cmd=testIncIntString str=foo23 amt=1 keep=true # new_str=foo24 str=foo23bar amt=3 keep=true # new_str=foo26 str=foo23bar34 amt=1 keep=true # new_str=foo2335 str=foo23bar34 amt=1 keep=false # new_str=2335 str=alpha88 amt=11 keep=false # new_str=99