unix" and insert our
   * hostname.
   */
  if ((ep = env_find ("DISPLAY"))
      && ((*ep->value == ':')
	  || (strncmp ((char *) ep->value, "unix:", 5) == 0)))
    {
      char *hostname = localhost ();
      char *cp2 = strchr ((char *) ep->value, ':');

      cp = xmalloc (strlen (hostname) + strlen (cp2) + 1);
      sprintf (cp, "%s%s", hostname, cp2);

      free (ep->value);
      ep->value = (unsigned char *) cp;

      free (hostname);
    }
  /*
   * If USER is not defined, but LOGNAME is, then add
   * USER with the value from LOGNAME.  By default, we
   * don't export the USER variable.
   */
  if ((env_find ("USER") == NULL) && (ep = env_find ("LOGNAME")))
    {
      env_define ("USER", (char *) ep->value);
      env_unexport ("USER", NULL);
    }
  env_export ("DISPLAY", NULL);
  env_export ("PRINTER", NULL);
}

struct env_lst *
env_define (const char *var, char *value)
{
  register struct env_lst *ep = env_find (var);
  if (ep)
    {
      free (ep->var);
      free (ep->value);
    }
  else
    {
      ep = (struct env_lst *) xmalloc (sizeof (struct env_lst));
      ep->next = envlisthead.next;
      envlisthead.next = ep;
      ep->prev = &envlisthead;
      if (ep->next)
	ep->next->prev = ep;
    }
  ep->welldefined = opt_welldefined ((char *) var);
  ep->export = 1;
  ep->var = (unsigned char *) strdup ((char *) var);
  ep->value = (unsigned char *) strdup ((char *) value);
  return (ep);
}

struct env_lst *
env_undefine (const char *var, char *d)
{
  register struct env_lst *ep = env_find (var);
  if (ep)
    {
      ep->prev->next = ep->next;
      if (ep->next)
	ep->next->prev = ep->prev;
      free (ep->var);
      free (ep->value);
      free (ep);
    }
  return NULL;
}

struct env_lst *
env_export (const char *var, char *d)
{
  register struct env_lst *ep = env_find (var);
  if (ep)
    ep->export = 1;
  return NULL;
}

struct env_lst *
env_unexport (const char *var, char *d)
{
  register struct env_lst *ep = env_find (var);
  if (ep)
    ep->export = 0;
  return NULL;
}

struct env_lst *
env_send (const char *var, char *d)
{
  register struct env_lst *ep;

  if (my_state_is_wont (TELOPT_NEW_ENVIRON)
#ifdef	OLD_ENVIRON
      && my_state_is_wont (TELOPT_OLD_ENVIRON)
#endif
    )
    {
      fprintf (stderr,
	       "Cannot send '%s': Telnet ENVIRON option not enabled\n", var);
      return NULL;
    }
  ep = env_find (var);
  if (ep == 0)
    {
      fprintf (stderr, "Cannot send '%s': variable not defined\n", var);
      return NULL;
    }
  env_opt_start_info ();
  env_opt_add (ep->var);
  env_opt_end (0);

  return NULL;
}

struct env_lst *
env_list (const char *d1, char *d2)
{
  register struct env_lst *ep;

  for (ep = envlisthead.next; ep; ep = ep->next)
    {
      printf ("%c %-20s %s\n", ep->export ? '*' : ' ', ep->var, ep->value);
    }
  return NULL;
}

unsigned char *
env_default (int init, int welldefined)
{
  static struct env_lst *nep = NULL;

  if (init)
    {
      nep = &envlisthead;
      return NULL;
    }
  if (nep)
    {
      while ((nep = nep->next))
	{
	  if (nep->export && (nep->welldefined == welldefined))
	    return (nep->var);
	}
    }
  return (NULL);
}

unsigned char *
env_getvalue (const char *var)
{
  register struct env_lst *ep = env_find (var);
  if (ep)
    return (ep->value);
  return (NULL);
}

