path: root/usr.bin/tset/tset.c

/*	$OpenBSD: tset.c,v 1.40 2019/03/12 11:01:25 nicm Exp $	*/

/****************************************************************************
 * Copyright (c) 1998-2007,2008 Free Software Foundation, Inc.              *
 *                                                                          *
 * Permission is hereby granted, free of charge, to any person obtaining a  *
 * copy of this software and associated documentation files (the            *
 * "Software"), to deal in the Software without restriction, including      *
 * without limitation the rights to use, copy, modify, merge, publish,      *
 * distribute, distribute with modifications, sublicense, and/or sell       *
 * copies of the Software, and to permit persons to whom the Software is    *
 * furnished to do so, subject to the following conditions:                 *
 *                                                                          *
 * The above copyright notice and this permission notice shall be included  *
 * in all copies or substantial portions of the Software.                   *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS  *
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF               *
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.   *
 * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,   *
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR    *
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR    *
 * THE USE OR OTHER DEALINGS IN THE SOFTWARE.                               *
 *                                                                          *
 * Except as contained in this notice, the name(s) of the above copyright   *
 * holders shall not be used in advertising or otherwise to promote the     *
 * sale, use or other dealings in this Software without prior written       *
 * authorization.                                                           *
 ****************************************************************************/

/****************************************************************************
 *  Author: Zeyd M. Ben-Halim <zmbenhal@netcom.com> 1992,1995               *
 *     and: Eric S. Raymond <esr@snark.thyrsus.com>                         *
 *     and: Thomas E. Dickey                        1996-on                 *
 ****************************************************************************/

/*
 * tset.c - terminal initialization utility
 *
 * This code was mostly swiped from 4.4BSD tset, with some obsolescent
 * cruft removed and substantial portions rewritten.  A Regents of the
 * University of California copyright applies to some portions of the
 * code, and is reproduced below:
 */
/*-
 * Copyright (c) 1980, 1991, 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.
 */

#define USE_LIBTINFO
#define __INTERNAL_CAPS_VISIBLE	/* we need to see has_hardware_tabs */
#include <progs.priv.h>

#include <errno.h>
#include <stdio.h>
#include <termcap.h>
#include <fcntl.h>

#if HAVE_GETTTYNAM && HAVE_TTYENT_H
#include <ttyent.h>
#endif
#ifdef NeXT
char *ttyname(int fd);
#endif

#if HAVE_SIZECHANGE
# if !defined(sun) || !TERMIOS
#  if HAVE_SYS_IOCTL_H
#   include <sys/ioctl.h>
#  endif
# endif
#endif

#if NEED_PTEM_H
/* they neglected to define struct winsize in termios.h -- it's only
   in termio.h	*/
#include <sys/stream.h>
#include <sys/ptem.h>
#endif

#include <dump_entry.h>
#include <transform.h>

extern char **environ;

#undef CTRL
#define CTRL(x)	((x) & 0x1f)

const char *_nc_progname = "tset";

static TTY mode, oldmode, original;

static bool opt_c;		/* set control-chars */
static bool opt_w;		/* set window-size */

static bool can_restore = FALSE;
static bool isreset = FALSE;	/* invoked as reset */
static int terasechar = -1;	/* new erase character */
static int intrchar = -1;	/* new interrupt character */
static int tkillchar = -1;	/* new kill character */
static int tlines, tcolumns;	/* window size */

#define LOWERCASE(c) ((isalpha(UChar(c)) && isupper(UChar(c))) ? tolower(UChar(c)) : (c))

static int
CaselessCmp(const char *a, const char *b)
{				/* strcasecmp isn't portable */
    while (*a && *b) {
	int cmp = LOWERCASE(*a) - LOWERCASE(*b);
	if (cmp != 0)
	    break;
	a++, b++;
    }
    return LOWERCASE(*a) - LOWERCASE(*b);
}

static void
exit_error(void)
{
    if (can_restore)
	SET_TTY(STDERR_FILENO, &original);
    (void) fprintf(stderr, "\n");
    fflush(stderr);
    ExitProgram(EXIT_FAILURE);
    /* NOTREACHED */
}

static void
err(const char *fmt,...)
{
    va_list ap;
    va_start(ap, fmt);
    (void) fprintf(stderr, "%s: ", _nc_progname);
    (void) vfprintf(stderr, fmt, ap);
    va_end(ap);
    exit_error();
    /* NOTREACHED */
}

static void
failed(const char *msg)
{
    fprintf(stderr, "%s: ", _nc_progname);
    perror(msg);
    exit_error();
    /* NOTREACHED */
}

static void
cat(char *file)
{
    FILE *fp;
    size_t nr;
    char buf[BUFSIZ];

    if ((fp = fopen(file, "r")) == 0)
	failed(file);

    while ((nr = fread(buf, sizeof(char), sizeof(buf), fp)) != 0)
	if (fwrite(buf, sizeof(char), nr, stderr) != nr)
	      failed("write to stderr");
    fclose(fp);
}

static int
outc(int c)
{
    return putc(c, stderr);
}

/* Prompt the user for a terminal type. */
static const char *
askuser(const char *dflt)
{
    static char answer[256];

