# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/("filterType":\h+"LOT_SIZE",(?:\R\h+"[^"]+":\h+"[^"]+",?){3})(?:\R\h+"[^"]+":\h+"[^"]+",?){3}/$1/gm;t' <<< "\"symbol\": \"ETHBTC\",
\"filterType\": \"LOT_SIZE\",
\"minQty\": \"0.00100000\",
\"maxQty\": \"100000.00000000\",
\"stepSize\": \"0.00100000\"
\"minQty\": \"0.00000000\",
\"maxQty\": \"9201.00570633\",
\"stepSize\": \"0.00000000\"
\"symbol\": \"LTCBTC\",
\"filterType\": \"LOT_SIZE\",
\"minQty\": \"0.01000000\",
\"maxQty\": \"100000.00000000\",
\"stepSize\": \"0.01000000\"
\"minQty\": \"0.00000000\",
\"maxQty\": \"33144.83294363\",
\"stepSize\": \"0.00000000\""
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