gen/getttyent.3

   1 .\" Copyright (c) 1989, 1991, 1993
   2 .\"     The Regents of the University of California.  All rights reserved.
   3 .\"
   4 .\" Redistribution and use in source and binary forms, with or without
   5 .\" modification, are permitted provided that the following conditions
   6 .\" are met:
   7 .\" 1. Redistributions of source code must retain the above copyright
   8 .\"    notice, this list of conditions and the following disclaimer.
   9 .\" 2. Redistributions in binary form must reproduce the above copyright
  10 .\"    notice, this list of conditions and the following disclaimer in the
  11 .\"    documentation and/or other materials provided with the distribution.
  12 .\" 3. All advertising materials mentioning features or use of this software
  13 .\"    must display the following acknowledgement:
  14 .\"     This product includes software developed by the University of
  15 .\"     California, Berkeley and its contributors.
  16 .\" 4. Neither the name of the University nor the names of its contributors
  17 .\"    may be used to endorse or promote products derived from this software
  18 .\"    without specific prior written permission.
  19 .\"
  20 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23 .\" ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30 .\" SUCH DAMAGE.
  31 .\"
  32 .\"     @(#)getttyent.3 8.1 (Berkeley) 6/4/93
  33 .\" $FreeBSD: src/lib/libc/gen/getttyent.3,v 1.12 2001/10/01 16:08:51 ru Exp $
  34 .\"
  35 .Dd November 17, 1996
  36 .Dt GETTTYENT 3
  37 .Os
  38 .Sh NAME
  39 .Nm getttyent ,
  40 .Nm getttynam ,
  41 .Nm setttyent ,
  42 .Nm endttyent
  43 .Nd get ttys file entry
  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 .Sh DESCRIPTION
  57 The
  58 .Fn getttyent ,
  59 and
  60 .Fn getttynam
  61 functions
  62 each return a pointer to an object, with the following structure,
  63 containing the broken-out fields of a line from the tty description
  64 file.
  65 .Bd -literal
  66 struct ttyent {
  67         char    *ty_name;       /* terminal device name */
  68         char    *ty_getty;      /* command to execute, usually getty */
  69         char    *ty_type;       /* terminal type for termcap */
  70 #define TTY_ON          0x01    /* enable logins (start ty_getty program) */
  71 #define TTY_SECURE      0x02    /* allow uid of 0 to login */
  72 #define TTY_DIALUP      0x04    /* is a dialup tty */
  73 #define TTY_NETWORK     0x08    /* is a network tty */
  74         int     ty_status;      /* status flags */
  75         char    *ty_window;     /* command to start up window manager */
  76         char    *ty_comment;    /* comment field */
  77         char    *ty_group;      /* tty group name */
  78 };
  79 .Ed
  80 .Pp
  81 The fields are as follows:
  82 .Bl -tag -width ty_comment
  83 .It Fa ty_name
  84 The name of the character-special file.
  85 .It Fa ty_getty
  86 The name of the command invoked by
  87 .Xr init 8
  88 to initialize tty line characteristics.
  89 .It Fa ty_type
  90 The name of the default terminal type connected to this tty line.
  91 .It Fa ty_status
  92 A mask of bit fields which indicate various actions allowed on this
  93 tty line.
  94 The possible flags are as follows:
  95 .Bl -tag -width TTY_NETWORK
  96 .It Dv TTY_ON
  97 Enables logins (i.e.,
  98 .Xr init 8
  99 will start the command referenced by
 100 .Fa ty_getty
 101 on this entry).
 102 .It Dv TTY_SECURE
 103 Allow users with a uid of 0 to login on this terminal.
 104 .It Dv TTY_DIALUP
 105 Identifies a tty as a dialin line.
 106 .It Dv TTY_NETWORK
 107 Identifies a tty used for network connections.
 108 .El
 109 .It Fa ty_window
 110 The command to execute for a window system associated with the line.
 111 .It Fa ty_group
 112 A group name to which the tty belongs.
 113 If no group is specified in the ttys description file,
 114 then the tty is placed in an anonymous group called "none".
 115 .It Fa ty_comment
 116 Any trailing comment field, with any leading hash marks (``#'') or
 117 whitespace removed.
 118 .El
 119 .Pp
 120 If any of the fields pointing to character strings are unspecified,
 121 they are returned as null pointers.
 122 The field
 123 .Fa ty_status
 124 will be zero if no flag values are specified.
 125 .Pp
 126 See
 127 .Xr ttys 5
 128 for a more complete discussion of the meaning and usage of the
 129 fields.
 130 .Pp
 131 The
 132 .Fn getttyent
 133 function
 134 reads the next line from the ttys file, opening the file if necessary.
 135 The
 136 .Fn setttyent
 137 function
 138 rewinds the file if open, or opens the file if it is unopened.
 139 The
 140 .Fn endttyent
 141 function
 142 closes any open files.
 143 .Pp
 144 The
 145 .Fn getttynam
 146 function
 147 searches from the beginning of the file until a matching
 148 .Fa name
 149 is found
 150 (or until
 151 .Dv EOF
 152 is encountered).
 153 .Sh RETURN VALUES
 154 The routines
 155 .Fn getttyent
 156 and
 157 .Fn getttynam
 158 return a null pointer on
 159 .Dv EOF
 160 or error.
 161 The
 162 .Fn setttyent
 163 function
 164 and
 165 .Fn endttyent
 166 return 0 on failure and 1 on success.
 167 .Sh FILES
 168 .Bl -tag -width /etc/ttys -compact
 169 .It Pa /etc/ttys
 170 .El
 171 .Sh SEE ALSO
 172 .Xr login 1 ,
 173 .Xr ttyslot 3 ,
 174 .Xr gettytab 5 ,
 175 .Xr termcap 5 ,
 176 .Xr ttys 5 ,
 177 .Xr getty 8 ,
 178 .Xr init 8
 179 .Sh HISTORY
 180 The
 181 .Fn getttyent ,
 182 .Fn getttynam ,
 183 .Fn setttyent ,
 184 and
 185 .Fn endttyent
 186 functions appeared in
 187 .Bx 4.3 .
 188 .Sh BUGS
 189 These functions use static data storage;
 190 if the data is needed for future use, it should be
 191 copied before any subsequent calls overwrite it.