Enum InputArg

pub enum InputArg {
    Stdin,
    Path(PathBuf),
}

An input path that can refer to either standard input or a file system path

Variants

Stdin

Refers to standard input.

This is the variant returned by InputArg::default().

Path(PathBuf)

Refers to a file system path (stored in .0)

Implementations

impl InputArg

pub fn from_arg<S: Into<PathBuf>>(arg: S) -> InputArg

Construct an InputArg from a string, usually one taken from command-line arguments. If the string equals "-" (i.e., it contains only a single hyphen/dash), InputArg::Stdin is returned; otherwise, an InputArg::Path is returned.

Example

use patharg::InputArg;
use std::path::PathBuf;

let p1 = InputArg::from_arg("-");
assert_eq!(p1, InputArg::Stdin);

let p2 = InputArg::from_arg("./-");
assert_eq!(p2, InputArg::Path(PathBuf::from("./-")));

pub fn is_stdin(&self) -> bool

Returns true if the input arg is the Stdin variant of InputArg.

Example

use patharg::InputArg;

let p1 = InputArg::from_arg("-");
assert!(p1.is_stdin());

let p2 = InputArg::from_arg("file.txt");
assert!(!p2.is_stdin());

pub fn is_path(&self) -> bool

Returns true if the input arg is the Path variant of InputArg.

Example

use patharg::InputArg;

let p1 = InputArg::from_arg("-");
assert!(!p1.is_path());

let p2 = InputArg::from_arg("file.txt");
assert!(p2.is_path());

pub fn path_ref(&self) -> Option<&PathBuf>

Retrieve a reference to the inner PathBuf. If the input arg is the Stdin variant, this returns None.

Example

use patharg::InputArg;
use std::path::PathBuf;

let p1 = InputArg::from_arg("-");
assert_eq!(p1.path_ref(), None);

let p2 = InputArg::from_arg("file.txt");
assert_eq!(p2.path_ref(), Some(&PathBuf::from("file.txt")));

pub fn path_mut(&mut self) -> Option<&mut PathBuf>

Retrieve a mutable reference to the inner PathBuf. If the input arg is the Stdin variant, this returns None.

Example

use patharg::InputArg;
use std::path::PathBuf;

let mut p1 = InputArg::from_arg("-");
assert_eq!(p1.path_mut(), None);

let mut p2 = InputArg::from_arg("file.txt");
assert_eq!(p2.path_mut(), Some(&mut PathBuf::from("file.txt")));

pub fn into_path(self) -> Option<PathBuf>

Consume the input arg and return the inner PathBuf. If the input arg is the Stdin variant, this returns None.

Example

use patharg::InputArg;
use std::path::PathBuf;

let p1 = InputArg::from_arg("-");
assert_eq!(p1.into_path(), None);

let p2 = InputArg::from_arg("file.txt");
assert_eq!(p2.into_path(), Some(PathBuf::from("file.txt")));

pub fn open(&self) -> Result<InputArgReader>

Open the input arg for reading.

If the input arg is the Stdin variant, this returns a locked reference to stdin. Otherwise, if the path arg is a Path variant, the given path is opened for reading.

The returned reader implements std::io::BufRead.

Errors

Has the same error conditions as std::fs::File::open.

Example

use patharg::InputArg;
use std::env::args_os;
use std::io::{self, Read};

fn main() -> io::Result<()> {
    let infile = args_os().nth(1)
                          .map(InputArg::from_arg)
                          .unwrap_or_default();
    let mut f = infile.open()?;
    let mut buffer = [0; 16];
    let n = f.read(&mut buffer)?;
    println!("First {} bytes: {:?}", n, &buffer[..n]);
    Ok(())
}

pub fn read(&self) -> Result<Vec<u8>>

Read the entire contents of the input arg into a bytes vector.

If the input arg is the Stdin variant, the entire contents of stdin are read. Otherwise, if the input arg is a Path variant, the contents of the given path are read.

Errors

Has the same error conditions as std::io::Read::read_to_end and std::fs::read.

Example

use patharg::InputArg;
use std::env::args_os;
use std::io;

fn main() -> io::Result<()> {
    let infile = args_os().nth(1)
                          .map(InputArg::from_arg)
                          .unwrap_or_default();
    let input = infile.read()?;
    println!("Read {} bytes from input", input.len());
    Ok(())
}

pub fn read_to_string(&self) -> Result<String>

Read the entire contents of the input arg into a string.

If the input arg is the Stdin variant, the entire contents of stdin are read. Otherwise, if the input arg is a Path variant, the contents of the given path are read.

Errors

Has the same error conditions as std::io::read_to_string and std::fs::read_to_string.

Example

use patharg::InputArg;
use std::env::args_os;
use std::io;

fn main() -> io::Result<()> {
    let infile = args_os().nth(1)
                          .map(InputArg::from_arg)
                          .unwrap_or_default();
    let input = infile.read_to_string()?;
    println!("Read {} characters from input", input.len());
    Ok(())
}

pub fn lines(&self) -> Result<Lines>

Return an iterator over the lines of the input arg.

If the input arg is the Stdin variant, this locks stdin and returns an iterator over its lines; the lock is released once the iterator is dropped. Otherwise, if the input arg is a Path variant, the given path is opened for reading, and an iterator over its lines is returned.

The returned iterator yields instances of std::io::Result<String>, where each individual item has the same error conditions as std::io::BufRead::read_line().

Errors

Has the same error conditions as InputArg::open().

