z (01/17/83)
Since I announced the availability of CCA EMACS last week, I have been flooded with questions such as "What is CCA EMACS?", "What are its major features?", etc. I am posting the following in the hope that it will answer many of these questions. I will be happy to answer further questions personally. Steve Zimmerman decvax!cca!z CCA EMACS is a powerful screen editor closely based on the original EMACS written at MIT. It currently runs on VAXes running Berkeley's 4.0BSD or 4.1BSD. Some of its major features are: - An interactive spelling checker and corrector, which allows the user to step through his text, pausing at each spelling error. The user can either correct the error himself, or have EMACS suggest possible correct spellings. - Text filling, justifying, and centering commands, which can work on lines, paragraphs, or arbitrary regions of text. - A word abbreviation mode, which allows words, phrases, or arbitrary regions to be abbreviated by a few characters. Abbreviations may be saved for use in later editing sessions. - A directory editor which allows viewing and deleting of files and directories, as well as editing their protection fields. - A crash recovery feature using keystroke files as protection against machine crashes. An auto save mode is also available. - A "Make" command for automatic compilation of programs, with an interface which provides easy location of errors. - The ability to run a shell and arbitrary subprocesses asynchronously in a buffer. Up to five such shell buffers may be present and in operation at any one time. _ Virtually complete compatibility with ITS EMACS. All major features of ITS EMACS (with the temporary exception of an extension language) and most minor features are included in CCA EMACS. - Multiple editing buffers (up to 200), which allow the user to easily alternate editing between different files in the same session. - Two window mode, which allows two different buffers (or two different parts of the same buffer) to be displayed on the screen at once. The user can adjust the size of each window. - Keyboard macros, which allow a user to encode a frequently used series of commands into a single command. A keyboard macro is defined by executing the commands which are its definition, so there are no special macro conventions to remember. Multiple keyboard macros may be defined in a single editing session, and they may be saved in libraries for later use. - A "Tags" package, which allows EMACS to move directly to any C function or variable in any file, without the user's having to know what file the function or variable is in. - Commands to pass regions of text through arbitrary Unix filters. - A ring of sixteen marks, which allow a user to mark various places in the buffer. These marks may be used as place holders, or they may be used to delimit regions for other commands. Each buffer has its own ring of marks. - A kill ring of sixteen levels, which automatically retains text which the user has deleted. Text can be later retrieved from any level of the kill ring into the current buffer. The same kill ring is used across all buffers, which makes it easy to transfer text from one buffer to another. - A set of 37 named registers (known as Q-registers) which are useful for storing numbers, marks, or text. - A full set of commands for manipulating rectangular regions. These are useful for operations such as moving columns around in tables. - An Auto Fill mode, which causes text to automatically be broken into separate lines once it reaches a user settable right margin. - An Undo facility, which allows the last change to the buffer to be undone. - Extensive online documentation, ranging from self-documenting commands to an interactive tutorial to a full hierarchical online manual, complete with its own specialized reading program. - A full set of forward and backward movement, deletion, and transposition commands for characters, words, sentences, paragraphs, program expressions, and arbitrary regions. - Powerful search and replace commands, which do case independent matching at the user's option. There is also a Query Replace command, which allows the user to decide at each occurrence of the specified string whether that occurrence should be replaced or not. All search and replace commands have variations which use Unix regular expressions, and all may optionally traverse buffer boundaries. - Optional numbering of the lines in the buffer by EMACS. - More than 50 user settable variables, which allow each user to customize EMACS in the way he or she prefers. The local variables feature allows the same variable to have different settings for different buffers. - Dynamic key binding, which allows users to determine themselves which commands they want to have bound to which keys. - Init files, which allow variable setting and key binding to be automatically done at the beginning of each editing session.