Gawk/Constant-Size

From Get docs

4.6 Reading Fixed-Width Data

This section discusses an advanced feature of gawk. If you are a novice awk user, you might want to skip it on the first reading.

gawk provides a facility for dealing with fixed-width fields with no distinctive field separator. We discuss this feature in the following subsections.

Fixed width data    Processing fixed-width data.
Skipping intervening    Skipping intervening fields.
Allowing trailing data    Capturing optional trailing data.
Fields with fixed data    Field values with fixed-width data.