# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/\[title(\s.*?)?](.*?)\[\/title]/[new_title$1 title="$2"]/gis;t' <<< "[title type=\"1\"]Test[/title] [title]Test2[/title]
[title type=\"6\"]Test With
Newline 3[/title]"
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