struct ttyent *getttyent(void);
struct ttyent *getttynam(const char *name);
int setttyent(void);
The function setttyent() opens the file or rewinds it if already open.
The function endttyent() closes the file.
The function getttynam() searches for a given ttyname in the file. It returns a pointer to a ttyent structure (description below).
The function getttyent() opens the file _PATH_TTYS (if necessary) and returns the first entry. If the file is already open, the next entry. The ttyent structure has the form:
struct ttyent {
    char *ty_name;     /* terminal device name */
    char *ty_getty;    /* command to execute, usually getty */
    char *ty_type;     /* terminal type for termcap */
    int   ty_status;   /* status flags */
    char *ty_window;   /* command to start up window manager */
    char *ty_comment;  /* comment field */
};
ty_status
can be:
#define TTY_ON 0x01 /* enable logins (start ty_getty program) */ #define TTY_SECURE 0x02 /* allow UID 0 to login */