Example

use patharg::InputArg;
use std::env::args_os;
use std::io;

fn main() -> io::Result<()> {
    let infile = args_os().nth(1)
                          .map(InputArg::from_arg)
                          .unwrap_or_default();
    for (i, r) in infile.lines()?.enumerate() {
        let line = r?;
        println!("Line {} is {} characters long.", i + 1, line.len());
    }
    Ok(())
}

impl InputArg

pub async fn async_open(&self) -> Result<AsyncInputArgReader>

Available on crate feature tokio only.

Asynchronously open the input arg for reading.

If the input arg is the Stdin variant, this returns a reference to stdin. Otherwise, if the path arg is a Path variant, the given path is opened for reading.

The returned reader implements tokio::io::AsyncRead.

Errors

Has the same error conditions as tokio::fs::File::open.

Example

use patharg::InputArg;
use std::env::args_os;
use tokio::io::AsyncReadExt;

#[tokio::main]
async fn main() -> std::io::Result<()> {
    let infile = args_os().nth(1)
                          .map(InputArg::from_arg)
                          .unwrap_or_default();
    let mut f = infile.async_open().await?;
    let mut buffer = [0; 16];
    let n = f.read(&mut buffer).await?;
    println!("First {} bytes: {:?}", n, &buffer[..n]);
    Ok(())
}

pub async fn async_read(&self) -> Result<Vec<u8>>

Available on crate feature tokio only.

Asynchronously read the entire contents of the input arg into a bytes vector.

If the input arg is the Stdin variant, the entire contents of stdin are read. Otherwise, if the input arg is a Path variant, the contents of the given path are read.

Errors

Has the same error conditions as tokio::io::AsyncReadExt::read_to_end and tokio::fs::read.

Example

use patharg::InputArg;
use std::env::args_os;

#[tokio::main]
async fn main() -> std::io::Result<()> {
    let infile = args_os().nth(1)
                          .map(InputArg::from_arg)
                          .unwrap_or_default();
    let input = infile.async_read().await?;
    println!("Read {} bytes from input", input.len());
    Ok(())
}

pub async fn async_read_to_string(&self) -> Result<String>

Available on crate feature tokio only.

Asynchronously read the entire contents of the input arg into a string.

If the input arg is the Stdin variant, the entire contents of stdin are read. Otherwise, if the input arg is a Path variant, the contents of the given path are read.

Errors

Has the same error conditions as tokio::io::AsyncReadExt::read_to_string and tokio::fs::read_to_string.

Example

use patharg::InputArg;
use std::env::args_os;

#[tokio::main]
async fn main() -> std::io::Result<()> {
    let infile = args_os().nth(1)
                          .map(InputArg::from_arg)
                          .unwrap_or_default();
    let input = infile.async_read_to_string().await?;
    println!("Read {} characters from input", input.len());
    Ok(())
}

pub async fn async_lines(&self) -> Result<AsyncLines>

Available on crate feature tokio only.

Return a stream over the lines of the input arg.

If the input arg is the Stdin variant, this returns a stream over the lines of stdin. Otherwise, if the input arg is a Path variant, the given path is opened for reading, and a stream over its lines is returned.

The returned stream yields instances of std::io::Result<String>, where each individual item has the same error conditions as tokio::io::AsyncBufReadExt::read_line().

Errors

Has the same error conditions as InputArg::async_open().

Example

use patharg::InputArg;
use std::env::args_os;
use tokio_stream::StreamExt;

#[tokio::main]
async fn main() -> std::io::Result<()> {
    let infile = args_os().nth(1)
                          .map(InputArg::from_arg)
                          .unwrap_or_default();
    let mut i = 1;
    let mut stream = infile.async_lines().await?;
    while let Some(r) = stream.next().await {
        let line = r?;
        println!("Line {} is {} characters long.", i, line.len());
        i += 1;
    }
    Ok(())
}

Trait Implementations

impl Clone for InputArg

fn clone(&self) -> InputArg

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for InputArg

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

Formats the value using the given formatter.

impl Default for InputArg

fn default() -> InputArg

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for InputArg

Available on crate feature serde only.

fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

where D: Deserializer<'de>,

Deserializes a PathBuf and converts it to an InputArg with InputArg::from_arg().

impl Display for InputArg

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

Displays InputArg::Stdin as - (a single hyphen/dash) or as <stdin> if the {:#} format is used. Always displays InputArg::Path using std::path::Path::display().

impl From<InputArg> for OsString

fn from(arg: InputArg) -> OsString

Convert an InputArg back to an OsString: InputArg::Stdin becomes "-", and InputArg::Path(p) becomes p.into().

impl<S: Into<PathBuf>> From<S> for InputArg

fn from(s: S) -> InputArg

Convert a string to an InputArg using InputArg::from_arg().

impl FromStr for InputArg

fn from_str(s: &str) -> Result<InputArg, Self::Err>

Convert a string to an InputArg using InputArg::from_arg().

type Err = Infallible

The associated error which can be returned from parsing.

impl Hash for InputArg

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Ord for InputArg

fn cmp(&self, other: &InputArg) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

impl PartialEq for InputArg

fn eq(&self, other: &InputArg) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for InputArg

fn partial_cmp(&self, other: &InputArg) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl Serialize for InputArg

Available on crate feature serde only.

fn serialize<S: Serializer>(&self, serializer: S) -> Result<S::Ok, S::Error>

Serializes InputArg::Stdin as "-" (a string containing a single hyphen/dash). Serializes InputArg::Path as the inner PathBuf; this will fail if the path is not valid UTF-8.

impl Eq for InputArg

impl StructuralPartialEq for InputArg