14.8.2 Specific header arguments

The following header arguments are defined:

• var: Pass arguments to code blocks
• results: Specify the type of results and how they will be collected and handled
• file: Specify a path for file output
• dir: Specify the default (possibly remote) directory for code block execution
• exports: Export code and/or results
• tangle: Toggle tangling and specify file name
• comments: Toggle insertion of comments in tangled code files
• no-expand: Turn off variable assignment and noweb expansion during tangling
• session: Preserve the state of code evaluation
• noweb: Toggle expansion of noweb references
• cache: Avoid re-evaluating unchanged code blocks
• hlines: Handle horizontal lines in tables
• colnames: Handle column names in tables
• rownames: Handle row names in tables
• shebang: Make tangled files executable
• eval: Limit evaluation of specific code blocks