язык сканирования и обработки шаблонов (pattern scanning and processing language)
Последствия ошибок (Consequences of errors)
If any file operand is specified and the named file cannot be
accessed, awk shall write a diagnostic message to standard error
and terminate without any further action.
If the program specified by either the program operand or a
progfile operand is not a valid awk program (as specified in the
EXTENDED DESCRIPTION section), the behavior is undefined.
The following sections are informative.
