.

[coreutils.git] / src / stty.c

/* stty -- change and print terminal line settings
   Copyright (C) 1990-2004 Free Software Foundation, Inc.

   This program 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 2, or (at your option)
   any later version.

   This program 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, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* Usage: stty [-ag] [--all] [--save] [-F device] [--file=device] [setting...]

   Options:
   -a, --all    Write all current settings to stdout in human-readable form.
   -g, --save   Write all current settings to stdout in stty-readable form.
   -F, --file   Open and use the specified device instead of stdin

   If no args are given, write to stdout the baud rate and settings that
   have been changed from their defaults.  Mode reading and changes
   are done on the specified device, or stdin if none was specified.

   David MacKenzie <djm@gnu.ai.mit.edu> */

#include <config.h>

#ifdef TERMIOS_NEEDS_XOPEN_SOURCE
# define _XOPEN_SOURCE
#endif

#include <stdio.h>
#include <sys/types.h>
#if HAVE_TERMIOS_H
# include <termios.h>
#endif
#ifdef GWINSZ_IN_SYS_IOCTL
# include <sys/ioctl.h>
#endif
#ifdef WINSIZE_IN_PTEM
# include <sys/stream.h>
# include <sys/ptem.h>
#endif
#ifdef GWINSZ_IN_SYS_PTY
# include <sys/ioctl.h>
# include <sys/tty.h>
# include <sys/pty.h>
#endif
#include <getopt.h>
#include <stdarg.h>
#define VA_START(args, lastarg) va_start(args, lastarg)

#include "system.h"
#include "long-options.h"
#include "error.h"
#include "xstrtol.h"

/* The official name of this program (e.g., no `g' prefix).  */
#define PROGRAM_NAME "stty"

#define AUTHORS "David MacKenzie"

#ifndef _POSIX_VDISABLE
# define _POSIX_VDISABLE ((unsigned char) 0)
#endif

#define Control(c) ((c) & 0x1f)
/* Canonical values for control characters. */
#ifndef CINTR
# define CINTR Control ('c')
#endif
#ifndef CQUIT
# define CQUIT 28
#endif
#ifndef CERASE
# define CERASE 127
#endif
#ifndef CKILL
# define CKILL Control ('u')
#endif
#ifndef CEOF
# define CEOF Control ('d')
#endif
#ifndef CEOL
# define CEOL _POSIX_VDISABLE
#endif
#ifndef CSTART
# define CSTART Control ('q')
#endif
#ifndef CSTOP
# define CSTOP Control ('s')
#endif
#ifndef CSUSP
# define CSUSP Control ('z')
#endif
#if defined(VEOL2) && !defined(CEOL2)
# define CEOL2 _POSIX_VDISABLE
#endif
/* ISC renamed swtch to susp for termios, but we'll accept either name.  */
#if defined(VSUSP) && !defined(VSWTCH)
# define VSWTCH VSUSP
# define CSWTCH CSUSP
#endif
#if defined(VSWTCH) && !defined(CSWTCH)
# define CSWTCH _POSIX_VDISABLE
#endif

/* SunOS 5.3 loses (^Z doesn't work) if `swtch' is the same as `susp'.
   So the default is to disable `swtch.'  */
#if defined (__sparc__) && defined (__svr4__)
# undef CSWTCH
# define CSWTCH _POSIX_VDISABLE
#endif

#if defined(VWERSE) && !defined (VWERASE)       /* AIX-3.2.5 */
# define VWERASE VWERSE
#endif
#if defined(VDSUSP) && !defined (CDSUSP)
# define CDSUSP Control ('y')
#endif
#if !defined(VREPRINT) && defined(VRPRNT)       /* Irix 4.0.5 */
# define VREPRINT VRPRNT
#endif
#if defined(VREPRINT) && !defined(CRPRNT)
# define CRPRNT Control ('r')
#endif
#if defined(CREPRINT) && !defined(CRPRNT)
# define CRPRNT Control ('r')
#endif
#if defined(VWERASE) && !defined(CWERASE)
# define CWERASE Control ('w')
#endif
#if defined(VLNEXT) && !defined(CLNEXT)
# define CLNEXT Control ('v')
#endif
#if defined(VDISCARD) && !defined(VFLUSHO)
# define VFLUSHO VDISCARD
#endif
#if defined(VFLUSH) && !defined(VFLUSHO)        /* Ultrix 4.2 */
# define VFLUSHO VFLUSH
#endif
#if defined(CTLECH) && !defined(ECHOCTL)        /* Ultrix 4.3 */
# define ECHOCTL CTLECH
#endif
#if defined(TCTLECH) && !defined(ECHOCTL)       /* Ultrix 4.2 */
# define ECHOCTL TCTLECH
#endif
#if defined(CRTKIL) && !defined(ECHOKE)         /* Ultrix 4.2 and 4.3 */
# define ECHOKE CRTKIL
#endif
#if defined(VFLUSHO) && !defined(CFLUSHO)
# define CFLUSHO Control ('o')
#endif
#if defined(VSTATUS) && !defined(CSTATUS)
# define CSTATUS Control ('t')
#endif

/* Which speeds to set.  */
enum speed_setting
  {
    input_speed, output_speed, both_speeds
  };

/* What to output and how.  */
enum output_type
  {
    changed, all, recoverable   /* Default, -a, -g.  */
  };

/* Which member(s) of `struct termios' a mode uses.  */
enum mode_type
  {
    control, input, output, local, combination
  };

/* Flags for `struct mode_info'. */
#define SANE_SET 1              /* Set in `sane' mode. */
#define SANE_UNSET 2            /* Unset in `sane' mode. */
#define REV 4                   /* Can be turned off by prepending `-'. */
#define OMIT 8                  /* Don't display value. */

/* Each mode.  */
struct mode_info
  {
    const char *name;           /* Name given on command line.  */
    enum mode_type type;        /* Which structure element to change. */
    char flags;                 /* Setting and display options.  */
    unsigned long bits;         /* Bits to set for this mode.  */
    unsigned long mask;         /* Other bits to turn off for this mode.  */
  };

static struct mode_info mode_info[] =
{
  {"parenb", control, REV, PARENB, 0},
  {"parodd", control, REV, PARODD, 0},
  {"cs5", control, 0, CS5, CSIZE},
  {"cs6", control, 0, CS6, CSIZE},
  {"cs7", control, 0, CS7, CSIZE},
  {"cs8", control, 0, CS8, CSIZE},
  {"hupcl", control, REV, HUPCL, 0},
  {"hup", control, REV | OMIT, HUPCL, 0},
  {"cstopb", control, REV, CSTOPB, 0},
  {"cread", control, SANE_SET | REV, CREAD, 0},
  {"clocal", control, REV, CLOCAL, 0},
#ifdef CRTSCTS
  {"crtscts", control, REV, CRTSCTS, 0},
#endif

  {"ignbrk", input, SANE_UNSET | REV, IGNBRK, 0},
  {"brkint", input, SANE_SET | REV, BRKINT, 0},
  {"ignpar", input, REV, IGNPAR, 0},
  {"parmrk", input, REV, PARMRK, 0},
  {"inpck", input, REV, INPCK, 0},
  {"istrip", input, REV, ISTRIP, 0},
  {"inlcr", input, SANE_UNSET | REV, INLCR, 0},
  {"igncr", input, SANE_UNSET | REV, IGNCR, 0},
  {"icrnl", input, SANE_SET | REV, ICRNL, 0},
  {"ixon", input, REV, IXON, 0},
  {"ixoff", input, SANE_UNSET | REV, IXOFF, 0},
  {"tandem", input, REV | OMIT, IXOFF, 0},
#ifdef IUCLC
  {"iuclc", input, SANE_UNSET | REV, IUCLC, 0},
#endif
#ifdef IXANY
  {"ixany", input, SANE_UNSET | REV, IXANY, 0},
#endif
#ifdef IMAXBEL
  {"imaxbel", input, SANE_SET | REV, IMAXBEL, 0},
#endif

