GETTTYENT(3) Library Functions Manual GETTTYENT(3)

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

Standard C Library (libc, -lc)

#include <ttyent.h>

struct ttyent *
getttyent(void);

struct ttyent *
getttynam(const char *name);

int
setttyent(void);

int
endttyent(void);

The (), 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:
Enables logins
Allow users with a uid of 0 to login on this terminal.
Identifies a tty as a dialin line.
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 () function reads the next line from the ttys file, opening the file if necessary. The () function rewinds the file if open, or opens the file if it is unopened. The () function closes any open files.

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

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.

/etc/ttys
 

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

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

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

November 17, 1996 macOS 15.6