//! Re-open a `fs::File` to produce an independent handle.
use crate::fs::{is_file_read_write, is_same_file, reopen_impl, OpenOptions};
use std::{fs, io};
/// Re-open an `fs::File` to produce an independent handle.
///
/// This operation isn't supported by all operating systems in all
/// circumstances, or in some operating systems in any circumstances,
/// so it may return an `io::ErrorKind::Other` error if the file
/// cannot be reopened.
#[inline]
pub fn reopen(file: &fs::File, options: &OpenOptions) -> io::Result<fs::File> {
let (read, write) = is_file_read_write(file)?;
// Don't grant more rights than the original file had. And don't allow
// it to create a file.
if options.create
|| options.create_new
|| (!read && options.read)
|| (!write && (options.write || options.append || options.truncate))
{
return Err(io::Error::new(
io::ErrorKind::PermissionDenied,
"Couldn't reopen file",
));
}
let new = reopen_impl(file, options)?;
if !is_same_file(file, &new)? {
return Err(io::Error::new(io::ErrorKind::Other, "Couldn't reopen file"));
}
Ok(new)
}