NAME

       getpgid - get the process group ID for a process

SYNOPSIS

       #include <unistd.h>

       pid_t getpgid(pid_t pid);

DESCRIPTION

       The getpgid() function shall return the process group ID of the process whose process ID is equal to pid.
       If pid is equal to 0, getpgid() shall return the process group ID of the calling process.

RETURN VALUE

       Upon  successful  completion,  getpgid()  shall  return  a  process  group ID. Otherwise, it shall return
       (pid_t)-1 and set errno to indicate the error.

ERRORS

       The getpgid() function shall fail if:

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

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

       The getpgid() function may fail if:

       EINVAL The value of the pid argument is invalid.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       exec() , fork() , getpgrp() , getpid() , getsid() , 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 .

IEEE/The Open Group                                   2003                                            GETPGID(P)