.\" $NetBSD: rename.2,v 1.11 1999/12/02 21:42:39 kleink Exp $ .\" .\" Copyright (c) 1983, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)rename.2 8.1 (Berkeley) 6/4/93 .\" .Dd June 4, 1993 .Dt RENAME 2 .Os .Sh NAME .Nm rename .Nd change the name of a file .Sh LIBRARY .Lb libc .Sh SYNOPSIS .Fd #include .Ft int .Fn rename "const char *from" "const char *to" .Sh DESCRIPTION .Fn rename causes the link named .Fa from to be renamed as .Fa to . If .Fa to exists, it is first removed. Both .Fa from and .Fa to must be of the same type (that is, both directories or both non-directories), and must reside on the same file system. .Pp .Fn rename guarantees that an instance of .Fa to will always exist, even if the system should crash in the middle of the operation. .Pp If the final component of .Fa from is a symbolic link, the symbolic link is renamed, not the file or directory to which it points. .Pp If both .Fa from and .Fa to are pathnames of the same existing file in the file system's name space, .Fn return returns successfully and performs no other action. .Sh CAVEAT The system can deadlock if a loop in the file system graph is present. This loop takes the form of an entry in directory .Ql Pa a , say .Ql Pa a/foo , being a hard link to directory .Ql Pa b , and an entry in directory .Ql Pa b , say .Ql Pa b/bar , being a hard link to directory .Ql Pa a . When such a loop exists and two separate processes attempt to perform .Ql rename a/foo b/bar and .Ql 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. .Sh RETURN VALUES A 0 value is returned if the operation succeeds, otherwise .Fn rename returns -1 and the global variable .Va errno indicates the reason for the failure. .Sh ERRORS .Fn rename will fail and neither of the argument files will be affected if: .Bl -tag -width Er .It Bq Er ENAMETOOLONG A component of a pathname exceeded .Dv {NAME_MAX} characters, or an entire path name exceeded .Dv {PATH_MAX} characters. .It Bq Er ENOENT A component of the .Fa from path does not exist, or a path prefix of .Fa to does not exist. .It Bq Er EACCES A component of either path prefix denies search permission. .It Bq Er EACCES The requested link requires writing in a directory with a mode that denies write permission. .It Bq Er EPERM The directory containing .Fa from is marked sticky, and neither the containing directory nor .Fa from are owned by the effective user ID. .It Bq Er EPERM The .Fa to file exists, the directory containing .Fa to is marked sticky, and neither the containing directory nor .Fa to are owned by the effective user ID. .It Bq Er ELOOP Too many symbolic links were encountered in translating either pathname. .It Bq Er ENOTDIR A component of either path prefix is not a directory. .It Bq Er ENOTDIR .Fa from is a directory, but .Fa to is not a directory. .It Bq Er EISDIR .Fa to is a directory, but .Fa from is not a directory. .It Bq Er EXDEV The link named by .Fa to and the file named by .Fa from are on different logical devices (file systems). Note that this error code will not be returned if the implementation permits cross-device links. .It Bq Er 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. .It Bq Er 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. .It Bq Er EIO An I/O error occurred while making or updating a directory entry. .It Bq Er EROFS The requested link requires writing in a directory on a read-only file system. .It Bq Er EFAULT .Em Path points outside the process's allocated address space. .It Bq Er EINVAL .Fa from is a parent directory of .Fa to , or an attempt is made to rename .Ql \&. or .Ql \&.. . .It Bq Er ENOTEMPTY .Fa to is a directory and is not empty. .El .Sh SEE ALSO .Xr open 2 , .Xr symlink 7 .Sh STANDARDS The .Fn rename function deviates from the semantics defined in .St -p1003.1-90 , which specifies that if both .Fa from and .Fa to .Em link to the same existing file, .Fn rename shall return successfully and performs no further action, whereas this implementation will remove the file specified by .Fa from unless both .Fa from and .Fa to are pathnames of the same file in the file system's name space. .Pp To retain conformance, a compatibility interface is provided by the .Lb libposix which is also be brought into scope if any of the .Dv _POSIX_SOURCE , .Dv _POSIX_C_SOURCE or .Dv _XOPEN_SOURCE preprocessor symbols are defined at compile-time: the .Fn rename function conforms to .St -p1003.1-90 and .St -xpg4.2 .