Echoproperties Task

## echoproperties

### Description

Displays all the current properties (or a subset of them specified by a nested `<propertyset>`) in the project. The output can be sent to a file if desired. This task can be used as a somewhat contrived means of returning data from an `<ant>` invocation, but is really for debugging build files.

### Parameters

Attribute | Description | Required
destfile | If specified, the value indicates the name of the file to send the output of the statement to. The generated output file is compatible for loading by any Java application as a property file. If not specified, then the output will go to the Apache Ant log. | No
prefix | a prefix which is used to filter the properties only those properties starting with this prefix will be echoed. | No
regex | a regular expression which is used to filter the properties only those properties whose names match it will be echoed. | No
failonerror | By default, the "failonerror" attribute is enabled. If an error occurs while writing the properties to a file, and this attribute is enabled, then a BuildException will be thrown, causing the build to fail. If disabled, then IO errors will be reported as a log statement, and the build will continue without failure from this task. | No
format | One of `text` or `xml`. Determines the output format. Defaults to `text`. | No

### Parameters specified as nested elements

#### propertyset

You can specify subsets of properties to be echoed with propertysets. Using `propertyset`s gives more control on which properties will be picked up. The attributes `prefix` and `regex` are just shortcuts that use `propertyset`s internally.

since Ant 1.6.

### Examples

>       <echoproperties/>

Report the current properties to the log.

>       <echoproperties destfile="my.properties"/>

Report the current properties to the file "my.properties", and will fail the build if the file could not be created or written to.

>       <echoproperties destfile="my.properties" failonerror="false"/>

Report the current properties to the file "my.properties", and will log a message if the file could not be created or written to, but will still allow the build to continue.

>       <echoproperties prefix="java."/>

List all properties beginning with "java."

>       <echoproperties>
>         <propertyset>
>           <propertyref prefix="java."/>
>         </propertyset>
>       </echoproperties>

This again lists all properties beginning with "java." using a nested `</propertyset>` which is an equivalent but longer way.

>       <echoproperties regex=".*ant.*"/>

Lists all properties that contain "ant" in their names. The equivalent snippet with `</propertyset>` is:

>       <echoproperties>
>         <propertyset>
>           <propertyref regex=".*ant.*"/>
>         </propertyset>
>       </echoproperties>