# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/<span\b[^>]*+>(?# Открывающий span с любыми атребутами
)\s*+(?# Пробелы
)(?<number>\-?+\d++(?:[\.\,]\d++)?+)(?# Число
)\s*+(?# Пробелы
)<\\/span>(?# Закрывающий span)/${number}/gus;t' <<< "<span class=\"company__segment__inner\">0</span>
<span class=\"company__segment__inner\">1</span>
<span class=\"company__segment__inner\">1.</span>
<span class=\"company__segment__inner\">1.0</span>
<span class=\"company__segment__inner\">-1</span>
<span class=\"company__segment__inner\">12121.12212</span>
<span class=\"company__segment__inner\">192.168.0.1</span>
<span class=\"company__segment__inner\">Только числа</span>
<span>1</span>
<spank>1</spank>
<span>-0,123</span>
<span>
-0,123
</span>"
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