Trait OpenOptions

pub trait OpenOptions: Clone + Debug {
    type File: File;

    // Required methods
    fn read(&mut self, read: bool) -> &mut Self;
    fn write(&mut self, write: bool) -> &mut Self;
    fn append(&mut self, append: bool) -> &mut Self;
    fn truncate(&mut self, truncate: bool) -> &mut Self;
    fn create(&mut self, create: bool) -> &mut Self;
    fn create_new(&mut self, create_new: bool) -> &mut Self;
    fn open<P: AsRef<Path>>(&self, path: P) -> Result<Self::File>;
}

Options and flags which can be used to configure how a file is opened.

This trait replaces [std::fs::OpenOption] with the exception of its new function. To create a new OpenOptions, use GenFS::new_openopts.

Examples

Opening a file to read:

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts().read(true).open("foo.txt")?;

Opening a file for reading and writing and creating it if it does not exist:

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts()
             .read(true)
             .write(true)
             .create(true)
             .open("foo.txt")?;

Required Associated Types

type File: File

The File type in the module implementing this trait.

Required Methods

fn read(&mut self, read: bool) -> &mut Self

Sets the option for read access.

This option, when true, indicates a file should be read-able if opened.

Examples

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts().read(true).open("foo.txt")?;

fn write(&mut self, write: bool) -> &mut Self

Sets the option for write access.

This option, when true, indicates a file should be write-able if opened.

If the file already exists, write calls will overwrite existing file contents.

Examples

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts().write(true).open("foo.txt")?;

fn append(&mut self, append: bool) -> &mut Self

Sets the option for append mode.

This option, when true, means the file will always append to the current end of the file as opposed to overwriting existing contents.

Note that .append(true) implies .write(true).

Examples

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts().append(true).open("foo.txt")?;

fn truncate(&mut self, truncate: bool) -> &mut Self

Sets the option for truncating an existing file.

The file must be opened with write access for truncate to work.

Examples

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts().write(true).truncate(true).open("foo.txt")?;

fn create(&mut self, create: bool) -> &mut Self

Sets the option to create the file if it does not exist.

In order for a file to be created, write or append must also be used with this option.

Examples

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts().write(true).create(true).open("foo.txt")?;

fn create_new(&mut self, create_new: bool) -> &mut Self

Sets the option to always create a new file.

This option indicates whether a new file must be created, ensuring the file cannot exist already.

In order for a file to be created, write or append must also be used with this option.

Examples

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts().write(true).create_new(true).open("foo.txt")?;

fn open<P: AsRef<Path>>(&self, path: P) -> Result<Self::File>

Opens a file at path with options specified by self.

Errors

This function will return an error under a number of different circumstances, including but not limited to:

• Opening a file that does not exist without setting create or create_new.
• Attempting to open a file with access that the user lacks permissions for
• Filesystem-level errors (full disk, etc)
• Invalid combinations of open options (truncate without write access, no access mode set, etc)

Examples

use rsfs::*;
use rsfs::mem::FS;
let fs = FS::new();

let file = fs.new_openopts().open("foo.txt")?;

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl OpenOptions for rsfs::disk::OpenOptions

type File = File

impl OpenOptions for rsfs::mem::OpenOptions

type File = File

impl OpenOptions for rsfs::mem::unix::OpenOptions

type File = File