files=... specifies the files to scan; wildcards '*' and '?' can be used as per normal Windows/DOS convention, and multiple names or patterns have to be separated with semicolons (no spaces!). For example,
files=*.cpp
will scan all files with the ".cpp" extension, while
files=*.c??
will use all files with three-character ones starting from a 'c'. If you want to scan all files with any length extensions starting from 'c', use
files=*.c*
and to scan all *.cpp, *.cc, and *.h files, use
files=*.cpp;*.cc;*.h
Of course, a number of explicitly named files can also be specified:
files=first.cpp;second.c;third.hxx;third.h
If the 'files' argument is not given, QDMet will use a default of *.cpp;*.c;*.cc;*.cxx;*.h;*.hpp;*.hxx;*.hh.