PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

RENAME(3P)                POSIX Programmer's Manual               RENAME(3P)

PROLOG         top

       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.

NAME         top

       rename, renameat — rename file relative to directory file descriptor

SYNOPSIS         top

       #include <stdio.h>

       int rename(const char *old, const char *new);
       int renameat(int oldfd, const char *old, int newfd,
           const char *new);

DESCRIPTION         top

       For rename(): The functionality described on this reference page is
       aligned with the ISO C standard. Any conflict between the
       requirements described here and the ISO C standard is unintentional.
       This volume of POSIX.1‐2008 defers to the ISO C standard.

       The rename() function shall change 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 pathname of the file.  If the new argument
       does not resolve to an existing directory entry for a file of type
       directory and the new argument contains at least one non-<slash>
       character and ends with one or more trailing <slash> characters after
       all symbolic links have been processed, rename() shall fail.

       If either the old or new argument names a symbolic link, rename()
       shall operate on the symbolic link itself, and shall not resolve the
       last component of the argument. If the old argument and the new
       argument resolve to either the same existing directory entry or
       different directory entries for the same existing file, rename()
       shall return successfully and perform no other action.

       If the old argument points to the pathname of a file that is not a
       directory, the new argument shall not point to the pathname of a
       directory. If the link named by the new argument exists, it shall be
       removed and old renamed to new.  In this case, a link named new shall
       remain visible to other processes throughout the renaming operation
       and refer either to the file referred to by new or old before the
       operation began. Write access permission is required for both the
       directory containing old and the directory containing new.

       If the old argument points to the pathname of a directory, the new
       argument shall not point to the pathname of a file that is not a
       directory. If the directory named by the new argument exists, it
       shall be removed and old renamed to new.  In this case, a link named
       new shall exist throughout the renaming operation and shall refer
       either to the directory referred to by new or old before the
       operation began. If new names an existing directory, it shall be
       required to be an empty directory.

       If either pathname argument refers to a path whose final component is
       either dot or dot-dot, rename() shall fail.

       If the old argument points to a pathname of a symbolic link, the
       symbolic link shall be renamed. If the new argument points to a
       pathname of a symbolic link, the symbolic link shall be removed.

       The old pathname shall not name an ancestor directory of the new
       pathname. Write access permission is required for the directory
       containing old and the directory containing new.  If the old argument
       points to the pathname of a directory, write access permission may be
       required for the directory named by old, and, if it exists, the
       directory named by new.

       If the link named by the new 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
       rename() returns, but the removal of the file contents shall be
       postponed until all references to the file are closed.

       Upon successful completion, rename() shall mark for update the last
       data modification and last file status change timestamps of the
       parent directory of each file.

       If the rename() function fails for any reason other than [EIO], any
       file named by new shall be unaffected.

       The renameat() function shall be equivalent to the rename() function
       except in the case where either old or new specifies a relative path.
       If old is a relative path, the file to be renamed is located relative
       to the directory associated with the file descriptor oldfd instead of
       the current working directory. If new is a relative path, the same
       happens only relative to the directory associated with newfd.  If the
       file descriptor was opened without O_SEARCH, the function shall check
       whether directory searches are permitted using the current
       permissions of the directory underlying the file descriptor. If the
       file descriptor was opened with O_SEARCH, the function shall not
       perform the check.

       If renameat() is passed the special value AT_FDCWD in the oldfd or
       newfd parameter, the current working directory shall be used in the
       determination of the file for the respective path parameter.

RETURN VALUE         top

       Upon successful completion, the rename() function shall return 0.
       Otherwise, it shall return −1, errno shall be set to indicate the
       error, and neither the file named by old nor the file named by new
       shall be changed or created.

       Upon successful completion, the renameat() function shall return 0.
       Otherwise, it shall return −1 and set errno to indicate the error.

ERRORS         top

       The rename() and renameat() functions shall fail if:

       EACCES A component of either path prefix denies search permission; or
              one of the directories containing old or new denies write
              permissions; or, write permission is required and is denied
              for a directory pointed to by the old or new arguments.

       EBUSY  The directory named by old or new is currently in use by the
              system or another process, and the implementation considers
              this an error.

       [EEXIST] or [ENOTEMPTY]
                   The link named by new is a directory that is not an empty
                   directory.

       EINVAL      The old pathname names an ancestor directory of the new
                   pathname, or either pathname argument contains a final
                   component that is dot or dot-dot.

       EIO         A physical I/O error has occurred.

       EISDIR      The new argument points to a directory and the old
                   argument points to a file that is not a directory.

       ELOOP       A loop exists in symbolic links encountered during
                   resolution of the path argument.

       EMLINK      The file named by old is a directory, and the link count
                   of the parent directory of new would exceed {LINK_MAX}.

