A regular expression to match a valid hostname (also called domain label) in DNS entries. Useful if you have to parse through a lot of DNS entries and need something to help you make sense of it. You can also easily use this to check if a DNS entry is valid or not if you wanted to.
Note that a valid hostname may contain only the ASCII letters a through z (in a case-insensitive manner), the digits 0 through 9, and the hyphen-minus character (‘-‘).
/^(?![0-9]+$)(?!.*-$)(?!-)[a-zA-Z0-9-]{1,63}$/g
Matches:
- regex
- regex-pattern
- regex01
Non-matches:
- regex pattern
- regex-
- 100110
See Also:
- Domain Name Regular Expression
- IP Address (V6) With Port Regular Expression
- IP Address (V4) With Port Regular Expression
- Subnet Mask Regular Expression
- URL (With And Without Port Number) Regular Expressions