From f217e0d0942f814e94ca45468869251e74cbf82b Mon Sep 17 00:00:00 2001
From: Gautam Mishra <mishragautam96@gmail.com>
Date: Thu, 2 Jul 2020 17:26:08 +0530
Subject: [PATCH] detectwsl

---
 base/sysinfo.jl | 16 ++++++++++++++--
 test/osutils.jl |  5 +++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/base/sysinfo.jl b/base/sysinfo.jl
index c88dc55278011..2d0f48b039177 100644
--- a/base/sysinfo.jl
+++ b/base/sysinfo.jl
@@ -31,7 +31,8 @@ export BINDIR,
        iswindows,
        isjsvm,
        isexecutable,
-       which
+       which,
+       detectwsl
 
 import ..Base: show
 
@@ -411,7 +412,18 @@ including e.g. a WebAssembly JavaScript embedding in a web browser.
 """
 isjsvm(os::Symbol) = (os === :Emscripten)
 
-for f in (:isunix, :islinux, :isbsd, :isapple, :iswindows, :isfreebsd, :isopenbsd, :isnetbsd, :isdragonfly, :isjsvm)
+"""
+    Sys.detectwsl([os])
+
+Runtime Predicate for testing if Julia is running inside WSL.
+"""
+function detectwsl(os::Symbol)
+    islinux(os) &&
+    isfile("/proc/sys/kernel/osrelease") &&
+    contains(read("/proc/sys/kernel/osrelease", String), r"Microsoft|WSL"i)
+end
+
+for f in (:detectwsl, :isunix, :islinux, :isbsd, :isapple, :iswindows, :isfreebsd, :isopenbsd, :isnetbsd, :isdragonfly, :isjsvm)
     @eval $f() = $(getfield(@__MODULE__, f)(KERNEL))
 end
 
diff --git a/test/osutils.jl b/test/osutils.jl
index c9e3b9d91a377..e426f0dfa8452 100644
--- a/test/osutils.jl
+++ b/test/osutils.jl
@@ -28,6 +28,11 @@
     else
         @test Sys.windows_version() >= v"1.0.0-"
     end
+
+    @test !Sys.detectwsl(:Windows)
+    if !Sys.islinux()
+        @test !Sys.detectwsl()
+    end
 end
 
 @testset "@static" begin