UnauthorizedAccessException F# snippets (#8053)

Author: albert-du

snippets/fsharp/System/UnauthorizedAccessException/Overview/fs.fsproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="withio.fs" />
+  </ItemGroup>
+</Project>

snippets/fsharp/System/UnauthorizedAccessException/Overview/withio.fs

@@ -0,0 +1,23 @@
+// <Snippet1>
+open System
+open System.IO
+
+
+let filePath = @".\ROFile.txt"
+if File.Exists filePath |> not then
+    File.Create filePath |> ignore
+// Keep existing attributes, and set ReadOnly attribute.
+File.SetAttributes(filePath, (FileInfo filePath).Attributes ||| FileAttributes.ReadOnly)
+
+do
+    use sw = new StreamWriter(filePath)
+    try
+        sw.Write "Test"
+    with :? UnauthorizedAccessException ->
+        let attr = (FileInfo filePath).Attributes
+        printf "UnAuthorizedAccessException: Unable to access file. "
+        if int (attr &&& FileAttributes.ReadOnly) > 0 then
+            printf "The file is read-only."
+// The example displays the following output:
+//    UnAuthorizedAccessException: Unable to access file. The file is read-only.
+// </Snippet1>

xml/System/UnauthorizedAccessException.xml

@@ -73,6 +73,7 @@
  The following example illustrates the <xref:System.UnauthorizedAccessException> exception that is thrown when attempting to write to a read-only file.  
   
  :::code language="csharp" source="~/snippets/csharp/System/UnauthorizedAccessException/Overview/withio.cs" id="Snippet1":::
+ :::code language="fsharp" source="~/snippets/fsharp/System/UnauthorizedAccessException/Overview/withio.fs" id="Snippet1":::
  :::code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.unauthorizedaccessexception/vb/withio.vb" id="Snippet1":::  
   
  ]]></format>