# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/^[^_]*_|_\d+_\d+\.[^.]*$//gm;t' <<< "Doc20191001119049_fotocontargasx_3962122_943000.jpg
Doc201810011052053_fotoAssicurazioneCartaceo_3962128_943000.jpg
Doc201910011214020_fotoesterna_ant_396024_947112.jpg
Doc201710071149010_foto_TargaMid_4007396_95010.jpg"
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