NAME
getttyent,
getttynam, setttyent,
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
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, 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:
- ty_name
- The name of the character-special file.
- ty_getty
- The name of the command invoked 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
TTY_SECURE- Allow users with a uid of 0 to login on this terminal.
TTY_DIALUP- Identifies a tty as a dialin line.
TTY_NETWORK- Identifies a tty used for network connections.
- ty_window
- The command to execute for a window system associated with the line.
- 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".
- 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 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.
FILES
- /etc/ttys
SEE ALSO
login(1), ttyslot(3), gettytab(5), termcap(5), ttys(5), getty(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 overwrite it.