.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 
.TH "FCHOWN" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" fchown 
.SH 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.
.SH NAME
fchown \- change owner and group of a file
.SH SYNOPSIS
.LP
\fB#include <unistd.h>
.br
.sp
int fchown(int\fP \fIfildes\fP\fB, uid_t\fP \fIowner\fP\fB, gid_t\fP
\fIgroup\fP\fB);
.br
\fP
.SH DESCRIPTION
.LP
The \fIfchown\fP() function shall be equivalent to \fIchown\fP() except
that the file
whose owner and group are changed is specified by the file descriptor
\fIfildes\fP.
.SH RETURN VALUE
.LP
Upon successful completion, \fIfchown\fP() shall return 0. Otherwise,
it shall return -1 and set \fIerrno\fP to indicate the
error.
.SH ERRORS
.LP
The \fIfchown\fP() function shall fail if:
.TP 7
.B EBADF
The \fIfildes\fP argument is not an open file descriptor.
.TP 7
.B EPERM
The effective user ID does not match the owner of the file or the
process does not have appropriate privilege and
_POSIX_CHOWN_RESTRICTED indicates that such privilege is required.
.TP 7
.B EROFS
The file referred to by \fIfildes\fP resides on a read-only file system.
.sp
.LP
The \fIfchown\fP() function may fail if:
.TP 7
.B EINVAL
The owner or group ID is not a value supported by the implementation.
The \fIfildes\fP argument refers to a pipe or socket
\ or an \fIfattach\fP()-ed STREAM and the implementation disallows
execution of \fIfchown\fP() on a pipe.
.TP 7
.B EIO
A physical I/O error has occurred.
.TP 7
.B EINTR
The \fIfchown\fP() function was interrupted by a signal which was
caught.
.sp
.LP
\fIThe following sections are informative.\fP
.SH EXAMPLES
.SS Changing the Current Owner of a File
.LP
The following example shows how to change the owner of a file named
\fB/home/cnd/mod1\fP to "jones" and the group to
"cnd".
.LP
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.
.sp
.RS
.nf

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

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);
\fP
.fi
.RE
.SH APPLICATION USAGE
.LP
None.
.SH RATIONALE
.LP
None.
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fIchown\fP(), the Base Definitions volume of IEEE\ Std\ 1003.1-2001,
\fI<unistd.h>\fP
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 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 .