Flesh out open() modes (#1282)

2 files changed, 41 insertions, 2 deletions

diff --git a/src/msg.fbs b/src/msg.fbs
index dcec126dd..9cdb628a1 100644
--- a/src/msg.fbs
+++ b/src/msg.fbs
@@ -348,6 +348,7 @@ table Truncate {
 table Open {
   filename: string;
   perm: uint;
+  mode: string;
 }
 
 table OpenRes {
diff --git a/src/ops.rs b/src/ops.rs
index 6d41fbe63..3cf466d0d 100644
--- a/src/ops.rs
+++ b/src/ops.rs
@@ -584,9 +584,47 @@ fn op_open(
   let cmd_id = base.cmd_id();
   let inner = base.inner_as_open().unwrap();
   let filename = PathBuf::from(inner.filename().unwrap());
-  // TODO let perm = inner.perm();
+  //  let perm = inner.perm();
+  let mode = inner.mode().unwrap();
 
-  let op = tokio::fs::File::open(filename)
+  let mut open_options = tokio::fs::OpenOptions::new();
+
+  match mode {
+    "r" => {
+      open_options.read(true);
+    }
+    "r+" => {
+      open_options.read(true).write(true);
+    }
+    "w" => {
+      open_options.create(true).write(true).truncate(true);
+    }
+    "w+" => {
+      open_options
+        .read(true)
+        .create(true)
+        .write(true)
+        .truncate(true);
+    }
+    "a" => {
+      open_options.create(true).append(true);
+    }
+    "a+" => {
+      open_options.read(true).create(true).append(true);
+    }
+    "x" => {
+      open_options.create_new(true).write(true);
+    }
+    "x+" => {
+      open_options.create_new(true).read(true).write(true);
+    }
+    &_ => {
+      panic!("Unknown file open mode.");
+    }
+  }
+
+  let op = open_options
+    .open(filename)
     .map_err(DenoError::from)
     .and_then(move |fs_file| -> OpResult {
       let resource = resources::add_fs_file(fs_file);