find . -iname '*.jar' -exec jar -tf {} \; > cls.dat

$ for i in ./a\ * ; do printf "file:%s:end\n" "$i"; done
file:./a  t:end
file:./a  y:end
file:./a b:end
file:./a multiline file
name.out.txt:end
file:./a z:end

$ find . -name "a *" -exec printf "file:%s:end\n" {} \;  
file:./a  t:end
file:./a  y:end
file:./a b:end
file:./a multiline file
name.out.txt:end
file:./a z:end
file:./fromdir/a  hg hg:end