fix(redirection): allow continuing past redir errors (#375)

brush-core/src/builtins/mapfile.rs

@@ -72,6 +72,7 @@ impl builtins::Command for MapFileCommand {
         }
 
         let input_file = context
+            .params
             .fd(self.fd)
             .ok_or_else(|| error::Error::BadFileDescriptor(self.fd))?;
 

brush-core/src/builtins/read.rs

@@ -82,6 +82,7 @@ impl builtins::Command for ReadCommand {
         let input_stream = if let Some(fd_num) = self.fd_num_to_read {
             let fd_num = fd_num as u32;
             context
+                .params
                 .fd(fd_num)
                 .ok_or_else(|| error::Error::BadFileDescriptor(fd_num))?
         } else {

brush-core/src/commands.rs

@@ -115,27 +115,17 @@ pub struct ExecutionContext<'a> {
 impl ExecutionContext<'_> {
     /// Returns the standard input file; usable with `write!` et al.
     pub fn stdin(&self) -> openfiles::OpenFile {
-        self.fd(0).unwrap()
+        self.params.stdin()
     }
 
     /// Returns the standard output file; usable with `write!` et al.
     pub fn stdout(&self) -> openfiles::OpenFile {
-        self.fd(1).unwrap()
+        self.params.stdout()
     }
 
     /// Returns the standard error file; usable with `write!` et al.
     pub fn stderr(&self) -> openfiles::OpenFile {
-        self.fd(2).unwrap()
-    }
-
-    /// Returns the file descriptor with the given number.
-    #[allow(clippy::unwrap_in_result)]
-    pub fn fd(&self, fd: u32) -> Option<openfiles::OpenFile> {
-        self.params
-            .open_files
-            .files
-            .get(&fd)
-            .map(|f| f.try_dup().unwrap())
+        self.params.stderr()
     }
 
     pub(crate) fn should_cmd_lead_own_process_group(&self) -> bool {

brush-core/src/interp.rs

@@ -114,6 +114,29 @@ pub struct ExecutionParameters {
     pub process_group_policy: ProcessGroupPolicy,
 }
 
+impl ExecutionParameters {
+    /// Returns the standard input file; usable with `write!` et al.
+    pub fn stdin(&self) -> openfiles::OpenFile {
+        self.fd(0).unwrap()
+    }
+
+    /// Returns the standard output file; usable with `write!` et al.
+    pub fn stdout(&self) -> openfiles::OpenFile {
+        self.fd(1).unwrap()
+    }
+
+    /// Returns the standard error file; usable with `write!` et al.
+    pub fn stderr(&self) -> openfiles::OpenFile {
+        self.fd(2).unwrap()
+    }
+
+    /// Returns the file descriptor with the given number.
+    #[allow(clippy::unwrap_in_result)]
+    pub fn fd(&self, fd: u32) -> Option<openfiles::OpenFile> {
+        self.open_files.files.get(&fd).map(|f| f.try_dup().unwrap())
+    }
+}
+
 #[derive(Clone, Debug, Default)]
 /// Policy for how to manage spawned external processes.
 pub enum ProcessGroupPolicy {
@@ -910,12 +933,16 @@ impl ExecuteInPipeline for ast::SimpleCommand {
         {
             match item {
                 CommandPrefixOrSuffixItem::IoRedirect(redirect) => {
-                    if setup_redirect(context.shell, &mut params, redirect)
-                        .await?
-                        .is_none()
-                    {
-                        // Something went wrong.
-                        return Ok(CommandSpawnResult::ImmediateExit(1));
+                    match setup_redirect(context.shell, &mut params, redirect).await {
+                        Err(e) => {
+                            writeln!(params.stderr(), "error: {e}")?;
+                            return Ok(CommandSpawnResult::ImmediateExit(1));
+                        }
+                        Ok(None) => {
+                            // Something went wrong.
+                            return Ok(CommandSpawnResult::ImmediateExit(1));
+                        }
+                        Ok(_) => (),
                     }
                 }
                 CommandPrefixOrSuffixItem::ProcessSubstitution(kind, subshell_command) => {

brush-shell/tests/cases/redirection.yaml

@@ -109,3 +109,8 @@ cases:
     ignore_stderr: true
     stdin: |
       ( : $(echo hi >&3); ) 3>output.txt
+
+  - name: "Redirection failure"
+    ignore_stderr: true
+    stdin: |
+      echo hi > /non-existent-dir/file.txt; echo following-command