rename(2) System Calls rename(2)NAME
rename, renameat - change the name of a file
SYNOPSIS
#include <stdio.h>
int rename(const char *old, const char *new);
#include <unistd.h>
int renameat(int fromfd, const char *old, int tofd, const char *new);
XPG3
#include <unistd.h>
int rename(const char *old, const char *new);
DESCRIPTION
The rename() function changes the name of a file. The old argument
points to the pathname of the file to be renamed. The new argument
points to the new path name of the file.
The renameat() function renames an entry in a directory, possibly mov‐
ing the entry into a different directory. See fsattr(5). If the old
argument is an absolute path, the fromfd is ignored. Otherwise it is
resolved relative to the fromfd argument rather than the current work‐
ing directory. Similarly, if the new argument is not absolute, it is
resolved relative to the tofd argument. If either fromfd or tofd have
the value AT_FDCWD, defined in <fcntl.h>, and their respective paths
are relative, the path is resolved relative to the current working
directory.
Current implementation restrictions will cause the renameat() function
to return an error if an attempt is made to rename an extended
attribute file to a regular (non-attribute) file, or to rename a regu‐
lar file to an extended attribute file.
If old and new both refer to the same existing file, the rename() and
renameat() functions return successfully and performs no other action.
If old points to the pathname of a file that is not a directory, new
must not point to the pathname of a directory. If the link named by new
exists, it will be removed and old will be renamed to new. In this
case, a link named new must remain visible to other processes through‐
out the renaming operation and will refer to either the file referred
to by new or the file referred to as old before the operation began.
If old points to the pathname of a directory, new must not point to
the pathname of a file that is not a directory. If the directory named
by new exists, it will be removed and old will be renamed to new. In
this case, a link named new will exist throughout the renaming opera‐
tion and will refer to either the file referred to by new or the file
referred to as old before the operation began. Thus, if new names an
existing directory, it must be an empty directory.
The new pathname must not contain a path prefix that names old. Write
access permission is required for both the directory containing old and
the directory containing new. If old points to the pathname of a
directory, write access permission is required for the directory named
by old, and, if it exists, the directory named by new.
If the directory containing old has the sticky bit set, at least one
of the following conditions listed below must be true:
· the user must own old
· the user must own the directory containing old
· old must be writable by the user
· the user must be a privileged user
If new exists, and the directory containing new is writable and has the
sticky bit set, at least one of the following conditions must be true:
· the user must own new
· the user must own the directory containing new
· new must be writable by the user
· the user must be a privileged user
If the link named by new exists, the file's link count becomes zero
when it is removed, and no process has the file open, then the space
occupied by the file will be freed and the file will no longer be
accessible. If one or more processes have the file open when the last
link is removed, the link will be removed before rename() or renameat()
returns, but the removal of the file contents will be postponed until
all references to the file have been closed.
Upon successful completion, the rename() and renameat() functions will
mark for update the st_ctime and st_mtime fields of the parent direc‐
tory of each file.
RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, −1 is returned
and errno is set to indicate an error.
ERRORS
The rename() function will fail if:
EACCES A component of either path prefix denies search permis‐
sion; one of the directories containing old and new
denies write permissions; or write permission is denied
by a directory pointed to by old or new.
EBUSY The new argument is a directory and the mount point for
a mounted file system.
EDQUOT The directory where the new name entry is being placed
cannot be extended because the user's quota of disk
blocks on that file system has been exhausted.
EEXIST The link named by new is a directory containing entries
other than `.' (the directory itself) and `..' (the
parent directory).
EFAULT Either old or new references an invalid address.
EINVAL The new argument directory pathname contains a path
prefix that names the old directory, or an attempt was
made to rename a regular file to an extended attribute
or from an extended attribute to a regular file.
EISDIR The new argument points to a directory but old points
to a file that is not a directory.
ELOOP Too many symbolic links were encountered in translating
the pathname.
ENAMETOOLONG The length of old or new exceeds PATH_MAX, or a path‐
name component is longer than NAME_MAX while
_POSIX_NO_TRUNC is in effect.
EMLINK The file named by old is a directory, and the link
count of the parent directory of new would exceed
LINK_MAX.
ENOENT The link named by old does not exist, or either old or
new points to an empty string.
ENOSPC The directory that would contain new cannot be
extended.
ENOTDIR A component of either path prefix is not a directory,
or old names a directory and new names a nondirectory
file, or tofd and dirfd in renameat() do not reference
a directory.
EROFS The requested operation requires writing in a directory
on a read-only file system.
EXDEV The links named by old and new are on different file
systems.
EIO An I/O error occurred while making or updating a direc‐
tory entry.
The renameat() functions will fail if:
ENOTSUP An attempt was made to rename a regular file as an
attribute file or to rename an attribute file as a reg‐
ular file.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │rename() is Standard; │
│ │renameat() is Evolving │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │Async-Signal-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOchmod(2), link(2), unlink(2), attributes(5), fsattr(5)NOTES
The system can deadlock if there is a loop in the file system graph.
Such a loop can occur if there is an entry in directory a, a/name1,
that is a hard link to directory b, and an entry in directory b,
b/name2, that is a hard link to directory a. When such a loop exists
and two separate processes attempt to rename a/name1 to b/name2 and
b/name2 to a/name1, the system may deadlock attempting to lock both
directories for modification. Use symbolic links instead of hard links
for directories.
SunOS 5.10 4 Nov 2002 rename(2)
