LeetCode in Kotlin
193. Valid Phone Numbers
Easy
Given a text file file.txt that contains a list of phone numbers (one per line), write a one-liner bash script to print all valid phone numbers.
You may assume that a valid phone number must appear in one of the following two formats: (xxx) xxx-xxxx or xxx-xxx-xxxx. (x means a digit)
You may also assume each line in the text file must not contain leading or trailing white spaces.
Example:
Assume that file.txt has the following content:
987-123-4567
123 456 7890
(123) 456-7890
Your script should output the following valid phone numbers:
987-123-4567
(123) 456-7890
Solution
# Read from the file file.txt and output all valid phone numbers to stdout.
egrep '^[0-9]{3}-[0-9]{3}-[0-9]{4}$|^\([0-9]{3}\)\s[0-9]{3}-[0-9]{4}$' file.txt