extension

<< obj1 extension obj2 >>
array of object obj1; object obj2; 
The first element of the obj1 should be the key word tag.
<< extension >> is used to install a new function to a system. cf.ext.c and plugin/
  [(parse) string] extension result-integer 
  [(chattr) num literal] extension result-object 
  [(chattrs) num ] extension result-object 
  [(defaultPolyRing) num ] extension result-object 
  [(flush) ] extension null 
  [(getpid) ] extension result-integer 
  [(getenv) envName] extension valueOfEnvName 
  [(stat) fname] extension v 
       v = [null,[(error no), p]] or [0, [size ]]
  [(forkExec) argList fdList sigblock] extension pid
  [(getchild)] extension listOfPid (generated by forkExec)
  [(keywords) ] extension array-of-names-of-primitives 
  [(nobody) ] extension null 
  [(getUniqueFileName) path] extension newName 
  [(outputObjectToFile) path obj] extension null 
  [(ostype)] extension list 
  [(regionMatches) string stringArray] extension list 
See also plugin-* in ??.