ttyio
Name
ttyio -- tty ioctl commands
Synopsis
#include <sys/ioctl.h>
#include <fcntl.h> |
int
ioctl
(int
fd, unsigned long
request, int *
argp);
Description
Tty ioctl commands are a subset of the
ioctl() calls, which can perform a variety of
functions on tty devices. fd shall be
an open file descriptor referring to a terminal device.
The following ioctl()s are provided:
TIOCGWINSZ | | Get the size attributes of the terminal or pseudo-terminal identified by
fd. On entry, argp shall
reference a winsize structure.
On return, the structure will have
ws_row set to the number of rows of text
(i.e. lines of text) that can be viewed on the device, and
ws_col set to the number of columns (i.e. text width).
Note: The number of columns stored in ws_col
assumes that the terminal device is using a mono-spaced font.
|
TIOCSWINSZ | | Sets the size attributes of the terminal or pseudo-terminal identified by
fd. On entry, argp shall
reference a winsize structure.
The value of the winsize structure's element
ws_row shall be the number of
rows of text (i.e. lines of text) that can be viewed on the device,
and the element ws_col shall be
the number of columns (i.e. text width).
Note that this call merely sets the size attributes for the kernel driver,
not the window size itself,
and is intended to be used to update the kernel driver when the
window size is changed. |
Return Value
On success, 0 is returned.
On error, -1 is returned and
the global variable errno
is set appropriately.
Errors
EBADF | | fd is not a valid descriptor. |
EFAULT | | argp references an inaccessible memory area. |
EINVAL | | request and argp are not valid. |