The *IF Lines

• These lines control the disabling and enabling of code (by adding or removing the comment character) depending on whether the specified EXTRACT option(s) were selected when EXTRACT was run. If the *IF has more than one option they form an OR list; selecting any option in the list enables the code.

• The options can be anything although the following have already been defined:-

  
  VAX 		 For VAX/VMS
  
  
  UNIX 		 For vanilla UNIX.
  
  
  APOLLO 		 For APOLLO deviations from vanilla UNIX.
  
  
  DECSTATION 		 For DECstation deviations from vanilla UNIX.
  
  
  

• The THEN is an optional extra for purists:

  *IF VAX is as good as *IF VAX THEN

• The *ELSE and 1 or more *ELSEIFs are optional.

• Nesting is allowed as shown in the example.