fix exit code (#5835)

* fix exit code

* fix usage

* add comment

crates/nu-cli/src/commands.rs

@@ -18,7 +18,7 @@ pub fn evaluate_commands(
     input: PipelineData,
     is_perf_true: bool,
     table_mode: Option<Value>,
-) -> Result<()> {
+) -> Result<Option<i64>> {
     // Run a command (or commands) given to us by the user
     let (block, delta) = {
         if let Some(ref t_mode) = table_mode {
@@ -74,7 +74,7 @@ pub fn evaluate_commands(
         std::process::exit(1);
     }
 
-    match eval_block(engine_state, stack, &block, input, false, false) {
+    let exit_code = match eval_block(engine_state, stack, &block, input, false, false) {
         Ok(pipeline_data) => {
             crate::eval_file::print_table_or_error(engine_state, stack, pipeline_data, &mut config)
         }
@@ -84,11 +84,11 @@ pub fn evaluate_commands(
             report_error(&working_set, &err);
             std::process::exit(1);
         }
-    }
+    };
 
     if is_perf_true {
         info!("evaluate {}:{}:{}", file!(), line!(), column!());
     }
 
-    Ok(())
+    Ok(exit_code)
 }

crates/nu-cli/src/eval_file.rs

@@ -66,7 +66,7 @@ pub fn print_table_or_error(
     stack: &mut Stack,
     mut pipeline_data: PipelineData,
     config: &mut Config,
-) {
+) -> Option<i64> {
     let exit_code = match &mut pipeline_data {
         PipelineData::ExternalStream { exit_code, .. } => exit_code.take(),
         _ => None,
@@ -130,6 +130,14 @@ pub fn print_table_or_error(
 
     // Make sure everything has finished
     if let Some(exit_code) = exit_code {
-        let _: Vec<_> = exit_code.into_iter().collect();
+        let mut exit_code: Vec<_> = exit_code.into_iter().collect();
+        exit_code
+            .pop()
+            .and_then(|last_exit_code| match last_exit_code {
+                Value::Int { val: code, .. } => Some(code),
+                _ => None,
+            })
+    } else {
+        None
     }
 }

src/main.rs

@@ -237,7 +237,11 @@ fn main() -> Result<()> {
                 if is_perf_true() {
                     info!("-c command execution {}:{}:{}", file!(), line!(), column!());
                 }
-                ret_val
+                match ret_val {
+                    Ok(Some(exit_code)) => std::process::exit(exit_code as i32),
+                    Ok(None) => Ok(()),
+                    Err(e) => Err(e),
+                }
             } else if !script_name.is_empty() && binary_args.interactive_shell.is_none() {
                 #[cfg(feature = "plugin")]
                 read_plugin_file(

tests/shell/pipeline/commands/external.rs

@@ -287,6 +287,8 @@ mod external_words {
 }
 
 mod nu_commands {
+    use nu_test_support::playground::Playground;
+
     use super::nu;
 
     #[test]
@@ -298,6 +300,18 @@ mod nu_commands {
         assert_eq!(actual.out, "foo");
     }
 
+    #[test]
+    fn failed_with_proper_exit_code() {
+        Playground::setup("external failed", |dirs, _sandbox| {
+            let actual = nu!(cwd: dirs.test(), r#"
+            nu -c "cargo build; print $env.LAST_EXIT_CODE"
+            "#);
+
+            // cargo for non rust project's exit code is 101.
+            assert_eq!(actual.out, "101")
+        })
+    }
+
     #[test]
     fn better_arg_quoting() {
         let actual = nu!(cwd: ".", r#"