feat: add command not found

src/error.rs

@@ -1,4 +1,7 @@
+use std::process::Command;
+
 pub enum ShellError {
     EmptyLine,
-    Execute(String),
+    NotFound(Command),
+    ExecuteFailure(String),
 }

src/execute.rs

@@ -1,7 +1,7 @@
+use std::io::ErrorKind::NotFound;
 use std::process::Command;
 
 use crate::error::ShellError;
-use crate::error::ShellError::Execute;
 use crate::parse::parse_line;
 
 pub fn interpret(line: &str) -> Result<(), ShellError> {
@@ -22,10 +22,15 @@ fn execute(mut command: Command) -> Result<(), ShellError> {
     match command.spawn() {
         Ok(mut child) => {
             if let Err(err) = child.wait() {
-                return Err(Execute(err.to_string()));
+                return Err(ShellError::ExecuteFailure(err.to_string()));
             }
             Ok(())
         }
-        Err(err) => Err(Execute(err.to_string())),
+        Err(err) => {
+            if err.kind() == NotFound {
+                return Err(ShellError::NotFound(command));
+            }
+            Err(ShellError::ExecuteFailure(err.to_string()))
+        }
     }
 }

src/main.rs

@@ -24,8 +24,11 @@ fn main() -> Result<()> {
                 Err(ShellError::EmptyLine) => {
                     continue;
                 }
-                Err(ShellError::Execute(err)) => {
-                    eprintln!("{}", err)
+                Err(ShellError::NotFound(cmd)) => {
+                    println!("{}: command not found", cmd.get_program().to_string_lossy())
+                }
+                Err(ShellError::ExecuteFailure(msg)) => {
+                    eprintln!("{}", msg)
                 }
             },
             Err(ReadlineError::Interrupted) => {