rename (2)
NAME
rename - change the name or location of a file
SYNOPSIS
#include <stdio.h>
int rename(const char *oldpath, const char *newpath);
DESCRIPTION
rename renames a file, moving it between directories if required.
Any other hard links to the file (as created using link(2)) are unaf-
fected.
If newpath already exists it will be atomically replaced (subject to a
few conditions - see ERRORS below), so that there is no point at which
another process attempting to access newpath will find it missing.
If newpath exists but the operation fails for some reason rename guar-
antees to leave an instance of newpath in place.
However, when overwriting there will probably be a window in which both
oldpath and newpath refer to the file being renamed.
If oldpath refers to a symbolic link the link is renamed; if newpath
refers to a symbolic link the link will be overwritten.
RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is
set appropriately.
ERRORS
EISDIR newpath is an existing directory, but oldpath is not a direc-
tory.
EXDEV oldpath and newpath are not on the same filesystem.
ENOTEMPTY or EEXIST
newpath is a non-empty directory, i.e., contains entries other
than "." and "..".
EBUSY The rename fails because oldpath or newpath is a directory that
is in use by some process (perhaps as current working directory,
or as root directory, or because it was open for reading) or is
in use by the system (for example as mount point), while the
system considers this an error. (Note that there is no require-
ment to return EBUSY in such cases - there is nothing wrong with
doing the rename anyway - but it is allowed to return EBUSY if
the system cannot otherwise handle such situations.)
EINVAL The new pathname contained a path prefix of the old, or, more
generally, an attempt was made to make a directory a subdirec-
tory of itself.
EMLINK oldpath already has the maximum number of links to it, or it was
EACCES Write access to the directory containing oldpath or newpath is
not allowed for the process's effective uid, or one of the
directories in oldpath or newpath did not allow search (execute)
permission, or oldpath was a directory and did not allow write
permission (needed to update the .. entry).
EPERM or EACCES
The directory containing oldpath has the sticky bit set and the
process's effective uid is neither that of root nor the uid of
the file to be deleted nor that of the directory containing it,
or newpath is an existing file and the directory containing it
has the sticky bit set and the process's effective uid is nei-
ther that of root nor the uid of the file to be replaced nor
that of the directory containing it, or the filesystem contain-
ing pathname does not support renaming of the type requested.
ENAMETOOLONG
oldpath or newpath was too long.
ENOENT A directory component in oldpath or newpath does not exist or
is a dangling symbolic link.
ENOMEM Insufficient kernel memory was available.
EROFS The file is on a read-only filesystem.
ELOOP Too many symbolic links were encountered in resolving oldpath or
newpath.
ENOSPC The device containing the file has no room for the new directory
entry.
CONFORMING TO
POSIX, 4.3BSD, ANSI C
BUGS
On NFS filesystems, you can not assume that if the operation failed the
file was not renamed. If the server does the rename operation and then
crashes, the retransmitted RPC which will be processed when the server
is up again causes a failure. The application is expected to deal with
this. See link(2) for a similar problem.
SEE ALSO
link(2), unlink(2), symlink(2), mv(1)
Linux 2.0 1998-06-04 rename(2)