0.How To Install Flex and Bison Under Ubuntu

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Flex and Bison are unix utilities that can help you to write very fast parsers for arbitrary file formats. If your synaptic package manager currently does not include these packages, you can install Flex and Bison through a simple terminal command.
Open a terminal by pressing [CTRL] + [ALT] + T. Then, type one of the following commands.

This command is more basic:

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install flex bison

which flex /*Sanity check to make sure flex is installed*/
which bison /*Sanity check to make sure bison is installed*/

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