.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved .TH "RENAME" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual" .\" rename .SH PROLOG This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux. .SH NAME rename \- rename a file .SH SYNOPSIS .LP \fB#include .br .sp int rename(const char *\fP\fIold\fP\fB, const char *\fP\fInew\fP\fB); .br \fP .SH DESCRIPTION .LP The \fIrename\fP() function shall change the name of a file. The \fIold\fP argument points to the pathname of the file to be renamed. The \fInew\fP argument points to the new pathname of the file. .LP If either the \fIold\fP or \fInew\fP argument names a symbolic link, \fIrename\fP() shall operate on the symbolic link itself, and shall not resolve the last component of the argument. If the \fIold\fP argument and the \fInew\fP argument resolve to the same existing file, \fIrename\fP() shall return successfully and perform no other action. .LP If the \fIold\fP argument points to the pathname of a file that is not a directory, the \fInew\fP argument shall not point to the pathname of a directory. If the link named by the \fInew\fP argument exists, it shall be removed and \fIold\fP renamed to \fInew\fP. In this case, a link named \fInew\fP shall remain visible to other processes throughout the renaming operation and refer either to the file referred to by \fInew\fP or \fIold\fP before the operation began. Write access permission is required for both the directory containing \fIold\fP and the directory containing \fInew\fP. .LP If the \fIold\fP argument points to the pathname of a directory, the \fInew\fP argument shall not point to the pathname of a file that is not a directory. If the directory named by the \fInew\fP argument exists, it shall be removed and \fIold\fP renamed to \fInew\fP. In this case, a link named \fInew\fP shall exist throughout the renaming operation and shall refer either to the directory referred to by \fInew\fP or \fIold\fP before the operation began. If \fInew\fP names an existing directory, it shall be required to be an empty directory. .LP If the \fIold\fP argument points to a pathname of a symbolic link, the symbolic link shall be renamed. If the \fInew\fP argument points to a pathname of a symbolic link, the symbolic link shall be removed. .LP The \fInew\fP pathname shall not contain a path prefix that names \fIold\fP. Write access permission is required for the directory containing \fIold\fP and the directory containing \fInew\fP. If the \fIold\fP argument points to the pathname of a directory, write access permission may be required for the directory named by \fIold\fP, and, if it exists, the directory named by \fInew\fP. .LP If the link named by the \fInew\fP argument exists and the file's link count becomes 0 when it is removed and no process has the file open, the space occupied by the file shall be freed and the file shall no longer be accessible. If one or more processes have the file open when the last link is removed, the link shall be removed before \fIrename\fP() returns, but the removal of the file contents shall be postponed until all references to the file are closed. .LP Upon successful completion, \fIrename\fP() shall mark for update the \fIst_ctime\fP and \fIst_mtime\fP fields of the parent directory of each file. .LP If the \fIrename\fP() function fails for any reason other than [EIO], any file named by \fInew\fP shall be unaffected. .SH RETURN VALUE .LP Upon successful completion, \fIrename\fP() shall return 0; otherwise, -1 shall be returned, \fIerrno\fP shall be set to indicate the error, and neither the file named by \fIold\fP nor the file named by \fInew\fP shall be changed or created. .SH ERRORS .LP The \fIrename\fP() function shall fail if: .TP 7 .B EACCES A component of either path prefix denies search permission; or one of the directories containing \fIold\fP or \fInew\fP denies write permissions; or, write permission is required and is denied for a directory pointed to by the \fIold\fP or \fInew\fP arguments. .TP 7 .B EBUSY The directory named by \fIold\fP or \fInew\fP is currently in use by the system or another process, and the implementation considers this an error. .TP 7 .B EEXIST \fRor\fP ENOTEMPTY .sp The link named by \fInew\fP is a directory