Patterns and Actions
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Pattern Summary

Quick overview of patterns.

Regexp Summary

Quick overview of regular expressions.

Actions Summary

Quick overview of actions. An `awk' program is mostly composed of rules, each consisting of a

pattern followed by an action. The action is enclosed in `{' and `}'.

Either the pattern may be missing, or the action may be missing, but,

of course, not both. If the pattern is missing, the action is executed

for every single line of input. A missing action is equivalent to this

action, { print }

which prints the entire line. Comments begin with the `#' character, and continue until the end of

the line. Blank lines may be used to separate statements. Normally, a

statement ends with a newline, however, this is not the case for lines

ending in a `,', `{', `?', `:', `&&', or `||'. Lines ending in `do' or

`else' also have their statements automatically continued on the

following line. In other cases, a line can be continued by ending it

with a `\', in which case the newline is ignored. Multiple statements may be put on one line by separating them with a

`;'. This applies to both the statements within the action part of a

rule (the usual case), and to the rule statements. See Comments in `awk' Programs: Comments, for information on

`awk''s commenting convention; *note `awk' Statements versus Lines:

Statements/Lines., for a description of the line continuation mechanism

in `awk'.