# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/^(?:\+?1?[-.\s]?)(\d{3})([-.\s])(\d{3})\2(\d{4})$/(\1) \3 \4/gmx;t' <<< "+1-555-235-2444
1-555-235-2444
1.555.235.2444
1 555 235 2444
555-235-2444
(555) 234-2341
5552342341
555 2341234
555-2341234"
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