The unit tag describes one input file for the package. This tag corresponds to the --input
command-line option.
The tag has 2 attributes:
     
- 
file 
 - The file tag contains the file name. This attribute is mandatory.
     
 - 
options 
 - The options attribute is optional, and specifies any options that must be passed on
     to the parser when parsing the input file.
 
Example:
                                                                            
                                                                            
<unit file="cthreads.pp" options="-S2"/>