xref: /freebsd/lib/libc/gen/getttyent.3 (revision fed1ca4b719c56c930f2259d80663cd34be812bb)
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28.\"     @(#)getttyent.3	8.1 (Berkeley) 6/4/93
29.\" $FreeBSD$
30.\"
31.Dd November 17, 1996
32.Dt GETTTYENT 3
33.Os
34.Sh NAME
35.Nm getttyent ,
36.Nm getttynam ,
37.Nm setttyent ,
38.Nm endttyent ,
39.Nm isdialuptty ,
40.Nm isnettty
41.Nd
42.Xr ttys 5
43file routines
44.Sh LIBRARY
45.Lb libc
46.Sh SYNOPSIS
47.In ttyent.h
48.Ft struct ttyent *
49.Fn getttyent void
50.Ft struct ttyent *
51.Fn getttynam "const char *name"
52.Ft int
53.Fn setttyent void
54.Ft int
55.Fn endttyent void
56.Ft int
57.Fn isdialuptty "const char *name"
58.Ft int
59.Fn isnettty "const char *name"
60.Sh DESCRIPTION
61The
62.Fn getttyent ,
63and
64.Fn getttynam
65functions
66each return a pointer to an object, with the following structure,
67containing the broken-out fields of a line from the tty description
68file.
69.Bd -literal
70struct ttyent {
71	char	*ty_name;	/* terminal device name */
72	char	*ty_getty;	/* command to execute, usually getty */
73	char	*ty_type;	/* terminal type for termcap */
74#define	TTY_ON		0x01	/* enable logins (start ty_getty program) */
75#define	TTY_SECURE	0x02	/* allow uid of 0 to login */
76#define	TTY_DIALUP	0x04	/* is a dialup tty */
77#define	TTY_NETWORK	0x08	/* is a network tty */
78	int	ty_status;	/* status flags */
79	char	*ty_window;	/* command to start up window manager */
80	char	*ty_comment;	/* comment field */
81	char	*ty_group;	/* tty group name */
82};
83.Ed
84.Pp
85The fields are as follows:
86.Bl -tag -width ty_comment
87.It Fa ty_name
88The name of the character-special file.
89.It Fa ty_getty
90The name of the command invoked by
91.Xr init 8
92to initialize tty line characteristics.
93.It Fa ty_type
94The name of the default terminal type connected to this tty line.
95.It Fa ty_status
96A mask of bit fields which indicate various actions allowed on this
97tty line.
98The possible flags are as follows:
99.Bl -tag -width TTY_NETWORK
100.It Dv TTY_ON
101Enables logins (i.e.,
102.Xr init 8
103will start the command referenced by
104.Fa ty_getty
105on this entry).
106.It Dv TTY_SECURE
107Allow users with a uid of 0 to login on this terminal.
108.It Dv TTY_DIALUP
109Identifies a tty as a dialin line.
110If this flag is set, then
111.Fn isdialuptty
112will return a non-zero value.
113.It Dv TTY_NETWORK
114Identifies a tty used for network connections.
115If this flag is set, then
116.Fn isnettty
117will return a non-zero value.
118.El
119.It Fa ty_window
120The command to execute for a window system associated with the line.
121.It Fa ty_group
122A group name to which the tty belongs.
123If no group is specified in the ttys description file,
124then the tty is placed in an anonymous group called "none".
125.It Fa ty_comment
126Any trailing comment field, with any leading hash marks (``#'') or
127whitespace removed.
128.El
129.Pp
130If any of the fields pointing to character strings are unspecified,
131they are returned as null pointers.
132The field
133.Fa ty_status
134will be zero if no flag values are specified.
135.Pp
136See
137.Xr ttys 5
138for a more complete discussion of the meaning and usage of the
139fields.
140.Pp
141The
142.Fn getttyent
143function
144reads the next line from the ttys file, opening the file if necessary.
145The
146.Fn setttyent
147function
148rewinds the file if open, or opens the file if it is unopened.
149The
150.Fn endttyent
151function
152closes any open files.
153.Pp
154The
155.Fn getttynam
156function
157searches from the beginning of the file until a matching
158.Fa name
159is found
160(or until
161.Dv EOF
162is encountered).
163.Sh RETURN VALUES
164The routines
165.Fn getttyent
166and
167.Fn getttynam
168return a null pointer on
169.Dv EOF
170or error.
171The
172.Fn setttyent
173function
174and
175.Fn endttyent
176return 0 on failure and 1 on success.
177.Pp
178The routines
179.Fn isdialuptty
180and
181.Fn isnettty
182return non-zero if the dialup or network flag is set for the
183tty entry relating to the tty named by the argument, and
184zero otherwise.
185.Sh FILES
186.Bl -tag -width /etc/ttys -compact
187.It Pa /etc/ttys
188.El
189.Sh SEE ALSO
190.Xr login 1 ,
191.Xr gettytab 5 ,
192.Xr termcap 5 ,
193.Xr ttys 5 ,
194.Xr getty 8 ,
195.Xr init 8
196.Sh HISTORY
197The
198.Fn getttyent ,
199.Fn getttynam ,
200.Fn setttyent ,
201and
202.Fn endttyent
203functions appeared in
204.Bx 4.3 .
205.Sh BUGS
206These functions use static data storage;
207if the data is needed for future use, it should be
208copied before any subsequent calls overwrite it.
209