Add support for 'open' (#573)

crates/nu-command/src/default_context.rs

@@ -149,6 +149,7 @@ pub fn create_default_context() -> EngineState {
             Ls,
             Mkdir,
             Mv,
+            Open,
             Rm,
             Touch,
         };

crates/nu-command/src/filesystem/ls.rs

@@ -1,10 +1,10 @@
 use chrono::{DateTime, Utc};
-use nu_engine::eval_expression;
+use nu_engine::CallExt;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
 use nu_protocol::{
     Category, DataSource, IntoInterruptiblePipelineData, PipelineData, PipelineMetadata,
-    ShellError, Signature, Span, SyntaxShape, Value,
+    ShellError, Signature, Span, Spanned, SyntaxShape, Value,
 };
 
 use std::io::ErrorKind;
@@ -42,11 +42,11 @@ impl Command for Ls {
                 "Only print the file names and not the path",
                 Some('s'),
             )
-            .switch(
-                "du",
-                "Display the apparent directory size in place of the directory metadata size",
-                Some('d'),
-            )
+            // .switch(
+            //     "du",
+            //     "Display the apparent directory size in place of the directory metadata size",
+            //     Some('d'),
+            // )
             .category(Category::FileSystem)
     }
 
@@ -63,22 +63,20 @@ impl Command for Ls {
 
         let call_span = call.head;
 
-        let (pattern, arg_span) = if let Some(expr) = call.positional.get(0) {
-            let result = eval_expression(engine_state, stack, expr)?;
-            let mut result = result.as_string()?;
-
-            let path = std::path::Path::new(&result);
-            if path.is_dir() {
-                if !result.ends_with(std::path::MAIN_SEPARATOR) {
-                    result.push(std::path::MAIN_SEPARATOR);
+        let (pattern, arg_span) =
+            if let Some(mut result) = call.opt::<Spanned<String>>(engine_state, stack, 0)? {
+                let path = std::path::Path::new(&result.item);
+                if path.is_dir() {
+                    if !result.item.ends_with(std::path::MAIN_SEPARATOR) {
+                        result.item.push(std::path::MAIN_SEPARATOR);
+                    }
+                    result.item.push('*');
                 }
-                result.push('*');
-            }
 
-            (result, expr.span)
-        } else {
-            ("*".into(), call_span)
-        };
+                (result.item, result.span)
+            } else {
+                ("*".into(), call_span)
+            };
 
         let glob = glob::glob(&pattern).map_err(|err| {
             nu_protocol::ShellError::SpannedLabeledError(

crates/nu-command/src/filesystem/mod.rs

@@ -3,6 +3,7 @@ mod cp;
 mod ls;
 mod mkdir;
 mod mv;
+mod open;
 mod rm;
 mod touch;
 mod util;
@@ -12,5 +13,6 @@ pub use cp::Cp;
 pub use ls::Ls;
 pub use mkdir::Mkdir;
 pub use mv::Mv;
+pub use open::Open;
 pub use rm::Rm;
 pub use touch::Touch;