    /* We can get recalled; if so, don't continue uselessly. */
    clearerr(stdin);
    if (feof(stdin) || ferror(stdin)) {
	(void) fprintf(stderr, "\n");
	exit_error();
	/* NOTREACHED */
    }
    for (;;) {
	if (dflt)
	    (void) fprintf(stderr, "Terminal type? [%s] ", dflt);
	else
	    (void) fprintf(stderr, "Terminal type? ");
	(void) fflush(stderr);

	if (fgets(answer, sizeof(answer), stdin) == NULL) {
	    if (dflt == 0) {
		exit_error();
		/* NOTREACHED */
	    }
	    return (dflt);
	}

	answer[strcspn(answer, "\n")] = '\0';
	if (answer[0])
	    return (answer);
	if (dflt != 0)
	    return (dflt);
    }
}

/**************************************************************************
 *
 * Mapping logic begins here
 *
 **************************************************************************/

/* Baud rate conditionals for mapping. */
#define	GT		0x01
#define	EQ		0x02
#define	LT		0x04
#define	NOT		0x08
#define	GE		(GT | EQ)
#define	LE		(LT | EQ)

typedef struct map {
    struct map *next;		/* Linked list of maps. */
    const char *porttype;	/* Port type, or "" for any. */
    const char *type;		/* Terminal type to select. */
    int conditional;		/* Baud rate conditionals bitmask. */
    int speed;			/* Baud rate to compare against. */
} MAP;

static MAP *cur, *maplist;

typedef struct speeds {
    const char *string;
    int speed;
} SPEEDS;

static const SPEEDS speeds[] =
{
    {"0", B0},
    {"50", B50},
    {"75", B75},
    {"110", B110},
    {"134", B134},
    {"134.5", B134},
    {"150", B150},
    {"200", B200},
    {"300", B300},
    {"600", B600},
    {"1200", B1200},
    {"1800", B1800},
    {"2400", B2400},
    {"4800", B4800},
    {"9600", B9600},
    /* sgttyb may define up to this point */
#ifdef B19200
    {"19200", B19200},
#endif
#ifdef B38400
    {"38400", B38400},
#endif
#ifdef B19200
    {"19200", B19200},
#endif
#ifdef B38400
    {"38400", B38400},
#endif
#ifdef B19200
    {"19200", B19200},
#else
#ifdef EXTA
    {"19200", EXTA},
#endif
#endif
#ifdef B38400
    {"38400", B38400},
#else
#ifdef EXTB
    {"38400", EXTB},
#endif
#endif
#ifdef B57600
    {"57600", B57600},
#endif
#ifdef B115200
    {"115200", B115200},
#endif
#ifdef B230400
    {"230400", B230400},
#endif
#ifdef B460800
    {"460800", B460800},
#endif
    {(char *) 0, 0}
};

static int
tbaudrate(char *rate)
{
    const SPEEDS *sp;
    int found = FALSE;

    /* The baudrate number can be preceded by a 'B', which is ignored. */
    if (*rate == 'B')
	++rate;

    for (sp = speeds; sp->string; ++sp) {
	if (!CaselessCmp(rate, sp->string)) {
	    found = TRUE;
	    break;
	}
    }
    if (!found)
	err("unknown baud rate %s", rate);
    return (sp->speed);
}

/*
 * Syntax for -m:
 * [port-type][test baudrate]:terminal-type
 * The baud rate tests are: >, <, @, =, !
 */
static void
add_mapping(const char *port, char *arg)
{
    MAP *mapp;
    char *copy, *p;
    const char *termp;
    char *base = 0;

    copy = strdup(arg);
    mapp = malloc(sizeof(MAP));
    if (copy == 0 || mapp == 0)
	failed("malloc");
    mapp->next = 0;
    if (maplist == 0)
	cur = maplist = mapp;
    else {
	cur->next = mapp;
	cur = mapp;
    }

    mapp->porttype = arg;
    mapp->conditional = 0;

    arg = strpbrk(arg, "><@=!:");

