Current File : //usr/local/share/zsh/5.8/help/ttyctl
ttyctl [ -fu ]
The -f option freezes the tty (i.e. terminal or terminal
emulator), and -u unfreezes it. When the tty is frozen, no
changes made to the tty settings by external programs will be
honored by the shell, except for changes in the size of the
screen; the shell will simply reset the settings to their previous
values as soon as each command exits or is suspended. Thus, stty
and similar programs have no effect when the tty is frozen.
Freezing the tty does not cause the current state to be
remembered: instead, it causes future changes to the state to be
blocked.
Without options it reports whether the terminal is frozen or not.
Note that, regardless of whether the tty is frozen or not, the
shell needs to change the settings when the line editor starts, so
unfreezing the tty does not guarantee settings made on the command
line are preserved. Strings of commands run between editing the
command line will see a consistent tty state. See also the shell
variable STTY for a means of initialising the tty before running
external commands.
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