man3/getttyent.3

   1 .\"  Copyright 2002 walter harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\"
   3 .\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
   4 .\" Distributed under GPL
   5 .\" %%%LICENSE_END
   6 .\"
   7 .TH GETTTYENT 3 2017-09-15  "GNU" "Linux Programmer's Manual"
   8 .SH NAME
   9 getttyent, getttynam, setttyent, endttyent \- get ttys file entry
  10 .SH SYNOPSIS
  11 .B "#include <ttyent.h>"
  12 .PP
  13 .B "struct ttyent *getttyent(void);"
  14 .PP
  15 .BI "struct ttyent *getttynam(const char *" name );
  16 .PP
  17 .B "int setttyent(void);"
  18 .PP
  19 .B "int endttyent(void);"
  20 .SH DESCRIPTION
  21 These functions provide an interface to the file
  22 .B _PATH_TTYS
  23 (e.g.,
  24 .IR /etc/ttys ).
  25 .PP
  26 The function
  27 .BR setttyent ()
  28 opens the file or rewinds it if already open.
  29 .PP
  30 The function
  31 .BR endttyent ()
  32 closes the file.
  33 .PP
  34 The function
  35 .BR getttynam ()
  36 searches for a given terminal name in the file.
  37 It returns a pointer to a
  38 .I ttyent
  39 structure (description below).
  40 .PP
  41 The function
  42 .BR getttyent ()
  43 opens the file
  44 .B _PATH_TTYS
  45 (if necessary) and returns the first entry.
  46 If the file is already open, the next entry.
  47 The
  48 .I ttyent
  49 structure has the form:
  50 .PP
  51 .in +4n
  52 .EX
  53 struct ttyent {
  54     char *ty_name;     /* terminal device name */
  55     char *ty_getty;    /* command to execute, usually getty */
  56     char *ty_type;     /* terminal type for termcap */
  57     int   ty_status;   /* status flags */
  58     char *ty_window;   /* command to start up window manager */
  59     char *ty_comment;  /* comment field */
  60 };
  61 .EE
  62 .in
  63 .PP
  64 .I ty_status
  65 can be:
  66 .PP
  67 .in +4n
  68 .EX
  69 #define TTY_ON     0x01  /* enable logins (start ty_getty program) */
  70 #define TTY_SECURE 0x02  /* allow UID 0 to login */
  71 .EE
  72 .in
  73 .SH ATTRIBUTES
  74 For an explanation of the terms used in this section, see
  75 .BR attributes (7).
  76 .TS
  77 allbox;
  78 lbw25 lb lb
  79 l l l.
  80 Interface       Attribute       Value
  81 T{
  82 .BR getttyent (),
  83 .BR setttyent (),
  84 .BR endttyent (),
  85 .BR getttynam ()
  86 T}      Thread safety   MT-Unsafe race:ttyent
  87 .TE
  88 .SH CONFORMING TO
  89 Not in POSIX.1.
  90 Present on the BSDs, and perhaps other systems.
  91 .SH NOTES
  92 Under Linux, the file
  93 .IR /etc/ttys ,
  94 and the functions described above, are not used.
  95 .SH SEE ALSO
  96 .BR ttyname (3),
  97 .BR ttyslot (3)