*----------------------------------------*
          =>    | Interactive Command Editor for VAX/VMS |    <=
                *----------------------------------------*
                |  IIIII                                 |
                |   III           CCCC           EEEE    |
                |   III          C    C         E    E   |
                |   III     *    C         *    EEEEE    |
                |   III          C              E        |
                |   III          C    C         E    E   |
                |  IIIII          CCCC           EEEE    |
                *----------------------------------------*
          =>    | Interactive Command Editor for VAX/VMS |    <=
                *----------------------------------------*
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                                  |I|c|e|
                        Interactive Command Editor
                                USERS GUIDE
                                Release 1.0
                 Copyright (c) 1982, Western Electric Co.
|I|c|e| Users Guide (Release 1.0)                                    Page 3


                   |I|c|e| - Interactive Command Editor
                                USERS GUIDE
                                Release 1.0
                            November 30th, 1982
                 Copyright (c) 1982, Western Electric Co.


    This will introduce you to ICE, the Interactive Command Editor for  the
    VAX/VMS  operating system.  A command editor is basically a convenience
    feature for a VAX/VMS user.  It "remembers" commands that are issued by
    that  user  to the operating system and allows him to recall them again
    for re-submittal (with optional modification) to DCL.


    There are four (4) types of commands that ICE  will  act  upon.   These
    fall into one of the categories below:

     o  Regular DCL commands to VMS
     o  ICE commands to recall previous DCL command lines
     o  ICE commands to EDIT recalled DCL command lines
     o  ICE commands to EXIT from ICE or get ON-LINE assistance


    Normal "DCL-type" commands are passed  straight  to  DCL,  after  being
    saved  by  ICE  for  future recall.  The only significant differences a
    user will notice between ICE and DCL are:


1.  Since ICE is run from a command file, DCL will not prompt  for  missing
    values or parameters.

2.  When running ICE,  users  cannot  use  either  the  CONTINUE  or  DEBUG
    commands.

3.  Continuation line support is handled slightly  differently  under  ICE.
    (Actually, better than DCL does.)

4.  On a "BUSY" system, the user may notice a slight delay in the return of
    the DCL-style prompt after a command is processed.


    ICE STACK MANIPULATION COMMANDS

    There are four commands that ICE recognizes to allow a user  to  recall
    previously executed DCL commands:

    These are CTRL/A, CTRL/B, CTRL/E and <ESC>.

    These commands allow a user  to  examine  the  contents  of  his  saved
    command "stack" (CTRL/E);  move either up or down the stack to recall a
    particular command (CTRL/A or  CTRL/B);   or  recall  the  most  recent
    command  (<ESC>).  These commands will work AT ANY POINT in ICE, either
|I|c|e| Users Guide (Release 1.0)                                    Page 4


    at the command prompt or in EDIT mode.

    Note that the users stack WRAPS AROUND;  i.e., when he  reaches  either
    the  top  or bottom of the stack, the stack pointer (shown by ">") will
    "wrap around" to the other end.  This allows quick traversing from  top
    to bottom or vice versa.

    The <ESC> key has a dual function.  It serves to immediately recall the
    last  executed  command and as such may be the most frequently used ICE
    command.  It is a TOGGLE command;  the next time a user  presses  <ESC>
    he will be returned to the DCL-style prompt.  In that way, <ESC> allows
    a user to  ESCAPE  from  the  EDIT  mode  of  ICE  (this  can  also  be
    accomplished with CTRL/C or CTRL/Y).

    The first time ICE is run, there will probably not  be  any  saved  DCL
    commands  (unless  a  previous  saved commands file exists).  If a user
    tries any of the recall commands he will be  alerted  with  a  BELL  to
    remind him there arent any yet!


    ICE EDITING COMMANDS

    There are six commands that ICE recognizes  for  editing  recalled  DCL
    commands:

    These are <BS>, <DEL>, <LF>, CTRL/D, CTRL/W, and CTRL/F.

    They allow a user to  move  backward  over  the  command  line  (<BS>);
    delete  characters  to the left of the cursor position (<DEL>);  delete
    words to the left of the cursor  position  (<LF>);   delete  characters
    directly  under  the cursor (CTRL/D);  delete words to the right of the
    cursor position (CTRL/W);  and  move  forward  over  the  command  line
    (CTRL/F).

