NAME
getttyent
,
getttynam
, setttyent
,
endttyent
—
get ttys file entry
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 */ 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 */ #define TTY_RTSCTS 0x08 /* set 'CRTSCTS' on open */ #define TTY_SOFTCAR 0x10 /* ignore hardware carrier */ #define TTY_MDMBUF 0x20 /* set 'MDMBUF' on open */ int ty_status; /* flag values */ char *ty_window; /* command for window manager */ char *ty_comment; /* comment field */ };
The fields are as follows:
- ty_name
- Name of the character-special file.
- ty_getty
- Name of the command invoked by init(8) to initialize tty line characteristics.
- ty_type
- 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
- 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.
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.
setttyent
()
rewinds the file if open, or opens the file if it is unopened.
endttyent
()
closes any open files.
getttynam
()
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 or 1 on success.
FILES
- /etc/ttys
SEE ALSO
login(1), ttyslot(3), gettytab(5), termcap(5), ttys(5), getty(8), init(8), ttyflags(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.