FCHOWN(3)                  POSIX Programmer's Manual                 FCHOWN(3)



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

NAME
       fchown -- change owner and group of a file

SYNOPSIS
       #include <unistd.h>

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

DESCRIPTION
       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.

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

ERRORS
       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.

       The following sections are informative.

EXAMPLES
   Changing the Current Owner of aa File
       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);

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       chown()

       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 .



IEEE/The Open Group                  2017                            FCHOWN(3)
