Struct clio::CachedInput

pub struct CachedInput { /* private fields */ }

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

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

use clap::Parser;
use clio::CachedInput;

#[derive(Parser)]
struct Opt {
    /// path to file, use '-' for stdin
    #[clap(value_parser)]
    input_file: CachedInput,
}

Implementations

impl CachedInput

pub fn new<S: TryInto<ClioPath>>(path: S) -> Result<Self>

where Error: From<<S as TryInto<ClioPath>>::Error>,

Reads all the data from an file (stdin for “-”) into memory and stores it in a new CachedInput. If it detects it is trying to read from a TTY then it will return an error.

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

This is mostly a wrapper around Input::read_all() so so that any errors reading the data will be shown automatically with claps pretty error formatting.

pub fn std() -> Result<Self>

Reads all the data from stdin into memory and stores it in a new CachedInput.

This will block until std in is closed.

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

Constructs a new CachedInput either by opening the file or for ‘-’ stdin and reading all the data into memory.

The error is converted to a OsString so that stuctopt can show it to the user.

It is recommended that you use TryFrom::try_from and clap 3.0 instead.

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) -> &ClioPath

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<u8>

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

Returns reference to the data from the input as a slice

Trait Implementations

impl BufRead for CachedInput

fn fill_buf(&mut self) -> IoResult<&[u8]>

Returns the contents of the internal buffer, filling it with more data from the inner reader if it is empty.

fn consume(&mut self, amt: usize)

Tells this buffer that amt bytes have been consumed from the buffer, so they should no longer be returned in calls to read.

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

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

Check if the underlying Read has any data left to be read.

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

Read all bytes into buf until the delimiter byte or EOF is reached.

fn skip_until(&mut self, byte: u8) -> Result<usize, Error>

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

Skip all bytes until the delimiter byte or EOF is reached.

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

Read all bytes until a newline (the 0xA byte) is reached, and append them to the provided String buffer.

fn split(self, byte: u8) -> Split<Self>

where Self: Sized,

Returns an iterator over the contents of this reader split on the byte byte.

fn lines(self) -> Lines<Self>

where Self: Sized,

Returns an iterator over the lines of this reader.

impl Clone for CachedInput

fn clone(&self) -> CachedInput

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CachedInput

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

Formats the value using the given formatter.

impl Display for CachedInput

formats as the path it was created from

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.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> 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 read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

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

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

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

Read the exact number of bytes required to fill cursor.

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

where Self: Sized,

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

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

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

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

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

where Self: Sized,

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.

fn seek_relative(&mut self, offset: i64) -> Result<(), Error>

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

Seeks relative to the current position.

impl TryFrom<&OsStr> for CachedInput

type Error = Error

The type returned in the event of a conversion error.

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

Performs the conversion.

impl TryFrom<&OsString> for CachedInput

type Error = Error

The type returned in the event of a conversion error.

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

Performs the conversion.

impl TryFrom<&Path> for CachedInput

type Error = Error

The type returned in the event of a conversion error.

fn try_from(file_name: &Path) -> Result<Self>

Performs the conversion.

impl TryFrom<&PathBuf> for CachedInput

type Error = Error

The type returned in the event of a conversion error.

fn try_from(file_name: &PathBuf) -> Result<Self>

Performs the conversion.

impl TryFrom<&String> for CachedInput

type Error = Error

The type returned in the event of a conversion error.

fn try_from(file_name: &String) -> Result<Self>

Performs the conversion.

impl TryFrom<&str> for CachedInput

type Error = Error

The type returned in the event of a conversion error.

fn try_from(file_name: &str) -> Result<Self>

Performs the conversion.

impl TryFrom<ClioPath> for CachedInput

type Error = Error

The type returned in the event of a conversion error.

fn try_from(file_name: ClioPath) -> Result<Self>

Performs the conversion.

impl ValueParserFactory for CachedInput

Available on crate feature clap-parse only.

type Parser = OsStrParser<CachedInput>

Generated parser, usually [ValueParser].

fn value_parser() -> Self::Parser

Create the specified [Self::Parser]