# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/<a href="entry:\\/\\/([^_]+)_([^_]+)_([^_]+)" title="/<a href="entry:\/\/$1 $2 $3" title="/gmsi;t' <<< "<ul><li><span class=\"Latn\" lang=\"en\"><a href=\"entry://Thousand_Island_dressing\" title=\"Thousand Island dressing\">Thousand Island dressing</a></span></li></ul>"
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