7.4 Control Statements in Actions

Control statements, such as if, while, and so on, control the flow of execution in awk programs. Most of awk’s control statements are patterned after similar statements in C.

All the control statements start with special keywords, such as if and while, to distinguish them from simple expressions. Many control statements contain other statements. For example, the if statement contains another statement that may or may not be executed. The contained statement is called the body. To include more than one statement in the body, group them into a single compound statement with braces, separating them with newlines or semicolons.

If Statement    Conditionally execute some awk

statements.

While Statement    Loop until some condition is satisfied.
Do Statement    Do specified action while looping until some

condition is satisfied.

For Statement    Another looping statement, that provides

initialization and increment clauses.

Switch Statement    Switch/case evaluation for conditional

execution of statements based on a value.

Break Statement    Immediately exit the innermost enclosing loop.
Continue Statement    Skip to the end of the innermost enclosing

loop.

Next Statement    Stop processing the current input record.
Nextfile Statement    Stop processing the current file.
Exit Statement    Stop execution of awk.