text and variables -->
Variable substitution is usually performed only in the expansion of include, or related commands, not in the top level file. This allows HIP to re-write the file in place, and allow it to be UNHIPped or HIPped again without losing any information. There are times, however, when the source document does not lend itself to this structure, and it would be convenient to have variable substitution performed in the top level file. The echo command allows this in a manner similar to the date command, by rewriting any text which follows the closing --> of the directive with the expansion of the 'text and variables' portion of the echo command.
For example, the following command would give the same output as the DATE command.
&&sys_mon; &&sys_dd;, &&sys_year;
Note that unlike other commands, variable substitution is not applied to the echo command BEFORE processing, and there is no provision for 'name=value' arguments.
This option is particularly useful in conjunction with the table directive. Although intended for use in the top level file, it works as expected in lower level includes as well.
An alternative to using echo is to use the build option of HIP, which produces a separate output file, so that the limitations of rerunability do not apply.