  {"opost", output, SANE_SET | REV, OPOST, 0},
#ifdef OLCUC
  {"olcuc", output, SANE_UNSET | REV, OLCUC, 0},
#endif
#ifdef OCRNL
  {"ocrnl", output, SANE_UNSET | REV, OCRNL, 0},
#endif
#ifdef ONLCR
  {"onlcr", output, SANE_SET | REV, ONLCR, 0},
#endif
#ifdef ONOCR
  {"onocr", output, SANE_UNSET | REV, ONOCR, 0},
#endif
#ifdef ONLRET
  {"onlret", output, SANE_UNSET | REV, ONLRET, 0},
#endif
#ifdef OFILL
  {"ofill", output, SANE_UNSET | REV, OFILL, 0},
#endif
#ifdef OFDEL
  {"ofdel", output, SANE_UNSET | REV, OFDEL, 0},
#endif
#ifdef NLDLY
  {"nl1", output, SANE_UNSET, NL1, NLDLY},
  {"nl0", output, SANE_SET, NL0, NLDLY},
#endif
#ifdef CRDLY
  {"cr3", output, SANE_UNSET, CR3, CRDLY},
  {"cr2", output, SANE_UNSET, CR2, CRDLY},
  {"cr1", output, SANE_UNSET, CR1, CRDLY},
  {"cr0", output, SANE_SET, CR0, CRDLY},
#endif
#ifdef TABDLY
  {"tab3", output, SANE_UNSET, TAB3, TABDLY},
  {"tab2", output, SANE_UNSET, TAB2, TABDLY},
  {"tab1", output, SANE_UNSET, TAB1, TABDLY},
  {"tab0", output, SANE_SET, TAB0, TABDLY},
#else
# ifdef OXTABS
  {"tab3", output, SANE_UNSET, OXTABS, 0},
# endif
#endif
#ifdef BSDLY
  {"bs1", output, SANE_UNSET, BS1, BSDLY},
  {"bs0", output, SANE_SET, BS0, BSDLY},
#endif
#ifdef VTDLY
  {"vt1", output, SANE_UNSET, VT1, VTDLY},
  {"vt0", output, SANE_SET, VT0, VTDLY},
#endif
#ifdef FFDLY
  {"ff1", output, SANE_UNSET, FF1, FFDLY},
  {"ff0", output, SANE_SET, FF0, FFDLY},
#endif

  {"isig", local, SANE_SET | REV, ISIG, 0},
  {"icanon", local, SANE_SET | REV, ICANON, 0},
#ifdef IEXTEN
  {"iexten", local, SANE_SET | REV, IEXTEN, 0},
#endif
  {"echo", local, SANE_SET | REV, ECHO, 0},
  {"echoe", local, SANE_SET | REV, ECHOE, 0},
  {"crterase", local, REV | OMIT, ECHOE, 0},
  {"echok", local, SANE_SET | REV, ECHOK, 0},
  {"echonl", local, SANE_UNSET | REV, ECHONL, 0},
  {"noflsh", local, SANE_UNSET | REV, NOFLSH, 0},
#ifdef XCASE
  {"xcase", local, SANE_UNSET | REV, XCASE, 0},
#endif
#ifdef TOSTOP
  {"tostop", local, SANE_UNSET | REV, TOSTOP, 0},
#endif
#ifdef ECHOPRT
  {"echoprt", local, SANE_UNSET | REV, ECHOPRT, 0},
  {"prterase", local, REV | OMIT, ECHOPRT, 0},
#endif
#ifdef ECHOCTL
  {"echoctl", local, SANE_SET | REV, ECHOCTL, 0},
  {"ctlecho", local, REV | OMIT, ECHOCTL, 0},
#endif
#ifdef ECHOKE
  {"echoke", local, SANE_SET | REV, ECHOKE, 0},
  {"crtkill", local, REV | OMIT, ECHOKE, 0},
#endif

  {"evenp", combination, REV | OMIT, 0, 0},
  {"parity", combination, REV | OMIT, 0, 0},
  {"oddp", combination, REV | OMIT, 0, 0},
  {"nl", combination, REV | OMIT, 0, 0},
  {"ek", combination, OMIT, 0, 0},
  {"sane", combination, OMIT, 0, 0},
  {"cooked", combination, REV | OMIT, 0, 0},
  {"raw", combination, REV | OMIT, 0, 0},
  {"pass8", combination, REV | OMIT, 0, 0},
  {"litout", combination, REV | OMIT, 0, 0},
  {"cbreak", combination, REV | OMIT, 0, 0},
#ifdef IXANY
  {"decctlq", combination, REV | OMIT, 0, 0},
#endif
#if defined (TABDLY) || defined (OXTABS)
  {"tabs", combination, REV | OMIT, 0, 0},
#endif
#if defined(XCASE) && defined(IUCLC) && defined(OLCUC)
  {"lcase", combination, REV | OMIT, 0, 0},
  {"LCASE", combination, REV | OMIT, 0, 0},
#endif
  {"crt", combination, OMIT, 0, 0},
  {"dec", combination, OMIT, 0, 0},

  {NULL, control, 0, 0, 0}
};

/* Control character settings.  */
struct control_info
  {
    const char *name;           /* Name given on command line.  */
    unsigned char saneval;      /* Value to set for `stty sane'.  */
    int offset;                 /* Offset in c_cc.  */
  };

/* Control characters. */

static struct control_info control_info[] =
{
  {"intr", CINTR, VINTR},
  {"quit", CQUIT, VQUIT},
  {"erase", CERASE, VERASE},
  {"kill", CKILL, VKILL},
  {"eof", CEOF, VEOF},
  {"eol", CEOL, VEOL},
#ifdef VEOL2
  {"eol2", CEOL2, VEOL2},
#endif
#ifdef VSWTCH
  {"swtch", CSWTCH, VSWTCH},
#endif
  {"start", CSTART, VSTART},
  {"stop", CSTOP, VSTOP},
  {"susp", CSUSP, VSUSP},
#ifdef VDSUSP
  {"dsusp", CDSUSP, VDSUSP},
#endif
#ifdef VREPRINT
  {"rprnt", CRPRNT, VREPRINT},
#else
# ifdef CREPRINT /* HPUX 10.20 needs this */
  {"rprnt", CRPRNT, CREPRINT},
# endif
#endif
#ifdef VWERASE
  {"werase", CWERASE, VWERASE},
#endif
#ifdef VLNEXT
  {"lnext", CLNEXT, VLNEXT},
#endif
#ifdef VFLUSHO
  {"flush", CFLUSHO, VFLUSHO},
#endif
#ifdef VSTATUS
  {"status", CSTATUS, VSTATUS},
#endif

  /* These must be last because of the display routines. */
  {"min", 1, VMIN},
  {"time", 0, VTIME},
  {NULL, 0, 0}
};

static const char *visible (unsigned int ch);
static unsigned long baud_to_value (speed_t speed);
static int recover_mode (char *arg, struct termios *mode);
static int screen_columns (void);
static int set_mode (struct mode_info *info, int reversed,
                             struct termios *mode);
static long integer_arg (const char *s);
static speed_t string_to_baud (const char *arg);
static tcflag_t *mode_type_flag (enum mode_type type, struct termios *mode);
static void display_all (struct termios *mode, int fd, const char *device_name);
static void display_changed (struct termios *mode);
static void display_recoverable (struct termios *mode);
static void display_settings (enum output_type output_type,
                              struct termios *mode, int fd,
                              const char *device_name);
static void display_speed (struct termios *mode, int fancy);
static void display_window_size (int fancy, int fd, const char *device_name);
static void sane_mode (struct termios *mode);
static void set_control_char (struct control_info *info,
                              const char *arg,
                              struct termios *mode);
static void set_speed (enum speed_setting type, const char *arg,
                       struct termios *mode);
static void set_window_size (int rows, int cols, int fd,
                             const char *device_name);

