getttyent(3)

NAME

getttyent, getttynam, setttyent, endttyent, isdialuptty,

isnettty ttys(5) file routines

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#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, usu

ally 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 win

dow 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 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 ac

tions 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 lo

gin on this

terminal.

TTY_DIALUP Identifies a tty as a dialin line.

If this flag

is set, then isdialuptty() will re

turn a nonzero value.

TTY_NETWORK Identifies a tty used for network

connections.

If this flag is set, then

isnettty() will return
a non-zero value.

ty_window The command to execute for a window system asso

ciated with

the line.

ty_group A group name to which the tty belongs. If no

group is speci

fied 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 un

specified, 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 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() 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.

FILES

/etc/ttys

SEE ALSO

login(1), ttyslot(3), gettytab(5), termcap(5), ttys(5), get

ty(8), init(8)

HISTORY

The getttyent(), getttynam(), setttyent(), and endttyent()

functions
appeared in 4.3BSD.

BUGS

These functions use static data storage; if the data is

needed for future
use, it should be copied before any subsequent calls over

write it.

BSD November 17, 1996

BSD