#if defined OLD_ENVIRON && defined ENV_HACK
void
env_varval (const char *what, char *d)
{
  extern int old_env_var, old_env_value, env_auto;
  int len = strlen (what);

  if (len == 0)
    goto unknown;

  if (strncasecmp ((char *) what, "status", len) == 0)
    {
      if (env_auto)
	printf ("%s%s", "VAR and VALUE are/will be ",
		"determined automatically\n");
      if (old_env_var == OLD_ENV_VAR)
	printf ("VAR and VALUE set to correct definitions\n");
      else
	printf ("VAR and VALUE definitions are reversed\n");
    }
  else if (strncasecmp ((char *) what, "auto", len) == 0)
    {
      env_auto = 1;
      old_env_var = OLD_ENV_VALUE;
      old_env_value = OLD_ENV_VAR;
    }
  else if (strncasecmp ((char *) what, "right", len) == 0)
    {
      env_auto = 0;
      old_env_var = OLD_ENV_VAR;
      old_env_value = OLD_ENV_VALUE;
    }
  else if (strncasecmp ((char *) what, "wrong", len) == 0)
    {
      env_auto = 0;
      old_env_var = OLD_ENV_VALUE;
      old_env_value = OLD_ENV_VAR;
    }
  else
    {
    unknown:
      printf
	("Unknown \"varval\" command. (\"auto\", \"right\", \"wrong\", \"status\")\n");
    }
}
#endif

#if defined AUTHENTICATION
/*
 * The AUTHENTICATE command.
 */

struct authlist
{
  const char *name;
  char *help;
  int (*handler) ();
  int narg;
};

extern int auth_enable (char *), auth_disable (char *), auth_status (void);
static int auth_help (void);

struct authlist AuthList[] = {
  {"status", "Display current status of authentication information",
   auth_status, 0},
  {"disable", "Disable an authentication type ('auth disable ?' for more)",
   auth_disable, 1},
  {"enable", "Enable an authentication type ('auth enable ?' for more)",
   auth_enable, 1},
  {"help", 0, auth_help, 0},
  {"?", "Print help information", auth_help, 0},
  {NULL, NULL, NULL, 0},
};

static int
auth_help ()
{
  struct authlist *c;

  for (c = AuthList; c->name; c++)
    {
      if (c->help)
	{
	  if (*c->help)
	    printf ("%-15s %s\n", c->name, c->help);
	  else
	    printf ("\n");
	}
    }
  return 0;
}

int
auth_cmd (int argc, char *argv[])
{
  struct authlist *c;

  if (argc < 2)
    {
      fprintf (stderr,
	       "Need an argument to 'auth' command.  'auth ?' for help.\n");
      return 0;
    }

  c = (struct authlist *)
    genget (argv[1], (char **) AuthList, sizeof (struct authlist));
  if (c == 0)
    {
      fprintf (stderr, "'%s': unknown argument ('auth ?' for help).\n",
	       argv[1]);
      return 0;
    }
  if (Ambiguous (c))
    {
      fprintf (stderr, "'%s': ambiguous argument ('auth ?' for help).\n",
	       argv[1]);
      return 0;
    }
  if (c->narg + 2 != argc)
    {
      fprintf (stderr,
	       "Need %s%d argument%s to 'auth %s' command.  'auth ?' for help.\n",
	       c->narg < argc + 2 ? "only " : "",
	       c->narg, c->narg == 1 ? "" : "s", c->name);
      return 0;
    }
  return ((*c->handler) (argv[2], argv[3]));
}
#endif

#ifdef	ENCRYPTION
/*
 * The ENCRYPT command.
 */

struct encryptlist
{
  const char *name;
  const char *help;
  int (*handler) ();
  int needconnect;
  int minarg;
  int maxarg;
};

extern int
EncryptEnable (char *, char *),
EncryptDisable (char *, char *),
EncryptType (char *, char *),
EncryptStart (char *),
EncryptStartInput (void),
EncryptStartOutput (void),
EncryptStop (char *),
EncryptStopInput (void), EncryptStopOutput (void), EncryptStatus (void);
static int EncryptHelp (void);

struct encryptlist EncryptList[] = {
  {"enable", "Enable encryption. ('encrypt enable ?' for more)",
   EncryptEnable, 1, 1, 2},
  {"disable", "Disable encryption. ('encrypt enable ?' for more)",
   EncryptDisable, 0, 1, 2},
  {"type", "Set encryption type. ('encrypt type ?' for more)",
   EncryptType, 0, 1, 1},
  {"start", "Start encryption. ('encrypt start ?' for more)",
   EncryptStart, 1, 0, 1},
  {"stop", "Stop encryption. ('encrypt stop ?' for more)",
   EncryptStop, 1, 0, 1},
  {"input", "Start encrypting the input stream",
   EncryptStartInput, 1, 0, 0},
  {"-input", "Stop encrypting the input stream",
   EncryptStopInput, 1, 0, 0},
  {"output", "Start encrypting the output stream",
   EncryptStartOutput, 1, 0, 0},
  {"-output", "Stop encrypting the output stream",
   EncryptStopOutput, 1, 0, 0},

