NAME

CoEd - a ToolTalk-based shared editor

SYNOPSIS

CoEd [ file ]

DESCRIPTION

CoEd a shared text editor built with DevGuide, the OLIT textedit widget, and libCoEd. libCoEd is a C++ library implementing a ToolTalk protocol that can turn any editor into a shared editor, using the dOPT algorithm. dOPT allows multiple users to edit the same text at the same time, without locking, and with all locally-generated edits being applied immediately to the local text. Being merely a demo, CoEd has the following limitations.

CoEd has no facility for saving the edited file to disk.

Each instance of CoEd must be started before any editing occurs. We have not implemented the part of the protocol that allows newcomers to join an ongoing editing session. However, any CoEd can quit at any time without disrupting the others. See the README file with the CoEd source code for a sketch of the rest of the protocol.

FILES

/.global_coed_file

If no file is named on the command line, all instances of CoEd on the same machine will rendezvous on this file.

SEE ALSO

ttsession(1)

C.A. Ellis and S.J. Gibbs, "Concurrency Control in Groupware Systems, "Proc. 1989 ACM SIGMOD, Int. Conf. on the Mgt. of Data

WARNINGS

Building CoEd requires DevGuide, C++, and ToolTalk (which is part of OpenWindows). CoEd is known to build with DevGuide 3.0.1, C++ from SPARCompilers 2.0.1, and either OpenWindows 3.1 or OpenWindows 3.2.

The libgolit in DevGuide 3.0.1 was based on the OW3.0.1/3.1 OLIT libraries, and has some incompatibilites with the OW3.2 OLIT libraries. A CoEd built with with libgolit 3.0.1 and running under OW3.2 will crash, e.g., if you press MENU or HELP over the OLIT textedit widget embedded in CoEd. However, the basic features of editing, selecting, copy/paste, drag-and-drop, and scrolling seem to work.