    if (arg == 0) {		/* [?]term */
	mapp->type = mapp->porttype;
	mapp->porttype = 0;
	goto done;
    }

    if (arg == mapp->porttype)	/* [><@=! baud]:term */
	termp = mapp->porttype = 0;
    else
	termp = base = arg;

    for (;; ++arg) {		/* Optional conditionals. */
	switch (*arg) {
	case '<':
	    if (mapp->conditional & GT)
		goto badmopt;
	    mapp->conditional |= LT;
	    break;
	case '>':
	    if (mapp->conditional & LT)
		goto badmopt;
	    mapp->conditional |= GT;
	    break;
	case '@':
	case '=':		/* Not documented. */
	    mapp->conditional |= EQ;
	    break;
	case '!':
	    mapp->conditional |= NOT;
	    break;
	default:
	    goto next;
	}
    }

  next:
    if (*arg == ':') {
	if (mapp->conditional)
	    goto badmopt;
	++arg;
    } else {			/* Optional baudrate. */
	arg = strchr(p = arg, ':');
	if (arg == 0)
	    goto badmopt;
	*arg++ = '\0';
	mapp->speed = tbaudrate(p);
    }

    if (arg == (char *) 0)	/* Non-optional type. */
	goto badmopt;

    mapp->type = arg;

    /* Terminate porttype, if specified. */
    if (termp != 0)
	*base = '\0';

    /* If a NOT conditional, reverse the test. */
    if (mapp->conditional & NOT)
	mapp->conditional = ~mapp->conditional & (EQ | GT | LT);

    /* If user specified a port with an option flag, set it. */
  done:
    if (port) {
	if (mapp->porttype) {
	  badmopt:
	    err("illegal -m option format: %s", copy);
	}
	mapp->porttype = port;
    }
    free(copy);
#ifdef MAPDEBUG
    (void) printf("port: %s\n", mapp->porttype ? mapp->porttype : "ANY");
    (void) printf("type: %s\n", mapp->type);
    (void) printf("conditional: ");
    p = "";
    if (mapp->conditional & GT) {
	(void) printf("GT");
	p = "/";
    }
    if (mapp->conditional & EQ) {
	(void) printf("%sEQ", p);
	p = "/";
    }
    if (mapp->conditional & LT)
	(void) printf("%sLT", p);
    (void) printf("\nspeed: %d\n", mapp->speed);
#endif
}

/*
 * Return the type of terminal to use for a port of type 'type', as specified
 * by the first applicable mapping in 'map'.  If no mappings apply, return
 * 'type'.
 */
static const char *
mapped(const char *type)
{
    MAP *mapp;
    int match;

    for (mapp = maplist; mapp; mapp = mapp->next)
	if (mapp->porttype == 0 || !strcmp(mapp->porttype, type)) {
	    switch (mapp->conditional) {
	    case 0:		/* No test specified. */
		match = TRUE;
		break;
	    case EQ:
		match = (ospeed == mapp->speed);
		break;
	    case GE:
		match = (ospeed >= mapp->speed);
		break;
	    case GT:
		match = (ospeed > mapp->speed);
		break;
	    case LE:
		match = (ospeed <= mapp->speed);
		break;
	    case LT:
		match = (ospeed < mapp->speed);
		break;
	    default:
		match = FALSE;
	    }
	    if (match)
		return (mapp->type);
	}
    /* No match found; return given type. */
    return (type);
}

/**************************************************************************
 *
 * Entry fetching
 *
 **************************************************************************/

/*
 * Figure out what kind of terminal we're dealing with, and then read in
 * its termcap entry.
 */
static const char *
get_termcap_entry(char *userarg)
{
    int errret;
    char *p;
    const char *ttype;
#if HAVE_GETTTYNAM
    struct ttyent *t;
#else
    FILE *fp;
#endif
    char *ttypath;

    if (userarg) {
	ttype = userarg;
	goto found;
    }

    /* Try the environment. */
    if ((ttype = getenv("TERM")) != 0)
	goto map;

    if ((ttypath = ttyname(STDERR_FILENO)) != 0) {
	p = _nc_basename(ttypath);
#if HAVE_GETTTYNAM
	/*
	 * We have the 4.3BSD library call getttynam(3); that means
	 * there's an /etc/ttys to look up device-to-type mappings in.
	 * Try ttyname(3); check for dialup or other mapping.
	 */
	if ((t = getttynam(p))) {
	    ttype = t->ty_type;
	    goto map;
	}
#else
	if ((fp = fopen("/etc/ttytype", "r")) != 0
	    || (fp = fopen("/etc/ttys", "r")) != 0) {
	    char buffer[BUFSIZ];
	    char *s, *t, *d;

