Go forward to Actions.
Go backward to One-liners.
Go up to Top.

Patterns
********

   Patterns in `awk' control the execution of rules: a rule is executed
when its pattern matches the current input record.  This chapter tells
all about how to write patterns.

Menu

Kinds of Patterns
A list of all kinds of patterns. The following subsections describe them in detail.
Regexp
Regular expressions such as `/foo/'.
Comparison Patterns
Comparison expressions such as `$1 > 10'.
Boolean Patterns
Combining comparison expressions.
Expression Patterns
Any expression can be used as a pattern.
Ranges
Pairs of patterns specify record ranges.
BEGIN/END
Specifying initialization and cleanup rules.
Empty
The empty pattern, which matches every record.