The following directories are the most substantial ones:
lib/
: common source code used by syslog-ngmodules/
: each module in syslog-ng has a directory here, likeredis
syslog-ng
: the source code of thesyslog-ng
binarysyslog-ng-ctl
: the source code of thesyslog-ng-ctl
command line utilitytests
: the home of unit tests and functional tests (but there are tests next to their tested functionality)