%general-entities; ]> Throughout this book, the environment variable CLFS will be used several times. It is paramount that this variable is always defined. It should be set to the mount point chosen for the CLFS partition. For the purposes of this book, it is assumed that the file system will be mounted under /mnt/clfs, but the directory choice is up to you. Decide on a directory location and set the variable with the following command: export CLFS=[/mnt/clfs] Having this variable set is beneficial in that commands such as install -dv ${CLFS}/tools can be typed literally. The shell will automatically replace ${CLFS} with /mnt/clfs (or whatever the variable was set to) when it processes the command line. Do not forget to check that ${CLFS} is set whenever you leave and reenter the current working environment (as when doing a su to root or another user). Check that the CLFS variable is set up properly with: echo ${CLFS} Make sure the output shows the path to the CLFS partition's mount point, which is /mnt/clfs if the provided example was followed. If the output is incorrect, use the command given earlier on this page to set ${CLFS} to the correct directory name.