UNIX® Shells by Example, Third Edition

7.6. Conditional Statements

The conditional statements in awk were borrowed from the C language. They are used to control the flow of the program in making decisions.

7.6.1. if Statements

Statements beginning with the if construct are action statements. With conditional patterns, the if is implied; with a conditional action statement, the if is explicitly stated, and followed by an expression enclosed in parentheses. If the expression evaluates true (nonzero or non-null), the statement or block of statements following the expression is executed. If there is more than one statement following the conditional expression, the statements are separated either by semicolons or a newline, and the group of statements must be enclosed in curly braces so ...