Add which command

src/cli.rs

@@ -191,6 +191,7 @@ pub async fn cli() -> Result<(), Box<dyn Error>> {
             static_command(Save),
             static_command(Table),
             static_command(VTable),
+            static_command(Which),
         ]);
     }
     let _ = load_plugins(&mut context);

src/commands.rs

@@ -48,6 +48,7 @@ crate mod to_yaml;
 crate mod trim;
 crate mod vtable;
 crate mod where_;
+crate mod which_;
 
 crate use autoview::Autoview;
 //crate use cd::Cd;
@@ -69,3 +70,4 @@ crate use skip_while::SkipWhile;
 crate use table::Table;
 crate use vtable::VTable;
 crate use where_::Where;
+crate use which_::Which;

src/commands/which_.rs

@@ -0,0 +1,70 @@
+use crate::errors::ShellError;
+use crate::object::Value;
+use crate::prelude::*;
+
+use crate::commands::StaticCommand;
+use crate::parser::registry::Signature;
+
+pub struct Which;
+
+impl StaticCommand for Which {
+    fn run(
+        &self,
+        args: CommandArgs,
+        registry: &CommandRegistry,
+    ) -> Result<OutputStream, ShellError> {
+        which(args, registry)
+    }
+    fn name(&self) -> &str {
+        "which"
+    }
+
+    fn signature(&self) -> Signature {
+        Signature::build("which").required("name", SyntaxType::Any)
+    }
+}
+
+pub fn which(args: CommandArgs, registry: &CommandRegistry) -> Result<OutputStream, ShellError> {
+    let args = args.evaluate_once(registry)?;
+
+    let mut which_out = VecDeque::new();
+    let span = args.call_info.name_span;
+
+    if let Some(v) = &args.call_info.args.positional {
+        if v.len() > 0 {
+            match &v[0] {
+                Tagged {
+                    item: Value::Primitive(Primitive::String(s)),
+                    tag,
+                } => match which::which(&s) {
+                    Ok(ok) => {
+                        which_out
+                            .push_back(Value::Primitive(Primitive::Path(ok)).tagged(tag.clone()));
+                    }
+                    _ => {}
+                },
+                Tagged { tag, .. } => {
+                    return Err(ShellError::labeled_error(
+                        "Expected a filename to find",
+                        "needs a filename",
+                        tag.span,
+                    ));
+                }
+            }
+        } else {
+            return Err(ShellError::labeled_error(
+                "Expected a binary to find",
+                "needs application name",
+                span,
+            ));
+        }
+    } else {
+        return Err(ShellError::labeled_error(
+            "Expected a binary to find",
+            "needs application name",
+            span,
+        ));
+    }
+
+    Ok(which_out.to_output_stream())
+}