add code

util/util.go

@@ -0,0 +1,15 @@
+package util
+
+import (
+	"os/exec"
+)
+
+// Not using "command -v" because it doesn't work with Windows.
+// testArg will usually be something like --version.
+func CheckInstalled(program, testArg string) bool {
+	cmd := exec.Command(program, testArg)
+	if err := cmd.Run(); err != nil {
+		return false
+	}
+	return true
+}