Function ncursesw::use_tioctl
source · [−]pub fn use_tioctl(flag: bool)
Expand description
Determine how to compute terminal size. The use_tioctl()
routine,
if used, should be called before initscr()
or newterm()
are called
(because those compute the screen size).
After use_tioctl()
is called with true
as an argument, NCurses
modifies the last step in its computation of screen size as follows:
- Checks if the $LINES and $COLUMNS environment variables are set to a number greater than zero.
- for each, NCurses updates the corresponding environment variable with the value that it has obtained via operating system call or from the terminal database.
- NCurses re-fetches the value of the environment variables so that it is still the environment variables which set the screen size.
The use_env()
and use_tioctl()
routines combine as summarized here:
use_env use_tioctl Summary
true false This is the default behavior. NCurses uses operating system calls unless overridden by $LINES or $COLUMNS environment variables. true true NCurses updates $LINES and $COLUMNS based on operating system calls. false true NCurses ignores $LINES and $COLUMNS, uses operating system calls to obtain size. false false NCurses relies on the terminal database to determine size.