util: Fix brew-update cross-platform

Author: danielbayley

util/brew-update

@@ -8,6 +8,12 @@ defn main(version):
   download-releases: version
   update-brew: version
 
+defn sha256sum(file):
+  os =: System/getProperty("os.name")
+  cond:
+    os =~ /Mac\s?OS/: sh("shasum -a 256 $file")
+    else: sh("sha256sum $file")
+
 defn update-brew(version):
   releases =: releases(version)
 
@@ -22,7 +28,7 @@ defn update-brew(version):
   text =:
     reduce-kv _ text releases:
       fn(text key file):
-        sha256 =: sh("sha256sum $file").out:words.0
+        sha256 =: sha256sum(file).out:words.0
         text: .replace(key sha256)
 
   say: "Updating homebrew-yamlscript/ys.rb"
@@ -51,7 +57,7 @@ defn download-releases(version):
       when-not fs-e(file):
         say: "Downloading $file"
         url =: "$releases-url/download/$version/$file"
-        res =: sh("wget -q $url")
+        res =: sh("curl --silent --location $url --output $file")
         when res.exit:N.?:
           die: "Download of '$url' failed:\n$(res.err)"