  {"status", "Display current status of authentication information",
   EncryptStatus, 0, 0, 0},
  {"help", 0, EncryptHelp, 0, 0, 0},
  {"?", "Print help information", EncryptHelp, 0, 0, 0},
  {NULL, NULL, NULL, 0, 0, 0},
};

static int
EncryptHelp ()
{
  struct encryptlist *c;

  for (c = EncryptList; c->name; c++)
    {
      if (c->help)
	{
	  if (*c->help)
	    printf ("%-15s %s\n", c->name, c->help);
	  else
	    printf ("\n");
	}
    }
  return 0;
}

int
encrypt_cmd (int argc, char *argv[])
{
  struct encryptlist *c;

  if (argc < 2)
    {
      fprintf (stderr,
	       "Need an argument to 'encrypt' command.  'encrypt ?' for help.\n");
      return 0;
    }

  c = (struct encryptlist *)
    genget (argv[1], (char **) EncryptList, sizeof (struct encryptlist));
  if (c == 0)
    {
      fprintf (stderr, "'%s': unknown argument ('encrypt ?' for help).\n",
	       argv[1]);
      return 0;
    }
  if (Ambiguous (c))
    {
      fprintf (stderr, "'%s': ambiguous argument ('encrypt ?' for help).\n",
	       argv[1]);
      return 0;
    }
  argc -= 2;
  if (argc < c->minarg || argc > c->maxarg)
    {
      if (c->minarg == c->maxarg)
	{
	  fprintf (stderr, "Need %s%d argument%s ",
		   c->minarg < argc ? "only " : "", c->minarg,
		   c->minarg == 1 ? "" : "s");
	}
      else
	{
	  fprintf (stderr, "Need %s%d-%d arguments ",
		   c->maxarg < argc ? "only " : "", c->minarg, c->maxarg);
	}
      fprintf (stderr, "to 'encrypt %s' command.  'encrypt ?' for help.\n",
	       c->name);
      return 0;
    }
  if (c->needconnect && !connected)
    {
      if (!(argc && (isprefix (argv[2], "help") || isprefix (argv[2], "?"))))
	{
	  printf ("?Need to be connected first.\n");
	  return 0;
	}
    }
  return ((*c->handler) (argc > 0 ? argv[2] : 0,
			 argc > 1 ? argv[3] : 0, argc > 2 ? argv[4] : 0));
}
#endif /* ENCRYPTION */

#if (defined unix || defined __unix || defined __unix__) && defined TN3270
static void
filestuff (int fd)
{
  int res;

# ifdef	F_GETOWN
  setconnmode (0);
  res = fcntl (fd, F_GETOWN, 0);
  setcommandmode ();

  if (res == -1)
    {
      perror ("fcntl");
      return;
    }
  printf ("\tOwner is %d.\n", res);
# endif

  setconnmode (0);
  res = fcntl (fd, F_GETFL, 0);
  setcommandmode ();

  if (res == -1)
    {
      perror ("fcntl");
      return;
    }
}
#endif /* (unix || __unix || __unix__) && TN3270 */

/*
 * Print status about the connection.
 */
static int
status (int argc, char *argv[])
{
  if (connected)
    {
      printf ("Connected to %s.\n", hostname);
      if ((argc < 2) || strcmp (argv[1], "notmuch"))
	{
	  int mode = getconnmode ();

