# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/<url>\s*<loc>[^<]+login.+?<\/url>\s*//sg;t' <<< "<url>
<loc>http://review-pref.ru/literatura/49/131/</loc>
<changefreq>monthly</changefreq>
<priority>0.3</priority>
</url>
<url>
<loc>http://review-pref.ru/folklor/4/178/4/javascript/login</loc>
<changefreq>monthly</changefreq>
<priority>0.3</priority>
</url>
<url>
<loc>http://review-pref.ru/literatura/56/65/login/javascript/login/login/</loc>
<changefreq>monthly</changefreq>
<priority>0.3</priority>
</url>
<url>
<loc>http://review-pref.ru/folklor/4/164/</loc>
<changefreq>monthly</changefreq>
<priority>0.3</priority>
</url>
"
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