Question

In perl I am trying to use a regex to search through specific hex characters but i’m not sure if the xB syntax is valid (ie to refer to the Vertical Tab character) or whether it should just be \B? Also, is x9 valid or should it just be 9?

perl -ane '{ if(m/([\x0-\x9]|[\xB-\xC]|[\xE-\x1F]|[\x7F-\xFF])/) { print } }'

Answer 1

perl -lne 'print if /[\x00-\x09\x0b\x0c\x0e-\x1f\x7f-\xff]/'

Documented in http://perldoc.perl.org/perlrecharclass.html#Bracketed-Character-Classes:

[Some sequences, including] \x are also special and have the same meanings as they do outside a bracketed character class.