Why does my Mac (OS X 10.7.3) have an old version (2.3) of Gnu Bison?

Question

The version of GNU Bison on my mac is 2.3 but I know that Bison 2.5 was released long ago. The book Flex & Bison uses version 2.5.

Should I upgrade to 2.5 m

Answer 1

If you are using zsh:

$ brew unlink bison
$ echo 'export PATH="/usr/local/opt/bison/bin:$PATH"' >> ~/.zshrc
$ export LDFLAGS="-L/usr/local/opt/bison/lib"
$ source ~/.zshrc
$ bison -V
bison (GNU Bison) 3.4.1
Written by Robert Corbett and Richard Stallman.

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