The Jack compiler is a program that gets a Jack program as input and generates executable VM code as output.

Usage: The compiler accepts a single command-line argument, as follows,

prompt> JackCompiler source

where source is either a file name of the form Xxx.jack (the extension is mandatory) or the name of a folder (in which case there is no extension) containing one or more .jack files. The file/folder name may contain a file path. If no path is specified, the compiler operates on the current folder. For each Xxx.jack file, the parser creates an output file Xxx.vm and writes the VM commands into it. The output file is created in the same folder as the input file. If there is a file by this name in the folder, it will be overwritten.