--- name: "renamex_np" section: "2" platform: "macos" package: "xnu" version: "12377.121.6" release: "macOS 26.5" platforms: ["macos"] url: "https://new.carta.tech/rename/2" --- # renamex\_np(2) change the name of a file Part of [rename(2)](/rename/2.md). ## NAME **rename**, **renameat**, **renamex\_np**, **renameatx\_np** – change the name of a file ## SYNOPSIS **#include \** *int*\ **rename**(*const char \*old*, *const char \*new*); *int*\ **renameat**(*int fromfd*, *const char \*from*, *int tofd*, *const char \*to*); *int*\ **renamex\_np**(*const char \*from*, *const char \*to*, *unsigned int flags*); *int*\ **renameatx\_np**(*int fromfd*, *const char \*from*, *int tofd*, *const char \*to*, *unsigned int flags*); ## DESCRIPTION The **rename**() system call causes the link named *old* to be renamed as *new*. If *new* exists, it is first removed. Both *old* and *new* must be of the same type (that is, both must be either directories or non-directories) and must reside on the same file system. The **rename**() system call guarantees that an instance of *new* will always exist, even if the system should crash in the middle of the operation. If the final component of *old* is a symbolic link, the symbolic link is renamed, not the file or directory to which it points. The **renameat**() system call is equivalent to **rename**() except in the case where either *from* or *to* specifies a relative path. If *from* is a relative path, the file to be renamed is located relative to the directory associated with the file descriptor *fromfd* instead of the current working directory. If the *to* is a relative path, the same happens only relative to the directory associated with *tofd*. If the **renameat**() is passed the special value AT\_FDCWD in the *fromfd* or *tofd* parameter, the current working directory is used in the determination of the file for the respective path parameter. The **renamex\_np**() and **renameatx\_np**() system calls are similar to their counterparts except that they take a *flags* argument. Values for *flags* are constructed with below bits set: - RENAME\_SWAP On file systems that support it (see [getattrlist(2)](/getattrlist/2.md) VOL\_CAP\_INT\_RENAME\_SWAP), it will cause the source and target to be atomically swapped. Source and target need not be of the same type, i.e. it is possible to swap a file with a directory. EINVAL is returned in case of bitwise-inclusive OR with RENAME\_EXCL. - RENAME\_EXCL On file systems that support it (see [getattrlist(2)](/getattrlist/2.md) VOL\_CAP\_INT\_RENAME\_EXCL), it will cause EEXIST to be returned if the destination already exists. EINVAL is returned in case of bitwise-inclusive OR with RENAME\_SWAP. - RENAME\_NOFOLLOW\_ANY If any symbolic links are encountered during pathname resolution, an error is returned. - RENAME\_RESOLVE\_BENEATH Either *from* or *to* does not reside in the hierarchy beneath the starting directory, an error is returned. ## CAVEATS The system can deadlock if a loop is present in the file system graph. This loop takes the form of an entry in directory ‘*a*’, say ‘*a/foo*’, being a hard link to directory ‘*b*’, and an entry in directory ‘*b*’, say ‘*b/bar*’, being a hard link to directory ‘*a*’. When such a loop exists and two separate processes attempt to perform ‘rename a/foo b/bar’ and ‘rename b/bar a/foo’, respectively, the system may deadlock attempting to lock both directories for modification. Whether or not hard links to directories are supported is specific to the underlying filesystem implementation. It is recommended that any hard links to directories in an underlying filesystem should be replaced by symbolic links by the system administrator to avoid the possibility of deadlocks. Moving or renaming a file or directory into a directory with inheritable ACLs does not result in ACLs being set on the file or directory. Use [acl(3)](/acl/3.md) in conjunction with **rename**() to set ACLs on the file or directory. ## RETURN VALUES A 0 value is returned if the operation succeeds, otherwise **rename**() returns -1 and the global variable *errno* indicates the reason for the failure. ## ERRORS The **rename**() system call will fail and neither of the argument files will be affected if: - \[EACCES\] A component of either path prefix denies search permission. - \[EACCES\] The requested operation requires writing in a directory (e.g., *new*, new/.., or old/..) whose modes disallow this. - \[EACCES\] *old* is a directory and it, or some descendent in the namespace, is open and the file system format does does not support renaming a directory with open descendents (see [getattrlist(2)](/getattrlist/2.md) VOL\_CAP\_INT\_RENAME\_OPENFAIL). - \[EDQUOT\] The directory in which the entry for the new name is being placed cannot be extended because the user's quota of disk blocks on the file system containing the directory has been exhausted. - \[EEXIST\] *flags* has RENAME\_EXCL set but *new* already exists. - \[EFAULT\] *Path* points outside the process's allocated address space. - \[EINVAL\] *Old* is a parent directory of *new*, or an attempt is made to rename ‘.’ or ‘..’. If RENAME\_SWAP is used, then EINVAL will also be returned if *new* is a parent directory of *old*. If both RENAME\_SWAP and RENAME\_EXCL bits are set in *flags*, then EINVAL will be returned. - \[EINVAL\] *flags* has an invalid value. - \[EIO\] An I/O error occurs while making or updating a directory entry. - \[EISDIR\] *new* is a directory, but *old* is not a directory. - \[ELOOP\] Too many symbolic links are encountered in translating either pathname. This is taken to be indicative of a looping symbolic link. - \[ELOOP\] If RENAME\_NOFOLLOW\_ANY was passed and a symbolic link was encountered in translating either pathname. - \[ENOTCAPABLE\] RENAME\_RESOLVE\_BENEATH was passed and either *from* or *to* does not reside in the directory hierarchy beneath the starting directory. - \[ENAMETOOLONG\] A component of a pathname exceeds {NAME\_MAX} characters, or an entire path name exceeds {PATH\_MAX} characters. - \[ENOENT\] A component of the *old* path does not exist, or a path prefix of *new* does not exist. - \[ENOENT\] *flags* has RENAME\_SWAP set but *new* does not exist. - \[ENOSPC\] The directory in which the entry for the new name is being placed cannot be extended because there is no space left on the file system containing the directory. - \[ENOTDIR\] A component of either path prefix is not a directory. - \[ENOTDIR\] *old* is a directory, but *new* is not a directory. - \[ENOTEMPTY\] *New* is a directory and is not empty. - \[ENOTSUP\] *flags* has a value that is not supported by the file system. - \[EPERM\] The directory containing *old* is marked sticky, and neither the containing directory nor *old* are owned by the effective user ID. - \[EPERM\] The *new* file exists, the directory containing *new* is marked sticky, and neither the containing directory nor *new* are owned by the effective user ID. - \[EROFS\] The requested link requires writing in a directory on a read-only file system. - \[EXDEV\] The link named by *new* and the file named by *old* are on different logical devices (file systems). Note that this error code will not be returned if the implementation permits cross-device links. - \[EDEADLK\] A component of either pathname refers to a “dataless” directory that requires materialization and the I/O policy of the current thread or process disallows dataless directory materialization (see [getiopolicy\_np(3)](/getiopolicy_np/3.md)). - \[EDEADLK\] The *from* pathname refers to a “dataless” file or directory that must be materialized before being moved to its new location and the I/O policy of the current thread or process disallows file or directory materialization (see [getiopolicy\_np(3)](/getiopolicy_np/3.md)). The **renameat**() and **renameatx\_np**() calls may also fail with: - \[EBADF\] The *from* argument does not specify an absolute path and the *fromfd* argument is neither AT\_FDCWD nor a valid file descriptor open for searching, or the *to* argument does not specify an absolute path and the *tofd* argument is neither AT\_FDCWD nor a valid file descriptor open for searching. - \[ENOTDIR\] The *from* argument is not an absolute path and *fromfd* is neither AT\_FDCWD nor a file descriptor associated with a directory, or the *to* argument is not an absolute path and *tofd* is neither AT\_FDCWD nor a file descriptor associated with a directory. ## CONFORMANCE The restriction on renaming a directory whose permissions disallow writing is based on the fact that UFS directories contain a ".." entry. If renaming a directory would move it to another parent directory, this entry needs to be changed. This restriction has been generalized to disallow renaming of any write-disabled directory, even when this would not require a change to the ".." entry. For consistency, HFS+ directories emulate this behavior. ## SEE ALSO [open(2)](/open/2.md), [symlink(7)](/symlink/7.md) ## STANDARDS The **rename**() function conforms to IEEE Std 1003.1-1988 (“POSIX.1”). The **renameat**() system call is expected to conform to POSIX.1-2008 .