isNumericFieldGroupWithHyphenFirstOrLast determines if a field-group is a field
number with a leading or trailing hyphen. (Private function.)
This routine is used for better error handling. Currently, incomplete field ranges
are not supported. That is, field ranges leaving off the first or last field,
defaulting to the end of the line. This syntax is available in cut, e.g.
$ cut -f 2-
In cut, this represents field 2 to the end of the line. This routine identifies
these forms so an error message specific to this case can be generated.
isNumericFieldGroupWithHyphenFirstOrLast determines if a field-group is a field number with a leading or trailing hyphen. (Private function.)
This routine is used for better error handling. Currently, incomplete field ranges are not supported. That is, field ranges leaving off the first or last field, defaulting to the end of the line. This syntax is available in cut, e.g.
In cut, this represents field 2 to the end of the line. This routine identifies these forms so an error message specific to this case can be generated.