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 terminal name 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 */
The setttyent() and endttyent() functions use a static variable, so they are not thread-safe.
The getttynam() function calls thread-unsafe function getttyent() so it is not thread-safe.