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NAME

       rename, renameat, renameat2 - change the name or location of a file

SYNOPSIS

       #include <stdio.h>

       int rename(const char *oldpath, const char *newpath);

       #include <fcntl.h>           /* Definition of AT_* constants */
       #include <stdio.h>

       int renameat(int olddirfd, const char *oldpath,
                    int newdirfd, const char *newpath);

       int renameat2(int olddirfd, const char *oldpath,
                     int newdirfd, const char *newpath, unsigned int flags);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       renameat():
           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:
               _ATFILE_SOURCE
       renameat2():
           _GNU_SOURCE

DESCRIPTION

       rename()  renames a file, moving it between directories if required.  Any other hard links
       to the file (as created using link(2)) are unaffected.  Open file descriptors for  oldpath
       are also unaffected.

       Various  restrictions  determine  whether or not the rename operation succeeds: see ERRORS
       below.

       If newpath already exists, it will be atomically replaced, so that there is  no  point  at
       which  another  process attempting to access newpath will find it missing.  However, there
       will probably be a window in which both oldpath  and  newpath  refer  to  the  file  being
       renamed.

       If  oldpath  and newpath are existing hard links referring to the same file, then rename()
       does nothing, and returns a success status.

       If newpath exists but the operation fails for some reason, rename() guarantees to leave an
       instance of newpath in place.

       oldpath  can specify a directory.  In this case, newpath must either not exist, or it must
       specify an empty directory.

       If oldpath refers to a symbolic link, the link is renamed; if newpath refers to a symbolic
       link, the link will be overwritten.

   renameat()
       The  renameat()  system  call operates in exactly the same way as rename(), except for the
       differences described here.

       If the pathname given in oldpath is relative, then  it  is  interpreted  relative  to  the
       directory referred to by the file descriptor olddirfd (rather than relative to the current
       working directory of the calling process, as is done by rename() for a relative pathname).

       If oldpath is relative and olddirfd  is  the  special  value  AT_FDCWD,  then  oldpath  is
       interpreted  relative  to  the  current  working  directory  of  the calling process (like
       rename()).

       If oldpath is absolute, then olddirfd is ignored.

       The interpretation of newpath is as for  oldpath,  except  that  a  relative  pathname  is
       interpreted relative to the directory referred to by the file descriptor newdirfd.

       See openat(2) for an explanation of the need for renameat().

   renameat2()
       renameat2()  has  an  additional  flags  argument.   A  renameat2() call with a zero flags
       argument is equivalent to renameat().

       The flags argument is a bit mask consisting of zero or more of the following flags:

       RENAME_EXCHANGE
              Atomically exchange oldpath and newpath.  Both pathnames must exist but may  be  of
              different  types (e.g., one could be a non-empty directory and the other a symbolic
              link).

       RENAME_NOREPLACE
              Don't overwrite newpath of the rename.  Return an error if newpath already exists.

              RENAME_NOREPLACE can't be employed together with RENAME_EXCHANGE.

              RENAME_NOREPLACE requires support from  the  underlying  filesystem.   Support  for
              various filesystems was added as follows:

              *  ext4 (Linux 3.15);

              *  btrfs, shmem, and cifs (Linux 3.17);

              *  xfs (Linux 4.0);

              *  Support  for  many  other  filesystems  was  added in Linux 4.9, including etx2,
                 minix, reiserfs, jfs, vfat, and bpf.

       RENAME_WHITEOUT (since Linux 3.18)
              This operation makes sense only for overlay/union filesystem implementations.

              Specifying RENAME_WHITEOUT creates a "whiteout" object at the source of the  rename
              at  the same time as performing the rename.  The whole operation is atomic, so that
              if the rename succeeds then the whiteout will also have been created.

              A "whiteout" is an object that has  special  meaning  in  union/overlay  filesystem
              constructs.   In  these  constructs,  multiple layers exist and only the top one is
              ever modified.  A whiteout on an upper layer will effectively hide a matching  file
              in the lower layer, making it appear as if the file didn't exist.

              When  a file that exists on the lower layer is renamed, the file is first copied up
              (if not already on the upper layer) and  then  renamed  on  the  upper,  read-write
              layer.   At  the  same  time, the source file needs to be "whiteouted" (so that the
              version of the source file in the lower layer is rendered  invisible).   The  whole
              operation needs to be done atomically.

              When not part of a union/overlay, the whiteout appears as a character device with a
              {0,0} device number.  (Note that other  union/overlay  implementations  may  employ
              different  methods  for  storing  whiteout  entries;  specifically, BSD union mount
              employs a separate inode type, DT_WHT, which, while supported by  some  filesystems
              available  in  Linux,  such  as  CODA  and XFS, is ignored by the kernel's whiteout
              support code, as of Linux 4.19, at least.)

              RENAME_WHITEOUT requires the same privileges as creating a device node  (i.e.,  the
              CAP_MKNOD capability).

              RENAME_WHITEOUT can't be employed together with RENAME_EXCHANGE.

              RENAME_WHITEOUT  requires  support  from  the  underlying  filesystem.   Among  the
              filesystems that provide that support are tmpfs (since  Linux  3.18),  ext4  (since
              Linux  3.18),  XFS  (since  Linux 4.1), f2fs (since Linux 4.2).  btrfs (since Linux
              4.7), and ubifs (since Linux 4.9).

