NAME

IO::Stty - Change and print terminal line settings

SYNOPSIS

# calling the script directly
stty.pl [setting...]
stty.pl {-a,-g,-v,--version}

# Calling Stty module
use IO::Stty;
IO::Stty::stty(\*TTYHANDLE, @modes);

 use IO::Stty;
 $old_mode=IO::Stty::stty(\*STDIN,'-g');

 # Turn off echoing.
 IO::Stty::stty(\*STDIN,'-echo');

 # Do whatever.. grab input maybe?
 $read_password = <>;

 # Now restore the old mode.
 IO::Stty::stty(\*STDIN,$old_mode);

 # What settings do we have anyway?
 print IO::Stty::stty(\*STDIN,'-a');

DESCRIPTION

This is the PERL POSIX compliant stty.

INTRO

This has not been tailored to the IO::File stuff but will work with it as indicated. Before you go futzing with term parameters it's a good idea to grab the current settings and restore them when you finish.

stty accepts the following non-option arguments that change aspects of the terminal line operation. A `[-]' before a capability means that it can be turned off by preceding it with a `-'.

stty parameters

Control settings

• [-]parenb

  Generate parity bit in output and expect parity bit in input.

• [-]parodd

  Set odd parity (even with `-').

• cs5 cs6 cs7 cs8

  Set character size to 5, 6, 7, or 8 bits.

• [-]hupcl [-]hup

  Send a hangup signal when the last process closes the tty.

• [-]cstopb

  Use two stop bits per character (one with `-').

• [-]cread

  Allow input to be received.

• [-]clocal

  Disable modem control signals.

Input settings

• [-]ignbrk

  Ignore break characters.

• [-]brkint

  Breaks cause an interrupt signal.

• [-]ignpar

  Ignore characters with parity errors.

• [-]parmrk

  Mark parity errors (with a 255-0-character sequence).

• [-]inpck

  Enable input parity checking.

• [-]istrip

  Clear high (8th) bit of input characters.

• [-]inlcr

  Translate newline to carriage return.

• [-]igncr

  Ignore carriage return.

• [-]icrnl

  Translate carriage return to newline.

• [-]ixon

  Enable XON/XOFF flow control.

• [-]ixoff

  Enable sending of stop character when the system input buffer is almost full, and start character when it becomes almost empty again.

Output settings

• [-]opost

  Postprocess output.

Local settings

• [-]isig

  Enable interrupt, quit, and suspend special characters.

• [-]icanon

  Enable erase, kill, werase, and rprnt special characters.

• [-]echo

  Echo input characters.

• [-]echoe, [-]crterase

  Echo erase characters as backspace-space-backspace.

• [-]echok

  Echo a newline after a kill character.

• [-]echonl

  Echo newline even if not echoing other characters.

• [-]noflsh

  Disable flushing after interrupt and quit special characters.

  * Though this claims non-posixhood it is supported by the perl POSIX.pm.

• [-]tostop (np)

  Stop background jobs that try to write to the terminal.

Combination settings

• ek

  Reset the erase and kill special characters to their default values.

• sane

  Same as:

    cread -ignbrk brkint -inlcr -igncr icrnl -ixoff opost
    isig icanon iexten echo echoe echok -echonl -noflsh -tostop
  

  also sets all special characters to their default values.

• [-]cooked

  Same as:

    brkint ignpar istrip icrnl ixon opost isig icanon
  

  plus sets the eof and eol characters to their default values if they are the same as the min and time characters. With `-', same as raw.

• [-]raw

  Same as:

    -ignbrk -brkint -ignpar -parmrk -inpck -istrip -inlcr -igncr
    -icrnl -ixon -ixoff -opost -isig -icanon min 1 time 0
  

  With `-', same as cooked.

• [-]pass8

  Same as:

    -parenb -istrip cs8
  

  With `-', same as parenb istrip cs7.

• dec

  Same as:

    echoe echoctl echoke -ixany
  

  Also sets the interrupt special character to Ctrl-C, erase to Del, and kill to Ctrl-U.

Special characters

The special characters' default values vary from system to system. They are set with the syntax `name value', where the names are listed below and the value can be given either literally, in hat notation (`^c'), or as an integer which may start with `0x' to indicate hexadecimal, `0' to indicate octal, or any other digit to indicate decimal. Giving a value of `^-' or `undef' disables that special character.

• intr

  Send an interrupt signal.

• quit

  Send a quit signal.

• erase

  Erase the last character typed.

• kill

  Erase the current line.

• eof

  Send an end of file (terminate the input).

• eol

  End the line.

• start

  Restart the output after stopping it.

• stop

  Stop the output.

• susp

  Send a terminal stop signal.

Special settings

• min N

  Set the minimum number of characters that will satisfy a read until the time value has expired, when -icanon is set.

• time N

  Set the number of tenths of a second before reads time out if the min number of characters have not been read, when -icanon is set.

• N

  Set the input and output speeds to N. N can be one of: 0 50 75 110 134 134.5 150 200 300 600 1200 1800 2400 4800 9600 19200 38400 exta extb. exta is the same as 19200; extb is the same as 38400. 0 hangs up the line if -clocal is set.

OPTIONS

• -a

  Print all current settings in human-readable form.

• -g

  Print all current settings in a form that can be used as an argument to another stty command to restore the current settings.

• -v,--version

  Print version info.

Direct Subroutines

• _parse_char_value()

    my $numeric = IO::Stty::_parse_char_value($value);
  

  Parse a special character value from any of the supported notations: literal integers, hat notation (^c), hexadecimal (0x...), octal (0...), or undef/^- to disable.

• stty()

    IO::Stty::stty(\*STDIN, @params);
  

  From comments:

    I'm not feeling very inspired about this. Terminal parameters are obscure
    and boring. Basically what this will do is get the current setting,
    take the parameters, modify the setting and write it back. Zzzz.
    This is not especially efficent and probably not too fast. Assuming the POSIX
    spec has been implemented properly it should mostly work.
  

• show_me_the_crap()

    my $output = IO::Stty::show_me_the_crap(
        $c_cflag, $c_iflag, $ispeed, $c_lflag, $c_oflag,
        $ospeed,  \%control_chars
    );
  

  Format terminal settings as a human-readable string, equivalent to stty -a output. Returns a multi-line string showing the current baud rate, special character assignments (in hat notation), and the state of all control, input, output, and local flags.

  This is the back-end for stty(\*FH, '-a').

AUTHOR

Austin Schutz auschutz@cpan.org (Initial version and maintenance)

Todd Rinaldo toddr@cpan.org (Maintenance)

BUGS

This is use at your own risk software. Do anything you want with it except blame me for it blowing up your machine because it's full of bugs.

See above for what functions are supported. It's mostly standard POSIX stuff. If any of the settings are wrong and you actually know what some of these extremely arcane settings (like what 'sane' should be in POSIX land) really should be, please open an RT ticket.

ACKNOWLEDGEMENTS

None

COPYRIGHT & LICENSE

Copyright 1997 Austin Schutz, all rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.