# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/^(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)(?:[ ]+(.*))?/$1;$2;$3;$4;$5;$6;$7/gm;t' <<< "Interface Link Speed Duplex Type PVID Description
BAGG51 UP 4G(a) F(a) T 1
FGE1/0/42 DOWN auto A T 1 ### LIVRE ###
GE6/0/20 UP 100M(a) F(a) A 1 LIVRE (MGMT - [WAN8-P8] "
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