Is a makefile basically the same thing as a batch file?

Question

I know all about batch files and made them before, but I'm unclear on what a makefile is. It looks like a batch file. What are the similarities and diffferences?

Answer 1

Similar, yes, except for the dependencies, the topological sort, the macro processing, and the expert system

If you do nothing but put shell commands in a Makefile then it is in fact a lot like a catalog of "batch files," and it executes each one when its associated named target is specified.

However, it is more typical to specify a graph of dependencies in a makefile, in which case make does a topological sort of all the dependencies in order to cleverly build everything only once and in the right order starting with the earliest prerequisites.

And to be complete, I should add that make is also a macro processor. It's oriented towards software build systems, so it provides handles on symbolic elements in its problem domain, such as the names of sources and targets.

Now, make is not specifically a general purpose expert system,¹ but it does do more than just package up shellcode, and technically it does fit the expert system definition.

Make contains an inference engine. All versions of make have suffix rules, some versions also implement pattern rules. When combined with your specification (more rules, typically ones defining a software application) the result is an expert system which will decide what needs to be compiled, linked, purchased on eBay, whatever, all depending on the data and commands you have provided.

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^{1. It's an *easy-to-use* expert system, instead. Skynet will probably not emerge from an accidental typo in a complicated Makefile.}

Answer 2

No. A makefile has special rules which relate how files depend on each other. It does not necessarily execute in the order it is written.

A batch file is a sequence of commands and control statements.

Makefiles often contain the same things as batch files, but batch files do not have a direct way of indicating dependencies or provide an inferred method of processing one kind of file into another kind.