This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       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 .

IEEE/The Open Group                                   2017                                        FCHOWN(3POSIX)

       The  fchown()  function  shall  be  equivalent  to chown() except that the file whose owner and group are
       changed is specified by the file descriptor fildes.

       The fchown() function shall fail if:

       EBADF  The fildes argument is not an open file descriptor.

       EPERM  The  effective  user  ID  does  not  match  the  owner  of  the  file or the process does not have
              appropriate privileges and _POSIX_CHOWN_RESTRICTED indicates that such privilege is required.

       EROFS  The file referred to by fildes resides on a read-only file system.

       The fchown() function may fail if:

       EINVAL The owner or group ID is not a value supported by the implementation.  The fildes argument  refers
              to  a  pipe  or  socket  or  an  fattach()-ed STREAM and the implementation disallows execution of
              fchown() on a pipe.

       EIO    A physical I/O error has occurred.

       EINTR  The fchown() function was interrupted by a signal which was caught.

       Thefollowingsectionsareinformative.

ChangingtheCurrentOwnerofaFile
       The following example shows how to change the owner of a file named /home/cnd/mod1 to ``jones''  and  the
       group to ``cnd''.

       The  numeric  value  for  the  user ID is obtained by extracting the user ID from the user database entry
       associated with ``jones''. Similarly, the numeric value for the group ID is obtained  by  extracting  the
       group  ID from the group database entry associated with ``cnd''. This example assumes the calling program
       has appropriate privileges.

           #include <sys/types.h>
           #include <unistd.h>
           #include <fcntl.h>
           #include <pwd.h>
           #include <grp.h>

           struct passwd *pwd;
           struct group  *grp;
           int            fildes;
           ...
           fildes = open("/home/cnd/mod1", O_RDWR);
           pwd = getpwnam("jones");
           grp = getgrnam("cnd");
           fchown(fildes, pwd->pw_uid, grp->gr_gid);

       None.

       fchown — change owner and group of a file

       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.

       None.

       Upon successful completion, fchown() shall return 0. Otherwise, it shall  return  -1  and  set  errno  to
       indicate the error.

chown()

       The Base Definitions volume of POSIX.1‐2017, <unistd.h>

       #include <unistd.h>

       int fchown(int fildes, uid_t owner, gid_t group);