ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/DESQVIEW/APPS/SPAWN15.ZIP/UTIL.DOC

Text File | 1990-11-01 | 14.4 KB | 341 lines

                             SPAWN UTILITIES
                     Copyright 1990, Albert H. Ariail


                           DVTEST  version 1.0

Dvtest is a simple program that displays a message stating whether or not
Desqview is active.  If so, the current application name and number are
listed.  More importantly, dvtest exits setting the dos return code as
follows:

0     desqview is not active
nonzero  desqview is active. return code set to current application number

This way you may use an "if errorlevel" test to make batch files desqview
specific or desqview aware.  A particular example, of a sort that I
actually use is as follows:

dvtest >nul
if not errorlevel 1 goto nodv
spawn/d/f/x/p:ed c:\bin\edit.exe %1
goto stop
:nodv
c:\bin\edit.exe %1
:stop

If desqview is active, the program is loaded in its own window as
determined by the pif file ed-pif.dvp, otherwise, the program is just
executed.  With the current version of spawn, you could just invoke
spawn, both inside and outside desqview.  This method will save a bit
of memory, however, when used outside of desqview.


                         RELEASE.COM  Version 1.0

This program provides a way to pass a byte return code from batch file
started by spawn.  In order for spawn to process a return code, it
must be waiting to receive one, ie, you must use spawn/w . Given this,
then in the batch program started by spawn if you include the statement:
release 3
spawn will exit with a dos return code of 3.
Processing continues as normal in the child process.
If you do not include any argument, release assumes a value of 0.
This program will only function with desqview active.


                           KILL.COM Version 1.0

This program allows you to close the current desqview window, or another
window for which you have a "process handle".

First, to close the window in which kill is executed, enter

kill

The action of kill is more like selecting "Close Window" from the
desqview menu, or keying Ctrl-Alt-Del.  The current window is just
closed, without any clean up.  This is generally safe, at least, in a
batch file.  The only side effect of this that I have found is that under
certain circumstances, 4dos will dribble "swap" files around.

To close another window, enter

kill HANDLE

where HANDLE is a window specifier described below.  When used in this
manner, no action is take to inform spawn that a window is being closed.
If spawn is waiting for a return code, it will just sit there until you
abort the wait by keying ESC.

The window handle can be given as an 4 byte hexadecimal number in the
format ?hhhhhhhh . This is not very useful, but is included for
completeness.  Otherwise you may use a symbolic name for the parameter
such as:

kill PARENT

Kill will search the DOS environment for a handle listed under the
specified name.  If a valid desqview handle is found, the window it
represents will be summarily dispatched.  It just so happens that when
spawn starts a process, it installs an entry of just this sort called
"PARENT" in the child's environment, which can be used for this purpose.

If the argument specified is not found in the environment, kill uses the
argument as a file name and tries to find the correct handle by reading
its contents.  You may use spawn/n to create such a file, as in

spawn/n ... >child

then the command "kill child" will terminate the specified process.

While all of this may satisfy some of your latent homicidal tendencies,
it isn't of any great utility.  A more satisfying application of kill
is provided below, in conjunction with the program ALERT.

Using fixed "temporary" files in this manner in a multitasking
environment can cause a bit of unpleasantness.  It is possible that
some day you may start the same batch process twice.  The second process
will overwrite the same file "child", and when the first process hits
the "kill" part, it will promptly shut down the wrong process.  This may
or may not be a major disaster, depending on who is doing what to whom.

If you are using 4dos, there is a better way.  4dos has an internal
function "INPUT" which copies text from standard input to an environment
variable.  Since the environment is local to each process, you will not
have this sort of problem.  For example,

spawn /n mytask | input %%child
...
kill child

This is one example of about 1000 ways in which 4dos is better behaved
that command.com .  There are, I believe, public domain utilities that
purport to do this sort of thing with a standard DOS system.  I do not
know if any of them work, especially with desqview, but if you can find
one that does, using it for this would be recommended.


