Table of Contents

6 Expression macros


Expression macros are useful for formula calculations. They are calculated by expanding all macros inside and evaluating the resulting expression.

Expression macros have a special syntax:


The syntax in EXPRESSION is the same as in trigger expressions (see usage limitations below).

{HOST.HOST<1-9>} and {ITEM.KEY<1-9>} macros are supported inside expression macros.


In the following locations:

  • graph names
  • map element labels
  • map shape labels
  • map link labels

only a single function, from the following set: avg, last, max, min, is allowed as an expression macro, e.g.:


Expressions such as {?last(/host/item1)/last(/host/item2)}, {?count(/host/item1,5m)} and {?last(/host/item1)*10} are incorrect in these locations.

However, in:

  • trigger event names
  • trigger-based notifications and commands
  • problem update notifications and commands

complex expressions are allowed, e.g.:


See also:

  • Supported macros for a list of supported locations of the expression macro
  • Example of using an expression macro in the event name