# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(第.*?条)\n(?:.*?)(\d+)\n([^\s]+)/$1\n【$3】$2/gsm;t' <<< "第四百六十三条
【条文主旨】17
本条是关于合同编调整对象的规定。
第四百六十四条
【条文主旨】23
本条是关于合同的概念及适用的规定。"
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