Use the following syntax to check a string against a regular expression:
env.regexpMatch(stringToMatch, someRegularExpression)
For example, the string outputLine is checked to determine whether it starts with the value System:
<# if env.regexpMatch(outputLine, "^System") #>
. . .
<# endif #>
In this example, the string interface is checked to determine whether it has the correct syntax:
<# interface := env.argv(1) #>
<# if env.regexpMatch(interface, "^[0-9]+/[0-9]+$") #>
. . .
<# endif #>