2.7.1. Emacs

Emacs is a highly customizable editor—indeed, it has been customized to the point where it is more like an operating system than an editor! Many developers and sysadmins do in fact spend practically all their time working inside Emacs, leaving it only to log out.

It is impossible even to summarize everything Emacs can do here, but here are some of the features of interest to developers:

Very powerful editor, allowing search-and-replace on both strings and regular expressions (patterns), jumping to start/end of block expression, etc, etc.

Pull-down menus and online help.

Language-dependent syntax highlighting and indentation.

Completely customizable.

You can compile and debug programs within Emacs.

On a compilation error, you can jump to the offending line of source code.

Friendly-ish front-end to the info program used for reading GNU hypertext documentation, including the documentation on Emacs itself.

Friendly front-end to gdb , allowing you to look at the source code as you step through your program.

And doubtless many more that have been overlooked.

Emacs can be installed on FreeBSD using the editors/emacs port.

Once it is installed, start it up and do C-h t to read an Emacs tutorial—that means hold down control, press h, let go of control, and then press t. (Alternatively, you can use the mouse to select Emacs Tutorial from the Help menu.)

Although Emacs does have menus, it is well worth learning the key bindings, as it is much quicker when you are editing something to press a couple of keys than to try to find the mouse and then click on the right place. And, when you are talking to seasoned Emacs users, you will find they often casually throw around expressions like “ M-x replace-s RET foo RET bar RET ” so it is useful to know what they mean. And in any case, Emacs has far too many useful functions for them to all fit on the menu bars.

Fortunately, it is quite easy to pick up the key-bindings, as they are displayed next to the menu item. My advice is to use the menu item for, say, opening a file until you understand how it works and feel confident with it, then try doing C-x C-f. When you are happy with that, move on to another menu command.

If you cannot remember what a particular combination of keys does, select Describe Key from the Help menu and type it in—Emacs will tell you what it does. You can also use the Command Apropos menu item to find out all the commands which contain a particular word in them, with the key binding next to it.

By the way, the expression above means hold down the Meta key, press x, release the Meta key, type replace-s (short for replace-string —another feature of Emacs is that you can abbreviate commands), press the return key, type foo (the string you want replaced), press the return key, type bar (the string you want to replace foo with) and press return again. Emacs will then do the search-and-replace operation you have just requested.

If you are wondering what on earth Meta is, it is a special key that many UNIX® workstations have. Unfortunately, PC's do not have one, so it is usually alt (or if you are unlucky, the escape key).