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 <unistd.h>
  44 .Ft pid_t
  45 .Fo setsid
  46 .Fa void
  47 .Fc
  48 .Sh DESCRIPTION
  49 The
  50 .Nm setsid
  51 function creates a new session.
  52 The calling process is the session leader of the new session, is the
  53 process group leader of a new process group and has no controlling
  54 terminal.
  55 The calling process is the only process in either the session or the
  56 process group.
  57 .Pp
  58 Upon successful completion, the
  59 .Nm setsid
  60 function returns the value of the process group ID of the new process
  61 group, which is the same as the process ID of the calling process.
  62 .Sh ERRORS
  63 If an error occurs,
  64 .Nm setsid
  65 returns -1 and the global variable
  66 .Va errno
  67 is set to indicate the error, as follows:
  68 .Bl -tag -width Er
  69 .It Bq Er EPERM
  70 The calling process is already a process group leader, or the process
  71 group ID of a process other than the calling process matches the process
  72 ID of the calling process.
  73 .El
  74 .Sh LEGACY SYNOPSIS
  75 .Fd #include <sys/types.h>
  76 .Fd #include <unistd.h>
  77 .Pp
  78 The include file
  79 .In sys/types.h
  80 is necessary.
  81 .Sh SEE ALSO
  82 .Xr setpgid 3 ,
  83 .Xr tcgetpgrp 3 ,
  84 .Xr tcsetpgrp 3 ,
  85 .Xr compat 5
  86 .Sh STANDARDS
  87 The
  88 .Nm setsid
  89 function is expected to be compliant with the
  90 .St -p1003.1-88
  91 specification.