Struct File

pub struct File(/* private fields */);

Represents an open File

Implementations

impl File

pub fn open(path: Path<'_>, flags: Flags) -> Result<Self>

Open a file, given a path as UTF-8 string.

If the file does not exist, or is already open, it returns an error.

Path may be relative to current directory, or it may be an absolute path.

Limitations

• You cannot open a file if it is currently open.
• Paths must confirm to the rules for the filesystem for the given drive.
• Relative paths are taken relative to the current directory (see Api::chdir).

pub fn write(&self, buffer: &[u8]) -> Result<()>

Write to an open file handle, blocking until everything is written.

Some files do not support writing and will produce an error. You will also get an error if you run out of disk space.

The buffer is only borrowed for the duration of the function call and is then forgotten.

pub fn read(&self, buffer: &mut [u8]) -> Result<usize>

Read from an open file, returning how much was actually read.

You might get less data than you asked for. If you do an Api::read and you are already at the end of the file you will get Err(Error::EndOfFile).

Data is stored to the given buffer. The buffer` is only borrowed for the duration of the function call and is then forgotten.

pub fn close(self) -> Result<()>

Close a file

pub fn seek_set(&self, position: u64) -> Result<()>

Move the file offset (for the given file handle) to the given position.

Some files do not support seeking and will produce an error.

pub fn seek_cur(&self, offset: i64) -> Result<u64>

Move the file offset (for the given file handle) relative to the current position.

Returns the new position, or an error.

Some files do not support seeking and will produce an error.

pub fn seek_end(&self) -> Result<u64>

Move the file offset (for the given file handle) to the end of the file

Returns the new position, or an error.

Some files do not support seeking and will produce an error.

pub fn rename(old_path: Path<'_>, new_path: Path<'_>) -> Result<()>

Rename a file.

Limitations

• You cannot rename a file if it is currently open.
• You cannot rename a file where the old_path and the new_path are not on the same drive.
• Paths must confirm to the rules for the filesystem for the given drive.

pub fn ioctl(&self, command: u64, value: u64) -> Result<u64>

Perform a special I/O control operation.

The allowed values of command and value are TBD.

pub fn stat(&self) -> Result<Stat>

Get information about this file.

Trait Implementations

impl Drop for File

fn drop(&mut self)

Executes the destructor for this type.

impl Write for &File

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result<(), Error>

Writes a char into this writer, returning whether the write succeeded.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Glue for usage of the write! macro with implementors of this trait.

impl Write for File

fn write_str(&mut self, s: &str) -> Result

Writes a string slice into this writer, returning whether the write succeeded.

fn write_char(&mut self, c: char) -> Result<(), Error>

Writes a char into this writer, returning whether the write succeeded.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Glue for usage of the write! macro with implementors of this trait.