bsd/man/man2/getsid.2

   1 .\" Copyright (c) 1997 Peter Wemm <peter@FreeBSD.org>
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  24 .\" $FreeBSD: src/lib/libc/sys/getsid.2,v 1.3.2.5 2001/12/14 18:34:00 ru Exp $
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  26 .Dd August 19, 1997
  27 .Dt GETSID 2
  28 .Os
  29 .Sh NAME
  30 .Nm getsid
  31 .Nd get process session
  32 .Sh LIBRARY
  33 .Lb libc
  34 .Sh SYNOPSIS
  35 .In unistd.h
  36 .Ft pid_t
  37 .Fn getsid "pid_t pid"
  38 .Sh DESCRIPTION
  39 The session ID of the process identified by
  40 .Fa pid
  41 is returned by
  42 .Fn getsid .
  43 If
  44 .Fa pid
  45 is zero,
  46 .Fn getsid
  47 returns the session ID of the current process.
  48 .Sh RETURN VALUES
  49 Upon successful completion, the function
  50 .Fn getsid
  51 returns the session ID of
  52 the specified process; otherwise, it returns a value of -1 and
  53 sets errno to indicate an error.
  54 .Sh ERRORS
  55 .Fn getsid
  56 will succeed unless:
  57 .Bl -tag -width Er
  58 .It Bq Er ESRCH
  59 if there is no process with a process ID equal to
  60 .Fa pid .
  61 .El
  62 .Pp
  63 Note that an implementation may restrict this function call to
  64 processes within the same session ID as the calling process.
  65 .Sh SEE ALSO
  66 .Xr getpgid 2 ,
  67 .Xr getpgrp 2 ,
  68 .Xr setpgid 2 ,
  69 .Xr setsid 2 ,
  70 .Xr termios 4
  71 .Sh HISTORY
  72 The
  73 .Fn getsid
  74 function call appeared in
  75 .Fx 3.0 .
  76 The
  77 .Fn getsid
  78 function call is derived from its usage in
  79 .At V .