Given a text file file.txt that contains 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
在文本中找出(xxx) xxx-xxxx or xxx-xxx-xxxx 这样的字符串
grep -e ‘^[0-9]\{3\}-[0-9]\{3\}-[0-9]\{4\}$‘ -e ‘^([0-9]\{3\}) [0-9]\{3\}-[0-9]\{4\}$‘ file.txt
原文：https://www.cnblogs.com/mengchunchen/p/9305776.html