RETURN VALUE

       On success, zero is returned.  On error, -1 is returned, and errno is set appropriately.

ERRORS

       EACCES Write permission is denied for the directory containing  oldpath  or  newpath,  or,
              search  permission  is  denied  for  one  of  the directories in the path prefix of
              oldpath or newpath, or oldpath is a directory and does not allow  write  permission
              (needed to update the ..  entry).  (See also path_resolution(7).)

       EBUSY  The  rename  fails because oldpath or newpath is a directory that is in use by some
              process (perhaps as current working directory, or as root directory, or because  it
              was  open  for  reading)  or  is in use by the system (for example as mount point),
              while the system considers this an error.  (Note that there is  no  requirement  to
              return  EBUSY in such cases—there is nothing wrong with doing the rename anyway—but
              it is  allowed  to  return  EBUSY  if  the  system  cannot  otherwise  handle  such
              situations.)

       EDQUOT The user's quota of disk blocks on the filesystem has been exhausted.

       EFAULT oldpath or newpath points outside your accessible address space.

       EINVAL The new pathname contained a path prefix of the old, or, more generally, an attempt
              was made to make a directory a subdirectory of itself.

       EISDIR newpath is an existing directory, but oldpath is not a directory.

       ELOOP  Too many symbolic links were encountered in resolving oldpath or newpath.

       EMLINK oldpath already has the maximum number of links to it, or it was  a  directory  and
              the directory containing newpath has the maximum number of links.

       ENAMETOOLONG
              oldpath or newpath was too long.

       ENOENT The link named by oldpath does not exist; or, a directory component in newpath does
              not exist; or, oldpath or newpath is an empty string.

       ENOMEM Insufficient kernel memory was available.

       ENOSPC The device containing the file has no room for the new directory entry.

       ENOTDIR
              A component used as a directory in oldpath or newpath is not, in fact, a directory.
              Or, oldpath is a directory, and newpath exists but is not a directory.

       ENOTEMPTY or EEXIST
              newpath is a nonempty directory, that is, contains entries other than "." and "..".

       EPERM or EACCES
              The directory containing oldpath has the sticky bit (S_ISVTX) set and the process's
              effective user ID is neither the user ID of the file to be deleted nor that of  the
              directory  containing  it,  and the process is not privileged (Linux: does not have
              the CAP_FOWNER capability); or newpath  is  an  existing  file  and  the  directory
              containing it has the sticky bit set and the process's effective user ID is neither
              the user ID of the file to be replaced nor that of the directory containing it, and
              the  process is not privileged (Linux: does not have the CAP_FOWNER capability); or
              the filesystem containing pathname does not support renaming of the type requested.

       EROFS  The file is on a read-only filesystem.

       EXDEV  oldpath and newpath are not on the  same  mounted  filesystem.   (Linux  permits  a
              filesystem  to  be  mounted  at  multiple points, but rename() does not work across
              different mount points, even if the same filesystem is mounted on both.)

       The following additional errors can occur for renameat() and renameat2():

       EBADF  olddirfd or newdirfd is not a valid file descriptor.

       ENOTDIR
              oldpath is relative and olddirfd is a file descriptor referring  to  a  file  other
              than a directory; or similar for newpath and newdirfd

       The following additional errors can occur for renameat2():

       EEXIST flags contains RENAME_NOREPLACE and newpath already exists.

       EINVAL An invalid flag was specified in flags.

       EINVAL Both RENAME_NOREPLACE and RENAME_EXCHANGE were specified in flags.

       EINVAL Both RENAME_WHITEOUT and RENAME_EXCHANGE were specified in flags.

       EINVAL The filesystem does not support one of the flags in flags.

       ENOENT flags contains RENAME_EXCHANGE and newpath does not exist.

       EPERM  RENAME_WHITEOUT  was specified in flags, but the caller does not have the CAP_MKNOD
              capability.

VERSIONS

       renameat() was added to Linux in kernel 2.6.16; library support  was  added  to  glibc  in
       version 2.4.

       renameat2() was added to Linux in kernel 3.15; library support was added in glibc 2.28.

CONFORMING TO

       rename(): 4.3BSD, C89, C99, POSIX.1-2001, POSIX.1-2008.

       renameat(): POSIX.1-2008.

       renameat2() is Linux-specific.

NOTES

   Glibc notes
       On older kernels where renameat() is unavailable, the glibc wrapper function falls back to
       the use of rename().  When oldpath and newpath are relative  pathnames,  glibc  constructs
       pathnames based on the symbolic links in /proc/self/fd that correspond to the olddirfd and
       newdirfd arguments.

BUGS

       On NFS filesystems, you can not assume that if the operation  failed,  the  file  was  not
       renamed.   If the server does the rename operation and then crashes, the retransmitted RPC
       which will be processed when the server is up again causes a failure.  The application  is
       expected to deal with this.  See link(2) for a similar problem.

SEE ALSO

       mv(1), chmod(2), link(2), symlink(2), unlink(2), path_resolution(7), symlink(7)

COLOPHON

       This  page  is  part of release 5.02 of the Linux man-pages project.  A description of the
       project, information about reporting bugs, and the latest version of  this  page,  can  be
       found at https://www.kernel.org/doc/man-pages/.