# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/"([^,]*),([^,]*)"/$1$2/gm;t' <<< "Day,Total,,,,,\"48,303\",100.00%,\"41,429\",100.00%,\"9,302\",100.00%,\"3,948\",100.00%
Day,\"Nov 11, 2014\",,,,,\"7,050\",14.60%,\"6,428\",15.52%,\"1,646\",17.70%,698,17.68%\""
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