язык сканирования и обработки шаблонов (pattern scanning and processing language)
Описание (Description)
The awk utility shall execute programs written in the awk
programming language, which is specialized for textual data
manipulation. An awk program is a sequence of patterns and
corresponding actions. When input is read that matches a pattern,
the action associated with that pattern is carried out.
Input shall be interpreted as a sequence of records. By default,
a record is a line, less its terminating <newline>, but this can
be changed by using the RS built-in variable. Each record of
input shall be matched in turn against each pattern in the
program. For each pattern matched, the associated action shall be
executed.
The awk utility shall interpret each input record as a sequence
of fields where, by default, a field is a string of non-<blank>
non-<newline> characters. This default <blank> and <newline>
field delimiter can be changed by using the FS built-in variable
or the -F sepstring option. The awk utility shall denote the
first field in a record $1, the second $2, and so on. The symbol
$0 shall refer to the entire record; setting any other field
causes the re-evaluation of $0. Assigning to $0 shall reset the
values of all other fields and the NF built-in variable.
