getsid

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