The file extension of the given path or empty string if no extension

Summary

Extract the file extension from a file path, returning the part after the last dot in the filename.

Syntax 

${extension;<path>}

Parameters

  • path: File path from which to extract the extension

Behavior

The macro:

  1. Normalizes the path (handles different path separators)
  2. Extracts the last segment (filename) from the path
  3. Returns the part after the last . in the filename
  4. Returns an empty string if no extension is present

The extension is returned without the leading dot.

Examples 

# Extract extension from file path
${extension;myfile.txt}                    # Returns: txt
${extension;/path/to/document.pdf}        # Returns: pdf
${extension;archive.tar.gz}               # Returns: gz (only last extension)

# No extension cases
${extension;README}                        # Returns: (empty)
${extension;/path/to/folder/}             # Returns: (empty)

# Multiple dots
${extension;my.file.name.java}            # Returns: java

# Original examples
${extension;abcdef.def}                   # Returns: def
${extension;/foo.bar/abcdefxyz.def}      # Returns: def
${extension;abcdefxyz}                    # Returns: (empty)
${extension;/foo.bar/abcdefxyz}          # Returns: (empty)

# Used with other macros
-include ${extension;${workspace}/.project} == project

Use Cases

  1. File Type Detection: Determine the type of file being processed
  2. Conditional Logic: Apply different processing based on file extension
  3. File Filtering: Select files based on their extensions
  4. Path Construction: Build new paths with modified extensions
  • basenameext - Extract basename, optionally removing an extension
  • stem - Get filename without extension
  • basename - Get the last path segment

See test cases in MacroTestsForDocsExamples.java