                          ALERT.EXE Version 1.0

Alert is general purpose "error message" / "status message" utility . It
has be primarily designed as a means in which batch processes can display
status or request operator intervention, even though they are running in
a desqview window which is not currently visible.  ALERT by no means
requires desqview to function, however.  You may wish to use it as well
outside of desqview as a fancy version of the DOS command "pause".

INSTALLATION (Read me, Please)
Since desqview is not required to use Alert, you may wish to copy the
executable file into a standard dos directory, such as \bin, rather than
hiding it away in \dv .  When you are using Alert with desqview, you
configure 1K of "system memory" in any window which may use Alert.  If
you do not, you will have to respond to a non-fatal but irritating error
message when Alert is invoked.    If this is not convenient, the switch
options (/a/t/s) do not require any system memory.

Command Syntax:

Alert [/x] "message"

The quotation marks are not really required, but if you do not include
them, Alert (actually Turbo-C) will strip white space for you.
In Desqview, Alert will create a small window containing the message,
punch it through to the foreground and wait for you to respond.  You may
acknowledge a message by pressing any key, or clicking the mouse.  Please
note that, in Desqview, the mouse cursor must be inside the message
window in order for the mouse to work.  Otherwise, you will be telling
desqview to push the message window back into the background (something
you may also want to do on occasion).

Options:

/h     display help
     as you might expect, this displays a brief summary
     of the option available with this program

/q     quiet alarm
     beeps the speaker. Alert is silent by default.

/l:tune  loud alarm
     really beeps the speaker. The tune to play is a list of
     numbers in the format: freq,duration;freq,duration;...
     the duration is measured in "tics" (about 18 milliseconds).
     The maximum length is 32 freq,duration pairs.    The default
     tune is: 450,4;500,4;550,4;500,4;450,4

/m     ignore mouse
     this should seldom be needed with desqview, but is included
     to prevent conflicts with menu software and the like.

/w:n     this displays the message text for n seconds or until
     any key is pressed .  The message window will be in
     the foreground and will have possession of the keyboard
     /w:0 (the default) will wait forever

/d:n     display message for n seconds
     this also displays the message for n seconds, but does not
     look at the keyboard or the mouse (and does not own them).
     /d or /d:0 will cause alert to exit leaving the message
     window intact.  In desqview, the message will be redisplayed
     every time you switch to the window which ran alert.

/a    alternate format
    this uses a different method for displaying the error window.
    It has primarily been included because in desqview no
    "system memory" is required.  You cannot control the color,
    position, or the keyboard usage.  To respond to a /a format
    message, key ESC or click the mouse.  One additional use of
    this method is that since the error window is always displayed
    in the upper left corner of the window in question, /a will
    allow you to post a message that is closely associated with
    a given window.  This is useful if there are a number of small
    desqview windows on the display.

/t    this is brain dead format.
    The text message is just printed using standard dos channels.
    This is supplied in case you have a need to use a 30k program
    to simulate the function of the DOS internal command "pause".
    Well, that's not completely true.  Pause won't whistle dixie or
    respond to the mouse.

/s    use bios only.
    when this is specified outside of desqview, this cause the
    display routines to use the video bios rather that manipulating
    the display hardware directly.    This may be needed on some machines.
    Inside desqview, this option causes alert to ignore the desqview
    window manager and function as though desqview were not present.

/p:n    uses physical attribute n (hex)
    controls the color of the message, the default is a boring
    white on black (see note on this below).

/r:n    position (row) of message window
    the default is 1

/c:n    position (col) of message window
    the default is selected to center the message text on the display.
    Outside of desqview, alert will support more than 80 columns.
    At this writing, desqview is a bit twitchy about doing that, so
    I don't recommend that you use more than 80 columns inside
    desqview.

