Reference

getttyent(3)

get ttys file entry

NAME

getttyent, getttynam, setttyent, endttyent – get ttys file entry

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <ttyent.h>

struct ttyent *

getttyent(void);

struct ttyent *

getttynam(const char *name);

int

setttyent(void);

int

endttyent(void);

DESCRIPTION

The getttyent(), and getttynam() functions each return a pointer to an object, with the following structure, containing the broken-out fields of a line from the tty description file.

struct ttyent {
	char	*ty_name;	/* terminal device name */
	char	*ty_getty;	/* command to execute, usually getty */
	char	*ty_type;	/* terminal type for termcap */
#define	TTY_ON		0x01	/* enable logins (start ty_getty program) */
#define	TTY_SECURE	0x02	/* allow uid of 0 to login */
#define	TTY_DIALUP	0x04	/* is a dialup tty */
#define	TTY_NETWORK	0x08	/* is a network tty */
	int	ty_status;	/* status flags */
	char	*ty_window;	/* command to start up window manager */
	char	*ty_comment;	/* comment field */
	char	*ty_group;	/* tty group name */
};

The fields are as follows:

ty_name

The name of the character-special file.

ty_getty

The name of the command invoked to initialize tty line characteristics.

ty_type

The name of the default terminal type connected to this tty line.

ty_status

A mask of bit fields which indicate various actions allowed on this tty line. The possible flags are as follows:

TTY_ON

Enables logins

TTY_SECURE

Allow users with a uid of 0 to login on this terminal.

TTY_DIALUP

Identifies a tty as a dialin line.

TTY_NETWORK

Identifies a tty used for network connections.

ty_window

The command to execute for a window system associated with the line.

ty_group

A group name to which the tty belongs. If no group is specified in the ttys description file, then the tty is placed in an anonymous group called "none".

ty_comment

Any trailing comment field, with any leading hash marks (``#'') or whitespace removed.

If any of the fields pointing to character strings are unspecified, they are returned as null pointers. The field ty_status will be zero if no flag values are specified.

See ttys(5) for a more complete discussion of the meaning and usage of the fields.

The getttyent() function reads the next line from the ttys file, opening the file if necessary. The setttyent() function rewinds the file if open, or opens the file if it is unopened. The endttyent() function closes any open files.

The getttynam() function searches from the beginning of the file until a matching name is found (or until EOF is encountered).

RETURN VALUES

The routines getttyent() and getttynam() return a null pointer on EOF or error. The setttyent() function and endttyent() return 0 on failure and 1 on success.

FILES

/etc/ttys

SEE ALSO

login(1), ttyslot(3), gettytab(5), termcap(5), ttys(5), getty(8),

HISTORY

The getttyent(), getttynam(), setttyent(), and endttyent() functions appeared in 4.3BSD.

BUGS

These functions use static data storage; if the data is needed for future use, it should be copied before any subsequent calls overwrite it.

History