Shell Programming and Scripting

The right hand side should not use double quotes (these would only be used in the case of a string comparison).
[[ ... =~ t70cra2[01-40] ]], and also [01-40]*is not a range in regex, nor is it a meaningful range in pattern matching (pattern matching uses the == operator).. In the case of regex we would also need to use anchors ( ^ and $ )

IMO it would be preferable to use pattern matching rather than of regex here: Something like this should work :

Code:

if [[ `hostname` == t70cra2[0-4][0-9] || `hostname` == t70c6n2[0-2][0-8] ]]; then

or

Code:

case `hostname` in 
  t70cra2[0-4][0-9]|t70c6n2[0-2][0-8]) echo hello ;;
esac

Yep, there is certainly a misunderstanding of the [character_range].
E.g. t70cra2[01-40] is a 0 or the 1-4 range i.e. t70cra2[0-4]

Like Scrutinizer said, with double quotes on the RHS, you are trying for a literal string match.
Though ugly and not easily maintainable, this does the work and also matches what you want (and not some other strings):

Code:

hostnm=$(hostname)
if [[ $hostnm =~ t70cra2([0-3][1-9]|(1|2|3|4)0)|t70c6n2([0-1][1-9]|(1|2)0|2[1-8]) ]]; then