ch03

Introduction to Gofer                                 3. STARTING GOFER


3. STARTING GOFER

The Gofer interpreter is usually entered by giving the command `gofer',
after which a display something like the  following  will  normally  be
produced:

    Gofer Version 2.20
 
    Reading script file "/gofer/prelude":
    Parsing........................................................
    Dependency analysis............................................
    Type checking..................................................
    Compiling......................................................

    Gofer session for:
    /gofer/prelude
    Type :? for help
    ?

The file name "/gofer/prelude" mentioned in the  output  above  is  the
name of a file of standard definitions which are loaded into Gofer each
time that the interpreter is started.  By default,  Gofer  reads  these
definitions from  a  file  called  "prelude"  in  the  current  working
directory.  Alternatively you can set the environment variable GOFER to
the name of the  standard  prelude  file,  which  will  then  be  used,
whatever the current working directory might be.

Most commands in Gofer take the form of a colon followed by one or more
characters which distinguish one command from another.  There  are  two
commands which are particularly worth remembering:

  o  :q  exits the  Gofer  interpreter.   On most systems, you can also
     exit from Gofer by typing the end of  file  character  (^Z  on  an
     MS-DOS machine, usually ^D on a unix based machine).

  o  :?  prints a list of all the commands,  which can be useful if you
     forget the name of the command that you want to use.

The complete range of commands supported by the  Gofer  interpreter  is
described in appendix F.

Note that the interrupt key (^C on most systems) can  be  used  at  any
time whilst using Gofer to abandon the process of reading in a file  of
function definitions or the evaluation  of  an  expression.   When  the
interrupt key is detected, Gofer prints the string "{Interrupted!}" and
prints the "? " prompt so that further commands can be entered.












                                      4