	    while (fgets(buffer, sizeof(buffer), fp) != NULL) {
		for (s = buffer, t = d = 0; *s; s++) {
		    if (isspace(UChar(*s)))
			*s = '\0';
		    else if (t == 0)
			t = s;
		    else if (d == 0 && s != buffer && s[-1] == '\0')
			d = s;
		}
		if (t != 0 && d != 0 && !strcmp(d, p)) {
		    ttype = strdup(t);
		    fclose(fp);
		    goto map;
		}
	    }
	    fclose(fp);
	}
#endif /* HAVE_GETTTYNAM */
    }

    /* If still undefined, use "unknown". */
    ttype = "unknown";

  map:ttype = mapped(ttype);

    /*
     * If not a path, remove TERMCAP from the environment so we get a
     * real entry from /etc/termcap.  This prevents us from being fooled
     * by out of date stuff in the environment.
     */
  found:if ((p = getenv("TERMCAP")) != 0 && !_nc_is_abs_path(p)) {
	/* 'unsetenv("TERMCAP")' is not portable.
	 * The 'environ' array is better.
	 */
	int n;
	for (n = 0; environ[n] != 0; n++) {
	    if (!strncmp("TERMCAP=", environ[n], 8)) {
		while ((environ[n] = environ[n + 1]) != 0) {
		    n++;
		}
		break;
	    }
	}
    }

    /*
     * ttype now contains a pointer to the type of the terminal.
     * If the first character is '?', ask the user.
     */
    if (ttype[0] == '?') {
	if (ttype[1] != '\0')
	    ttype = askuser(ttype + 1);
	else
	    ttype = askuser(0);
    }
    /* Find the terminfo entry.  If it doesn't exist, ask the user. */
    while (setupterm((NCURSES_CONST char *) ttype, STDOUT_FILENO, &errret)
	   != OK) {
	if (errret == 0) {
	    (void) fprintf(stderr, "%s: unknown terminal type %s\n",
			   _nc_progname, ttype);
	    ttype = 0;
	} else {
	    (void) fprintf(stderr,
			   "%s: can't initialize terminal type %s (error %d)\n",
			   _nc_progname, ttype, errret);
	    ttype = 0;
	}
	ttype = askuser(ttype);
    }
#if BROKEN_LINKER
    tgetflag("am");		/* force lib_termcap.o to be linked for 'ospeed' */
#endif
    return (ttype);
}

/**************************************************************************
 *
 * Mode-setting logic
 *
 **************************************************************************/

/* some BSD systems have these built in, some systems are missing
 * one or more definitions. The safest solution is to override unless the
 * commonly-altered ones are defined.
 */
#if !(defined(CERASE) && defined(CINTR) && defined(CKILL) && defined(CQUIT))
#undef CEOF
#undef CERASE
#undef CINTR
#undef CKILL
#undef CLNEXT
#undef CRPRNT
#undef CQUIT
#undef CSTART
#undef CSTOP
#undef CSUSP
#endif

/* control-character defaults */
#ifndef CEOF
#define CEOF	CTRL('D')
#endif
#ifndef CERASE
#define CERASE	CTRL('H')
#endif
#ifndef CINTR
#define CINTR	127		/* ^? */
#endif
#ifndef CKILL
#define CKILL	CTRL('U')
#endif
#ifndef CLNEXT
#define CLNEXT  CTRL('v')
#endif
#ifndef CRPRNT
#define CRPRNT  CTRL('r')
#endif
#ifndef CQUIT
#define CQUIT	CTRL('\\')
#endif
#ifndef CSTART
#define CSTART	CTRL('Q')
#endif
#ifndef CSTOP
#define CSTOP	CTRL('S')
#endif
#ifndef CSUSP
#define CSUSP	CTRL('Z')
#endif

#if defined(_POSIX_VDISABLE)
#define DISABLED(val)   (((_POSIX_VDISABLE != -1) \
		       && ((val) == _POSIX_VDISABLE)) \
		      || ((val) <= 0))
#else
#define DISABLED(val)   ((int)(val) <= 0)
#endif

#define CHK(val, dft)   (DISABLED(val) ? dft : val)

static bool set_tabs(void);

/*
 * Reset the terminal mode bits to a sensible state.  Very useful after
 * a child program dies in raw mode.
 */
static void
reset_mode(void)
{
#ifdef TERMIOS
    tcgetattr(STDERR_FILENO, &mode);
#else
    stty(STDERR_FILENO, &mode);
#endif

