| @node renameat |
| @section @code{renameat} |
| @findex renameat |
| |
| POSIX specification:@* @url{https://pubs.opengroup.org/onlinepubs/9699919799/functions/renameat.html} |
| |
| Gnulib module: renameat |
| |
| Portability problems fixed by Gnulib: |
| @itemize |
| @item |
| This function is missing on some platforms: |
| glibc 2.3.6, Mac OS X 10.5, FreeBSD 6.0, NetBSD 5.0, OpenBSD 3.8, Minix 3.1.8, AIX 5.1, HP-UX 11, IRIX 6.5, Cygwin 1.5.x, mingw, MSVC 14. |
| But the replacement function is not safe to be used in libraries and is not |
| multithread-safe. |
| @item |
| This function is declared in @code{<unistd.h>}, not in @code{<stdio.h>}, |
| on some platforms: |
| NetBSD 7.0, Solaris 11.4. |
| @item |
| This function is declared in @code{<sys/stat.h>}, not in @code{<stdio.h>}, |
| on some platforms: |
| Android 4.3. |
| @item |
| This function does not reject trailing slashes on non-directories on |
| some platforms, as in @code{renameat(fd,"file",fd,"new/")}: |
| Solaris 11.4. |
| @item |
| This function ignores trailing slashes on symlinks on some platforms, |
| such that @code{renameat(fd,"link/",fd,"new")} corrupts @file{link}: |
| Solaris 9. |
| @end itemize |
| |
| Portability problems not fixed by Gnulib: |
| @itemize |
| @item |
| POSIX requires that @code{renameat(fd,"symlink-to-dir/",fd,"dir2")} rename |
| @file{dir} and leave @file{symlink-to-dir} dangling; likewise, it |
| requires that @code{renameat(fd,"dir",fd,"dangling/")} rename @file{dir} so |
| that @file{dangling} is no longer a dangling symlink. This behavior |
| is counter-intuitive, so on some systems, @code{renameat} fails with |
| @code{ENOTDIR} if either argument is a symlink with a trailing slash: |
| glibc, OpenBSD, Cygwin 1.7. |
| @item |
| POSIX requires that @code{renameat} 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 |