The PHP realpath() function returns the absolute pathname.

The PHP realpath_cache_get() function returns realpath cache entries.

The PHP realpath_cache_size() function returns realpath cache size.

The PHP rename() function renames a file or directory.

The PHP rewind() function rewinds the position of the file pointer to the beginning of the file.

The PHP rmdir() function removes an empty directory.

The PHP set_file_buffer() function specifies the number of bytes to buffer on the given file.

The PHP stat() function returns information about a file. The informational array may contain the number index, the name index, or both.

The PHP symlink() function creates a symbolic link from the existing target with the specified name link.

The PHP tempnam() function creates a temporary file with a unique name in the specified directory.

The PHP tmpfile() function creates a temporary file with a unique name in read-write (w+) mode.

The PHP touch() function sets the access and modification time of the specified file.

The PHP umask() function changes the file permissions for files.

The PHP unlink() function deletes a file.