RENAME(2) BSD Programmer's Manual RENAME(2)
rename - change the name of a file
#include <stdio.h>
int
rename(const char *from, const char *to);
rename() causes the link named from to be renamed as to. If to exists, it
is first removed. Both from and to must be of the same type (that is,
both directories or both non-directories), and must reside on the same
filesystem.
rename() guarantees that if to already exists, an instance of to will al-
ways exist, even if the system should crash in the middle of the opera-
tion.
If the final component of from is a symbolic link, the symbolic link is
renamed, not the file or directory to which it points.
A 0 value is returned if the operation succeeds, otherwise rename() re-
turns -1 and the global variable errno indicates the reason for the
failure.
rename() will fail and neither of the argument files will be affected if:
[ENAMETOOLONG]
A component of a pathname exceeded {NAME_MAX} characters,
or an entire path name exceeded {PATH_MAX} characters.
[ENOENT] A component of the from path does not exist, or a path pre-
fix of to does not exist.
[EACCES] A component of either path prefix denies search permission.
[EACCES] The requested link requires writing in a directory with a
mode that denies write permission.
[EPERM] The directory containing from is marked sticky, and neither
the containing directory nor from are owned by the effec-
tive user ID.
[EPERM] The to file exists, the directory containing to is marked
sticky, and neither the containing directory nor to are
owned by the effective user ID.
[ELOOP] Too many symbolic links were encountered in translating ei-
ther pathname.
[EMLINK] The link count on the source file or destination directory
is at the maximum. A rename cannot be completed under these
conditions.
[ENOTDIR] A component of either path prefix is not a directory.
[ENOTDIR] from is a directory, but to is not a directory.
[EISDIR] to is a directory, but from is not a directory.
[EXDEV] The link named by to and the file named by from are on dif-
ferent logical devices (filesystems). Note that this error
code will not be returned if the implementation permits
cross-device links.
[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.
[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 filesystem containing the directory has been
exhausted.
[EIO] An I/O error occurred while making or updating a directory
entry.
[EROFS] The requested link requires writing in a directory on a
read-only file system.
[EFAULT] Path points outside the process's allocated address space.
[EINVAL] from is a parent directory of to, or an attempt is made to
rename '.' or '..'.
[ENOTEMPTY] to is a directory and is not empty.
open(2), symlink(7)
The rename() function conforms to IEEE Std 1003.1-1988 ("POSIX.1").
The system can deadlock if a loop in the filesystem graph is present.
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. Hard links to directories should be
replaced by symbolic links by the system administrator.
MirBSD #10-current June 4, 1993 1