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ioctl_vt(2) System Calls Manual ioctl_vt(2)

NAME

ioctl_vt - ioctls for console terminal and virtual consoles

SYNOPSIS

#include <linux/vt.h>  /* Definition of VT_* constants */
#include <sys/ioctl.h>
int ioctl(int fd, unsigned long op, void *argp);

DESCRIPTION

The following Linux-specific ioctl(2) operations are supported for console terminals and virtual consoles.

Returns the first available (non-opened) console. argp points to an int which is set to the number of the vt (1 <= *argp <= MAX_NR_CONSOLES).
Get mode of active vt. argp points to a

struct vt_mode {

char mode; /* vt mode */
char waitv; /* if set, hang on writes if not active */
short relsig; /* signal to raise on release op */
short acqsig; /* signal to raise on acquisition */
short frsig; /* unused (set to 0) */ };

which is set to the mode of the active vt. mode is set to one of these values:
VT_AUTO auto vt switching
VT_PROCESS process controls switching
VT_ACKACQ acknowledge switch
Set mode of active vt. argp points to a struct vt_mode.
Get global vt state info. argp points to a

struct vt_stat {

unsigned short v_active; /* active vt */
unsigned short v_signal; /* signal to send */
unsigned short v_state; /* vt bit mask */ };

For each vt in use, the corresponding bit in the v_state member is set. (Linux 1.0 through Linux 1.1.92.)
Release a display.
Switch to vt argp (1 <= argp <= MAX_NR_CONSOLES).
Wait until vt argp has been activated.
Deallocate the memory associated with vt argp. (Since Linux 1.1.54.)
Set the kernel's idea of screensize. argp points to a

struct vt_sizes {

unsigned short v_rows; /* # rows */
unsigned short v_cols; /* # columns */
unsigned short v_scrollsize; /* no longer used */ };

Note that this does not change the videomode. See resizecons(8). (Since Linux 1.1.54.)
Set the kernel's idea of various screen parameters. argp points to a

struct vt_consize {

unsigned short v_rows; /* number of rows */
unsigned short v_cols; /* number of columns */
unsigned short v_vlin; /* number of pixel rows
on screen */
unsigned short v_clin; /* number of pixel rows
per character */
unsigned short v_vcol; /* number of pixel columns
on screen */
unsigned short v_ccol; /* number of pixel columns
per character */ };

Any parameter may be set to zero, indicating "no change", but if multiple parameters are set, they must be self-consistent. Note that this does not change the videomode. See resizecons(8). (Since Linux 1.3.3.)

RETURN VALUE

On success, 0 is returned (except where indicated). On failure, -1 is returned, and errno is set to indicate the error.

ERRORS

argp is invalid.

STANDARDS

Linux.

SEE ALSO

ioctl(2), ioctl_console(2)

2024-06-13 Linux man-pages (unreleased)