Installation of flex and bison in ubuntu

if the packages of flex and bison are not available in synaptic package manager,then how can one install flex and bison in ubuntu 10.04? and if i download a开发者_C百科ny of these packages, can you just tell me the way to use them so that they get available in synaptic package manager?

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Even better is:

sudo apt-get update
sudo apt-get install flex
sudo apt-get install 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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Download the src for e.g. bison from http://ftp.gnu.org/gnu/bison/ and then do the normal

./configure
make
sudo make install

Download flex from https://github.com/westes/flex/releases