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.1‐2017, <unistd.h>

COPYRIGHT

       Portions of this text are reprinted and  reproduced  in  electronic  form  from  IEEE  Std
       1003.1-2017,  Standard  for  Information Technology -- Portable Operating System Interface
       (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C)  2018  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 .

       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 .