Determining running environment and platform capabilities in Emacs.

To proper work on different Emacs releases and on different platforms large/complex .emacs config file must check certain condition.

I collect come of them and by this post make it public.

emacs.info under Debian

Because of Debian policy documentation covered by FDL license with invariant sections is not allowed in packets repository tree. So it must be installed manually.

You can set INFOPATH env var in your ~/.profile, but I done this in .emacs in such way:

;; Because of Debian policy documentation covered by FDL license ;; with invariant sections is not allowed in packets ;; repository tree. So it must be installed manually. ;; My usual configuration is install user local software ;; into ~/usr DISTDIR. (unless (getenv "INFOPATH") (setenv "INFOPATH" "~/usr/share/info:"))

This code also useful as manually builded software I configure like this:

$ configure --prefix=$HOME/use

so their info documentation automatically become available in Emacs Info system.

• FDL text on gnu.org
• http://en.wikipedia.org/wiki/GNU_Free_Documentation_License

Sort and uniquify lines in Emacs.

For only sort lines exist built-in func: C-x sort-lines.

Sort and uniquify lines:

• select region
• C-u M-| sort -u RET

With transient-mark-mode and delete-selection-mode enabled:

• select region
• M-| sort -u RET

to replace selection with sorted and uniquified lines.

Switching from Gnu Emacs 22.x to 23.1 on Windows.

When moving from GNU Emacs 22.x to GNU Emacs 23.1 I get only two trubles.