Here is a list of all documented files with brief descriptions:

log4c
appender.h	Implement this interface for your own strategies for printing log statements
appender_type_mmap.h	Log4c mmap(2) appender interface
appender_type_rollingfile.h	Log4c rolling file appender interface
appender_type_stream.h	Log4c stream appender interface
appender_type_stream2.h	Log4c stream2 appender interface
appender_type_syslog.h	Log4c syslog(3) appender interface
buffer.h	Log4c buffer
category.h	Central class in the log4c package
config-win32.h
init.h	Log4c constructors and destructors
layout.h	Interface for user specific layout format of log4c_logging_event events
layout_type_basic.h	Implement a basic layout
layout_type_basic_r.h	Implement a basic_r layout
layout_type_dated.h	Implement a dated layout
layout_type_dated_local.h	Implement a dated layout with local time
layout_type_dated_local_r.h	Implement a dated layout (reentrant) with local time
layout_type_dated_r.h	Implement a dated_r layout
location_info.h	The internal representation of caller location information
logging_event.h	Internal representation of logging events
priority.h	The priority class provides importance levels with which one can categorize log messages
rc.h	Log4c resource configuration
rollingpolicy.h	Log4c rolling policy interface. Defines the interface for managing and providing rolling policies
rollingpolicy_type_sizewin.h	Log4c rolling file size-win interface. Log4c ships with (and defaults to) the classic size-window rollover policy: this triggers rollover when files reach a maximum size. The first file in the list is always the current file; when a rollover event occurs files are shifted up by one position in the list–if the number of files in the list has already reached the max then the oldest file is rotated out of the window
version.h	Log4c version information