1 files changed, 73 insertions, 0 deletions
diff --git a/src/mscorlib/shared/Interop/Unix/System.Native/Interop.PathConf.cs b/src/mscorlib/shared/Interop/Unix/System.Native/Interop.PathConf.cs
new file mode 100644
index 0000000000..4a1fcf67d0
--- /dev/null
+++ b/src/mscorlib/shared/Interop/Unix/System.Native/Interop.PathConf.cs
@@ -0,0 +1,73 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Runtime.InteropServices;
+
+internal static partial class Interop
+{
+    internal static partial class Sys
+    {
+        internal static int DEFAULT_PC_NAME_MAX = 255;
+
+        internal enum PathConfName : int
+        {
+            PC_LINK_MAX         = 1,
+            PC_MAX_CANON        = 2,
+            PC_MAX_INPUT        = 3,
+            PC_NAME_MAX         = 4,
+            PC_PATH_MAX         = 5,
+            PC_PIPE_BUF         = 6,
+            PC_CHOWN_RESTRICTED = 7,
+            PC_NO_TRUNC         = 8,
+            PC_VDISABLE         = 9,
+        }
+
+        /// <summary>The maximum path length for the system.  -1 if it hasn't yet been initialized.</summary>
+        private static int s_maxPath = -1;
+
+        /// <summary>The maximum name length for the system.  -1 if it hasn't yet been initialized.</summary>
+        private static int s_maxName = -1;
+
+        internal static int MaxPath
+        {
+            get
+            {
+                // Benign race condition on cached value
+                if (s_maxPath < 0) 
+                {
+                    // GetMaximumPath returns a long from PathConf
+                    // but our callers expect an int so we need to convert.
+                    long temp = GetMaximumPath();
+                    if (temp > int.MaxValue)
+                        s_maxPath = int.MaxValue;
+                    else
+                        s_maxPath = Convert.ToInt32(temp);
+                }
+                return s_maxPath; 
+            }
+        }
+
+        internal static int MaxName
+        {
+            get
+            {
+                // Benign race condition on cached value
+                if (s_maxName < 0)
+                {
+                    int result = PathConf("/", PathConfName.PC_NAME_MAX);
+                    s_maxName = result >= 0 ? result : DEFAULT_PC_NAME_MAX;
+                }
+                
+                return s_maxName;
+            }
+        }
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_PathConf", SetLastError = true)]
+        private static extern int PathConf(string path, PathConfName name);
+
+        [DllImport(Libraries.SystemNative, EntryPoint = "SystemNative_GetMaximumPath")]
+        private static extern long GetMaximumPath();
+    }
+}