	  if (my_want_state_is_will (TELOPT_LINEMODE))
	    {
	      printf ("Operating with LINEMODE option\n");
	      printf ("%s line editing\n",
		      (mode & MODE_EDIT) ? "Local" : "No");
	      printf ("%s catching of signals\n",
		      (mode & MODE_TRAPSIG) ? "Local" : "No");
	      slcstate ();
#ifdef	KLUDGELINEMODE
	    }
	  else if (kludgelinemode && my_want_state_is_dont (TELOPT_SGA))
	    {
	      printf ("Operating in obsolete linemode\n");
#endif
	    }
	  else
	    {
	      printf ("Operating in single character mode\n");
	      if (localchars)
		printf ("Catching signals locally\n");
	    }
	  printf ("%s character echo\n",
		  (mode & MODE_ECHO) ? "Local" : "Remote");
	  if (my_want_state_is_will (TELOPT_LFLOW))
	    printf ("%s flow control\n", (mode & MODE_FLOW) ? "Local" : "No");
#ifdef	ENCRYPTION
	  encrypt_display ();
#endif /* ENCRYPTION */
	}
    }
  else
    {
      printf ("No connection.\n");
    }
#if !defined TN3270
  printf ("Escape character is '%s'.\n", control (escape));
  fflush (stdout);
#else /* !defined(TN3270) */
  if ((!In3270) && ((argc < 2) || strcmp (argv[1], "notmuch")))
    {
      printf ("Escape character is '%s'.\n", control (escape));
    }
# if defined unix || defined __unix || defined __unix__
  if ((argc >= 2) && !strcmp (argv[1], "everything"))
    {
      printf ("SIGIO received %d time%s.\n",
	      sigiocount, (sigiocount == 1) ? "" : "s");
      if (In3270)
	{
	  printf ("Process ID %d, process group %d.\n",
		  getpid (), getpgrp (getpid ()));
	  printf ("Terminal input:\n");
	  filestuff (tin);
	  printf ("Terminal output:\n");
	  filestuff (tout);
	  printf ("Network socket:\n");
	  filestuff (net);
	}
    }
  if (In3270 && transcom)
    {
      printf ("Transparent mode command is '%s'.\n", transcom);
    }
# endif/* unix || __unix || __unix__ */
  fflush (stdout);
  if (In3270)
    {
      return 0;
    }
#endif /* defined(TN3270) */
  return 1;
}

#ifdef	SIGINFO
/*
 * Function that gets called when SIGINFO is received.
 */
int
ayt_status ()
{
  call (status, "status", "notmuch", 0);
  return 1;			/* not used */
}
#endif /* SIGINFO */

static void cmdrc (char *m1, char *m2);

int
tn (int argc, char *argv[])
{
#ifdef IPV6
  struct addrinfo *result, *aip, hints, *hostaddr;
#else
  struct hostent *host = 0;
  struct sockaddr_in sin;
  struct servent *sp = 0;
  in_addr_t temp;
#endif
  const int on = 1;
  int err;
  char *cmd, *hostp = 0, *portp = 0, *user = 0, *srchostp = 0;
#if defined HAVE_IDN || defined HAVE_IDN2
  char *hosttmp = 0;
#endif

#ifdef IPV6
  memset (&hints, 0, sizeof (hints));
#else
  /* clear the socket address prior to use */
  memset ((char *) &sin, 0, sizeof (sin));
#endif

  if (connected)
    {
      printf ("?Already connected to %s\n", hostname);
      return 0;
    }
  if (argc < 2)
    {
      strcpy (line, "open ");
      printf ("(to) ");
      if (fgets (&line[strlen (line)], sizeof (line) - strlen (line), stdin))
	{
	  makeargv ();
	  argc = margc;
	  argv = margv;
	}
      else
	printf ("?Name of host was not understood.\n");
    }
  cmd = *argv;
  --argc;
  ++argv;
  while (argc)
    {
      if (strcmp (*argv, "help") == 0 || isprefix (*argv, "?"))
	goto usage;
      if (strcmp (*argv, "-l") == 0)
	{
	  --argc;
	  ++argv;
	  if (argc == 0)
	    goto usage;
	  user = *argv++;
	  --argc;
	  continue;
	}
      if (strcmp (*argv, "-b") == 0)
	{
	  --argc;
	  ++argv;
	  if (argc == 0)
	    goto usage;
	  srchostp = *argv++;
	  --argc;
	  continue;
	}
      if (strcmp (*argv, "-a") == 0)
	{
	  --argc;
	  ++argv;
	  autologin = 1;
	  continue;
	}
      if (strcmp (*argv, "-6") == 0)
	{
	  --argc;
	  ++argv;
#ifdef IPV6
	  hints.ai_family = AF_INET6;
#else
	  puts ("IPv6 isn't supported");
#endif
	  continue;
	}
      if (strcmp (*argv, "-4") == 0)
	{
	  --argc;
	  ++argv;
#ifdef IPV6
	  hints.ai_family = AF_INET;
#endif
	  continue;
	}
      if (hostp == 0)
	{
	  hostp = *argv++;
	  --argc;
	  continue;
	}
      if (portp == 0)
	{
	  portp = *argv++;
	  --argc;
	  continue;
	}
    usage:
      printf
	("usage: %s [-4] [-6] [-l user] [-b addr] [-a] host-name [port]\n",
	 cmd);
      return 0;
    }
  if (hostp == 0)
    goto usage;

