Pattern Layout

Overview of Pattern Layouts

A pattern layout is a template that you create in order to format log messages for the appender classes in the SAS logging facility. The pattern layout that you define identifies the type of data, the order of the data, and the format of the data that is generated in a log event and that is delivered as output. A unique pattern layout is created for each instance of an appender class. You configure a pattern layout by using the <layout> appender subelement in a logging configuration file or the PATTERN attribute of an appender language element.

The pattern layout is created by using a conversion pattern, which consists of literal text and format-control directives. Format-control directory are also called conversion specifiers.

The conversion patterns that you use to format log messages are similar to, but not identical to, the conversion patterns that are used in the C language PRINTF statement.

Note: The conversion patterns that you use to format log messages are also similar to, but not identical to, these formatting methods that are used in these contexts:

the directives that are used in the SAS LOGPARM= system option to format log names.
the set of conversion patterns that are used by the ARMAppender. For details, see ARMAppender Pattern Layouts in SAS Interface to Application Response Measurement (ARM): Reference

The meaning of a specific character that is used in a pattern can vary according to the context. Do not interchange characters. [cautionend]

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