       ENAMETOOLONG
                   The length of a component of a pathname is longer than
                   {NAME_MAX}.

       ENOENT      The link named by old does not name an existing file, a
                   component of the path prefix of new 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 names an existing file
                   that is neither a directory nor a symbolic link to a
                   directory; or the old argument names a directory and the
                   new argument names a non-directory file; or the old
                   argument contains at least one non-<slash> character and
                   ends with one or more trailing <slash> characters and the
                   last pathname component names an existing file that is
                   neither a directory nor a symbolic link to a directory;
                   or the old argument names an existing non-directory file
                   and the new argument names a nonexistent file, contains
                   at least one non-<slash> character, and ends with one or
                   more trailing <slash> characters; or the new argument
                   names an existing non-directory file, contains at least
                   one non-<slash> character, and ends with one or more
                   trailing <slash> characters.

       EPERM or EACCES
                   The S_ISVTX flag is set on the directory containing the
                   file referred to by old and the process does not satisfy
                   the criteria specified in the Base Definitions volume of
                   POSIX.1‐2008, Section 4.2, Directory Protection with
                   respect to old; or new refers to an existing file, the
                   S_ISVTX flag is set on the directory containing this
                   file, and the process does not satisfy the criteria
                   specified in the Base Definitions volume of POSIX.1‐2008,
                   Section 4.2, Directory Protection with respect to this
                   file.

       EROFS       The requested operation requires writing in a directory
                   on a read-only file system.

       EXDEV       The links named by new and old are on different file
                   systems and the implementation does not support links
                   between file systems.

       In addition, the renameat() function shall fail if:

       EACCES oldfd or newfd was not opened with O_SEARCH and the
              permissions of the directory underlying oldfd or newfd
              respectively do not permit directory searches.

       EBADF  The old argument does not specify an absolute path and the
              oldfd argument is neither AT_FDCWD nor a valid file descriptor
              open for reading or searching, or the new argument does not
              specify an absolute path and the newfd argument is neither
              AT_FDCWD nor a valid file descriptor open for reading or
              searching.

       ENOTDIR
              The old or new argument is not an absolute path and oldfd or
              newfd, respectively, is a file descriptor associated with a
              non-directory file.

       The rename() and renameat() functions may fail if:

       EBUSY  The file named by the old or new arguments is a named STREAM.

       ELOOP  More than {SYMLOOP_MAX} symbolic links were encountered during
              resolution of the path argument.

       ENAMETOOLONG
              The length of a pathname exceeds {PATH_MAX}, or pathname
              resolution of a symbolic link produced an intermediate result
              with a length that exceeds {PATH_MAX}.

       ETXTBSY
              The file named by new exists and is the last directory entry
              to a pure procedure (shared text) file that is being executed.

       The following sections are informative.

EXAMPLES         top

   Renaming a File
       The following example shows how to rename a file named /home/cnd/mod1
       to /home/cnd/mod2.

           #include <stdio.h>

           int status;
           ...
           status = rename("/home/cnd/mod1", "/home/cnd/mod2");

APPLICATION USAGE         top

       Some implementations mark for update the last file status change
       timestamp of renamed files and some do not. Applications which make
       use of the last file status change timestamp may behave differently
       with respect to renamed files unless they are designed to allow for
       either behavior.

RATIONALE         top

       This rename() 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 new parameter names a file that already exists. That
       specification requires that the action of the function be atomic.

       One of the reasons for introducing this function was to have a means
       of renaming directories while permitting implementations to prohibit
       the use of link() and unlink() with directories, thus constraining
       links to directories to those made by mkdir().

       The specification that if old and new refer to the same file is
       intended to guarantee that:

           rename("x", "x");

       does not remove the file.

       Renaming dot or dot-dot is prohibited in order to prevent cyclical
       file system paths.

       See also the descriptions of [ENOTEMPTY] and [ENAMETOOLONG] in
       rmdir() and [EBUSY] in unlink().  For a discussion of [EXDEV], see
       link().

       The purpose of the renameat() function is to rename files in
       directories other than the current working directory without exposure
       to race conditions. Any part of the path of a file could be changed
       in parallel to a call to rename(), resulting in unspecified behavior.
       By opening file descriptors for the source and target directories and
       using the renameat() function it can be guaranteed that that renamed
       file is located correctly and the resulting file is in the desired
       directory.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       link(3p), rmdir(3p), symlink(3p), unlink(3p)

       The Base Definitions volume of POSIX.1‐2008, Section 4.2, Directory
       Protection, stdio.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                          RENAME(3P)

Pages that refer to this page: stdio.h(0p)mv(1p)link(3p)rmdir(3p)symlink(3p)unlink(3p)