/* The width of the screen, for output wrapping. */
static int max_col;

/* Current position, to know when to wrap. */
static int current_col;

static struct option longopts[] =
{
  {"all", no_argument, NULL, 'a'},
  {"save", no_argument, NULL, 'g'},
  {"file", required_argument, NULL, 'F'},
  {NULL, 0, NULL, 0}
};

/* The name this program was run with. */
char *program_name;

static void wrapf (const char *message, ...)
     __attribute__ ((__format__ (__printf__, 1, 2)));

/* Print format string MESSAGE and optional args.
   Wrap to next line first if it won't fit.
   Print a space first unless MESSAGE will start a new line. */

/* VARARGS */
static void
wrapf (const char *message,...)
{
  va_list args;
  char buf[1024];               /* Plenty long for our needs. */
  int buflen;

  VA_START (args, message);
  vsprintf (buf, message, args);
  va_end (args);
  buflen = strlen (buf);
  if (0 < current_col
      && max_col <= current_col + (0 < current_col) + buflen)
    {
      putchar ('\n');
      current_col = 0;
    }
  if (0 < current_col)
    {
      putchar (' ');
      current_col++;
    }
  fputs (buf, stdout);
  current_col += buflen;
}

void
usage (int status)
{
  if (status != EXIT_SUCCESS)
    fprintf (stderr, _("Try `%s --help' for more information.\n"),
             program_name);
  else
    {
      printf (_("\
Usage: %s [-F DEVICE] [--file=DEVICE] [SETTING]...\n\
  or:  %s [-F DEVICE] [--file=DEVICE] [-a|--all]\n\
  or:  %s [-F DEVICE] [--file=DEVICE] [-g|--save]\n\
"),
              program_name, program_name, program_name);
      fputs (_("\
Print or change terminal characteristics.\n\
\n\
  -a, --all          print all current settings in human-readable form\n\
  -g, --save         print all current settings in a stty-readable form\n\
  -F, --file=DEVICE  open and use the specified DEVICE instead of stdin\n\
"), stdout);
      fputs (HELP_OPTION_DESCRIPTION, stdout);
      fputs (VERSION_OPTION_DESCRIPTION, stdout);
      fputs (_("\
\n\
Optional - before SETTING indicates negation.  An * marks non-POSIX\n\
settings.  The underlying system defines which settings are available.\n\
"), stdout);
      fputs (_("\
\n\
Special characters:\n\
 * dsusp CHAR    CHAR will send a terminal stop signal once input flushed\n\
   eof CHAR      CHAR will send an end of file (terminate the input)\n\
   eol CHAR      CHAR will end the line\n\
"), stdout);
      fputs (_("\
 * eol2 CHAR     alternate CHAR for ending the line\n\
   erase CHAR    CHAR will erase the last character typed\n\
   intr CHAR     CHAR will send an interrupt signal\n\
   kill CHAR     CHAR will erase the current line\n\
"), stdout);
      fputs (_("\
 * lnext CHAR    CHAR will enter the next character quoted\n\
   quit CHAR     CHAR will send a quit signal\n\
 * rprnt CHAR    CHAR will redraw the current line\n\
   start CHAR    CHAR will restart the output after stopping it\n\
"), stdout);
      fputs (_("\
   stop CHAR     CHAR will stop the output\n\
   susp CHAR     CHAR will send a terminal stop signal\n\
 * swtch CHAR    CHAR will switch to a different shell layer\n\
 * werase CHAR   CHAR will erase the last word typed\n\
"), stdout);
      fputs (_("\
\n\
Special settings:\n\
  N             set the input and output speeds to N bauds\n\
 * cols N        tell the kernel that the terminal has N columns\n\
 * columns N     same as cols N\n\
"), stdout);
      fputs (_("\
   ispeed N      set the input speed to N\n\
 * line N        use line discipline N\n\
   min N         with -icanon, set N characters minimum for a completed read\n\
   ospeed N      set the output speed to N\n\
"), stdout);
      fputs (_("\
 * rows N        tell the kernel that the terminal has N rows\n\
 * size          print the number of rows and columns according to the kernel\n\
   speed         print the terminal speed\n\
   time N        with -icanon, set read timeout of N tenths of a second\n\
"), stdout);
      fputs (_("\
\n\
Control settings:\n\
   [-]clocal     disable modem control signals\n\
   [-]cread      allow input to be received\n\
 * [-]crtscts    enable RTS/CTS handshaking\n\
   csN           set character size to N bits, N in [5..8]\n\
"), stdout);
      fputs (_("\
   [-]cstopb     use two stop bits per character (one with `-')\n\
   [-]hup        send a hangup signal when the last process closes the tty\n\
   [-]hupcl      same as [-]hup\n\
   [-]parenb     generate parity bit in output and expect parity bit in input\n\
   [-]parodd     set odd parity (even with `-')\n\
"), stdout);
      fputs (_("\
\n\
Input settings:\n\
   [-]brkint     breaks cause an interrupt signal\n\
   [-]icrnl      translate carriage return to newline\n\
   [-]ignbrk     ignore break characters\n\
   [-]igncr      ignore carriage return\n\
"), stdout);
      fputs (_("\
   [-]ignpar     ignore characters with parity errors\n\
 * [-]imaxbel    beep and do not flush a full input buffer on a character\n\
   [-]inlcr      translate newline to carriage return\n\
   [-]inpck      enable input parity checking\n\
   [-]istrip     clear high (8th) bit of input characters\n\
"), stdout);
      fputs (_("\
 * [-]iuclc      translate uppercase characters to lowercase\n\
 * [-]ixany      let any character restart output, not only start character\n\
   [-]ixoff      enable sending of start/stop characters\n\
   [-]ixon       enable XON/XOFF flow control\n\
   [-]parmrk     mark parity errors (with a 255-0-character sequence)\n\
   [-]tandem     same as [-]ixoff\n\
"), stdout);
      fputs (_("\
\n\
Output settings:\n\
 * bsN           backspace delay style, N in [0..1]\n\
 * crN           carriage return delay style, N in [0..3]\n\
 * ffN           form feed delay style, N in [0..1]\n\
 * nlN           newline delay style, N in [0..1]\n\
"), stdout);
      fputs (_("\
 * [-]ocrnl      translate carriage return to newline\n\
 * [-]ofdel      use delete characters for fill instead of null characters\n\
 * [-]ofill      use fill (padding) characters instead of timing for delays\n\
 * [-]olcuc      translate lowercase characters to uppercase\n\
 * [-]onlcr      translate newline to carriage return-newline\n\
 * [-]onlret     newline performs a carriage return\n\
"), stdout);
      fputs (_("\
 * [-]onocr      do not print carriage returns in the first column\n\
   [-]opost      postprocess output\n\
 * tabN          horizontal tab delay style, N in [0..3]\n\
 * tabs          same as tab0\n\
 * -tabs         same as tab3\n\
 * vtN           vertical tab delay style, N in [0..1]\n\
"), stdout);
      fputs (_("\
\n\
Local settings:\n\
   [-]crterase   echo erase characters as backspace-space-backspace\n\
 * crtkill       kill all line by obeying the echoprt and echoe settings\n\
 * -crtkill      kill all line by obeying the echoctl and echok settings\n\
"), stdout);
      fputs (_("\
 * [-]ctlecho    echo control characters in hat notation (`^c')\n\
   [-]echo       echo input characters\n\
 * [-]echoctl    same as [-]ctlecho\n\
   [-]echoe      same as [-]crterase\n\
   [-]echok      echo a newline after a kill character\n\
"), stdout);
      fputs (_("\
 * [-]echoke     same as [-]crtkill\n\
   [-]echonl     echo newline even if not echoing other characters\n\
 * [-]echoprt    echo erased characters backward, between `\\' and '/'\n\
   [-]icanon     enable erase, kill, werase, and rprnt special characters\n\
   [-]iexten     enable non-POSIX special characters\n\
"), stdout);
      fputs (_("\
   [-]isig       enable interrupt, quit, and suspend special characters\n\
   [-]noflsh     disable flushing after interrupt and quit special characters\n\
 * [-]prterase   same as [-]echoprt\n\
 * [-]tostop     stop background jobs that try to write to the terminal\n\
 * [-]xcase      with icanon, escape with `\\' for uppercase characters\n\
"), stdout);
      fputs (_("\
\n\
Combination settings:\n\
 * [-]LCASE      same as [-]lcase\n\
   cbreak        same as -icanon\n\
   -cbreak       same as icanon\n\
"), stdout);
      fputs (_("\
   cooked        same as brkint ignpar istrip icrnl ixon opost isig\n\
                 icanon, eof and eol characters to their default values\n\
   -cooked       same as raw\n\
   crt           same as echoe echoctl echoke\n\
"), stdout);
      fputs (_("\
   dec           same as echoe echoctl echoke -ixany intr ^c erase 0177\n\
                 kill ^u\n\
 * [-]decctlq    same as [-]ixany\n\
   ek            erase and kill characters to their default values\n\
   evenp         same as parenb -parodd cs7\n\
"), stdout);
      fputs (_("\
   -evenp        same as -parenb cs8\n\
 * [-]lcase      same as xcase iuclc olcuc\n\
   litout        same as -parenb -istrip -opost cs8\n\
   -litout       same as parenb istrip opost cs7\n\
   nl            same as -icrnl -onlcr\n\
   -nl           same as icrnl -inlcr -igncr onlcr -ocrnl -onlret\n\
"), stdout);
      fputs (_("\
   oddp          same as parenb parodd cs7\n\
   -oddp         same as -parenb cs8\n\
   [-]parity     same as [-]evenp\n\
   pass8         same as -parenb -istrip cs8\n\
   -pass8        same as parenb istrip cs7\n\
"), stdout);
      fputs (_("\
   raw           same as -ignbrk -brkint -ignpar -parmrk -inpck -istrip\n\
                 -inlcr -igncr -icrnl  -ixon  -ixoff  -iuclc  -ixany\n\
                 -imaxbel -opost -isig -icanon -xcase min 1 time 0\n\
   -raw          same as cooked\n\
"), stdout);
      fputs (_("\
   sane          same as cread -ignbrk brkint -inlcr -igncr icrnl\n\
                 -ixoff -iuclc -ixany imaxbel opost -olcuc -ocrnl onlcr\n\
                 -onocr -onlret -ofill -ofdel nl0 cr0 tab0 bs0 vt0 ff0\n\
                 isig icanon iexten echo echoe echok -echonl -noflsh\n\
                 -xcase -tostop -echoprt echoctl echoke, all special\n\
                 characters to their default values.\n\
"), stdout);
      fputs (_("\
\n\
Handle the tty line connected to standard input.  Without arguments,\n\
prints baud rate, line discipline, and deviations from stty sane.  In\n\
settings, CHAR is taken literally, or coded as in ^c, 0x37, 0177 or\n\
127; special values ^- or undef used to disable special characters.\n\
"), stdout);
      printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    }
  exit (status);
}

/* Return 1 if the string contains only valid options.  */
static int
valid_options (char *opt, const char *valid_opts,
               const char *valid_arg_opts)
{
  char ch;

  if (*opt++ != '-' || *opt == 0)
    return 0;

  while ((ch = *opt))
    {
      opt++;
      if (strchr (valid_opts, ch))
        continue;
      if (strchr (valid_arg_opts, ch))
        return 1;
      return 0;
    }
  return 1;
}

int
main (int argc, char **argv)
{
  struct termios mode;
  enum output_type output_type;
  int optc;
  int require_set_attr;
  int speed_was_set;
  int verbose_output;
  int recoverable_output;
  int k;
  int noargs = 1;
  char *file_name = NULL;
  int fd;
  const char *device_name;
  const char *posixly_correct = getenv ("POSIXLY_CORRECT");
  int invalid_long_option = 0;

  initialize_main (&argc, &argv);
  program_name = argv[0];
  setlocale (LC_ALL, "");
  bindtextdomain (PACKAGE, LOCALEDIR);
  textdomain (PACKAGE);

  atexit (close_stdout);

  parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
                      usage, AUTHORS, (char const *) NULL);

  output_type = changed;
  verbose_output = 0;
  recoverable_output = 0;

  /* Don't print error messages for unrecognized options.  */
  opterr = 0;

  while ((optc = getopt_long (argc, argv, "agF:", longopts, NULL)) != -1)
    {
      int unrecognized_option = 0;
      switch (optc)
        {
        case 'a':
          verbose_output = 1;
          output_type = all;
          break;

        case 'g':
          recoverable_output = 1;
          output_type = recoverable;
          break;

        case 'F':
          if (file_name)
            error (EXIT_FAILURE, 0, _("only one device may be specified"));
          file_name = optarg;
          break;

        default:
          unrecognized_option = 1;
          break;
        }

      if (unrecognized_option)
        break;
    }

  /* FIXME: what is this?!? */
  if (invalid_long_option)
    usage (EXIT_FAILURE);

  /* Clear out the options that have been parsed.  This is really
     gross, but it's needed because stty SETTINGS look like options to
     getopt(), so we need to work around things in a really horrible
     way.  If any new options are ever added to stty, the short option
     MUST NOT be a letter which is the first letter of one of the
     possible stty settings.  If you change anything about how stty
     parses options, be sure it still works with combinations of
     short and long options, --, POSIXLY_CORRECT, etc.  */
  for (k = 1; k < argc; k++)
    {
      size_t len;
      char *eq;

      if (argv[k] == NULL)
        continue;

      /* Handle --, and reset noargs if there are arguments following it.  */
      if (STREQ (argv[k], "--"))
        {
          argv[k] = NULL;
          if (k < argc - 1)
            noargs = 0;
          break;
        }

      /* Handle "--file device" */
      len = strlen (argv[k]);
      if (len >= 3 && strstr ("--file", argv[k]))
        {
          argv[k] = NULL;
          argv[k + 1] = NULL;
          continue;
        }

      /* Handle "--all" and "--save".  */
      if (len >= 3
          && (strstr ("--all", argv[k])
              || strstr ("--save", argv[k])))
        {
          argv[k] = NULL;
          continue;
        }

      /* Handle "--file=device".  */
      eq = strchr (argv[k], '=');
      if (eq && eq - argv[k] >= 3)
        {
          *eq = '\0';
          if (strstr ("--file", argv[k]))
            {
              argv[k] = NULL;
              continue;
            }
          /* Put the equals sign back for the error message.  */
          *eq = '=';
        }

      /* Handle "-a", "-ag", "-aF/dev/foo", "-aF /dev/foo", etc.  */
      if (valid_options (argv[k], "ag", "F"))
        {
          /* FIXME: this loses when the device name ends in `F'.
             e.g. `stty -F/dev/BARF nl' would clobber the `nl' argument.  */
          if (argv[k][strlen (argv[k]) - 1] == 'F')
            argv[k + 1] = NULL;
          argv[k] = NULL;
        }
      /* Everything else must be a normal, non-option argument.  */
      else
        {
          noargs = 0;
          if (posixly_correct)
            break;
        }
    }

  /* Specifying both -a and -g gets an error.  */
  if (verbose_output && recoverable_output)
    error (EXIT_FAILURE, 0,
           _("the options for verbose and stty-readable output styles are\n\
mutually exclusive"));

