Struct clio::CachedInput

pub struct CachedInput { /* fields omitted */ }

A struct that contains all the connents of a command line input stream, either std in or a file

It is designed to be used with the structopt crate when taking a file name as an argument to CLI app

use structopt::StructOpt;
use clio::CachedInput;

#[derive(StructOpt)]
struct Opt {
    /// path to file, use '-' for stdin
    #[structopt(parse(try_from_os_str = CachedInput::try_from_os_str))]
    input_file: CachedInput,
}

Implementations

impl CachedInput

pub fn new(source: Input) -> Result<Self>

Reads all the data from an input into memmory and stores it in a new CachedInput.

Useful if you want to use the input twice (see reset), or need to know the size.

pub fn try_from_os_str(path: &OsStr) -> Result<Self, OsString>

Contructs a new input either by opening the file or for ‘-’ returning stdin. The error is converted to a OsString so that stuctopt can show it to the user.

pub fn len(&self) -> u64

Returns the size of the file in bytes.

Examples

let file = clio::CachedInput::try_from_os_str("foo.txt".as_ref()).unwrap();

assert_eq!(3, file.len());

pub fn is_empty(&self) -> bool

Returns a boolean saying if the file is empty

Examples

let file = clio::CachedInput::try_from_os_str("foo.txt".as_ref()).unwrap();

assert_eq!(true, file.is_empty());

pub fn path(&self) -> &OsStr

Returns the path/url used to create the input

pub fn reset(&mut self)

Resets the reader back to the start of the file

pub fn into_vec(self) -> Vec<u8>

Returns data from the input as a Vec

pub fn get_data(&self) -> &[u8]

Returns reference to the data from the input as a slice

Trait Implementations

impl Debug for CachedInput

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for CachedInput

fn fmt(&self, fmt: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Read for CachedInput

fn read(&mut self, buf: &mut [u8]) -> IoResult<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, bufs: &mut [IoSliceMut<'_>]) -> Result<usize, Error>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬 This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

unsafe fn initializer(&self) -> Initializer

🔬 This is a nightly-only experimental API. (read_initializer)

Determines if this Reader can work with buffers of uninitialized memory.

fn read_to_end(&mut self, buf: &mut Vec<u8, Global>) -> Result<usize, Error>

Read all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Read all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Read the exact number of bytes required to fill buf.

fn by_ref(&mut self) -> &mut Self

Creates a “by reference” adapter for this instance of Read.

fn bytes(self) -> Bytes<Self>

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R> where
    R: Read, 

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

Creates an adapter which will read at most limit bytes from it.

impl Seek for CachedInput

fn seek(&mut self, pos: SeekFrom) -> IoResult<u64>

Seek to an offset, in bytes, in a stream.

fn rewind(&mut self) -> Result<(), Error>

Rewind to the beginning of a stream.

fn stream_len(&mut self) -> Result<u64, Error>

🔬 This is a nightly-only experimental API. (seek_stream_len)

Returns the length of this stream (in bytes).

fn stream_position(&mut self) -> Result<u64, Error>

Returns the current seek position from the start of the stream.

impl TryFrom<&'_ OsStr> for CachedInput

type Error = OsString

The type returned in the event of a conversion error.

fn try_from(file_name: &OsStr) -> Result<Self, OsString>

Performs the conversion.