This function will set one or more fields, a named variable or fields listed in a named variable to their first non empty line. Which fields or named variable you are processing is discussed in Statement Source/Target Determination.
The function proceeds as follows: All leading spaces and line terminators are removed. All text after the first remaining line terminator is removed. All trailing spaces and line terminators are removed.
The named variable field may contain any of the escape sequences described in Escape Sequences When a named variable is specified and the execution mode is stepwise, the statement is only executed once.