  if (!portp)
    {
      portp = "telnet";
      telnetport = 1;
    }
  else
    {
      if (*portp == '-')
	{
	  portp++;
	  telnetport = 1;
	}
      else
	telnetport = 0;
      if (*portp >= '0' && *portp <= '9')
	{
	  long long int val;
	  char *endp;

	  val = strtoll (portp, &endp, 10);

	  if ((errno == ERANGE && (val == LLONG_MAX || val == LLONG_MIN))
	      || (*endp == '\0' && (val < 1 || val > 65535)))
	    {
	      printf ("Port number %s is out of range.\n", portp);
	      return 0;
	    }
	  else if (*endp)
	    {
	      printf ("Invalid port name '%s'.\n", portp);
	      return 0;
	    }
	}
    }

  free (hostname);
  hostname = strdup (hostp);
  if (!hostname)
    {
      printf ("Can't allocate memory to copy hostname\n");
      return 0;
    }

#if defined AUTHENTICATION || defined ENCRYPTION
  {
    /* Extract instance name of server, eliminating
     * the Kerberos principal prefix.
     */
    char *p = strchr (hostp, '/');

    if (p)
      hostp = ++p;
  }
#endif /* AUTHENTICATION || ENCRYPTION */

#if defined HAVE_IDN || defined HAVE_IDN2
  err = idna_to_ascii_lz (hostp, &hosttmp, 0);
  if (err)
    {
      printf ("Server lookup failure:  %s:%s, %s\n",
	      hostp, portp, idna_strerror (err));
      return 0;
    }
  hostp = hosttmp;
#endif /* !HAVE_IDN && !HAVE_IDN2 */

#ifdef IPV6
  hints.ai_socktype = SOCK_STREAM;
# ifdef AI_IDN
  hints.ai_flags = AI_IDN;
# endif

  if (srchostp)
    {
      err = getaddrinfo (srchostp, "0", &hints, &hostaddr);
      if (err < 0)
	{
	  printf ("Could not resolve %s: %s\n", srchostp, gai_strerror (err));
	  return 0;
	}
      hints.ai_family = hostaddr->ai_family;
    }

  err = getaddrinfo (hostp, portp, &hints, &result);
  if (err)
    {
      const char *errmsg;

      if (err == EAI_SYSTEM)
	errmsg = strerror (errno);
      else
	errmsg = gai_strerror (err);

      printf ("Server lookup failure:  %s:%s, %s\n", hostp, portp, errmsg);
      return 0;
    }

  aip = result;

  do
    {
      char buf[256];

      err = getnameinfo (aip->ai_addr, aip->ai_addrlen, buf, sizeof (buf),
			 NULL, 0, NI_NUMERICHOST);
      if (err)
	{
	  /* I don't know how thing can happen, but we just handle it.  */
	  const char *errmsg;

	  if (err == EAI_SYSTEM)
	    errmsg = strerror (errno);
	  else
	    errmsg = gai_strerror (err);

	  printf ("getnameinfo error: %s\n", errmsg);
	  return 0;
	}

      printf ("Trying %s...\n", buf);

      net = socket (aip->ai_family, SOCK_STREAM, 0);
      if (net < 0)
	{
	  perror ("telnet: socket");
	  return 0;
	}

      if (srchostp)
	{
	  err = bind (net, hostaddr->ai_addr, hostaddr->ai_addrlen);
	  if (err < 0)
	    {
	      perror ("telnet: bind");
	      return 0;
	    }
	}

      if (debug)
	{
	  err = setsockopt (net, SOL_SOCKET, SO_DEBUG, &on, sizeof (on));
	  if (err < 0)
	    perror ("setsockopt (SO_DEBUG)");
	}

      err = connect (net, (struct sockaddr *) aip->ai_addr, aip->ai_addrlen);
      if (err < 0)
	{
	  if (aip->ai_next)
	    {
	      perror ("Connection failed");
	      aip = aip->ai_next;
	      close (net);
	      continue;
	    }