that is not an empty directory. .TP 7 .B EINVAL The \fInew\fP directory pathname contains a path prefix that names the \fIold\fP directory. .TP 7 .B EIO A physical I/O error has occurred. .TP 7 .B EISDIR The \fInew\fP argument points to a directory and the \fIold\fP argument points to a file that is not a directory. .TP 7 .B ELOOP A loop exists in symbolic links encountered during resolution of the \fIpath\fP argument. .TP 7 .B EMLINK The file named by \fIold\fP is a directory, and the link count of the parent directory of \fInew\fP would exceed {LINK_MAX}. .TP 7 .B ENAMETOOLONG .sp The length of the \fIold\fP or \fInew\fP argument exceeds {PATH_MAX} or a pathname component is longer than {NAME_MAX}. .TP 7 .B ENOENT The link named by \fIold\fP does not name an existing file, or either \fIold\fP or \fInew\fP points to an empty string. .TP 7 .B ENOSPC The directory that would contain \fInew\fP cannot be extended. .TP 7 .B ENOTDIR A component of either path prefix is not a directory; or the \fIold\fP argument names a directory and \fInew\fP argument names a non-directory file. .TP 7 .B EPERM \fRor\fP EACCES .sp The S_ISVTX flag is set on the directory containing the file referred to by \fIold\fP and the caller is not the file owner, nor is the caller the directory owner, nor does the caller have appropriate privileges; or \fInew\fP refers to an existing file, the S_ISVTX flag is set on the directory containing this file, and the caller is not the file owner, nor is the caller the directory owner, nor does the caller have appropriate privileges. .TP 7 .B EROFS The requested operation requires writing in a directory on a read-only file system. .TP 7 .B EXDEV The links named by \fInew\fP and \fIold\fP are on different file systems and the implementation does not support links between file systems. .sp .LP The \fIrename\fP() function may fail if: .TP 7 .B EBUSY The file named by the \fIold\fP or \fInew\fP arguments is a named STREAM. .TP 7 .B ELOOP More than {SYMLOOP_MAX} symbolic links were encountered during resolution of the \fIpath\fP argument. .TP 7 .B ENAMETOOLONG .sp As a result of encountering a symbolic link in resolution of the \fIpath\fP argument, the length of the substituted pathname string exceeded {PATH_MAX}. .TP 7 .B ETXTBSY The file to be renamed is a pure procedure (shared text) file that is being executed. .sp .LP \fIThe following sections are informative.\fP .SH EXAMPLES .SS Renaming a File .LP The following example shows how to rename a file named \fB/home/cnd/mod1\fP to \fB/home/cnd/mod2\fP. .sp .RS .nf \fB#include .sp int status; \&... status = rename("/home/cnd/mod1", "/home/cnd/mod2"); \fP .fi .RE .SH APPLICATION USAGE .LP Some implementations mark for update the \fIst_ctime\fP field of renamed files and some do not. Applications which make use of the \fIst_ctime\fP field may behave differently with respect to renamed files unless they are designed to allow for either behavior. .SH RATIONALE .LP This \fIrename\fP() function is equivalent for regular files to that defined by the ISO\ C standard. Its inclusion here expands that definition to include actions on directories and specifies behavior when the \fInew\fP parameter names a file that already exists. That specification requires that the action of the function be atomic. .LP One of the reasons for introducing this function was to have a means of renaming directories while permitting implementations to prohibit the use of \fIlink\fP() and \fIunlink\fP() with directories, thus constraining links to directories to those made by \fImkdir\fP(). .LP The specification that if \fIold\fP and \fInew\fP refer to the same file is intended to guarantee that: .sp .RS .nf \fBrename("x", "x"); \fP .fi .RE .LP does not remove the file. .LP Renaming dot or dot-dot is prohibited in order to prevent cyclical file system paths. .LP See also the descriptions of [ENOTEMPTY] and [ENAMETOOLONG] in \fIrmdir\fP() and [EBUSY] in \fIunlink\fP(). For a discussion of [EXDEV], see \fIlink\fP() \&. .SH FUTURE DIRECTIONS .LP None. .SH SEE ALSO .LP \fIlink\fP(), \fIrmdir\fP(), \fIsymlink\fP(), \fIunlink\fP(), the Base Definitions volume of IEEE\ Std\ 1003.1-2001, \fI\fP .SH COPYRIGHT Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .