HELP SYSSAVE                                          A.Sloman, Nov 1983

    syssave(<filename>) -> <boolean>

This procedure saves the state of the POPLOG system in the specified
<filename>. The procedure then returns FALSE. When the saved state is
subsequently restored (see HELP *SYSRESTORE) the restored call of
SYSSAVE returns TRUE. Saved images can also be restored with UNIX shell
or VMS DCL commands, like this:

    pop11 +foo

which is equivalent to:

    pop11
    ...
    sysrestore('foo.psv');

except that if the saved image is not found in the current directory
it will be looked for in the directories in '$popsavepath' (UNIX) or
'popsavepath:' (VMS).

The <filename> may be a string or a word; in the latter case '.psv' is
appended.

SYS_LOCK_SYSTEM (described in REF * SYSTEM) is a version of SYSSAVE that
can be used to make 'layered' saved images, i.e. images relative to
which other saved images can be built, so that different users can share
a basic saved image and construct their own extensions. This facility is
used to create the saved images for PROLOG and CLISP, for example. On
VMS and some versions of Unix, it is possible for layered saved images
also to be shared in the computer's memory.

Examples of the use of SYSSAVE and SYS_LOCK_SYSTEM can be found in the
following command files:

    $usepop/pop/com/mkeliza         (UNIX)

    usepop:[pop.com]mkeliza.com     (VMS)


See also:

    HELP *SYSRESTORE  - restores the system to its saved state
    HELP *SYSSAVEINCR - on saving part of an image
    HELP *INITIAL     - on initialization of POPLOG (without parameters)
    HELP *PARAMETERS  - on running POP-11 with parameters
    REF  *SYSTEM     - for further details (especially SYS_LOCK_SYSTEM)


--- C.all/help/syssave
--- Copyright University of Sussex 1991. All rights reserved. ----------
