Merge c28cac9 into 299300a

doc/src/manual/faq.md

@@ -645,6 +645,13 @@ as nothing but rather a tuple of zero values.
 The empty (or "bottom") type, written as `Union{}` (an empty union type), is a type with
 no values and no subtypes (except itself). You will generally not need to use this type.
 
+
+### How do I check if the current file is being run as the main script?
+
+When a file is run as the main script using `julia file.jl` one might want to activate extra
+functionality like command line argument handling. A way to determine that a file is run in
+such as fashion is to check if `abspath(PROGRAM_FILE) == @__FILE__` is `true`.
+
 ## Memory
 
 ### Why does `x += y` allocate memory when `x` and `y` are arrays?