1 files changed, 83 insertions, 0 deletions
diff --git a/ext/node/ops/util.rs b/ext/node/ops/util.rs
new file mode 100644
index 000000000..1cb80e0e3
--- /dev/null
+++ b/ext/node/ops/util.rs
@@ -0,0 +1,83 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+use deno_core::error::AnyError;
+use deno_core::op2;
+use deno_core::OpState;
+use deno_core::ResourceHandle;
+use deno_core::ResourceHandleFd;
+
+#[repr(u32)]
+enum HandleType {
+  #[allow(dead_code)]
+  Tcp = 0,
+  Tty,
+  #[allow(dead_code)]
+  Udp,
+  File,
+  Pipe,
+  Unknown,
+}
+
+#[op2(fast)]
+pub fn op_node_guess_handle_type(
+  state: &mut OpState,
+  rid: u32,
+) -> Result<u32, AnyError> {
+  let handle = state.resource_table.get_handle(rid)?;
+
+  let handle_type = match handle {
+    ResourceHandle::Fd(handle) => guess_handle_type(handle),
+    _ => HandleType::Unknown,
+  };
+
+  Ok(handle_type as u32)
+}
+
+#[cfg(windows)]
+fn guess_handle_type(handle: ResourceHandleFd) -> HandleType {
+  use winapi::um::consoleapi::GetConsoleMode;
+  use winapi::um::fileapi::GetFileType;
+  use winapi::um::winbase::FILE_TYPE_CHAR;
+  use winapi::um::winbase::FILE_TYPE_DISK;
+  use winapi::um::winbase::FILE_TYPE_PIPE;
+
+  // SAFETY: Call to win32 fileapi. `handle` is a valid fd.
+  match unsafe { GetFileType(handle) } {
+    FILE_TYPE_DISK => HandleType::File,
+    FILE_TYPE_CHAR => {
+      let mut mode = 0;
+      // SAFETY: Call to win32 consoleapi. `handle` is a valid fd.
+      //         `mode` is a valid pointer.
+      if unsafe { GetConsoleMode(handle, &mut mode) } == 1 {
+        HandleType::Tty
+      } else {
+        HandleType::File
+      }
+    }
+    FILE_TYPE_PIPE => HandleType::Pipe,
+    _ => HandleType::Unknown,
+  }
+}
+
+#[cfg(unix)]
+fn guess_handle_type(handle: ResourceHandleFd) -> HandleType {
+  use std::io::IsTerminal;
+  // SAFETY: The resource remains open for the duration of borrow_raw.
+  if unsafe { std::os::fd::BorrowedFd::borrow_raw(handle).is_terminal() } {
+    return HandleType::Tty;
+  }
+
+  // SAFETY: It is safe to zero-initialize a `libc::stat` struct.
+  let mut s = unsafe { std::mem::zeroed() };
+  // SAFETY: Call to libc
+  if unsafe { libc::fstat(handle, &mut s) } == 1 {
+    return HandleType::Unknown;
+  }
+
+  match s.st_mode & 61440 {
+    libc::S_IFREG | libc::S_IFCHR => HandleType::File,
+    libc::S_IFIFO => HandleType::Pipe,
+    libc::S_IFSOCK => HandleType::Tcp,
+    _ => HandleType::Unknown,
+  }
+}