Use
curl -sb session=<token> https://adventofcode.com/2020/day/<day>/inputwith valid <token> and <day>, then pipe with sed command of the day.
sed -r 's/\x2D/\x20/;s/([a-z])\x3A/\\\1/;s/([a-z]{2,})/\x22\1\x22/g;s/^/\[/;s/$/\]/'Copyright © 2020 Patrick Schaffrath
This program and the accompanying materials are made available under the terms of the Eclipse Public License 2.0 which is available at http://www.eclipse.org/legal/epl-2.0.
This Source Code may also be made available under the following Secondary Licenses when the conditions for such availability set forth in the Eclipse Public License, v. 2.0 are satisfied: GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version, with the GNU Classpath Exception which is available at https://www.gnu.org/software/classpath/license.html.