crates/nu-command/src/filesystem/open.rs

@@ -0,0 +1,160 @@
+use nu_engine::CallExt;
+use nu_protocol::ast::Call;
+use nu_protocol::engine::{Command, EngineState, Stack};
+use nu_protocol::{
+    ByteStream, Category, PipelineData, ShellError, Signature, Spanned, SyntaxShape, Value,
+};
+use std::io::{BufRead, BufReader, Read};
+
+#[cfg(unix)]
+use std::os::unix::fs::PermissionsExt;
+use std::path::Path;
+
+#[derive(Clone)]
+pub struct Open;
+
+//NOTE: this is not a real implementation :D. It's just a simple one to test with until we port the real one.
+impl Command for Open {
+    fn name(&self) -> &str {
+        "open"
+    }
+
+    fn usage(&self) -> &str {
+        "List the files in a directory."
+    }
+
+    fn signature(&self) -> nu_protocol::Signature {
+        Signature::build("open")
+            .required(
+                "filename",
+                SyntaxShape::GlobPattern,
+                "the glob pattern to use",
+            )
+            .switch("raw", "open file as binary", Some('r'))
+            .category(Category::FileSystem)
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        let raw = call.has_flag("raw");
+
+        let call_span = call.head;
+        let ctrlc = engine_state.ctrlc.clone();
+
+        let path = call.req::<Spanned<String>>(engine_state, stack, 0)?;
+        let arg_span = path.span;
+        let path = Path::new(&path.item);
+
+        if permission_denied(&path) {
+            #[cfg(unix)]
+            let error_msg = format!(
+                "The permissions of {:o} do not allow access for this user",
+                path.metadata()
+                    .expect("this shouldn't be called since we already know there is a dir")
+                    .permissions()
+                    .mode()
+                    & 0o0777
+            );
+            #[cfg(not(unix))]
+            let error_msg = String::from("Permission denied");
+            Ok(PipelineData::Value(
+                Value::Error {
+                    error: ShellError::SpannedLabeledError(
+                        "Permission denied".into(),
+                        error_msg,
+                        arg_span,
+                    ),
+                },
+                None,
+            ))
+        } else {
+            let file = match std::fs::File::open(path) {
+                Ok(file) => file,
+                Err(err) => {
+                    return Ok(PipelineData::Value(
+                        Value::Error {
+                            error: ShellError::SpannedLabeledError(
+                                "Permission denied".into(),
+                                err.to_string(),
+                                arg_span,
+                            ),
+                        },
+                        None,
+                    ));
+                }
+            };
+
+            let buf_reader = BufReader::new(file);
+
+            let output = PipelineData::ByteStream(
+                ByteStream {
+                    stream: Box::new(BufferedReader { input: buf_reader }),
+                    ctrlc,
+                },
+                call_span,
+                None,
+            );
+
+            let ext = if raw {
+                None
+            } else {
+                path.extension()
+                    .map(|name| name.to_string_lossy().to_string())
+            };
+
+            if let Some(ext) = ext {
+                match engine_state.find_decl(format!("from {}", ext).as_bytes()) {
+                    Some(converter_id) => engine_state.get_decl(converter_id).run(
+                        engine_state,
+                        stack,
+                        &Call::new(),
+                        output,
+                    ),
+                    None => Ok(output),
+                }
+            } else {
+                Ok(output)
+            }
+        }
+    }
+}
+
+fn permission_denied(dir: impl AsRef<Path>) -> bool {
+    match dir.as_ref().read_dir() {
+        Err(e) => matches!(e.kind(), std::io::ErrorKind::PermissionDenied),
+        Ok(_) => false,
+    }
+}
+
+pub struct BufferedReader<R: Read> {
+    input: BufReader<R>,
+}
+
+impl<R: Read> Iterator for BufferedReader<R> {
+    type Item = Result<Vec<u8>, ShellError>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let buffer = self.input.fill_buf();
+        match buffer {
+            Ok(s) => {
+                let result = s.to_vec();
+
+                let buffer_len = s.len();
+
+                if buffer_len == 0 {
+                    None
+                } else {
+                    self.input.consume(buffer_len);
+
+                    Some(Ok(result))
+                }
+            }
+            Err(e) => Some(Err(ShellError::IOError(e.to_string()))),
+        }
+    }
+}

crates/nu-command/src/filters/each.rs

@@ -113,7 +113,10 @@ impl Command for Each {
                 .into_iter()
                 .enumerate()
                 .map(move |(idx, x)| {
-                    let x = Value::Binary { val: x, span };
+                    let x = match x {
+                        Ok(x) => Value::Binary { val: x, span },
+                        Err(err) => return Value::Error { error: err },
+                    };
 
                     if let Some(var) = block.signature.get_positional(0) {
                         if let Some(var_id) = &var.var_id {

crates/nu-command/src/filters/par_each.rs

@@ -227,7 +227,11 @@ impl Command for ParEach {
                 .enumerate()
                 .par_bridge()
                 .map(move |(idx, x)| {
-                    let x = Value::Binary { val: x, span };
+                    let x = match x {
+                        Ok(x) => Value::Binary { val: x, span },
+                        Err(err) => return Value::Error { error: err }.into_pipeline_data(),
+                    };
+
                     let block = engine_state.get_block(block_id);
 
                     let mut stack = stack.clone();

crates/nu-command/src/filters/wrap.rs

@@ -56,7 +56,7 @@ impl Command for Wrap {
             }
             .into_pipeline_data()),
             PipelineData::ByteStream(stream, ..) => Ok(Value::Binary {
-                val: stream.into_vec(),
+                val: stream.into_vec()?,
                 span,
             }
             .into_pipeline_data()),

crates/nu-command/src/strings/decode.rs

@@ -45,7 +45,7 @@ impl Command for Decode {
 
         match input {
             PipelineData::ByteStream(stream, ..) => {
-                let bytes: Vec<u8> = stream.flatten().collect();
+                let bytes: Vec<u8> = stream.into_vec()?;
 
                 let encoding = match Encoding::for_label(encoding.item.as_bytes()) {
                     None => Err(ShellError::SpannedLabeledError(

crates/nu-command/src/system/run_external.rs

@@ -359,11 +359,11 @@ impl ChannelReceiver {
 }
 
 impl Iterator for ChannelReceiver {
-    type Item = Vec<u8>;
+    type Item = Result<Vec<u8>, ShellError>;
 
