fchown(3p) — Linux manual page

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(3p)

       The Base Definitions volume of POSIX.1‐2017, unistd.h(0p)

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)

Pages that refer to this page: unistd.h(0p)

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