Install flex on ubuntu

Before starting, please check to see if there is a latest version available to download. Visit http://flex.sourceforge.net/ to find out about the available versions. IMPORTANT: See "Configuring Ubuntu Linux After Installation" to install the development tools required to compile and install flex from source code.

Steps to download, compile, and install are as follows. Note: Replace 2.5.33 with your version number:

• Downloading Flex (The fast lexical analyzer):

  Run the command below,

  wget http://prdownloads.sourceforge.net/flex/flex-2.5.33.tar.gz?download

• Extracting files from the downloaded package:

  tar -xvzf flex-2.5.33.tar.gz

  Now, enter the directory where the package is extracted.

  cd flex-2.5.33

• Configuring flex before installation:

  If you haven't installed m4 yet then please do so. Run the commands below to include m4 in your PATH variable.

  PATH=$PATH:/usr/local/m4/bin/

  NOTE: Replace '/usr/local/m4/bin' with the location of m4 binary. Now, configure the source code before installation.

  ./configure --prefix=/usr/local/flex

  Replace "/usr/local/flex" above with the directory path where you want to copy the files and folders. Note: check for any error message.

• Compiling flex:

  make

  Note: check for any error message.

• Installing flex:

      

• As root (for privileges on destination directory), run the following.
  With sudo,

  sudo make install

  Without sudo,

  make install

  Note: check for any error messages.

That’s it. Flex has been successfully installed.

Posted in flex, Ubuntu