fchown

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



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 .



IEEE/The Open Group                   2017                            FCHOWN(3P)