cweb: use elisp shorthand

Formula/cweb.rb

@@ -1,6 +1,6 @@
 class Cweb < Formula
   desc "Literate documentation system for C, C++, and Java"
-  homepage "http://www-cs-faculty.stanford.edu/~uno/cweb.html"
+  homepage "https://cs.stanford.edu/~uno/cweb.html"
   url "ftp://ftp.cs.stanford.edu/pub/cweb/cweb-3.64ad.tar.gz"
   sha256 "1f0bb7aa35b8d43b721d588ed5003620d38de1959652f23bac2847ffcb922c0f"
 
@@ -15,19 +15,18 @@ class Cweb < Formula
   def install
     ENV.deparallelize
 
-    macrosdir = (share/"texmf/tex/generic")
-    emacsdir = (share/"emacs/site-lisp/cweb")
-    cwebinputs = (lib/"cweb")
+    macrosdir = share/"texmf/tex/generic"
+    cwebinputs = lib/"cweb"
 
     # make install doesn't use `mkdir -p` so this is needed
-    [bin, man1, macrosdir, emacsdir, cwebinputs].each(&:mkpath)
+    [bin, man1, macrosdir, elisp, cwebinputs].each(&:mkpath)
 
     system "make", "install",
       "DESTDIR=#{bin}/",
       "MANDIR=#{man1}",
       "MANEXT=1",
       "MACROSDIR=#{macrosdir}",
-      "EMACSDIR=#{emacsdir}",
+      "EMACSDIR=#{elisp}",
       "CWEBINPUTS=#{cwebinputs}"
   end
 
@@ -44,6 +43,6 @@ class Cweb < Formula
     EOS
     system bin/"ctangle", "test.w"
     system ENV.cc, "test.c", "-o", "hello"
-    assert_equal "Hello world!", `./hello`
+    assert_equal "Hello world!", pipe_output("./hello")
   end
 end