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 privilege 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 IEEE Std 1003.1-2001,
<unistd.h>
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 .