Performs a regular expression match on the specified expression. If the expression matches the pattern, the feature is output via the Matched port, and the portion of the original search string that matched the regular expression is stored in the attribute specified in the “Matched Result Attribute” (and optionally matching pieces of the expressed are stored in the attribute list specified in the "Matched Parts Attribute", along with the starting indices of each piece). Otherwise, it is output via the NotMatched port.

This transformer takes its name and inspiration from the UNIX utility grep, which searches for patterns in text files.



Related Transformers

To replace substrings matching a regular expression in a string, use the StringReplacer transformer.

Additional Resources

Test regular expressions with the Regular Expression Editor in the Contains Regular Expression field’s context menu.

For more information on regular expression syntax, see

Editing Transformer Parameters

Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.

Transformer Categories


Transformer History

This transformer was previously named Grepper.

Technical History

Associated FME function or factory: TestFactory, @Tcl2 (regexp procedure)

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Tags Keywords: Grepper