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

       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 a 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 .