1 files changed, 38 insertions, 0 deletions
diff --git a/cli/ops/fs.rs b/cli/ops/fs.rs
index ad1283c12..df5ad7bef 100644
--- a/cli/ops/fs.rs
+++ b/cli/ops/fs.rs
@@ -23,6 +23,7 @@ use std::os::unix::fs::{MetadataExt, PermissionsExt};
 pub fn init(i: &mut Isolate, s: &State) {
   i.register_op("op_open", s.stateful_json_op(op_open));
   i.register_op("op_seek", s.stateful_json_op(op_seek));
+  i.register_op("op_umask", s.stateful_json_op(op_umask));
   i.register_op("op_chdir", s.stateful_json_op(op_chdir));
   i.register_op("op_mkdir", s.stateful_json_op(op_mkdir));
   i.register_op("op_chmod", s.stateful_json_op(op_chmod));
@@ -222,6 +223,43 @@ fn op_seek(
 }
 
 #[derive(Deserialize)]
+struct UmaskArgs {
+  mask: Option<u32>,
+}
+
+fn op_umask(
+  _state: &State,
+  args: Value,
+  _zero_copy: Option<ZeroCopyBuf>,
+) -> Result<JsonOp, OpError> {
+  let args: UmaskArgs = serde_json::from_value(args)?;
+  // TODO implement umask for Windows
+  // see https://github.com/nodejs/node/blob/master/src/node_process_methods.cc
+  // and https://docs.microsoft.com/fr-fr/cpp/c-runtime-library/reference/umask?view=vs-2019
+  #[cfg(not(unix))]
+  {
+    let _ = args.mask; // avoid unused warning.
+    return Err(OpError::not_implemented());
+  }
+  #[cfg(unix)]
+  {
+    use nix::sys::stat::mode_t;
+    use nix::sys::stat::umask;
+    use nix::sys::stat::Mode;
+    let r = if let Some(mask) = args.mask {
+      // If mask provided, return previous.
+      umask(Mode::from_bits_truncate(mask as mode_t))
+    } else {
+      // If no mask provided, we query the current. Requires two syscalls.
+      let prev = umask(Mode::from_bits_truncate(0o777));
+      let _ = umask(prev);
+      prev
+    };
+    Ok(JsonOp::Sync(json!(r.bits() as u32)))
+  }
+}
+
+#[derive(Deserialize)]
 struct ChdirArgs {
   directory: String,
 }