stty: Print or change terminal characteristics
stty prints or changes terminal characteristics, such as baud rate.
stty [option] [setting]… stty [option]
If given no line settings,
stty prints the baud rate, line
discipline number (on systems that support it), and line settings
that have been changed from the values set by ‘stty sane’.
By default, mode reading and setting are performed on the tty line
connected to standard input, although this can be modified by the
stty accepts many non-option arguments that change aspects of
the terminal line operation, as described below.
The program accepts the following options. Also see Common options.
Print all current settings in human-readable form. This option may not be used in combination with any line settings.
Set the line opened by the file name specified in device instead of
the tty line connected to standard input. This option is necessary
because opening a POSIX tty requires use of the
O_NONDELAY flag to prevent a POSIX tty from blocking
until the carrier detect line is high if
clocal flag is not set. Hence, it is not always possible
to allow the shell to open the device in the traditional manner.
Print all current settings in a form that can be used as an argument to
stty command to restore the current settings. This option
may not be used in combination with any line settings.
Many settings can be turned off by preceding them with a ‘-’. Such arguments are marked below with “May be negated” in their description. The descriptions themselves refer to the positive case, that is, when not negated (unless stated otherwise, of course).
Some settings are not available on all POSIX systems, since they use extensions. Such arguments are marked below with “Non-POSIX” in their description. On non-POSIX systems, those or other settings also may not be available, but it’s not feasible to document all the variations: just try it and see.
stty is installed only on platforms with the POSIX terminal
interface, so portable scripts should not rely on its existence on
An exit status of zero indicates success, and a nonzero value indicates failure.