	  perror ("telnet: Unable to connect to remote host");
	  return 0;
	}

      connected++;
# if defined AUTHENTICATION || defined ENCRYPTION
      auth_encrypt_connect (connected);
# endif/* defined(AUTHENTICATION) || defined(ENCRYPTION) */
    }
  while (!connected);

  if (srchostp)
    freeaddrinfo (hostaddr);
  freeaddrinfo (result);
#else /* !IPV6 */
  temp = inet_addr (hostp);
  if (temp != (in_addr_t) - 1)
    {
      sin.sin_addr.s_addr = temp;
      sin.sin_family = AF_INET;
    }
  else
    {
      host = gethostbyname (hostp);
      if (host)
	{
	  sin.sin_family = host->h_addrtype;
	  memmove (&sin.sin_addr, host->h_addr_list[0], host->h_length);
	}
      else
	{
	  printf ("Can't lookup hostname %s\n", hostp);
	  return 0;
	}
    }

  sin.sin_port = atoi (portp);
  if (sin.sin_port == 0)
    {
      sp = getservbyname (portp, "tcp");
      if (sp == 0)
	{
	  printf ("tcp/%s: unknown service\n", portp);
	  return 0;
	}
      sin.sin_port = sp->s_port;
    }
  else
    sin.sin_port = htons (sin.sin_port);

  printf ("Trying %s...\n", inet_ntoa (sin.sin_addr));
  do
    {
      net = socket (AF_INET, SOCK_STREAM, 0);
      if (net < 0)
	{
	  perror ("telnet: socket");
	  return 0;
	}
# if defined IPPROTO_IP && defined IP_TOS
      {
#  ifdef IPTOS_LOWDELAY
	const int tos = IPTOS_LOWDELAY;
#  else
	const int tos = 0x10;
#  endif

	err = setsockopt (net, IPPROTO_IP, IP_TOS,
			  (char *) &tos, sizeof (tos));
	if (err < 0 && errno != ENOPROTOOPT)
	  perror ("telnet: setsockopt (IP_TOS) (ignored)");
      }
# endif/* defined(IPPROTO_IP) && defined(IP_TOS) */

      if (debug
	  && setsockopt (net, SOL_SOCKET, SO_DEBUG, &on, sizeof (on)) < 0)
	perror ("setsockopt (SO_DEBUG)");

      if (connect (net, (struct sockaddr *) &sin, sizeof (sin)) < 0)
	{
	  if (host && host->h_addr_list[1])
	    {
	      int oerrno = errno;

	      fprintf (stderr, "telnet: connect to address %s: ",
		       inet_ntoa (sin.sin_addr));
	      errno = oerrno;
	      perror ((char *) 0);
	      host->h_addr_list++;
	      memmove ((caddr_t) & sin.sin_addr,
		       host->h_addr_list[0], host->h_length);
	      close (net);
	      continue;
	    }
	  perror ("telnet: Unable to connect to remote host");
	  return 0;
	}
      connected++;
# if defined AUTHENTICATION || defined ENCRYPTION
      auth_encrypt_connect (connected);
# endif/* defined(AUTHENTICATION) || defined(ENCRYPTION) */
    }
  while (connected == 0);
#endif /* !IPV6 */

  cmdrc (hostp, hostname);
#if defined HAVE_IDN || defined HAVE_IDN2
  /* Last use of HOSTP, alias HOSTTMP.  */
  free (hosttmp);
#endif

  if (autologin && user == NULL)
    {
      struct passwd *pw;

      user = getenv ("USER");
      if (user == NULL || ((pw = getpwnam (user)) && pw->pw_uid != getuid ()))
	{
	  if ((pw = getpwuid (getuid ())))
	    user = pw->pw_name;
	  else
	    user = NULL;
	}
    }
  if (user)
    {
      env_define ("USER", user);
      env_export ("USER", NULL);
    }
  call (status, "status", "notmuch", 0);
  err = 0;
  if (setjmp (peerdied) == 0)
    telnet (user);
  else
    err = 1;

  close (net);
  ExitString ("Connection closed by foreign host.\n", err);
  /* NOT REACHED */
  return 0;
}

