LAYERS

NAME

layers - MacLayers Multiwindow Terminal Emulator for Unix  

SYNOPSIS

layers [options] [command]  

WARNING

DESCRIPTION

MacLayers provides multi-window capability for a Macintosh (MacPlus or better running System 6.0.x or System 7) connected to a host UNIX(TM) system with sockets support. Each window may be associated with a shell, login to a different host, or an individual command. Complete facilities are available for controlling the window and the associated host processes attached thereto.  

OPTIONS

-v

displays current version information

-help

displays a one-line synopsis of all layers command line arguments; will not start layers mode

The following options can be used to modify the behavoir of layers when it starts layers mode, or of the new shell window layers will create when executed while already operating under layers mode.

-l

causes new shell to be a login shell, if layers has been compiled to not login new shells by default; otherwise, causes new shell to not be a login shell.

-u

explicitly forces new shell to not be logged in

-g wwxhh

allows user to size the new shell; see next option below for details:

-g wwxhh+xx+yy

allows user to both place and size the new shell; window is started with width ww characters and height hh lines; if xx and yy are present, window is placed with upper-left corner at (xx,yy) on the Macintosh screen; note that either xx or yy may be negative (useful on systems with multiple monitors). Beware: no sanity checking of the window size or position is performed.

The following options are not likely to be very useful to the typical user:

-d

starts layers running in debugging dump mode; a file layers.dump is created in the current directory (if it does not already exist) and internal debugging messages continuously appended; useful for debugging situations where layers mode fails to startup properly, but otherwise not too interesting; severely adversely affects performance and gobbles disk space.

-m

forces layers to run as a server (master) and not as a client (slave)

-f

enables flow control; obsolete

-n

disables flow control; obsolete

Command-line arguments following valid options are interpreted as a shell command-line to execute. UNIX host.  

MACLAYERS OPERATION

To use MacLayers, you must have the MacLayers application running on your Macintosh, as well as the UNIX side layers program described herein.

The Maclayers application on the Macintosh starts up as a garden variety host-to-terminal vt-100 emulator. (As such you can run it with any host, not just a UNIX machine.) Baud rate and other configurations are set by selections in the Control Menu.

Once connected to your UNIX host, enter the layers command to the UNIX host using no options or parameters to start the layers protocol. The initial terminal window will be closed and replaced with a layers protocol window. A shell is run in this window, either /bin/sh or the shell indicated by your $SHELL variable.

You can start a new shell layer (with its own separate window) by picking "New" on the Layers menu. You can also start a new layer window by issuing the layers command to a shell layer window. If you use no operands, then the new layer window will be a shell. However, you can specify any command you wish by simply adding it as a parameter. Examples: "layers vi testfile.c", "layers telnet earth."

If you are specifying a shell then you can also elect to have it be a login shell by adding a -l option. This allows broadcast/write/talk capabilities for that window. The initial layer window shell defaults to a login shell.

When a layer process group terminates, its window is automatically closed. MacLayers exits layers mode when the last (or only) layer window is closed. You may also use the Layers Menu "Shutdown" to terminate layers mode. You cannot quit the MacLayers application while in layers mode but must Shutdown the multi-window mode first.

You can abort host layers by using the Control Menu "Abort Host Layers" item which is always available. This may be necessary if your Macintosh loses contact with the host and you restart the MacLayers application at which time the host would still be in multi-window layers mode while the application would not. If the MacLayers application terminates due to a non-recoverable problem, it will always issue an order to terminate layers mode on the host before returning to the Finder.  

DOWNLOADING

MacLayers has an admittedly primitive download facility for downloading text, binary, and MacBinary files (the macbput command). Straight vanilla XMODEM is not supported. Only one window can be doing a macbput download at any one time. Downloading does not effect any other MacLayers operations so you can freely use any other windows or applications (with MultiFinder) while a download is in progress. Remember though that the topmost window receives the highest priority data transfer from the host. So for the fastest downloading keep the download layer window the active window.  

LAYERSRC

layer [ [flag [arg]] [flag [arg]] ... [flag [arg]] ]

Valid flags are described below; flags can be abbreviated to their first characters:

-login

Takes no argument; specifies that the layer should be a login window.

-geometry

Takes as argument a string of the form wwxhh or wwxhh+xx+yy as described earlier under OPTIONS for the -g option; sizes the window to ww characters by hh lines and places it at (xx,yy) on the Macintosh host screen.

-title

Takes as argument a string and uses string as window title for new layer.

-exec

Takes as argument a command followed by a series of optional arguments to the command; specifies that the new layer should run the program with any arguments provided instead of the default shell. Note: this flag should always be the last of any series of flags provided.

As an example of some entries in a .layersrc file, consider:

# weird window, named 'Purple', running mail program
layer -geometry 56x9+2+130 -t Purple -exec mail

FILES

 /tmp/layers/<login>           Directory created by  layers
 /tmp/layers/<login>/host.tty  Socket Created by  layers
 $HOME/.layersrc               User window definitions

AUTHORS

BUGS AND CAVEATS

*

The shell TERM variable must have the same value in your layer shells as it does when you initially start layers up. If you set the BSD shell TERMCAP variable, then that variable must be set in your .login file. It may not be changed to something different in .cshrc.

*

The layers command will not properly work when being issued from a remote login into the same machine which is already running the initial layers startup command.

*

There is currently no file upload facility.

*

Layers must be installed as set-uid with owner root in order to be able to correctly change the owner of the tty device file for each window. On some systems, special permission may also be required to write the file "/etc/utmp".

*

On many System V platforms, /etc/utmp logging is broken.

SEE ALSO

layertitle, layersize, macbput

The MacLayers program is completely described in the MacLayers Manual that accompanies the Macintosh side. Please read this for far more information than is contained here.

Manual page courtesy of Peter Newton.  

DISCLAIMER

Permissiom is granted to freely use, copy, modify, and redistribute this software, provided that no attempt is made to gain profit from it, the authors are not construed to be liable for any results of using the software, alterations are clearly marked as such, and this notice is not modified.

UNIX(TM) is a registered trademark of American Telephone and Telegraph. Macintosh is a trademark of McIntosh Laboratories and is licensed to Apple Computer.

Index

NAME

SYNOPSIS

WARNING

DESCRIPTION

OPTIONS

MACLAYERS OPERATION

DOWNLOADING

LAYERSRC

FILES

AUTHORS

BUGS AND CAVEATS

SEE ALSO

DISCLAIMER