Regular Expressions Cookbook

6.6. Hexadecimal Numbers Within a Certain Range

Problem

You want to match a hexadecimal number within a certain range of numbers. You want the regular expression to specify the range accurately, rather than just limiting the number of digits.

Solution

1 to C (1 to 12: hour or month):

^[1-9a-c]$

Regex options: Case insensitive

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

1 to 18 (1 to 24: hour):

^(1[0-8]|[1-9a-f])$

Regex options: Case insensitive

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

1 to 1F (1 to 31: day of the month):

^(1[0-9a-f]|[1-9a-f])$

Regex options: Case insensitive

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

1 to 35 (1 to 53: week of the year):

^(3[0-5]|[12][0-9a-f]|[1-9a-f])$

Regex options: Case insensitive

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

0 to 3B (0 to 59: minute or second):

^(3[0-9a-b]|[12]?[0-9a-f])$

Regex options: Case insensitive

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

0 to 64 (0 to 100: percentage):

^(6[0-4]|[1-5]?[0-9a-f])$

Regex options: Case insensitive

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

1 to 64 (1 to 100):

^(6[0-4]|[1-5][0-9a-f]|[1-9a-f])$

Regex options: Case insensitive

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

20 to 7E (32 to 126: printable ASCII codes):

^(7[0-9a-e]|[2-6][0-9a-f])$

Regex options: Case insensitive

Regex flavors: .NET, Java, JavaScript, PCRE, Perl, Python, Ruby

0 to 7F (0 to 127: 7-bit number):

^[1-7]?[0-9a-f]$ ...