NAME

       getsid - get the process group ID of a session leader

SYNOPSIS

       #include <unistd.h>

       pid_t getsid(pid_t pid);

DESCRIPTION

       The getsid() function shall obtain the process group ID of the process that is the session
       leader of the process specified by pid. If pid  is  (pid_t)0,  it  specifies  the  calling
       process.

RETURN VALUE

       Upon  successful  completion,  getsid()  shall  return the process group ID of the session
       leader of the specified process.  Otherwise, it shall return (pid_t)-1 and  set  errno  to
       indicate the error.

ERRORS

       The getsid() function shall fail if:

       EPERM  The process specified by pid is not in the same session as the calling process, and
              the implementation does not allow access to the process group  ID  of  the  session
              leader of that process from the calling process.

       ESRCH  There is no process with a process ID equal to pid.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       exec()  ,  fork()  ,  getpid()  ,  getpgid() , setpgid() , setsid() , the Base Definitions
       volume of IEEE Std 1003.1-2001, <unistd.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1,  2003  Edition,  Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003  by
       the  Institute  of  Electrical  and  Electronics Engineers, Inc and The Open Group. In the
       event of any discrepancy between this version and the original IEEE  and  The  Open  Group
       Standard,  the  original  IEEE  and  The  Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .