Data File Management (The GNU Awk User’s Guide)

From Get docs

10.3 Data file Management

This section presents functions that are useful for managing command-line data files.

Filetrans Function    A function for handling data file transitions.
Rewind Function    A function for rereading the current file.
File Checking    Checking that data files are readable.
Empty Files    Checking for zero-length files.
Ignoring Assigns    Treating assignments as file names.