Struct FileOrStdout 

pub struct FileOrStdout { /* private fields */ }

FileOrStdout can be used as a proxy output writer to write to whichever destination was specified by the CLI args, a file or stdout.

use std::path::PathBuf;
use std::io::Write;
use clap::Parser;
use clap_stdin::FileOrStdout;

#[derive(Debug, Parser)]
struct Args {
    output: FileOrStdout,
}

if let Ok(args) = Args::try_parse() {
    let mut writer = args.output.into_writer()?;
    write!(&mut writer, "1 2 3 4");
}

$ ./example output.txt
1 2 3 4
$ cat output.txt | ./example -
1 2 3 4

Implementations

impl FileOrStdout

pub fn is_stdout(&self) -> bool

Was this value read from stdout

pub fn is_file(&self) -> bool

Was this value read from a file (path passed in from argument values)

pub fn filename(&self) -> &str

The value passed to this arg (Either “-” for stdout or a filepath)

pub fn into_writer(self) -> Result<impl Write, Error>

Create a writer for the dest, to allow user flexibility of how to write output (e.g. all at once or in chunks)

use std::io::Write;

use clap_stdin::FileOrStdout;
use clap::Parser;

#[derive(Parser)]
struct Args {
  output: FileOrStdout,
}

let args = Args::parse();
let mut writer = args.output.into_writer()?;
let mut buf = vec![0;8];
writer.write_all(&mut buf)?;

Trait Implementations

impl Clone for FileOrStdout

fn clone(&self) -> FileOrStdout

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FileOrStdout

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

Formats the value using the given formatter.

impl FromStr for FileOrStdout

type Err = Error

The associated error which can be returned from parsing.

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

Parses a string s to return a value of this type.