I am using this one-liner to find duplicate lines in a text file:
:syn clear Repeat | g/^\(.*\)\n\ze\%(.*\n\)*\1$/exe 'syn match Repeat "^' . escape(getline('.'), '".\^$*[]') . '$"' | nohlsearch
When I execute it on C source files, it correctly returns so many { and break; and empty lines. However, they are not the most interesting lines. Howe I can exclude one or multiple characters from the result of this one-liner?