in reply to Re^2: \s matches newline in regex?
in thread \s matches newline in regex?

If you want just a space use just a space! If you want to match everything except some specific white space characters use a negated character class with \S and the other white space characters you want to keep:

s/Hi[^\S\n\r\f]+//g

for example.

Premature optimization is the root of all job security