[leetcode]Valid Phone Numbers

Valid Phone Numbers

#using sed
sed -n -E '/^([0-9]{3}-|\([0-9]{3}\) )[0-9]{3}-[0-9]{4}$/p' file.txt
#using awk
awk '/^([0-9]{3}-|\([0-9]{3}\) )[0-9]{3}-[0-9]{4}$/' file.txt
#using grep in Perl mode
grep -P '^(\d{3}-|\(\d{3}\) )\d{3}-\d{4}$' file.txt
#using grep in E mode
grep -E '^(\d{3}-|\(\d{3}\) )\d{3}-\d{4}$' file.txt