  /* Specifying any other arguments with -a or -g gets an error.  */
  if (!noargs && (verbose_output || recoverable_output))
    error (EXIT_FAILURE, 0,
           _("when specifying an output style, modes may not be set"));

  /* FIXME: it'd be better not to open the file until we've verified
     that all arguments are valid.  Otherwise, we could end up doing
     only some of the requested operations and then failing, probably
     leaving things in an undesirable state.  */

  if (file_name)
    {
      int fdflags;
      device_name = file_name;
      fd = open (device_name, O_RDONLY | O_NONBLOCK);
      if (fd < 0)
        error (EXIT_FAILURE, errno, "%s", device_name);
      if ((fdflags = fcntl (fd, F_GETFL)) == -1
          || fcntl (fd, F_SETFL, fdflags & ~O_NONBLOCK) < 0)
        error (EXIT_FAILURE, errno, _("%s: couldn't reset non-blocking mode"),
               device_name);
    }
  else
    {
      fd = 0;
      device_name = _("standard input");
    }

  /* Initialize to all zeroes so there is no risk memcmp will report a
     spurious difference in an uninitialized portion of the structure.  */
  memset (&mode, 0, sizeof (mode));
  if (tcgetattr (fd, &mode))
    error (EXIT_FAILURE, errno, "%s", device_name);

  if (verbose_output || recoverable_output || noargs)
    {
      max_col = screen_columns ();
      current_col = 0;
      display_settings (output_type, &mode, fd, device_name);
      exit (EXIT_SUCCESS);
    }

  speed_was_set = 0;
  require_set_attr = 0;
  k = 1;
  while (k < argc)
    {
      int match_found = 0;
      int reversed = 0;
      int i;

      if (argv[k] == 0)
        {
          k++;
          continue;
        }

      if (argv[k][0] == '-')
        {
          ++argv[k];
          reversed = 1;
        }
      for (i = 0; mode_info[i].name != NULL; ++i)
        {
          if (STREQ (argv[k], mode_info[i].name))
            {
              match_found = set_mode (&mode_info[i], reversed, &mode);
              require_set_attr = 1;
              break;
            }
        }
      if (match_found == 0 && reversed)
        {
          error (0, 0, _("invalid argument `%s'"), --argv[k]);
          usage (EXIT_FAILURE);
        }
      if (match_found == 0)
        {
          for (i = 0; control_info[i].name != NULL; ++i)
            {
              if (STREQ (argv[k], control_info[i].name))
                {
                  if (k == argc - 1)
                    {
                      error (0, 0, _("missing argument to `%s'"), argv[k]);
                      usage (EXIT_FAILURE);
                    }
                  match_found = 1;
                  ++k;
                  set_control_char (&control_info[i], argv[k], &mode);
                  require_set_attr = 1;
                  break;
                }
            }
        }
      if (match_found == 0)
        {
          if (STREQ (argv[k], "ispeed"))
            {
              if (k == argc - 1)
                {
                  error (0, 0, _("missing argument to `%s'"), argv[k]);
                  usage (EXIT_FAILURE);
                }
              ++k;
              set_speed (input_speed, argv[k], &mode);
              speed_was_set = 1;
              require_set_attr = 1;
            }
          else if (STREQ (argv[k], "ospeed"))
            {
              if (k == argc - 1)
                {
                  error (0, 0, _("missing argument to `%s'"), argv[k]);
                  usage (EXIT_FAILURE);
                }
              ++k;
              set_speed (output_speed, argv[k], &mode);
              speed_was_set = 1;
              require_set_attr = 1;
            }
#ifdef TIOCGWINSZ
          else if (STREQ (argv[k], "rows"))
            {
              if (k == argc - 1)
                {
                  error (0, 0, _("missing argument to `%s'"), argv[k]);
                  usage (EXIT_FAILURE);
                }
              ++k;
              set_window_size ((int) integer_arg (argv[k]), -1,
                               fd, device_name);
            }
          else if (STREQ (argv[k], "cols")
                   || STREQ (argv[k], "columns"))
            {
              if (k == argc - 1)
                {
                  error (0, 0, _("missing argument to `%s'"), argv[k]);
                  usage (EXIT_FAILURE);
                }
              ++k;
              set_window_size (-1, (int) integer_arg (argv[k]),
                               fd, device_name);
            }
          else if (STREQ (argv[k], "size"))
            {
              max_col = screen_columns ();
              current_col = 0;
              display_window_size (0, fd, device_name);
            }
#endif
#ifdef HAVE_C_LINE
          else if (STREQ (argv[k], "line"))
            {
              if (k == argc - 1)
                {
                  error (0, 0, _("missing argument to `%s'"), argv[k]);
                  usage (EXIT_FAILURE);
                }
              ++k;
              mode.c_line = integer_arg (argv[k]);
              require_set_attr = 1;
            }
#endif
          else if (STREQ (argv[k], "speed"))
            {
              max_col = screen_columns ();
              display_speed (&mode, 0);
            }
          else if (string_to_baud (argv[k]) != (speed_t) -1)
            {
              set_speed (both_speeds, argv[k], &mode);
              speed_was_set = 1;
              require_set_attr = 1;
            }
          else
            {
              if (recover_mode (argv[k], &mode) == 0)
                {
                  error (0, 0, _("invalid argument `%s'"), argv[k]);
                  usage (EXIT_FAILURE);
                }
              require_set_attr = 1;
            }
        }
      k++;
    }

  if (require_set_attr)
    {
      struct termios new_mode;

      if (tcsetattr (fd, TCSADRAIN, &mode))
        error (EXIT_FAILURE, errno, "%s", device_name);

      /* POSIX (according to Zlotnick's book) tcsetattr returns zero if
         it performs *any* of the requested operations.  This means it
         can report `success' when it has actually failed to perform
         some proper subset of the requested operations.  To detect
         this partial failure, get the current terminal attributes and
         compare them to the requested ones.  */

      /* Initialize to all zeroes so there is no risk memcmp will report a
         spurious difference in an uninitialized portion of the structure.  */
      memset (&new_mode, 0, sizeof (new_mode));
      if (tcgetattr (fd, &new_mode))
        error (EXIT_FAILURE, errno, "%s", device_name);

      /* Normally, one shouldn't use memcmp to compare structures that
         may have `holes' containing uninitialized data, but we have been
         careful to initialize the storage of these two variables to all
         zeroes.  One might think it more efficient simply to compare the
         modified fields, but that would require enumerating those fields --
         and not all systems have the same fields in this structure.  */

      if (memcmp (&mode, &new_mode, sizeof (mode)) != 0)
        {
#ifdef CIBAUD
          /* SunOS 4.1.3 (at least) has the problem that after this sequence,
             tcgetattr (&m1); tcsetattr (&m1); tcgetattr (&m2);
             sometimes (m1 != m2).  The only difference is in the four bits
             of the c_cflag field corresponding to the baud rate.  To save
             Sun users a little confusion, don't report an error if this
             happens.  But suppress the error only if we haven't tried to
             set the baud rate explicitly -- otherwise we'd never give an
             error for a true failure to set the baud rate.  */

          new_mode.c_cflag &= (~CIBAUD);
          if (speed_was_set || memcmp (&mode, &new_mode, sizeof (mode)) != 0)
#endif
            {
              error (EXIT_FAILURE, 0,
                     _("%s: unable to perform all requested operations"),
                     device_name);
#ifdef TESTING
              {
                size_t i;
                printf (_("new_mode: mode\n"));
                for (i = 0; i < sizeof (new_mode); i++)
                  printf ("0x%02x: 0x%02x\n",
                          *(((unsigned char *) &new_mode) + i),
                          *(((unsigned char *) &mode) + i));
              }
#endif
            }
        }
    }

