awk Debugging ¶Debugging an awk program has some specific aspects that are
not shared with programs written in other languages.
First of all, the fact that awk programs usually take input
line by line from a file or files and operate on those lines using specific
rules makes it especially useful to organize viewing the execution of
the program in terms of these rules. As we will see, each awk
rule is treated almost like a function call, with its own specific block
of instructions.
In addition, because awk is by design a very concise language,
it is easy to lose sight of everything that is going on “inside”
each line of awk code. The debugger provides the opportunity
to look at the individual primitive instructions carried out
by the higher-level awk commands.98
The “primitive
instructions” are defined by gawk itself; the debugger
does not work at the level of machine instructions.