5 files changed, 45 insertions, 0 deletions
diff --git a/cli/dts/lib.deno.unstable.d.ts b/cli/dts/lib.deno.unstable.d.ts
index 0ed27c5d5..b8eb886e4 100644
--- a/cli/dts/lib.deno.unstable.d.ts
+++ b/cli/dts/lib.deno.unstable.d.ts
@@ -317,6 +317,18 @@ declare namespace Deno {
    */
   export function getUid(): number | null;
 
+  /** **Unstable** new API. yet to be vetted.
+   *
+   * Returns the group id of the process on POSIX platforms. Returns null on windows.
+   *
+   * ```ts
+   * console.log(Deno.getGid());
+   * ```
+   *
+   * Requires `allow-env` permission.
+   */
+  export function getGid(): number | null;
+
   /** All possible types for interfacing with foreign functions */
   export type NativeType =
     | "void"
diff --git a/cli/tests/unit/os_test.ts b/cli/tests/unit/os_test.ts
index 6ed1126f1..b5ff6f29f 100644
--- a/cli/tests/unit/os_test.ts
+++ b/cli/tests/unit/os_test.ts
@@ -204,3 +204,13 @@ Deno.test({ permissions: { env: true } }, function getUid() {
     assert(uid > 0);
   }
 });
+
+Deno.test({ permissions: { env: true } }, function getGid() {
+  if (Deno.build.os === "windows") {
+    assertEquals(Deno.getGid(), null);
+  } else {
+    const gid = Deno.getGid();
+    assert(typeof gid === "number");
+    assert(gid > 0);
+  }
+});
diff --git a/runtime/js/30_os.js b/runtime/js/30_os.js
index 9cc2ba5c7..f9df42305 100644
--- a/runtime/js/30_os.js
+++ b/runtime/js/30_os.js
@@ -30,6 +30,10 @@
     return core.opSync("op_network_interfaces");
   }
 
+  function getGid() {
+    return core.opSync("op_getgid");
+  }
+
   function getUid() {
     return core.opSync("op_getuid");
   }
@@ -94,6 +98,7 @@
     env,
     execPath,
     exit,
+    getGid,
     getUid,
     hostname,
     loadavg,
diff --git a/runtime/js/90_deno_ns.js b/runtime/js/90_deno_ns.js
index 879e63e57..24a31bc31 100644
--- a/runtime/js/90_deno_ns.js
+++ b/runtime/js/90_deno_ns.js
@@ -124,6 +124,7 @@
     osRelease: __bootstrap.os.osRelease,
     systemMemoryInfo: __bootstrap.os.systemMemoryInfo,
     networkInterfaces: __bootstrap.os.networkInterfaces,
+    getGid: __bootstrap.os.getGid,
     getUid: __bootstrap.os.getUid,
     sleepSync: __bootstrap.timers.sleepSync,
     listen: __bootstrap.netUnstable.listen,
diff --git a/runtime/ops/os.rs b/runtime/ops/os.rs
index c74a423ab..37da410ca 100644
--- a/runtime/ops/os.rs
+++ b/runtime/ops/os.rs
@@ -22,6 +22,7 @@ pub fn init(maybe_exit_code: Option<Arc<AtomicI32>>) -> Extension {
       op_exit::decl(),
       op_delete_env::decl(),
       op_get_env::decl(),
+      op_getgid::decl(),
       op_getuid::decl(),
       op_hostname::decl(),
       op_loadavg::decl(),
@@ -227,6 +228,22 @@ fn op_system_memory_info(
 
 #[cfg(not(windows))]
 #[op]
+fn op_getgid(state: &mut OpState) -> Result<Option<u32>, AnyError> {
+  super::check_unstable(state, "Deno.getGid");
+  state.borrow_mut::<Permissions>().env.check_all()?;
+  unsafe { Ok(Some(libc::getgid())) }
+}
+
+#[cfg(windows)]
+#[op]
+fn op_getgid(state: &mut OpState) -> Result<Option<u32>, AnyError> {
+  super::check_unstable(state, "Deno.getGid");
+  state.borrow_mut::<Permissions>().env.check_all()?;
+  Ok(None)
+}
+
+#[cfg(not(windows))]
+#[op]
 fn op_getuid(state: &mut OpState) -> Result<Option<u32>, AnyError> {
   super::check_unstable(state, "Deno.getUid");
   state.borrow_mut::<Permissions>().env.check_all()?;