#include <ttyent.h> struct ttyent *
getttyent (void); struct ttyent *
getttynam (const char *name); int
setttyent (void); int
endttyent (void); int
isdialuptty (const char *name); int
isnettty (const char *name);
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:
Fa ty_name
The name of the character-special file.
Fa ty_getty
The name of the command invoked by
init(8)
to initialize tty line characteristics.
Fa ty_type
The name of the default terminal type connected to this tty line.
Fa 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
Fa ty_getty
on this entry).
TTY_SECURE
Allow users with a uid of 0 to login on this terminal.
TTY_DIALUP
Identifies a tty as a dialin line.
If this flag is set, then
isdialuptty ();
will return a non-zero value.
TTY_NETWORK
Identifies a tty used for network connections.
If this flag is set, then
isnettty ();
will return a non-zero value.
Fa ty_window
The command to execute for a window system associated with the line.
Fa 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".
Fa 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
Fa 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
Fa 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.
The routines
isdialuptty ();
and
isnettty ();
return non-zero if the dialup or network flag is set for the
tty entry relating to the tty named by the argument, and
zero otherwise.
