man3/tcgetsid.3

   1 .\" Copyright (C) 2002 Andries Brouwer <aeb@cwi.nl>
   2 .\"
   3 .\" Permission is granted to make and distribute verbatim copies of this
   4 .\" manual provided the copyright notice and this permission notice are
   5 .\" preserved on all copies.
   6 .\"
   7 .\" Permission is granted to copy and distribute modified versions of this
   8 .\" manual under the conditions for verbatim copying, provided that the
   9 .\" entire resulting derived work is distributed under the terms of a
  10 .\" permission notice identical to this one.
  11 .\"
  12 .\" Since the Linux kernel and libraries are constantly changing, this
  13 .\" manual page may be incorrect or out-of-date.  The author(s) assume no
  14 .\" responsibility for errors or omissions, or for damages resulting from
  15 .\" the use of the information contained herein.  The author(s) may not
  16 .\" have taken the same level of care in the production of this manual,
  17 .\" which is licensed free of charge, as they might when working
  18 .\" professionally.
  19 .\"
  20 .\" Formatted or processed versions of this manual, if unaccompanied by
  21 .\" the source, must acknowledge the copyright and authors of this work.
  22 .\"
  23 .TH TCGETSID 3 2007-07-26 "GNU" "Linux Programmer's Manual"
  24 .SH NAME
  25 tcgetsid \- get session ID
  26 .SH SYNOPSIS
  27 .sp
  28 .B #define _XOPEN_SOURCE 500
  29 .br
  30 .BR "#include <termios.h>"
  31 .sp
  32 .BI "pid_t tcgetsid(int " fd );
  33 .SH DESCRIPTION
  34 The function
  35 .BR tcgetsid ()
  36 returns the session ID of the current session that has the
  37 terminal associated to
  38 .I fd
  39 as controlling terminal.
  40 This terminal must be the controlling terminal of the calling process.
  41 .SH "RETURN VALUE"
  42 When
  43 .I fd
  44 refers to the controlling terminal of our session,
  45 the function
  46 .BR tcgetsid ()
  47 will return the session ID of this session.
  48 Otherwise, \-1 is returned, and
  49 .I errno
  50 is set appropriately.
  51 .SH ERRORS
  52 .TP
  53 .B EBADF
  54 .I fd
  55 is not a valid file descriptor.
  56 .TP
  57 .B ENOTTY
  58 The calling process does not have a controlling terminal, or
  59 it has one but it is not described by
  60 .IR fd .
  61 .SH "CONFORMING TO"
  62 POSIX.1-2001
  63 .SH NOTES
  64 This function is implemented via the
  65 .B TIOCGSID
  66 .BR ioctl (2),
  67 present
  68 since Linux 2.1.71.
  69 .SH "SEE ALSO"
  70 .BR getsid (2)