    CTRL/R support also works in EDIT mode;  it will  re-type  the  current
    line  (with all editing in tact) should it become disturbed due to line
    noise or terminal output from other processes.

    These commands allow ICE to behave much like a screen  editor  (with  a
    screen  size  of  ONE  LINE!).  Anyone who has used screen editors like
    EDT, KED, VTEDIT etc.  will feel right at home with ICE.  The best  way
    to  learn the editing commands is just to TRY THEM OUT.  These commands
    ONLY work when ICE is in EDIT mode, i.e., after a recalled command  has
    been selected with <ESC>, CTRL/A or CTRL/B.


    ICE MISCELLANEOUS COMMANDS

    There are two commands under this category:

    These commands are STOP (or EXIT) and "?" (followed by a <RETURN>).
|I|c|e| Users Guide (Release 1.0)                                    Page 5


    They allow a user to EXIT from ICE and return to DCL  or  to  obtain  a
    quick ON-LINE summary of ICE commands.


    THEORY OF OPERATION

    ICE runs much as any  regular  image  does  within  the  users  process
    context,  that  is it is invoked by the command line interpreter (DCL).
    It presents the user with a transparent interface to DCL,  reading  and
    parsing  command lines, saving them internally and finally sending them
    to DCL for final processing by  the  VMS  operating  system.   The  BIG
    difference  is that it allows a user to RECALL and EDIT any of up to 22
    previous DCL commands!

    Since DCL is single-threaded, i.e, it only allows a single image to run
    per  process  (exclusive  of sub-processes), the control of ICE is from
    within a command file.  The flow of ICE is basically:

     o  The command "ICE" invokes ICEDITOR.COM ...
     o  ICEDITOR.COM runs ICE.EXE ...
     o  ICE.EXE accepts, parses, saves and sends a user command to DCL ...
     o  (The above includes optional RECALL and EDITING)
     o  DCL executes the users command and returns control to  ICEDITOR.COM
        ...
     o  ICEDITOR.COM re-runs ICE.EXE ...
     o  (This process is repeated until the user either logs off  or  types
        "STOP" to return to DCL)


    ICE  saves  up  to  22  DCL  commands   in   a   direct   access   file
    (SYS$LOGIN:COMMANDS.ICE)  After  22  commands  have  been  stored,  the
    "STACK" wraps around beginning at the oldest command.   This  way,  ICE
    users  will  always  have  the  latest  22 unique DCL commands at their
    fingertips.

    ICE is smart enough not to save DCL commands that are  already  on  its
    "STACK".  See the RELEASE notes for details on this feature.

    ICE works on any DEC-compatible terminal (VT52 or VT100  series),  even
    without a KEYPAD.
|I|c|e| Users Guide (Release 1.0)                                    Page 6


EXAMPLE SESSION

The example session below illustrates the type of thing you  can  do  using
ICE:


        Command Line            Comment                 User Action
        ------------            -------                 -----------
$ Type DRA1:[JONES]login.cm     (User wants to type     Press RETURN
                                a file)
%TYPE-W-OPENIN, file not found  (User gets an error)    Press <ESC>
                                                        to retrieve
                                                        the command.
$ Type DRA1:[JONES]login.cm     (Command is recalled)   Command can
                                                        now be edited..
                                                        Press <DEL> to
$ Type DRA1:[JONES]login.c      (The "m" was deleted)   delete the bad
                                                        character.
$ Type DRA1:[JONES]login.com    (Correct characters     Now add the "om"
                                are now added)          characters and
                                                        press <RETURN>
$ (The contents of login.com                            to re-submit the
  are now typed....                                     command to DCL.
$                               (User wants to see      Press CTRL/E
                                the saved commands)
(screen cleared)
Saved DCL commands (currently at >)
> Type DRA1:[JONES]login.com    (Saved commands are displayed.  The ">"
  directory/full                shows the CURRENT command position on the
  systat                        "STACK", i.e. that command that will be
                                recalled with the <ESC> key.
                                The user can move up and down the stack
                                with CTRL/A or CTRL/B to
                                select other previously issued DCL commands
                                for editing or re-submittal. 


The RELEASE notes can be found in USR:ICEBEWARE.BWR.  Read this for tips on
installation and information on special features and restrictions of ICE.


                                                Stuart Renes
                                                Manard Stewart

                                                Western Electric Co.