     fn next(&mut self) -> Option<Self::Item> {
         match self.rx.recv() {
-            Ok(v) => Some(v),
+            Ok(v) => Some(Ok(v)),
             Err(_) => None,
         }
     }

crates/nu-command/src/viewers/table.rs

@@ -65,9 +65,9 @@ impl Command for Table {
                 StringStream::from_stream(
                     stream.map(move |x| {
                         Ok(if x.iter().all(|x| x.is_ascii()) {
-                            format!("{}", String::from_utf8_lossy(&x))
+                            format!("{}", String::from_utf8_lossy(&x?))
                         } else {
-                            format!("{}\n", nu_pretty_hex::pretty_hex(&x))
+                            format!("{}\n", nu_pretty_hex::pretty_hex(&x?))
                         })
                     }),
                     ctrlc,

crates/nu-plugin/src/plugin/declaration.rs

@@ -89,7 +89,7 @@ impl Command for PluginDeclaration {
                 }
             }
             PipelineData::ByteStream(stream, ..) => {
-                let val = stream.into_vec();
+                let val = stream.into_vec()?;
 
                 Value::Binary {
                     val,

crates/nu-protocol/src/pipeline_data.rs

@@ -87,10 +87,21 @@ impl PipelineData {
                     span, // FIXME?
                 }
             }
-            PipelineData::ByteStream(s, ..) => Value::Binary {
-                val: s.flatten().collect(),
-                span, // FIXME?
-            },
+            PipelineData::ByteStream(s, ..) => {
+                let mut output = vec![];
+
+                for item in s {
+                    match item {
+                        Ok(s) => output.extend(&s),
+                        Err(err) => return Value::Error { error: err },
+                    }
+                }
+
+                Value::Binary {
+                    val: output,
+                    span, // FIXME?
+                }
+            }
         }
     }
 
@@ -110,7 +121,7 @@ impl PipelineData {
             PipelineData::ListStream(s, ..) => Ok(s.into_string(separator, config)),
             PipelineData::StringStream(s, ..) => s.into_string(separator),
             PipelineData::ByteStream(s, ..) => {
-                Ok(String::from_utf8_lossy(&s.flatten().collect::<Vec<_>>()).to_string())
+                Ok(String::from_utf8_lossy(&s.into_vec()?).to_string())
             }
         }
     }
@@ -324,9 +335,12 @@ impl Iterator for PipelineIterator {
                 },
                 Err(err) => Value::Error { error: err },
             }),
-            PipelineData::ByteStream(stream, span, ..) => stream.next().map(|x| Value::Binary {
-                val: x,
-                span: *span,
+            PipelineData::ByteStream(stream, span, ..) => stream.next().map(|x| match x {
+                Ok(x) => Value::Binary {
+                    val: x,
+                    span: *span,
+                },
+                Err(err) => Value::Error { error: err },
             }),
         }
     }

crates/nu-protocol/src/value/stream.rs

@@ -10,12 +10,17 @@ use std::{
 /// A single buffer of binary data streamed over multiple parts. Optionally contains ctrl-c that can be used
 /// to break the stream.
 pub struct ByteStream {
-    pub stream: Box<dyn Iterator<Item = Vec<u8>> + Send + 'static>,
+    pub stream: Box<dyn Iterator<Item = Result<Vec<u8>, ShellError>> + Send + 'static>,
     pub ctrlc: Option<Arc<AtomicBool>>,
 }
 impl ByteStream {
-    pub fn into_vec(self) -> Vec<u8> {
-        self.flatten().collect::<Vec<u8>>()
+    pub fn into_vec(self) -> Result<Vec<u8>, ShellError> {
+        let mut output = vec![];
+        for item in self.stream {
+            output.append(&mut item?);
+        }
+
+        Ok(output)
     }
 }
 impl Debug for ByteStream {
@@ -25,7 +30,7 @@ impl Debug for ByteStream {
 }
 
 impl Iterator for ByteStream {
-    type Item = Vec<u8>;
+    type Item = Result<Vec<u8>, ShellError>;
 
     fn next(&mut self) -> Option<Self::Item> {
         if let Some(ctrlc) = &self.ctrlc {

src/main.rs

@@ -594,9 +594,9 @@ fn print_pipeline_data(
         PipelineData::ByteStream(stream, _, _) => {
             for v in stream {
                 let s = if v.iter().all(|x| x.is_ascii()) {
-                    format!("{}", String::from_utf8_lossy(&v))
+                    format!("{}", String::from_utf8_lossy(&v?))
                 } else {
-                    format!("{}\n", nu_pretty_hex::pretty_hex(&v))
+                    format!("{}\n", nu_pretty_hex::pretty_hex(&v?))
                 };
                 println!("{}", s);
             }