  exit (EXIT_SUCCESS);
}

/* Return 0 if not applied because not reversible; otherwise return 1.  */

static int
set_mode (struct mode_info *info, int reversed, struct termios *mode)
{
  tcflag_t *bitsp;

  if (reversed && (info->flags & REV) == 0)
    return 0;

  bitsp = mode_type_flag (info->type, mode);

  if (bitsp == NULL)
    {
      /* Combination mode. */
      if (STREQ (info->name, "evenp") || STREQ (info->name, "parity"))
        {
          if (reversed)
            mode->c_cflag = (mode->c_cflag & ~PARENB & ~CSIZE) | CS8;
          else
            mode->c_cflag = (mode->c_cflag & ~PARODD & ~CSIZE) | PARENB | CS7;
        }
      else if (STREQ (info->name, "oddp"))
        {
          if (reversed)
            mode->c_cflag = (mode->c_cflag & ~PARENB & ~CSIZE) | CS8;
          else
            mode->c_cflag = (mode->c_cflag & ~CSIZE) | CS7 | PARODD | PARENB;
        }
      else if (STREQ (info->name, "nl"))
        {
          if (reversed)
            {
              mode->c_iflag = (mode->c_iflag | ICRNL) & ~INLCR & ~IGNCR;
              mode->c_oflag = (mode->c_oflag
#ifdef ONLCR
                               | ONLCR
#endif
                )
#ifdef OCRNL
                & ~OCRNL
#endif
#ifdef ONLRET
                & ~ONLRET
#endif
                ;
            }
          else
            {
              mode->c_iflag = mode->c_iflag & ~ICRNL;
#ifdef ONLCR
              mode->c_oflag = mode->c_oflag & ~ONLCR;
#endif
            }
        }
      else if (STREQ (info->name, "ek"))
        {
          mode->c_cc[VERASE] = CERASE;
          mode->c_cc[VKILL] = CKILL;
        }
      else if (STREQ (info->name, "sane"))
        sane_mode (mode);
      else if (STREQ (info->name, "cbreak"))
        {
          if (reversed)
            mode->c_lflag |= ICANON;
          else
            mode->c_lflag &= ~ICANON;
        }
      else if (STREQ (info->name, "pass8"))
        {
          if (reversed)
            {
              mode->c_cflag = (mode->c_cflag & ~CSIZE) | CS7 | PARENB;
              mode->c_iflag |= ISTRIP;
            }
          else
            {
              mode->c_cflag = (mode->c_cflag & ~PARENB & ~CSIZE) | CS8;
              mode->c_iflag &= ~ISTRIP;
            }
        }
      else if (STREQ (info->name, "litout"))
        {
          if (reversed)
            {
              mode->c_cflag = (mode->c_cflag & ~CSIZE) | CS7 | PARENB;
              mode->c_iflag |= ISTRIP;
              mode->c_oflag |= OPOST;
            }
          else
            {
              mode->c_cflag = (mode->c_cflag & ~PARENB & ~CSIZE) | CS8;
              mode->c_iflag &= ~ISTRIP;
              mode->c_oflag &= ~OPOST;
            }
        }
      else if (STREQ (info->name, "raw") || STREQ (info->name, "cooked"))
        {
          if ((info->name[0] == 'r' && reversed)
              || (info->name[0] == 'c' && !reversed))
            {
              /* Cooked mode. */
              mode->c_iflag |= BRKINT | IGNPAR | ISTRIP | ICRNL | IXON;
              mode->c_oflag |= OPOST;
              mode->c_lflag |= ISIG | ICANON;
#if VMIN == VEOF
              mode->c_cc[VEOF] = CEOF;
#endif
#if VTIME == VEOL
              mode->c_cc[VEOL] = CEOL;
#endif
            }
          else
            {
              /* Raw mode. */
              mode->c_iflag = 0;
              mode->c_oflag &= ~OPOST;
              mode->c_lflag &= ~(ISIG | ICANON
#ifdef XCASE
                                 | XCASE
#endif
                );
              mode->c_cc[VMIN] = 1;
              mode->c_cc[VTIME] = 0;
            }
        }
#ifdef IXANY
      else if (STREQ (info->name, "decctlq"))
        {
          if (reversed)
            mode->c_iflag |= IXANY;
          else
            mode->c_iflag &= ~IXANY;
        }
#endif
#ifdef TABDLY
      else if (STREQ (info->name, "tabs"))
        {
          if (reversed)
            mode->c_oflag = (mode->c_oflag & ~TABDLY) | TAB3;
          else
            mode->c_oflag = (mode->c_oflag & ~TABDLY) | TAB0;
        }
#else
# ifdef OXTABS
      else if (STREQ (info->name, "tabs"))
        {
          if (reversed)
            mode->c_oflag = mode->c_oflag | OXTABS;
          else
            mode->c_oflag = mode->c_oflag & ~OXTABS;
        }
# endif
#endif
#if defined(XCASE) && defined(IUCLC) && defined(OLCUC)
      else if (STREQ (info->name, "lcase")
               || STREQ (info->name, "LCASE"))
        {
          if (reversed)
            {
              mode->c_lflag &= ~XCASE;
              mode->c_iflag &= ~IUCLC;
              mode->c_oflag &= ~OLCUC;
            }
          else
            {
              mode->c_lflag |= XCASE;
              mode->c_iflag |= IUCLC;
              mode->c_oflag |= OLCUC;
            }
        }
#endif
      else if (STREQ (info->name, "crt"))
        mode->c_lflag |= ECHOE
#ifdef ECHOCTL
          | ECHOCTL
#endif
#ifdef ECHOKE
          | ECHOKE
#endif
          ;
      else if (STREQ (info->name, "dec"))
        {
          mode->c_cc[VINTR] = 3;        /* ^C */
          mode->c_cc[VERASE] = 127;     /* DEL */
          mode->c_cc[VKILL] = 21;       /* ^U */
          mode->c_lflag |= ECHOE
#ifdef ECHOCTL
            | ECHOCTL
#endif
#ifdef ECHOKE
            | ECHOKE
#endif
            ;
#ifdef IXANY
          mode->c_iflag &= ~IXANY;
#endif
        }
    }
  else if (reversed)
    *bitsp = *bitsp & ~info->mask & ~info->bits;
  else
    *bitsp = (*bitsp & ~info->mask) | info->bits;

  return 1;
}

static void
set_control_char (struct control_info *info, const char *arg,
                  struct termios *mode)
{
  unsigned char value;

  if (STREQ (info->name, "min") || STREQ (info->name, "time"))
    value = integer_arg (arg);
  else if (arg[0] == '\0' || arg[1] == '\0')
    value = arg[0];
  else if (STREQ (arg, "^-") || STREQ (arg, "undef"))
    value = _POSIX_VDISABLE;
  else if (arg[0] == '^' && arg[1] != '\0')     /* Ignore any trailing junk. */
    {
      if (arg[1] == '?')
        value = 127;
      else
        value = arg[1] & ~0140; /* Non-letters get weird results. */
    }
  else
    value = integer_arg (arg);
  mode->c_cc[info->offset] = value;
}

static void
set_speed (enum speed_setting type, const char *arg, struct termios *mode)
{
  speed_t baud;

  baud = string_to_baud (arg);
  if (type == input_speed || type == both_speeds)
    cfsetispeed (mode, baud);
  if (type == output_speed || type == both_speeds)
    cfsetospeed (mode, baud);
}

#ifdef TIOCGWINSZ

static int
get_win_size (int fd, struct winsize *win)
{
  int err = ioctl (fd, TIOCGWINSZ, (char *) win);
  return err;
}

static void
set_window_size (int rows, int cols, int fd, const char *device_name)
{
  struct winsize win;

  if (get_win_size (fd, &win))
    {
      if (errno != EINVAL)
        error (EXIT_FAILURE, errno, "%s", device_name);
      memset (&win, 0, sizeof (win));
    }

  if (rows >= 0)
    win.ws_row = rows;
  if (cols >= 0)
    win.ws_col = cols;

# ifdef TIOCSSIZE
  /* Alexander Dupuy <dupuy@cs.columbia.edu> wrote:
     The following code deals with a bug in the SunOS 4.x (and 3.x?) kernel.
     This comment from sys/ttold.h describes Sun's twisted logic - a better
     test would have been (ts_lines > 64k || ts_cols > 64k || ts_cols == 0).
     At any rate, the problem is gone in Solaris 2.x.