#ifdef TERMIOS
#if defined(VDISCARD) && defined(CDISCARD)
    mode.c_cc[VDISCARD] = CHK(mode.c_cc[VDISCARD], CDISCARD);
#endif
    mode.c_cc[VEOF] = CHK(mode.c_cc[VEOF], CEOF);
    mode.c_cc[VERASE] = CHK(mode.c_cc[VERASE], CERASE);
#if defined(VFLUSH) && defined(CFLUSH)
    mode.c_cc[VFLUSH] = CHK(mode.c_cc[VFLUSH], CFLUSH);
#endif
    mode.c_cc[VINTR] = CHK(mode.c_cc[VINTR], CINTR);
    mode.c_cc[VKILL] = CHK(mode.c_cc[VKILL], CKILL);
#if defined(VLNEXT) && defined(CLNEXT)
    mode.c_cc[VLNEXT] = CHK(mode.c_cc[VLNEXT], CLNEXT);
#endif
    mode.c_cc[VQUIT] = CHK(mode.c_cc[VQUIT], CQUIT);
#if defined(VREPRINT) && defined(CRPRNT)
    mode.c_cc[VREPRINT] = CHK(mode.c_cc[VREPRINT], CRPRNT);
#endif
#if defined(VSTART) && defined(CSTART)
    mode.c_cc[VSTART] = CHK(mode.c_cc[VSTART], CSTART);
#endif
#if defined(VSTOP) && defined(CSTOP)
    mode.c_cc[VSTOP] = CHK(mode.c_cc[VSTOP], CSTOP);
#endif
#if defined(VSUSP) && defined(CSUSP)
    mode.c_cc[VSUSP] = CHK(mode.c_cc[VSUSP], CSUSP);
#endif
#if defined(VWERASE) && defined(CWERASE)
    mode.c_cc[VWERASE] = CHK(mode.c_cc[VWERASE], CWERASE);
#endif

    mode.c_iflag &= ~(IGNBRK | PARMRK | INPCK | ISTRIP | INLCR | IGNCR
#ifdef IUCLC
		      | IUCLC
#endif
#ifdef IXANY
		      | IXANY
#endif
		      | IXOFF);

    mode.c_iflag |= (BRKINT | IGNPAR | ICRNL | IXON
#ifdef IMAXBEL
		     | IMAXBEL
#endif
	);

    mode.c_oflag &= ~(0
#ifdef OLCUC
		      | OLCUC
#endif
#ifdef OCRNL
		      | OCRNL
#endif
#ifdef ONOCR
		      | ONOCR
#endif
#ifdef ONLRET
		      | ONLRET
#endif
#ifdef OFILL
		      | OFILL
#endif
#ifdef OFDEL
		      | OFDEL
#endif
#ifdef NLDLY
		      | NLDLY
#endif
#ifdef CRDLY
		      | CRDLY
#endif
#ifdef TABDLY
		      | TABDLY
#endif
#ifdef BSDLY
		      | BSDLY
#endif
#ifdef VTDLY
		      | VTDLY
#endif
#ifdef FFDLY
		      | FFDLY
#endif
	);

    mode.c_oflag |= (OPOST
#ifdef ONLCR
		     | ONLCR
#endif
	);

    mode.c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD | CLOCAL);
    mode.c_cflag |= (CS8 | CREAD);
    mode.c_lflag &= ~(ECHONL | NOFLSH
#ifdef TOSTOP
		      | TOSTOP
#endif
#ifdef ECHOPTR
		      | ECHOPRT
#endif
#ifdef XCASE
		      | XCASE
#endif
	);

    mode.c_lflag |= (ISIG | ICANON | ECHO | ECHOE | ECHOK
#ifdef ECHOCTL
		     | ECHOCTL
#endif
#ifdef ECHOKE
		     | ECHOKE
#endif
	);
#endif

    SET_TTY(STDERR_FILENO, &mode);
}

/*
 * Returns a "good" value for the erase character.  This is loosely based on
 * the BSD4.4 logic.
 */
#ifdef TERMIOS
static int
default_erase(void)
{
    int result;

    if (over_strike
	&& key_backspace != 0
	&& strlen(key_backspace) == 1)
	result = key_backspace[0];
    else
	result = CERASE;

    return result;
}
#endif

/*
 * Update the values of the erase, interrupt, and kill characters in 'mode'.
 *
 * SVr4 tset (e.g., Solaris 2.5) only modifies the intr, quit or erase
 * characters if they're unset, or if we specify them as options.  This differs
 * from BSD 4.4 tset, which always sets erase.
 */
static void
set_control_chars(void)
{
#ifdef TERMIOS
    if (DISABLED(mode.c_cc[VERASE]) || terasechar >= 0)
	mode.c_cc[VERASE] = (terasechar >= 0) ? terasechar : default_erase();

    if (DISABLED(mode.c_cc[VINTR]) || intrchar >= 0)
	mode.c_cc[VINTR] = (intrchar >= 0) ? intrchar : CINTR;

    if (DISABLED(mode.c_cc[VKILL]) || tkillchar >= 0)
	mode.c_cc[VKILL] = (tkillchar >= 0) ? tkillchar : CKILL;
#endif
}

