" " ~ [[:blank:]]
" " ~ [[:space:]]
\a !~ [[:blank:]]
\a !~ [[:space:]]
\b !~ [[:blank:]]
\b !~ [[:space:]]
\f ~ [[:blank:]]
\f ~ [[:space:]]
\n ~ [[:blank:]]
\n ~ [[:space:]]
\r ~ [[:blank:]]
\r ~ [[:space:]]
\t ~ [[:blank:]]
\t ~ [[:space:]]
\v ~ [[:blank:]]
\v ~ [[:space:]]