#define HELPINDENT (sizeof ("connect"))

static char
  openhelp[] = "connect to a site",
  closehelp[] = "close current connection",
  logouthelp[] = "forcibly logout remote user and close the connection",
  quithelp[] = "exit telnet",
  statushelp[] = "print status information",
  helphelp[] = "print help information",
  sendhelp[] = "transmit special characters ('send ?' for more)",
  sethelp[] = "set operating parameters ('set ?' for more)",
  unsethelp[] = "unset operating parameters ('unset ?' for more)",
  togglestring[] = "toggle operating parameters ('toggle ?' for more)",
  slchelp[] = "change state of special characters ('slc ?' for more)",
  displayhelp[] = "display operating parameters",
#if defined TN3270 && (defined unix || defined __unix || defined __unix__)
  transcomhelp[] = "specify Unix command for transparent mode pipe",
#endif
  /* TN3270 && (unix || __unix || __unix__) */
#if defined AUTHENTICATION
  authhelp[] = "turn on (off) authentication ('auth ?' for more)",
#endif
#ifdef	ENCRYPTION
  encrypthelp[] = "turn on (off) encryption ('encrypt ?' for more)",
#endif
  /* ENCRYPTION */
#if defined unix || defined __unix || defined __unix__
  zhelp[] = "suspend telnet",
#endif
  /* unix || __unix || __unix__ */
  shellhelp[] = "invoke a subshell",
  envhelp[] = "change environment variables ('environ ?' for more)",
  modestring[] = "try to enter line or character mode ('mode ?' for more)";

static int help (int argc, char **argv);

static Command cmdtab[] = {
  {"close", closehelp, bye, 1},
  {"logout", logouthelp, logoutcmd, 1},
  {"display", displayhelp, display, 0},
  {"mode", modestring, modecmd, 0},
  {"open", openhelp, tn, 0},
  {"quit", quithelp, quit, 0},
  {"send", sendhelp, sendcmd, 0},
  {"set", sethelp, setcmd, 0},
  {"unset", unsethelp, unsetcmd, 0},
  {"status", statushelp, status, 0},
  {"toggle", togglestring, toggle, 0},
  {"slc", slchelp, slccmd, 0},
#if defined TN3270 && (defined unix || defined __unix || defined __unix__)
  {"transcom", transcomhelp, settranscom, 0},
#endif /* TN3270 && (unix || __unix || __unix__) */
#if defined AUTHENTICATION
  {"auth", authhelp, auth_cmd, 0},
#endif
#ifdef	ENCRYPTION
  {"encrypt", encrypthelp, encrypt_cmd, 0},
#endif /* ENCRYPTION */
#if defined unix || defined __unix || defined __unix__
  {"z", zhelp, suspend, 0},
#endif /* unix || __unix || __unix__ */
#if defined TN3270
  {"!", shellhelp, shell, 1},
#else
  {"!", shellhelp, shell, 0},
#endif
  {"environ", envhelp, env_cmd, 0},
  {"?", helphelp, help, 0},
  {NULL, NULL, NULL, 0}
};

static char crmodhelp[] = "deprecated command -- use 'toggle crmod' instead";
static char escapehelp[] = "deprecated command -- use 'set escape' instead";

static Command cmdtab2[] = {
  {"help", helphelp, help, 0},
  {"escape", escapehelp, setescape, 0},
  {"crmod", crmodhelp, togcrmod, 0},
  {NULL, NULL, NULL, 0}
};


/*
 * Call routine with argc, argv set from args (terminated by 0).
 */

static int
call (intrtn_t routine, ...)
{
  va_list ap;
  char *args[100];
  int argno = 0;

  va_start (ap, routine);
  while ((args[argno++] = va_arg (ap, char *)) != 0)
    {
      ;
    }
  va_end (ap);
  return (*routine) (argno - 1, args);
}


static Command *
getcmd (char *name)
{
  Command *cm;

  if ((cm = (Command *) genget (name, (char **) cmdtab, sizeof (Command))))
    return cm;
  return (Command *) genget (name, (char **) cmdtab2, sizeof (Command));
}

void
command (int top, char *tbuf, int cnt)
{
  register Command *c;

