NAME
getttyent,
getttynam,
setttyent,
setttyentpath,
endttyent —
get ttys file
entry
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <ttyent.h>
struct ttyent *
getttyent(
void);
struct ttyent *
getttynam(
const
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 capfile 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),
capfile(5),
gettytab(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.