GETTTYENT(3)

NAME
getttyent, getttynam, setttyent, setttyentpath, endttyent - get ttys file entry

LIBRARY
libc

SYNOPSIS
#include <ttyent.h>
struct ttyent *
getttyent();
struct ttyent *
getttynam(char *name);
int
setttyent(void);
int
setttyentpath(const char *path);
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 */
    	char	*ty_type;	/* terminal type */
    #define	TTY_ON		0x01	/* enable logins */
    #define	TTY_SECURE	0x02	/* allow uid of 0 to login */
    #define	TTY_LOCAL	0x04	/* set 'CLOCAL' on open (dev. specific) */
    #define	TTY_RTSCTS	0x08	/* set 'CRTSCTS' on open (dev. specific) */
    #define	TTY_SOFTCAR	0x10	/* ignore hardware carrier (dev. spec.) */
    #define	TTY_MDMBUF	0x20	/* set 'MDMBUF' on open (dev. specific) */
    #define	TTY_DTRCTS	0x40	/* set 'CDTRCTS' on open (dev. specific) */
    	int	ty_status;	/* flag values */
    	char	*ty_window;	/* command for window manager */
    	char	*ty_comment;	/* comment field */
    	char	*ty_class;	/* category of tty usage */
    };

The fields are as follows:

ty_name
    The name of the character-special file.

ty_getty
    The name of the command invoked by init(8) 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 (i.e., init(8) will start the command referenced by ty_getty on this entry).

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

    TTY_LOCAL
        If the terminal port's driver supports it, cause the line to be treated as ``local.''

    TTY_MDMBUF
        If the terminal port's driver supports it, use DTR/DCD hardware flow control on the line by default.

    TTY_RTSCTS
        If the terminal port's driver supports it, use full-duplex RTS/CTS hardware flow control on the line by default.

    TTY_SOFTCAR
        If the terminal port's driver supports it, ignore hardware carrier on the line.

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

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

ty_class
    A key indexing into a termcap-style database (/etc/ttyclasses) of attributes for this class of tty. No attributes are currently defined or used, so there are currently no functions to retrieve them.

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 setttyentpath() function is equivalent to setttyent() but accepts an additional argument to read the ttys information from an alternate file instead of the default location (defined in _PATH_TTYS). 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() and setttyentpath() functions 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), init(8), ttyflags(8)

HISTORY
The getttyent(), getttynam(), setttyent(), and endttyent() functions appeared in 4.3BSD. The setttyentpath() function appeared in NetBSD 4.0.

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.