:- [auxiliaries,tools].it behaves like an include/1 directive, i.e. it instructs the compiler (or any other source-processing tool) to process the given files as if they were part of the file containing the directive.
When called as a query (e.g. at the interactive toplevel) or goal, it will compile source files or load precompiled files. If a precompiled file exists (usually characterized by a .eco file suffix), then this file is loaded, otherwise a source file is expected and compiled using compile/1. See the specification of compile/1 for details.
A particular common use at the toplevel is the special form:
?- [user].which is used for interactively compiling code from the standard input.
Success:
     [hanoi].         % compiles the file hanoi.pl
     [eclipse]: sh('cat file1').
     p:-writeln(hello).
     yes.
     [eclipse]: sh('cat file2').
     q(X) :- write(X).
     yes.
     [eclipse]: [user], p.
      p :- writeln(hi).
      user compiled 92 bytes in 0.00 seconds
     hi
     yes.
     [eclipse]: [file1, file2], p.
     /home/lp/user/file1 compiled 32 bytes in 0.02 seconds
     /home/lp/user/file2 compiled 92 bytes in 0.00 seconds
     hello
     yes.
Error:
     [F].            (Error 4).
     [file1/1].      (Error 5).
     [noexist].      (Error 171).