     Unfortunately, the old TIOCSSIZE code does collide with TIOCSWINSZ,
     but they can be disambiguated by checking whether a "struct ttysize"
     structure's "ts_lines" field is greater than 64K or not.  If so,
     it's almost certainly a "struct winsize" instead.

     At any rate, the bug manifests itself when ws_row == 0; the symptom is
     that ws_row is set to ws_col, and ws_col is set to (ws_xpixel<<16) +
     ws_ypixel.  Since GNU stty sets rows and columns separately, this bug
     caused "stty rows 0 cols 0" to set rows to cols and cols to 0, while
     "stty cols 0 rows 0" would do the right thing.  On a little-endian
     machine like the sun386i, the problem is the same, but for ws_col == 0.

     The workaround is to do the ioctl once with row and col = 1 to set the
     pixel info, and then do it again using a TIOCSSIZE to set rows/cols.  */

  if (win.ws_row == 0 || win.ws_col == 0)
    {
      struct ttysize ttysz;

      ttysz.ts_lines = win.ws_row;
      ttysz.ts_cols = win.ws_col;

      win.ws_row = 1;
      win.ws_col = 1;

      if (ioctl (fd, TIOCSWINSZ, (char *) &win))
        error (EXIT_FAILURE, errno, "%s", device_name);

      if (ioctl (fd, TIOCSSIZE, (char *) &ttysz))
        error (EXIT_FAILURE, errno, "%s", device_name);
      return;
    }
# endif

  if (ioctl (fd, TIOCSWINSZ, (char *) &win))
    error (EXIT_FAILURE, errno, "%s", device_name);
}

static void
display_window_size (int fancy, int fd, const char *device_name)
{
  struct winsize win;

  if (get_win_size (fd, &win))
    {
      if (errno != EINVAL)
        error (EXIT_FAILURE, errno, "%s", device_name);
      if (!fancy)
        error (EXIT_FAILURE, 0,
               _("%s: no size information for this device"), device_name);
    }
  else
    {
      wrapf (fancy ? "rows %d; columns %d;" : "%d %d\n",
             win.ws_row, win.ws_col);
      if (!fancy)
        current_col = 0;
    }
}
#endif

static int
screen_columns (void)
{
#ifdef TIOCGWINSZ
  struct winsize win;

  /* With Solaris 2.[123], this ioctl fails and errno is set to
     EINVAL for telnet (but not rlogin) sessions.
     On ISC 3.0, it fails for the console and the serial port
     (but it works for ptys).
     It can also fail on any system when stdout isn't a tty.
     In case of any failure, just use the default.  */
  if (get_win_size (STDOUT_FILENO, &win) == 0 && 0 < win.ws_col)
    return win.ws_col;
#endif
  {
    /* Use $COLUMNS if it's in [1..INT_MAX-1].  */
    char *col_string = getenv ("COLUMNS");
    long n_columns;
    if (!(col_string != NULL
          && xstrtol (col_string, NULL, 0, &n_columns, "") == LONGINT_OK
          && 0 < n_columns
          && n_columns < INT_MAX))
      n_columns = 80;
    return n_columns;
  }
}

static tcflag_t *
mode_type_flag (enum mode_type type, struct termios *mode)
{
  switch (type)
    {
    case control:
      return &mode->c_cflag;

    case input:
      return &mode->c_iflag;

    case output:
      return &mode->c_oflag;

    case local:
      return &mode->c_lflag;

    case combination:
      return NULL;

    default:
      abort ();
    }
}

static void
display_settings (enum output_type output_type, struct termios *mode,
                  int fd, const char *device_name)
{
  switch (output_type)
    {
    case changed:
      display_changed (mode);
      break;

    case all:
      display_all (mode, fd, device_name);
      break;

    case recoverable:
      display_recoverable (mode);
      break;
    }
}

static void
display_changed (struct termios *mode)
{
  int i;
  int empty_line;
  tcflag_t *bitsp;
  unsigned long mask;
  enum mode_type prev_type = control;

  display_speed (mode, 1);
#ifdef HAVE_C_LINE
  wrapf ("line = %d;", mode->c_line);
#endif
  putchar ('\n');
  current_col = 0;

  empty_line = 1;
  for (i = 0; !STREQ (control_info[i].name, "min"); ++i)
    {
      if (mode->c_cc[control_info[i].offset] == control_info[i].saneval)
        continue;
      /* If swtch is the same as susp, don't print both.  */
#if VSWTCH == VSUSP
      if (STREQ (control_info[i].name, "swtch"))
        continue;
#endif
      /* If eof uses the same slot as min, only print whichever applies.  */
#if VEOF == VMIN
      if ((mode->c_lflag & ICANON) == 0
          && (STREQ (control_info[i].name, "eof")
              || STREQ (control_info[i].name, "eol")))
        continue;
#endif

      empty_line = 0;
      wrapf ("%s = %s;", control_info[i].name,
             visible (mode->c_cc[control_info[i].offset]));
    }
  if ((mode->c_lflag & ICANON) == 0)
    {
      wrapf ("min = %d; time = %d;\n", (int) mode->c_cc[VMIN],
             (int) mode->c_cc[VTIME]);
    }
  else if (empty_line == 0)
    putchar ('\n');
  current_col = 0;

  empty_line = 1;
  for (i = 0; mode_info[i].name != NULL; ++i)
    {
      if (mode_info[i].flags & OMIT)
        continue;
      if (mode_info[i].type != prev_type)
        {
          if (empty_line == 0)
            {
              putchar ('\n');
              current_col = 0;
              empty_line = 1;
            }
          prev_type = mode_info[i].type;
        }

      bitsp = mode_type_flag (mode_info[i].type, mode);
      mask = mode_info[i].mask ? mode_info[i].mask : mode_info[i].bits;
      if ((*bitsp & mask) == mode_info[i].bits)
        {
          if (mode_info[i].flags & SANE_UNSET)
            {
              wrapf ("%s", mode_info[i].name);
              empty_line = 0;
            }
        }
      else if ((mode_info[i].flags & (SANE_SET | REV)) == (SANE_SET | REV))
        {
          wrapf ("-%s", mode_info[i].name);
          empty_line = 0;
        }
    }
  if (empty_line == 0)
    putchar ('\n');
  current_col = 0;
}

static void
display_all (struct termios *mode, int fd, const char *device_name)
{
  int i;
  tcflag_t *bitsp;
  unsigned long mask;
  enum mode_type prev_type = control;

  display_speed (mode, 1);
#ifdef TIOCGWINSZ
  display_window_size (1, fd, device_name);
#endif
#ifdef HAVE_C_LINE
  wrapf ("line = %d;", mode->c_line);
#endif
  putchar ('\n');
  current_col = 0;

  for (i = 0; ! STREQ (control_info[i].name, "min"); ++i)
    {
      /* If swtch is the same as susp, don't print both.  */
#if VSWTCH == VSUSP
      if (STREQ (control_info[i].name, "swtch"))
        continue;
#endif
      /* If eof uses the same slot as min, only print whichever applies.  */
#if VEOF == VMIN
      if ((mode->c_lflag & ICANON) == 0
          && (STREQ (control_info[i].name, "eof")
              || STREQ (control_info[i].name, "eol")))
        continue;
#endif
      wrapf ("%s = %s;", control_info[i].name,
             visible (mode->c_cc[control_info[i].offset]));
    }
#if VEOF == VMIN
  if ((mode->c_lflag & ICANON) == 0)
#endif
    wrapf ("min = %d; time = %d;", mode->c_cc[VMIN], mode->c_cc[VTIME]);
  if (current_col != 0)
    putchar ('\n');
  current_col = 0;

