Debra Cameron - Learning GNU Emacs, 3rd Edition

If you are a programmer or if you use text formatters like LATEX , you will create files that are not meant for humans to read, such as object files created by compilers and print files created by text formatters. Ideally, you wouldn't want Emacs to bother with these files when you are doing completion; for example, if you have the files program.c and program.o (object-code output from the compiler), you want Emacs to recognize only the former. Emacs does have a feature that deals with this; indeed, you may already have noticed that in this kind of situation, if you type programand press Tab, Emacs ignores program.o and completes out to program.c . The variable completion-ignored-extensionscontrols this; it is a list of filename suffixes that Emacs ignores during filename completion. By default, the list includes tilde ( ~ ) for Emacs backup files, .o for programmers, various suffixes for users, .elc (byte-compiled Emacs Lisp) for Emacs customizers, and others. (Of course, if you really want to look at these files, you can type their names manually.)

You can add your own "ignored" suffix to the list by putting a line of this form in your .emacs file:

(setq completion-ignored-extensions

(cons " suffix " completion-ignored-extensions))

For example, let's say you are doing text processing with a printer that prints PostScript, and your text processor produces print files with the suffix .ps . If you don't want to look at these files, put the following line in your .emacs file:

(setq completion-ignored-extensions

(cons ".ps" completion-ignored-extensions))

Finally, you can tell Emacs to ignore case distinctions when doing completion by setting the variable completion-ignore-caseto t(or any value other than nil). Its default value is nil, meaning that Emacs respects case distinctions.

This appendix lists some Emacs variables. We chose them for their general usefulness and for their applicability to subjects in this book.

The variables below are grouped by category, and their default values are shown (where practical to do so). For more details on specific variables, see the chapters referred to at the beginning of each table. For information on variables used in programming language modes, see Chapter 9.

Table A-1. Backups, auto-save, and versioning ( Chapter 2, Chapter 12)

Table A-2. Searching and replacing ( Chapter 3 Chapter 3. Search and Replace The commands we discussed in the first two chapters are enough to get you started, but they're certainly not enough to do any serious editing. If you're using Emacs for anything longer than a few paragraphs, you'll want the support this chapter describes. In this chapter, we cover the various ways that Emacs lets you search for and replace text. Emacs provides the traditional search and replace facilities you would expect in any editor; it also provides several important variants, including incremental searches, regular expression searches, and query-replace. We also cover spell-checking here, because it is a type of replacement (errors are sought and replaced with corrections). Finally, we cover word abbreviation mode; this feature is a type of automatic replacement that can be a real timesaver. )