See section Extensions in
gawk Not in POSIX
for a summary of the GNU extensions to the
awk language and program.
All of these features can be turned off by invoking
gawk with the
--traditional option or with the
gawk is compiled for debugging with ‘
-DDEBUG’, then there
is one more option available on the command line:
This option is intended only for serious
and not for the casual user. It probably has not even been compiled into
your version of
gawk, since it slows down execution.