File Types

Use this window to edit the file patterns that determine the type of comparison window to use to compare files, and to specify programs that can transform content when files are opened and saved.


The checkboxes in this column can be used to enable and disable the file types in the table.


Shows the type of comparison that should be opened for files whose names or types match the patterns in the Filename Patterns column.

Filename Patterns

Double-click and enter one or more semicolon-separated patterns that match the files that should be compared using the comparison type shown above. For example, to match image files, you could use *.bmp;*.gif;*.jpg;*.png. Uniform Type Identifiers can also be used to match files based on their type. To use a UTI, prefix the UTI with uti:. For example: uti:public.image;uti:com.adobe.pdf would match image and PDF file types.

Filter Program

Double-click and enter an optional name or fully-qualified path of a program or script that should be used to filter files when they are opened or saved. Filters enable Merge to compare the contents of files in formats that it would otherwise not understand.

Filters located in the Araxis Merge application bundle’s Contents/Resources/Filters folder do not require a fully-qualified path. User-provided filter programs or scripts can either be copied into that folder, or located elsewhere. In the latter case, a fully-qualified path to the program or script should be specified in this column.

When Merge opens or saves a file that matches the pattern specified in the previous column, it runs the filter program with three filename arguments. The first specifies a file containing the data to be transformed by the filter program. The second specifies a file into which the transformed data should be written. The third filename argument specifies a file containing keys and values describing the transformation being performed. Merge will also pass an option argument of -f or -r to indicate that a forward (when reading a file) or reverse (when writing to a file) transformation is required.

If the filter program is unable to operate on the input file provided by Merge (if reverse transformations are not supported, for example), it should report an error to Standard Error, and return a non-zero exit code.