# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/^(?=.{6,})(?=.*?[A-Z])(?=.*?[a-z])(?=.*?\d)(?=.*?\W).*$//gm;t' <<< "Aæøåa6
asdA9'
sfdsfd89
Adsd87865634x"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html