POSIX Conventions for Command Line Arguments

Command-Line Arguments warns that the use of command-line arguments
in a Java program may cause that program to be unportable (that is,
it will not be 100% Pure Java). If a program requires command-line
arguments, then it should follow the POSIX conventions for them.
    
The POSIX conventions are summarized here:

  * An option is a hyphen followed by a single alphanumeric character, 
    like this: -o.
  * An option may require an argument (which must appear immediately
    after the option); for example, -o argument or -oargument.
  * Options that do not require arguments can be grouped after a hyphen,
    so, for example, -lst is equivalent to -t -l -s.
  * Options can appear in any order; thus -lst is equivalent to -tls.
  * Options can appear multiple times.
  * Options precede other nonoption arguments: -lst nonoption.
  * The -- argument terminates options.
  * The - option is typically used to represent one of the standard
    input streams. 
