PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult the corresponding Linux  manual  page  for  details  of
       Linux behavior), or the interface may not be implemented on Linux.

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 POSIX.1‐2008, <unistd.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1,  2013  Edition,  Standard  for Information Technology -- Portable Operating System
       Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013  by  the
       Institute  of  Electrical  and  Electronics  Engineers,  Inc and The Open Group.  (This is
       POSIX.1-2008 with the  2013  Technical  Corrigendum  1  applied.)  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.unix.org/online.html .

       Any  typographical  or  formatting errors that appear in this page are most likely to have
       been introduced during the conversion of the source files to man page  format.  To  report
       such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .