Instead of deleting the sources and downloading the entire tree every time you want to update, you can update just the files that have changed since the last revision. To do this, change into the directory containing the files you want to update and run the make update command:
# cd /usr/src/asterisk/ # make update # make clean # make upgrade
Note that this will work only with code obtained via the CVS method (see "make update," earlier in this chapter). The make upgrade command is used only in the Asterisk source directory. In other directories, use make install .