/*
 * Set up various conversions in 'mode', including parity, tabs, returns,
 * echo, and case, according to the termcap entry.  If the program we're
 * running was named with a leading upper-case character, map external
 * uppercase to internal lowercase.
 */
static void
set_conversions(void)
{
#ifdef __OBSOLETE__
    /*
     * Conversion logic for some *really* ancient terminal glitches,
     * not supported in terminfo.  Left here for succeeding generations
     * to marvel at.
     */
    if (tgetflag("UC")) {
#ifdef IUCLC
	mode.c_iflag |= IUCLC;
	mode.c_oflag |= OLCUC;
#endif
    } else if (tgetflag("LC")) {
#ifdef IUCLC
	mode.c_iflag &= ~IUCLC;
	mode.c_oflag &= ~OLCUC;
#endif
    }
    mode.c_iflag &= ~(PARMRK | INPCK);
    mode.c_lflag |= ICANON;
    if (tgetflag("EP")) {
	mode.c_cflag |= PARENB;
	mode.c_cflag &= ~PARODD;
    }
    if (tgetflag("OP")) {
	mode.c_cflag |= PARENB;
	mode.c_cflag |= PARODD;
    }
#endif /* __OBSOLETE__ */

#ifdef TERMIOS
#ifdef ONLCR
    mode.c_oflag |= ONLCR;
#endif
    mode.c_iflag |= ICRNL;
    mode.c_lflag |= ECHO;
#ifdef OXTABS
    mode.c_oflag |= OXTABS;
#endif /* OXTABS */

    /* test used to be tgetflag("NL") */
    if (newline != (char *) 0 && newline[0] == '\n' && !newline[1]) {
	/* Newline, not linefeed. */
#ifdef ONLCR
	mode.c_oflag &= ~ONLCR;
#endif
	mode.c_iflag &= ~ICRNL;
    }
#ifdef __OBSOLETE__
    if (tgetflag("HD"))		/* Half duplex. */
	mode.c_lflag &= ~ECHO;
#endif /* __OBSOLETE__ */
#ifdef OXTABS
    /* test used to be tgetflag("pt") */
    if (VALID_STRING(set_tab) && VALID_STRING(clear_all_tabs))
	mode.c_oflag &= ~OXTABS;
#endif /* OXTABS */
    mode.c_lflag |= (ECHOE | ECHOK);
#endif
}

/* Output startup string. */
static void
set_init(void)
{
    char *p;
    bool settle;

#ifdef __OBSOLETE__
    if (pad_char != (char *) 0)	/* Get/set pad character. */
	PC = pad_char[0];
#endif /* OBSOLETE */

#ifdef TAB3
    if (oldmode.c_oflag & (TAB3 | ONLCR | OCRNL | ONLRET)) {
	oldmode.c_oflag &= (TAB3 | ONLCR | OCRNL | ONLRET);
	SET_TTY(STDERR_FILENO, &oldmode);
    }
#endif
    settle = set_tabs();

    if (isreset) {
	if ((p = reset_1string) != 0) {
	    tputs(p, 0, outc);
	    settle = TRUE;
	}
	if ((p = reset_2string) != 0) {
	    tputs(p, 0, outc);
	    settle = TRUE;
	}
	/* What about rf, rs3, as per terminfo man page? */
	/* also might be nice to send rmacs, rmul, rmm */
	if ((p = reset_file) != 0
	    || (p = init_file) != 0) {
	    cat(p);
	    settle = TRUE;
	}
    }

    if (settle) {
	(void) putc('\r', stderr);
	(void) fflush(stderr);
	(void) napms(1000);	/* Settle the terminal. */
    }
}

/*
 * Set the hardware tabs on the terminal, using the ct (clear all tabs),
 * st (set one tab) and ch (horizontal cursor addressing) capabilities.
 * This is done before if and is, so they can patch in case we blow this.
 * Return TRUE if we set any tab stops, FALSE if not.
 */
static bool
set_tabs(void)
{
    if (set_tab && clear_all_tabs) {
	int c;

