TIOCLINUX - ioctls for console terminal and virtual consoles
#include <linux/tiocl.h> /* Definition of TIOCL_* constants */
#include <sys/ioctl.h>
int ioctl(int fd, TIOCLINUX, void *argp);
The action of the following ioctls depends on the first byte in
the struct pointed to by argp, referred to here as the
subcode. These are legal only for the superuser or the owner of the
current terminal.
- subcode=0
- Dump the screen. Disappeared in Linux 1.1.92. (With Linux 1.1.92 or later,
read from /dev/vcsN or /dev/vcsaN instead.)
- subcode=1
- Get task information. Disappeared in Linux 1.1.92.
- subcode=TIOCL_SETSEL
- Set selection. argp points to a
-
struct {
char subcode;
short xs, ys, xe, ye;
short sel_mode;
};
- xs and ys are the starting column and row. xe and
ye are the ending column and row. (Upper left corner is
row=column=1.) sel_mode is 0 for character-by-character selection,
1 for word-by-word selection, or 2 for line-by-line selection. The
indicated screen characters are highlighted and saved in a kernel
buffer.
- Since Linux 6.7, using this subcode requires the CAP_SYS_ADMIN
capability.
- subcode=TIOCL_PASTESEL
- Paste selection. The characters in the selection buffer are written to
fd.
- Since Linux 6.7, using this subcode requires the CAP_SYS_ADMIN
capability.
- subcode=TIOCL_UNBLANKSCREEN
- Unblank the screen.
- subcode=TIOCL_SELLOADLUT
- Sets contents of a 256-bit look up table defining characters in a
"word", for word-by-word selection. (Since Linux 1.1.32.)
- Since Linux 6.7, using this subcode requires the CAP_SYS_ADMIN
capability.
- subcode=TIOCL_GETSHIFTSTATE
- argp points to a char which is set to the value of the kernel
variable shift_state. (Since Linux 1.1.32.)
- subcode=TIOCL_GETMOUSEREPORTING
- argp points to a char which is set to the value of the kernel
variable report_mouse. (Since Linux 1.1.33.)
- subcode=8
- Dump screen width and height, cursor position, and all the
character-attribute pairs. (Linux 1.1.67 through Linux 1.1.91 only. With
Linux 1.1.92 or later, read from /dev/vcsa* instead.)
- subcode=9
- Restore screen width and height, cursor position, and all the
character-attribute pairs. (Linux 1.1.67 through Linux 1.1.91 only. With
Linux 1.1.92 or later, write to /dev/vcsa* instead.)
- subcode=TIOCL_SETVESABLANK
- Handles the Power Saving feature of the new generation of monitors. VESA
screen blanking mode is set to argp[1], which governs what screen
blanking does:
- 0
- Screen blanking is disabled.
- 1
- The current video adapter register settings are saved, then the controller
is programmed to turn off the vertical synchronization pulses. This puts
the monitor into "standby" mode. If your monitor has an Off_Mode
timer, then it will eventually power down by itself.
- 2
- The current settings are saved, then both the vertical and horizontal
synchronization pulses are turned off. This puts the monitor into
"off" mode. If your monitor has no Off_Mode timer, or if you
want your monitor to power down immediately when the blank_timer times
out, then you choose this option. (Caution: Powering down
frequently will damage the monitor.) (Since Linux 1.1.76.)
- subcode=TIOCL_SETKMSGREDIRECT
- Change target of kernel messages ("console"): by default, and if
this is set to 0, messages are written to the currently active VT.
The VT to write to is a single byte following subcode. (Since Linux
2.5.36.)
- subcode=TIOCL_GETFGCONSOLE
- Returns the number of VT currently in foreground. (Since Linux
2.5.36.)
- subcode=TIOCL_SCROLLCONSOLE
- Scroll the foreground VT by the specified amount of lines down, or
half the screen if 0. lines is *(((int32_t *)&subcode) +
1). (Since Linux 2.5.67.)
- subcode=TIOCL_BLANKSCREEN
- Blank the foreground VT, ignoring "pokes" (typing): can only be
unblanked explicitly (by switching VTs, to text mode, etc.). (Since Linux
2.5.71.)
- subcode=TIOCL_BLANKEDSCREEN
- Returns the number of VT currently blanked, 0 if none. (Since Linux
2.5.71.)
- subcode=16
- Never used.
- subcode=TIOCL_GETKMSGREDIRECT
- Returns target of kernel messages. (Since Linux 2.6.17.)
On success, 0 is returned (except where indicated). On failure, -1
is returned, and errno is set to indicate the error.