- Hewlett-Packard Printer User Guide

Syntax Used in VPO Conﬁguration Files

Syntax for Message Pattern Matching

Appendix A 291

Bracket

Expressions:

The brackets “ [ ” and “ ] ” are used as delimiters to group expressions. To

increase performance, avoid brackets wherever they are superﬂuous.

In the pattern ab[cd[ef]gh] all brackets are unnecessary - abcdefgh is

equivalent. Expressions with brackets are used frequently with the

Alternative Operator or the NOT Operator.

Brackets are also often useful when assigning values to variables.

Expressions

Matching

Multiple

Characters:

Patterns used to match strings consisting of an arbitrary number of

characters are represented by one of the following expressions. Depending

on the symbol used, the characters matched by the expression are

restricted to a certain set.

<*> Matches any string of zero or more arbitrary characters

(including separators).

<n*> Matches a string of n arbitrary characters (including

separators).

<#> Matches a sequence of one or more digits.

<n#> Matches a sequence of n digits.

<_> Matches a sequence of one or more separator characters.

<n_> Matches a string of n separators.

<@> Matches any string that contains no separator

characters, for example, a sequence of one or more

non-separators; this can be used to match words.

Table A-2 VPO Pattern Matching Language

Component Description