std::experimental::filesystem::rename - cppreference.com (original) (raw)
Moves or renames the filesystem object identified by old_p to new_p as if by the POSIX rename:
If old_p is a non-directory file, then new_p must be one of:
the same file as old_p or a hardlink to it: nothing is done in this case.
existing non-directory file: new_p is first deleted, then, without allowing other processes to observe new_p as deleted, the pathname new_p is linked to the file and old_p is unlinked from the file. Write permissions are required to both the directory that contains old_p and the directory that contains new_p.
non-existing file in an existing directory: The pathname new_p is linked to the file and old_p is unlinked from the file. Write permissions are required to both the directory that contains old_p and the directory that contains new_p.
If old_p is a directory, then new_p must be one of:
the same directory as old_p or a hardlink to it: nothing is done in this case.
existing directory: new_p is deleted if empty on POSIX systems, but this may be an error on other systems. If not an error, then new_p is first deleted, then, without allowing other processes to observe new_p as deleted, the pathname new_p is linked to the directory and old_p is unlinked from the directory. Write permissions are required to both the directory that contains old_p and the directory that contains new_p.
non-existing directory, not ending with a directory separator, and whose parent directory exists: The pathname new_p is linked to the directory and old_p is unlinked from the directory. Write permissions are required to both the directory that contains old_p and the directory that contains new_p.
Symlinks are not followed: if old_p is a symlink, it is itself renamed, not its target. If new_p is an existing symlink, it is itself erased, not its target.
Rename fails if
- new_p ends with dot or with dot-dot.
- new_p names a non-existing directory ending with a directory separator.
- old_p is a directory which is an ancestor of new_p.
[edit] Parameters
| old_p | - | path to move or rename |
|---|---|---|
| new_p | - | target path for the move/rename operation |
| ec | - | out-parameter for error reporting in the non-throwing overload |
[edit] Return value
(none)
[edit] Exceptions
The overload that does not take an error_code& parameter throws filesystem_error on underlying OS API errors, constructed with old_p as the first argument, new_p as the second argument, and the OS error code as the error code argument. std::bad_alloc may be thrown if memory allocation fails. The overload taking an error_code& parameter sets it to the OS API error code if an OS API call fails, and executes ec.clear() if no errors occur. This overload has
[edit] Example
#include <experimental/filesystem> #include #include namespace fs = std::experimental::filesystem; int main() { fs::path p = fs::current_path() / "sandbox"; fs::create_directories(p/"from"); std::ofstream(p/"from/file1.txt").put('a'); fs::create_directory(p/"to"); // fs::rename(p/"from/file1.txt", p/"to/"); // error: to is a directory fs::rename(p/"from/file1.txt", p/"to/file2.txt"); // OK // fs::rename(p/"from", p/"to"); // error: to is not empty fs::rename(p/"from", p/"to/subdir"); // OK fs::remove_all(p); }