  for (i = 0; mode_info[i].name != NULL; ++i)
    {
      if (mode_info[i].flags & OMIT)
        continue;
      if (mode_info[i].type != prev_type)
        {
          putchar ('\n');
          current_col = 0;
          prev_type = mode_info[i].type;
        }

      bitsp = mode_type_flag (mode_info[i].type, mode);
      mask = mode_info[i].mask ? mode_info[i].mask : mode_info[i].bits;
      if ((*bitsp & mask) == mode_info[i].bits)
        wrapf ("%s", mode_info[i].name);
      else if (mode_info[i].flags & REV)
        wrapf ("-%s", mode_info[i].name);
    }
  putchar ('\n');
  current_col = 0;
}

static void
display_speed (struct termios *mode, int fancy)
{
  if (cfgetispeed (mode) == 0 || cfgetispeed (mode) == cfgetospeed (mode))
    wrapf (fancy ? "speed %lu baud;" : "%lu\n",
           baud_to_value (cfgetospeed (mode)));
  else
    wrapf (fancy ? "ispeed %lu baud; ospeed %lu baud;" : "%lu %lu\n",
           baud_to_value (cfgetispeed (mode)),
           baud_to_value (cfgetospeed (mode)));
  if (!fancy)
    current_col = 0;
}

static void
display_recoverable (struct termios *mode)
{
  int i;

  printf ("%lx:%lx:%lx:%lx",
          (unsigned long) mode->c_iflag, (unsigned long) mode->c_oflag,
          (unsigned long) mode->c_cflag, (unsigned long) mode->c_lflag);
  for (i = 0; i < NCCS; ++i)
    printf (":%x", (unsigned int) mode->c_cc[i]);
  putchar ('\n');
}

static int
recover_mode (char *arg, struct termios *mode)
{
  int i, n;
  unsigned int chr;
  unsigned long iflag, oflag, cflag, lflag;

  /* Scan into temporaries since it is too much trouble to figure out
     the right format for `tcflag_t'.  */
  if (sscanf (arg, "%lx:%lx:%lx:%lx%n",
              &iflag, &oflag, &cflag, &lflag, &n) != 4)
    return 0;
  mode->c_iflag = iflag;
  mode->c_oflag = oflag;
  mode->c_cflag = cflag;
  mode->c_lflag = lflag;
  arg += n;
  for (i = 0; i < NCCS; ++i)
    {
      if (sscanf (arg, ":%x%n", &chr, &n) != 1)
        return 0;
      mode->c_cc[i] = chr;
      arg += n;
    }

  /* Fail if there are too many fields.  */
  if (*arg != '\0')
    return 0;

  return 1;
}

struct speed_map
{
  const char *string;           /* ASCII representation. */
  speed_t speed;                /* Internal form. */
  unsigned long value;          /* Numeric value. */
};

struct speed_map speeds[] =
{
  {"0", B0, 0},
  {"50", B50, 50},
  {"75", B75, 75},
  {"110", B110, 110},
  {"134", B134, 134},
  {"134.5", B134, 134},
  {"150", B150, 150},
  {"200", B200, 200},
  {"300", B300, 300},
  {"600", B600, 600},
  {"1200", B1200, 1200},
  {"1800", B1800, 1800},
  {"2400", B2400, 2400},
  {"4800", B4800, 4800},
  {"9600", B9600, 9600},
  {"19200", B19200, 19200},
  {"38400", B38400, 38400},
  {"exta", B19200, 19200},
  {"extb", B38400, 38400},
#ifdef B57600
  {"57600", B57600, 57600},
#endif
#ifdef B115200
  {"115200", B115200, 115200},
#endif
#ifdef B230400
  {"230400", B230400, 230400},
#endif
#ifdef B460800
  {"460800", B460800, 460800},
#endif
#ifdef B500000
  {"500000", B500000, 500000},
#endif
#ifdef B576000
  {"576000", B576000, 576000},
#endif
#ifdef B921600
  {"921600", B921600, 921600},
#endif
#ifdef B1000000
  {"1000000", B1000000, 1000000},
#endif
#ifdef B1152000
  {"1152000", B1152000, 1152000},
#endif
#ifdef B1500000
  {"1500000", B1500000, 1500000},
#endif
#ifdef B2000000
  {"2000000", B2000000, 2000000},
#endif
#ifdef B2500000
  {"2500000", B2500000, 2500000},
#endif
#ifdef B3000000
  {"3000000", B3000000, 3000000},
#endif
#ifdef B3500000
  {"3500000", B3500000, 3500000},
#endif
#ifdef B4000000
  {"4000000", B4000000, 4000000},
#endif
  {NULL, 0, 0}
};

static speed_t
string_to_baud (const char *arg)
{
  int i;

  for (i = 0; speeds[i].string != NULL; ++i)
    if (STREQ (arg, speeds[i].string))
      return speeds[i].speed;
  return (speed_t) -1;
}

static unsigned long
baud_to_value (speed_t speed)
{
  int i;

  for (i = 0; speeds[i].string != NULL; ++i)
    if (speed == speeds[i].speed)
      return speeds[i].value;
  return 0;
}

static void
sane_mode (struct termios *mode)
{
  int i;
  tcflag_t *bitsp;

  for (i = 0; control_info[i].name; ++i)
    {
#if VMIN == VEOF
      if (STREQ (control_info[i].name, "min"))
        break;
#endif
      mode->c_cc[control_info[i].offset] = control_info[i].saneval;
    }

  for (i = 0; mode_info[i].name != NULL; ++i)
    {
      if (mode_info[i].flags & SANE_SET)
        {
          bitsp = mode_type_flag (mode_info[i].type, mode);
          *bitsp = (*bitsp & ~mode_info[i].mask) | mode_info[i].bits;
        }
      else if (mode_info[i].flags & SANE_UNSET)
        {
          bitsp = mode_type_flag (mode_info[i].type, mode);
          *bitsp = *bitsp & ~mode_info[i].mask & ~mode_info[i].bits;
        }
    }
}

/* Return a string that is the printable representation of character CH.  */
/* Adapted from `cat' by Torbjorn Granlund.  */

static const char *
visible (unsigned int ch)
{
  static char buf[10];
  char *bpout = buf;

  if (ch == _POSIX_VDISABLE)
    return "<undef>";

  if (ch >= 32)
    {
      if (ch < 127)
        *bpout++ = ch;
      else if (ch == 127)
        {
          *bpout++ = '^';
          *bpout++ = '?';
        }
      else
        {
          *bpout++ = 'M',
            *bpout++ = '-';
          if (ch >= 128 + 32)
            {
              if (ch < 128 + 127)
                *bpout++ = ch - 128;
              else
                {
                  *bpout++ = '^';
                  *bpout++ = '?';
                }
            }
          else
            {
              *bpout++ = '^';
              *bpout++ = ch - 128 + 64;
            }
        }
    }
  else
    {
      *bpout++ = '^';
      *bpout++ = ch + 64;
    }
  *bpout = '\0';
  return (const char *) buf;
}

/* Parse string S as an integer, using decimal radix by default,
   but allowing octal and hex numbers as in C.  */
/* From `od' by Richard Stallman.  */

static long
integer_arg (const char *s)
{
  long value;
  if (xstrtol (s, NULL, 0, &value, "bB") != LONGINT_OK)
    {
      error (0, 0, _("invalid integer argument `%s'"), s);
      usage (EXIT_FAILURE);
    }
  return value;
}