bsd/man/man2/setsid.2

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  34 .\"     @(#)setsid.2    8.1 (Berkeley) 6/4/93
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  36 .Dd June 4, 1993
  37 .Dt SETSID 2
  38 .Os
  39 .Sh NAME
  40 .Nm setsid
  41 .Nd create session and set process group ID
  42 .Sh SYNOPSIS
  43 .Fd #include <sys/types.h>
  44 .Fd #include <unistd.h>
  45 .Ft pid_t
  46 .Fn setsid "void"
  47 .Sh DESCRIPTION
  48 The
  49 .Nm setsid
  50 function creates a new session.
  51 The calling process is the session leader of the new session, is the
  52 process group leader of a new process group and has no controlling
  53 terminal.
  54 The calling process is the only process in either the session or the
  55 process group.
  56 .Pp
  57 Upon successful completion, the
  58 .Nm setsid
  59 function returns the value of the process group ID of the new process
  60 group, which is the same as the process ID of the calling process.
  61 .Sh ERRORS
  62 If an error occurs,
  63 .Nm setsid
  64 returns -1 and the global variable
  65 .Va errno
  66 is set to indicate the error, as follows:
  67 .Bl -tag -width Er
  68 .It Bq Er EPERM
  69 The calling process is already a process group leader, or the process
  70 group ID of a process other than the calling process matches the process
  71 ID of the calling process.
  72 .El
  73 .Sh SEE ALSO
  74 .Xr setpgid 3 ,
  75 .Xr tcgetpgrp 3 ,
  76 .Xr tcsetpgrp 3
  77 .Sh STANDARDS
  78 The
  79 .Nm setsid
  80 function is expected to be compliant with the
  81 .St -p1003.1-88
  82 specification.