@node rename
@section @code{rename}
@findex rename

POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/rename.html}

Gnulib module: rename

Portability problems fixed by Gnulib:
@itemize
@item
This function does not allow trailing slashes when creating a
destination directory, as in @code{rename("dir","new/")}:
NetBSD 1.6.
@item
This function does not reject trailing slashes on the destination for
non-directories on some platforms, as in @code{rename("file","new/")}:
AIX 7.1, Solaris 11.3, Cygwin 1.5.x, mingw, MSVC 14.
@item
This function does not reject trailing slashes on symlinks to
non-directories on some platforms, as in
@code{rename("link-to-file/","f")}:
FreeBSD 7.2.
@item
This function ignores trailing slashes on symlinks on some platforms,
such that @code{rename("link/","new")} corrupts @file{link}:
Solaris 9.
@item
This function incorrectly reduces the link count when comparing two
spellings of a hard link on some platforms:
NetBSD 1.6, Cygwin 1.5.x.
@item
This function will not always replace an existing destination on some
platforms:
Cygwin 1.5.x, mingw, MSVC 14.
However, the replacement is not atomic for directories, and may end up
losing the empty destination if the source could not be renamed.
@item
This function mistakenly allows names ending in @samp{.} or @samp{..}
on some platforms:
Cygwin 1.5.x, mingw, MSVC 14.
@item
This function does not reject attempts to rename existing directories
and non-directories onto one another on some platforms:
Cygwin 1.5.x, mingw, MSVC 14.
@end itemize

Portability problems not fixed by Gnulib:
@itemize
@item
POSIX requires that @code{rename("symlink-to-dir/","dir2")} rename
@file{dir} and leave @file{symlink-to-dir} dangling; likewise, it
requires that @code{rename("dir","dangling/")} rename @file{dir} so
that @file{dangling} is no longer a dangling symlink.  This behavior
is counter-intuitive, so on some systems, @code{rename} fails with
@code{ENOTDIR} if either argument is a symlink with a trailing slash:
glibc, OpenBSD, Cygwin 1.7.
@item
POSIX requires that @code{rename} do nothing and return 0 if the
source and destination are hard links to the same file.  This behavior
is counterintuitive, and on some systems @code{renameat} is a no-op in
this way only if the source and destination identify the same
directory entry.  On these systems, for example, although renaming
@file{./f} to @file{f} is a no-op, renaming @file{f} to @file{g}
deletes @file{f} when @file{f} and @file{g} are hard links to the same
file:
NetBSD 7.0.
@item
After renaming a non-empty directory over an existing empty directory,
the old directory name is still visible through the @code{stat} function
for 30 seconds after the rename, on NFS file systems, on some platforms:
Linux 2.6.18.
@item
This function will not rename a source that is currently opened
by any process:
mingw, MSVC 14.
@end itemize