Provided by: systemtap-doc_4.7-1_amd64 bug

NAME

       function::ngroups - Number of subexpressions in the last match.

SYNOPSIS

           ngroups:long()

ARGUMENTS

       None

DESCRIPTION

       returns the number of subexpressions from the last successful use of the =~ regex matching
       operator.

       Note that this number includes subexpressions which are present in the regex but did not
       match any string; for example, given the regex “a|(b)”, the subexpressions will count the
       group for (b) regardless of whether it matched a string or not. Throws an error if the
       last use of =~ was a failed match.

SEE ALSO

       tapset::regex(3stap)