  setcommandmode ();
  if (!top)
    {
      putchar ('\n');
    }
#if defined unix || defined __unix || defined __unix__
  else
    {
      signal (SIGINT, SIG_DFL);
      signal (SIGQUIT, SIG_DFL);
    }
#endif /* unix || __unix || __unix__ */
  for (;;)
    {
      if (rlogin == _POSIX_VDISABLE)
	printf ("%s> ", prompt);
      if (tbuf)
	{
	  register char *cp;
	  cp = line;
	  while (cnt > 0 && (*cp++ = *tbuf++) != '\n')
	    cnt--;
	  tbuf = 0;
	  if (cp == line || *--cp != '\n' || cp == line)
	    goto getline;
	  *cp = '\0';
	  if (rlogin == _POSIX_VDISABLE)
	    printf ("%s\n", line);
	}
      else
	{
	getline:
	  if (rlogin != _POSIX_VDISABLE)
	    printf ("%s> ", prompt);
	  if (fgets (line, sizeof (line), stdin) == NULL)
	    {
	      if (feof (stdin) || ferror (stdin))
		{
		  printf ("\n");
		  (void) quit (0, NULL);
		 /*NOTREACHED*/}
	      break;
	    }
	}
      if (line[0] == 0)
	break;
      makeargv ();
      if (margv[0] == 0)
	{
	  break;
	}
      c = getcmd (margv[0]);
      if (Ambiguous (c))
	{
	  printf ("?Ambiguous command\n");
	  continue;
	}
      if (c == 0)
	{
	  printf ("?Invalid command\n");
	  continue;
	}
      if (c->needconnect && !connected)
	{
	  printf ("?Need to be connected first.\n");
	  continue;
	}
      if ((*c->handler) (margc, margv))
	{
	  break;
	}
    }
  if (!top)
    {
      if (!connected)
	{
	  longjmp (toplevel, 1);
	}
#if defined TN3270
      if (shell_active == 0)
	{
	  setconnmode (0);
	}
#else /* defined(TN3270) */
      setconnmode (0);
#endif /* defined(TN3270) */
    }
}

/*
 * Help command.
 */
static int
help (int argc, char *argv[])
{
  register Command *c;

  if (argc == 1)
    {
      printf ("Commands may be abbreviated.  Commands are:\n\n");
      for (c = cmdtab; c->name; c++)
	if (c->help)
	  {
	    printf ("%-*s\t%s\n", (int) HELPINDENT, c->name, c->help);
	  }
      return 0;
    }
  while (--argc > 0)
    {
      register char *arg;
      arg = *++argv;
      c = getcmd (arg);
      if (Ambiguous (c))
	printf ("?Ambiguous help command %s\n", arg);
      else if (c == (Command *) 0)
	printf ("?Invalid help command %s\n", arg);
      else if (c->help)
	printf ("%s\n", c->help);
    }
  return 0;
}

static char *rcname = 0;

static void
cmdrc (char *m1, char *m2)
{
  register Command *c;
  FILE *rcfile;
  int gotmachine = 0;
  int l1 = strlen (m1);
  int l2 = strlen (m2);

  if (skiprc)
    return;

  if (rcname == 0)
    {
      const char *home = getenv ("HOME");
      if (home)
	rcname = xasprintf ("%s/.telnetrc", home);
      else
	rcname = xstrdup ("/.telnetrc");
    }

  if ((rcfile = fopen (rcname, "r")) == 0)
    {
      return;
    }

  for (;;)
    {
      if (fgets (line, sizeof (line), rcfile) == NULL)
	break;
      if (line[0] == 0)
	break;
      if (line[0] == '#')
	continue;
      if (gotmachine)
	{
	  if (!isspace (line[0]))
	    gotmachine = 0;
	}
      if (gotmachine == 0)
	{
	  if (isspace (line[0]))
	    continue;
	  if (strncasecmp (line, m1, l1) == 0)
	    memmove (line, &line[l1], strlen (&line[l1]) + 1);
	  else if (strncasecmp (line, m2, l2) == 0)
	    memmove (line, &line[l2], strlen (&line[l2]) + 1);
	  else if (strncasecmp (line, "DEFAULT", 7) == 0)
	    memmove (line, &line[7], strlen (&line[7]) + 1);
	  else
	    continue;
	  if (line[0] != ' ' && line[0] != '\t' && line[0] != '\n')
	    continue;
	  gotmachine = 1;
	}
      makeargv ();
      if (margv[0] == 0)
	continue;
      c = getcmd (margv[0]);
      if (Ambiguous (c))
	{
	  printf ("?Ambiguous command: %s\n", margv[0]);
	  continue;
	}
      if (c == 0)
	{
	  printf ("?Invalid command: %s\n", margv[0]);
	  continue;
	}
      /*
       * This should never happen...
       */
      if (c->needconnect && !connected)
	{
	  printf ("?Need to be connected first for %s.\n", margv[0]);
	  continue;
	}
      (*c->handler) (margc, margv);
    }
  fclose (rcfile);
}