	(void) putc('\r', stderr);	/* Force to left margin. */
	tputs(clear_all_tabs, 0, outc);

	for (c = 8; c < tcolumns; c += 8) {
	    /* Get to the right column.  In BSD tset, this
	     * used to try a bunch of half-clever things
	     * with cup and hpa, for an average saving of
	     * somewhat less than two character times per
	     * tab stop, less than .01 sec at 2400cps. We
	     * lost all this cruft because it seemed to be
	     * introducing some odd bugs.
	     * -----------12345678----------- */
	    (void) fputs("        ", stderr);
	    tputs(set_tab, 0, outc);
	}
	putc('\r', stderr);
	return (TRUE);
    }
    return (FALSE);
}

/**************************************************************************
 *
 * Main sequence
 *
 **************************************************************************/

/*
 * Tell the user if a control key has been changed from the default value.
 */
#ifdef TERMIOS
static void
report(const char *name, int which, unsigned def)
{
    unsigned older, newer;
    char *p;

    newer = mode.c_cc[which];
    older = oldmode.c_cc[which];

    if (older == newer && older == def)
	return;

    (void) fprintf(stderr, "%s %s ", name, older == newer ? "is" : "set to");

    if (DISABLED(newer))
	(void) fprintf(stderr, "undef.\n");
    /*
     * Check 'delete' before 'backspace', since the key_backspace value
     * is ambiguous.
     */
    else if (newer == 0177)
	(void) fprintf(stderr, "delete.\n");
    else if ((p = key_backspace) != 0
	     && newer == (unsigned char) p[0]
	     && p[1] == '\0')
	(void) fprintf(stderr, "backspace.\n");
    else if (newer < 040) {
	newer ^= 0100;
	(void) fprintf(stderr, "control-%c (^%c).\n", UChar(newer), UChar(newer));
    } else
	(void) fprintf(stderr, "%c.\n", UChar(newer));
}
#endif

/*
 * Convert the obsolete argument forms into something that getopt can handle.
 * This means that -e, -i and -k get default arguments supplied for them.
 */
static void
obsolete(char **argv)
{
    for (; *argv; ++argv) {
	char *parm = argv[0];

	if (parm[0] == '-' && parm[1] == '\0') {
	    argv[0] = strdup("-q");
	    continue;
	}

	if ((parm[0] != '-')
	    || (argv[1] && argv[1][0] != '-')
	    || (parm[1] != 'e' && parm[1] != 'i' && parm[1] != 'k')
	    || (parm[2] != '\0'))
	    continue;
	switch (argv[0][1]) {
	case 'e':
	    argv[0] = strdup("-e^H");
	    break;
	case 'i':
	    argv[0] = strdup("-i^C");
	    break;
	case 'k':
	    argv[0] = strdup("-k^U");
	    break;
	}
    }
}

static void
usage(void)
{
    static const char *tbl[] =
    {
	""
	,"Options:"
	,"  -c          set control characters"
	,"  -e ch       erase character"
	,"  -I          no initialization strings"
	,"  -i ch       interrupt character"
	,"  -k ch       kill character"
	,"  -m mapping  map identifier to type"
	,"  -Q          do not output control key settings"
	,"  -r          display term on stderr"
	,"  -s          output TERM set command"
	,"  -V          print curses-version"
	,"  -w          set window-size"
    };
    unsigned n;
    (void) fprintf(stderr, "Usage: %s [-cIQqrsVw] [-] "
	"[-e ch] [-i ch] [-k ch] [-m mapping] [terminal]\n",
	_nc_progname);
    for (n = 0; n < sizeof(tbl) / sizeof(tbl[0]); ++n)
	fprintf(stderr, "%s\n", tbl[n]);

    exit_error();
    /* NOTREACHED */
}

static char
arg_to_char(void)
{
    return (char) ((optarg[0] == '^' && optarg[1] != '\0')
		   ? ((optarg[1] == '?') ? '\177' : CTRL(optarg[1]))
		   : optarg[0]);
}

int
main(int argc, char **argv)
{
    int ch, noinit, noset, quiet, Sflag, sflag, showterm;
    const char *p;
    const char *ttype;

    if (pledge("stdio rpath wpath tty", NULL) == -1)
	err("pledge: %s", strerror(errno));

