Support redirect err and out to different streams (#7685)

# Description

Closes: #7364 

# User-Facing Changes

Given the following shell script:
```bash
x=$(printf '=%.0s' {1..100})
echo $x
echo $x 1>&2
```

It supports the following command:
```
bash test.sh out> out.txt err> err.txt
```

Then both `out.txt` and `err.txt` will contain `=`(100 times)

## About the change

The core idea is that when doing lite-parsing, introduce a new variant
`LiteElement::SeparateRedirection` if we meet two Redirection
token(which is generated by `lex` function),
During converting from lite block to block,
`LiteElement::SeparateRedirection` will be converted to
`PipelineElement::SeparateRedirection`.

Then in the block eval process, if we get
`PipelineElement::SeparateRedirection`, we invoke `save` command with
`--stderr` arguments to acthive our behavior.



## What happened internally?
Take the following command as example:
```
^ls out> out.txt err> err.txt
```

lex parsing result(`Tokens`) are not changed, but `LiteBlock` and
`Block` is changed after this pr.

### LiteBlock before
```rust
LiteBlock {
    block: [
        LitePipeline { commands: [
            Command(None, LiteCommand { comments: [], parts: [Span { start: 39041, end: 39044 }] }),
            // actually the span of first Redirection is wrong too..
            Redirection(Span { start: 39058, end: 39062 }, Stdout, LiteCommand { comments: [], parts: [Span { start: 39050, end: 39057 }] }),
            Redirection(Span { start: 39058, end: 39062 }, Stderr, LiteCommand { comments: [], parts: [Span { start: 39063, end: 39070 }] })
        ]
    }]
}
```
### LiteBlock after
```rust
LiteBlock {
    block: [
        LitePipeline { commands: [
            Command(
                None, 
                LiteCommand { comments: [], parts: [Span { start: 38525, end: 38528 }] }),
                // new one! two Redirection merged into one SeparateRedirection.
                SeparateRedirection { 
                    out: (Span { start: 38529, end: 38533 }, LiteCommand { comments: [], parts: [Span { start: 38534, end: 38541 }] }),
                    err: (Span { start: 38542, end: 38546 }, LiteCommand { comments: [], parts: [Span { start: 38547, end: 38554 }] })
                }
        ]
    }]
}
```

### Block before
```rust
Pipeline {
    elements: [
        Expression(None, Expression {
            expr: ExternalCall(Expression { expr: String("ls"), span: Span { start: 39042, end: 39044 }, ty: String, custom_completion: None }, [], false),
            span: Span { start: 39041, end: 39044 },
            ty: Any, custom_completion: None 
        }),
        Redirection(Span { start: 39058, end: 39062 }, Stdout, Expression { expr: String("out.txt"), span: Span { start: 39050, end: 39057 }, ty: String, custom_completion: None }),
        Redirection(Span { start: 39058, end: 39062 }, Stderr, Expression { expr: String("err.txt"), span: Span { start: 39063, end: 39070 }, ty: String, custom_completion: None })] }
```

### Block after
```rust
Pipeline {
    elements: [
        Expression(None, Expression {
            expr: ExternalCall(Expression { expr: String("ls"), span: Span { start: 38526, end: 38528 }, ty: String, custom_completion: None }, [], false),
            span: Span { start: 38525, end: 38528 },
            ty: Any,
            custom_completion: None 
        }),
        // new one! SeparateRedirection
        SeparateRedirection {
            out: (Span { start: 38529, end: 38533 }, Expression { expr: String("out.txt"), span: Span { start: 38534, end: 38541 }, ty: String, custom_completion: None }),
            err: (Span { start: 38542, end: 38546 }, Expression { expr: String("err.txt"), span: Span { start: 38547, end: 38554 }, ty: String, custom_completion: None }) 
        }
    ]
}
```
# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.
This commit is contained in:
WindSoilder
2023-01-12 17:22:30 +08:00
committed by GitHub
parent 5419e8ae9d
commit 8aa2632661
10 changed files with 317 additions and 14 deletions

View File

@ -38,6 +38,11 @@ impl LiteCommand {
pub enum LiteElement {
Command(Option<Span>, LiteCommand),
Redirection(Span, Redirection, LiteCommand),
// SeparateRedirection variant can only be generated by two different Redirection variant
SeparateRedirection {
out: (Span, LiteCommand),
err: (Span, LiteCommand),
},
}
#[derive(Debug)]
@ -60,6 +65,10 @@ impl LitePipeline {
self.commands.push(element);
}
pub fn insert(&mut self, index: usize, element: LiteElement) {
self.commands.insert(index, element);
}
pub fn is_empty(&self) -> bool {
self.commands.is_empty()
}
@ -81,13 +90,65 @@ impl LiteBlock {
Self { block: vec![] }
}
pub fn push(&mut self, pipeline: LitePipeline) {
pub fn push(&mut self, mut pipeline: LitePipeline) {
// once we push `pipeline` to our block
// the block takes ownership of `pipeline`, which means that
// our `pipeline` is complete on collecting commands.
self.merge_redirections(&mut pipeline);
self.block.push(pipeline);
}
pub fn is_empty(&self) -> bool {
self.block.is_empty()
}
fn merge_redirections(&self, pipeline: &mut LitePipeline) {
// In case our command may contains both stdout and stderr redirection.
// We pick them out and Combine them into one LiteElement::SeparateRedirection variant.
let mut stdout_index = None;
let mut stderr_index = None;
for (index, cmd) in pipeline.commands.iter().enumerate() {
if let LiteElement::Redirection(_span, redirection, _target_cmd) = cmd {
match *redirection {
Redirection::Stderr => stderr_index = Some(index),
Redirection::Stdout => stdout_index = Some(index),
Redirection::StdoutAndStderr => {}
}
}
}
if let (Some(out_indx), Some(err_indx)) = (stdout_index, stderr_index) {
let (out_redirect, err_redirect, new_indx) = {
// to avoid panic, we need to remove commands which have larger index first.
if out_indx > err_indx {
let out_redirect = pipeline.commands.remove(out_indx);
let err_redirect = pipeline.commands.remove(err_indx);
(out_redirect, err_redirect, err_indx)
} else {
let err_redirect = pipeline.commands.remove(err_indx);
let out_redirect = pipeline.commands.remove(out_indx);
(out_redirect, err_redirect, out_indx)
}
};
// `out_redirect` and `err_redirect` should always be `LiteElement::Redirection`
if let (
LiteElement::Redirection(out_span, _, out_command),
LiteElement::Redirection(err_span, _, err_command),
) = (out_redirect, err_redirect)
{
// using insert with specific index to keep original
// pipeline commands order.
pipeline.insert(
new_indx,
LiteElement::SeparateRedirection {
out: (out_span, out_command),
err: (err_span, err_command),
},
)
}
}
}
}
pub fn lite_parse(tokens: &[Token]) -> (LiteBlock, Option<ParseError>) {
@ -130,21 +191,24 @@ pub fn lite_parse(tokens: &[Token]) -> (LiteBlock, Option<ParseError>) {
match last_connector {
TokenContents::OutGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::Stdout,
curr_command,
));
}
TokenContents::ErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::Stderr,
curr_command,
));
}
TokenContents::OutErrGreaterThan => {
curr_pipeline.push(LiteElement::Redirection(
token.span,
last_connector_span
.expect("internal error: redirection missing span information"),
Redirection::StdoutAndStderr,
curr_command,
));