Enum OutDest 

pub enum OutDest {
    Pipe,
    PipeSeparate,
    Value,
    Null,
    Inherit,
    Print,
    File(Arc<File>),
}

Describes where to direct a command’s stdout or stderr.

Used both for external-process stdio wiring and for Nushell’s internal pipeline destination (print vs pipe vs collect-to-value, etc.).

Variants

Pipe

Redirect the stdout and/or stderr of one command as the input for the next command in the pipeline.

The output pipe will be available as the stdout of ChildProcess.

If stdout and stderr are both set to Pipe, then they will combined into the stdout of ChildProcess.

PipeSeparate

Redirect the stdout and/or stderr of one command as the input for the next command in the pipeline.

The output stream(s) will be available in the stdout or stderr of ChildProcess.

This is similar to Pipe but will never combine stdout and stderr or place an external command’s stderr into stdout of ChildProcess.

Value

Signifies the result of the pipeline will be immediately collected into a value after this command.

So, it is fine to collect the stream ahead of time in the current command.

Null

Ignore output.

This will forward output to the null device for the platform.

Inherit

Output to nushell’s stdout or stderr (only for external commands).

This causes external commands to inherit nushell’s stdout or stderr. This also causes ListStreams to be drained, but not to be printed.

Print

Print to nushell’s stdout or stderr.

This is just like Inherit, except that ListStreams and Values are also printed.

This is the only destination treated as “not redirected” by OutDest::is_redirected / the is-redirected command.

File(Arc<File>)

Redirect output to a file.

Implementations

impl OutDest

pub fn is_redirected(&self) -> bool

Returns true when output is not sent through the interactive display path.

Only OutDest::Print is treated as displayed. Every other variant means the pipeline result is consumed elsewhere (next command, let/subexpression, file, null device, or inherit-without-printing).

This is not an OS-level TTY check. For whether process stdio is a terminal, use the is-terminal command (std::io::IsTerminal).

Examples

assert!(!OutDest::Print.is_redirected());
assert!(OutDest::Pipe.is_redirected());
assert!(OutDest::Value.is_redirected());

Trait Implementations

impl Clone for OutDest

fn clone(&self) -> OutDest

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for OutDest

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

Formats the value using the given formatter.

impl From<Arc<File>> for OutDest

fn from(file: Arc<File>) -> Self

Converts to this type from the input type.

impl From<File> for OutDest

fn from(file: File) -> Self

Converts to this type from the input type.

impl TryFrom<&OutDest> for Stdio

type Error = Error

The type returned in the event of a conversion error.

fn try_from(out_dest: &OutDest) -> Result<Self, Self::Error>

Performs the conversion.