/k:ab    keys to accept $=esc @=enter ?=any 1,2=mouse
    This represents a list of the keys that will be accepted to
    acknowledge the message. Case is not considered.  Any key
    not on the list is ignored.  You may use the special characters
    listed to represent some of the non-alphabetic keys. A space can
    be included, but you should enclose the entire parameter in
    quotes, eg, "/k: abc$"

/f    switch to the foreground
    This switches the entire process calling Alert into the
    foreground.  Normally, only the message window will go to
    the foreground

/b    stay in the background
    The message will go to the top of the application calling Alert
    but not necessarily all the way to the foreground.  If the Alert
    window is behind some other window, you will have to switch to
    the alert window to see the message.

/n    output window handle
    This only works with /d (or /d:0) since that is the only time
    a window remains behind after alert exits.  The window handle
    is compatible with kill.com, which can be used to remove the
    message window, as in
    alert /n /d "hello world" >handle
    ...
    kill handle

/z      exit with background operation disabled
        alert normally requires the window in which it is executing to
        have background operation enabled.  Alert will automatically set
        this, but will leave it enabled.  If this causes a problem, you
        can use this option to tell alert to set the background flag to
        disabled just before it exits

Notes:

1.  Format switches
    The switches /d /w /t and /a are mutually exclusive.  If you include
    more than one of these, only the last will have any effect. If no
    format switch is included, /w:0 is assumed

2.  Behavior outside of Desqview.
    Most of the features of the program will work without desqview. There
    are some format differences and, since, I do not have available
    Desqview's powerful screen virtualization capabilities, /d:0 will not
    work the same.  But the simulation is close enough so that you can
    put Alert calls into batch files without being overly concerned about
    what will happen if they are ever executed outside of desqview.
    The options /n /f /b /z  have no meaning whatever without desqview and
    are ignored.

3.  For best results with /d
    Using /d to display status messages will work better if the
    foreground window (that is, the window in which you are working, not
    the window which calls alert) has "runs in the background" set to
    "y".  If this is done, the original program will not lose control
    of the keyboard.  Otherwise, you will have to click the working
    window fully into the foreground to continue.

    In addition, if "writes directly to the screen" is set to "n", or
    "virtualize text" is on in the foreground window, the message window
    will not scroll off, but instead, the foreground text will scroll
    underneath the message window.

6   Color problems
    The default color for the message window is /p:07 (white on black).
    This value is used instead of something more interesting because
    of the way desqview handles color mapping in windows with "uses
    its own colors" set to "n".  In this case alert will display the
    message window with the same colors as the parent window.  When
    using /p:n, in this case, desqview will map the colors into something
    which is usually just awful. The only way to get true colors is to
    start alert with something like:
    spawn/w alert -p:31 "hello"

5.  The keyboard filter and return codes.
    /d always exits with a return code of 0. If /k is not used
    alert will exit with a return code equal to the ascii code of
    the key that was pressed or '1'/'2' for the mouse.  If /w:n times
    out without a keypress, alert sets the return code to 0.  Non
    Ascii keys (such as Fkeys) set the return code to -x, where x
    is the byte value of the bios scan code for the key that was used.
    This is a little complex, but usable if you can figure out just
    what the heck "minus the bios scan code" is.

    /k is bit easier to use.  /k will exit with a return code equal to
    the position of the key in the specified list. For example, if you
    use /k:abcd and respond with "C", alert will exit with a return
    code of 3 . You can then use "if errorlevel" tests to make the
    batch file do different things.  Remember, "if errorlevel 3" means
    "if the return code is 3 or higher" so you will have to process you
    return codes from highest to lowest, eg.

    alert -w:10 /k:abcd? "hello world"
    if errorlevel 5 goto key_any
    if errorlevel 4 goto key_d
    if errorlevel 3 goto key_c
    if errorlevel 2 goto key_b
    if errorlevel 1 goto key_a
    goto nokey

    If you frequent PC magazine, you may recall a neat trick for
    making this sort of stuff a little more elegant

    for %%d in (5 4 3 2 1 0) do if errorlevel %d goto key_%d
    goto nokey

    :key_0
    ...
    :key_1
    ...
    :nokey

    If I have done my job right (I don't always) the last "goto nokey"
    will never be executed.

    Enjoy.  AHA