    obsolete(argv);
    noinit = noset = quiet = Sflag = sflag = showterm = 0;
    while ((ch = getopt(argc, argv, "a:cd:e:Ii:k:m:np:qQSrsVw")) != -1) {
	switch (ch) {
	case 'c':		/* set control-chars */
	    opt_c = TRUE;
	    break;
	case 'a':		/* OBSOLETE: map identifier to type */
	    add_mapping("arpanet", optarg);
	    break;
	case 'd':		/* OBSOLETE: map identifier to type */
	    add_mapping("dialup", optarg);
	    break;
	case 'e':		/* erase character */
	    terasechar = arg_to_char();
	    break;
	case 'I':		/* no initialization strings */
	    noinit = 1;
	    break;
	case 'i':		/* interrupt character */
	    intrchar = arg_to_char();
	    break;
	case 'k':		/* kill character */
	    tkillchar = arg_to_char();
	    break;
	case 'm':		/* map identifier to type */
	    add_mapping(0, optarg);
	    break;
	case 'n':		/* OBSOLETE: set new tty driver */
	    break;
	case 'p':		/* OBSOLETE: map identifier to type */
	    add_mapping("plugboard", optarg);
	    break;
	case 'Q':		/* don't output control key settings */
	    quiet = 1;
	    break;
	case 'q':		/* display term only */
	    noset = 1;
	    break;
	case 'r':		/* display term on stderr */
	    showterm = 1;
	    break;
	case 'S':		/* OBSOLETE: output TERM & TERMCAP */
	    Sflag = 1;
	    break;
	case 's':		/* output TERM set command */
	    sflag = 1;
	    break;
	case 'V':		/* print curses-version */
	    puts(curses_version());
	    ExitProgram(EXIT_SUCCESS);
	case 'w':		/* set window-size */
	    opt_w = TRUE;
	    break;
	case '?':
	default:
	    usage();
	}
    }

    _nc_progname = _nc_rootname(*argv);
    argc -= optind;
    argv += optind;

    if (argc > 1)
	usage();

    if (!opt_c && !opt_w)
	opt_c = opt_w = TRUE;

    if (GET_TTY(STDERR_FILENO, &mode) < 0)
	failed("standard error");
    can_restore = TRUE;
    original = oldmode = mode;
#ifdef TERMIOS
    ospeed = (NCURSES_OSPEED) cfgetospeed(&mode);
#else
    ospeed = (NCURSES_OSPEED) mode.sg_ospeed;
#endif

    if (!strcmp(_nc_progname, PROG_RESET)) {
	isreset = TRUE;
	reset_mode();
    }

    ttype = get_termcap_entry(*argv);

    if (!noset) {
	tcolumns = columns;
	tlines = lines;

#if HAVE_SIZECHANGE
	if (opt_w) {
	    struct winsize win;
	    /* Set window size if not set already */
	    (void) ioctl(STDERR_FILENO, TIOCGWINSZ, &win);
	    if (win.ws_row == 0 &&
		win.ws_col == 0 &&
		tlines > 0 && tcolumns > 0) {
		win.ws_row = tlines;
		win.ws_col = tcolumns;
		(void) ioctl(STDERR_FILENO, TIOCSWINSZ, &win);
	    }
	}
#endif
	if (opt_c) {
	    set_control_chars();
	    set_conversions();

	    if (!noinit)
		set_init();

	    /* Set the modes if they've changed. */
	    if (memcmp(&mode, &oldmode, sizeof(mode))) {
		SET_TTY(STDERR_FILENO, &mode);
	    }
	}
    }

    /* Get the terminal name from the entry. */
    ttype = _nc_first_name(cur_term->type.term_names);

    if (noset)
	(void) printf("%s\n", ttype);
    else {
	if (showterm)
	    (void) fprintf(stderr, "Terminal type is %s.\n", ttype);
	/*
	 * If erase, kill and interrupt characters could have been
	 * modified and not -Q, display the changes.
	 */
#ifdef TERMIOS
	if (!quiet) {
	    report("Erase", VERASE, CERASE);
	    report("Kill", VKILL, CKILL);
	    report("Interrupt", VINTR, CINTR);
	}
#endif
    }

    if (Sflag)
	err("The -S option is not supported under terminfo.");

    if (sflag) {
	int len;
	char *var;
	char *leaf;
	/*
	 * Figure out what shell we're using.  A hack, we look for an
	 * environmental variable SHELL ending in "csh".
	 */
	if ((var = getenv("SHELL")) != 0
	    && ((len = (int) strlen(leaf = _nc_basename(var))) >= 3)
	    && !strcmp(leaf + len - 3, "csh"))
	    p = "set noglob;\nsetenv TERM %s;\nunset noglob;\n";
	else
	    p = "TERM=%s;\n";
	(void) printf(p, ttype);
    }

    ExitProgram(EXIT_SUCCESS);
}