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setsid(2)			 System	Calls			     setsid(2)

NAME
       setsid -	create session and set process group ID

SYNOPSIS
       #include	<sys/types.h>
       #include	<unistd.h>

       pid_t setsid(void);

DESCRIPTION
       The  setsid() function creates a	new session, if	the calling process is
       not a process group leader. Upon	return the calling process will	be the
       session leader of this new session, will	be the process group leader of
       a new process group, and	will have no controlling terminal. The process
       group  ID of the	calling	process	will be	set equal to the process ID of
       the calling process. The	calling	process	will be	the  only  process  in
       the new process group and the only process in the new session.

RETURN VALUES
       Upon  successful	 completion, setsid() returns the value	of the process
       group  ID of the	calling	process. Otherwise it  returns	(pid_t)-1  and
       sets errno to indicate the error.

ERRORS
       The setsid() function will fail if:

       EPERM	       The  calling process is already a process group leader,
		       or the process group  ID	of a process  other  than  the
		       calling	process	matches	the process  ID	of the calling
		       process.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE	TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Async-Signal-Safe		   |
       +-----------------------------+-----------------------------+

SEE ALSO
       getsid(2), setpgid(2), setpgrp(2), attributes(5), standards(5)

WARNINGS
       A call to setsid() by a process that is a  process  group  leader  will
       fail.  A	 process  can  become a	process	group leader by	being the last
       member of a pipeline started by a job control shell.  Thus,  a  process
       that  expects to	be part	of a pipeline, and that	calls setsid(),	should
       always first fork; the parent should exit and  the  child  should  call
       setsid().  This will ensure that	the calling process will work reliably
       when started by both job	control	shells and non-job control shells.

SunOS 5.10			  21 Aug 2002			     setsid(2)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | ATTRIBUTES | SEE ALSO | WARNINGS

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