# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/\(?(\d{3})\)?[ -.]?(\d{3})[ -.]?(\d{4})/(\1)\2-\3/g;t' <<< "(123)456-7890 (321)-654-0987
(111) 111-1111
222-222-2222
(333)333.3333
(444).444.4444
blah blah blah (555) 555.5555
666.666.6666 random text"
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