IO::Stty(3)

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.

[-]iexten
    Enable implementation-defined input processing. This is needed for special characters like werase and lnext to be recognized.

[-]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.

crt Same as:

        echoe echok

dec Same as:

        echoe echok

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

[-]cbreak
    Same as "-icanon" (with "-", same as "icanon").

evenp, parity
    Same as:

        parenb -parodd cs7

oddp
    Same as:

        parenb parodd cs7

-evenp, -parity, -oddp
    Same as:

        -parenb cs8

[-]litout
    Same as:

        -parenb -istrip -opost cs8

    With "-", same as "parenb istrip opost cs7".

  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 (sets it to "_POSIX_VDISABLE", which is 0 on Linux and 255 on macOS/BSD).

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 57600 115200 230400 exta extb. 134.5 is the same as 134; exta is the same as 19200; extb is the same as 38400. Modern rates (57600, 115200, 230400) are only available on platforms whose POSIX implementation defines them. 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.

speed
    Print the output baud rate.

-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 (returns "_POSIX_VDISABLE").

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

    Returns a string for query options ("-a", "-g", "-v"), "undef" if the handle is not a terminal or if the terminal parameters could not be read, and a true value on success when setting parameters.

    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.