tcsh 6.18.01 (new formula)

Closes Homebrew/homebrew#26405.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>

Formula/tcsh.rb

@@ -0,0 +1,24 @@
+require "formula"
+
+class Tcsh < Formula
+  homepage 'http://www.tcsh.org/'
+  url 'ftp://ftp.astron.com/pub/tcsh/tcsh-6.18.01.tar.gz'
+  sha1 'eee2035645737197ff8059c84933a75d23cd76f9'
+
+  def install
+    system "./configure", "--disable-dependency-tracking",
+                          "--prefix=#{prefix}"
+    system "make", "install"
+  end
+
+  test do
+    (testpath/'test.csh').write <<-EOS.undent
+      #!#{bin}/tcsh
+      set ARRAY=( "t" "e" "s" "t" )
+      foreach i ( `seq $#ARRAY` )
+        echo -n $ARRAY[$i]
+      end
+    EOS
+    assert_equal "test", `#{bin}/tcsh ./test.csh`
+  end
+end