8.16.1 X-Face

X-Face headers describe a 48x48 pixel black-and-white (1 bit depth) image that's supposed to represent the author of the message. It seems to be supported by an ever-growing number of mail and news readers.

Decoding an X-Face header either requires an Emacs that has `compface' support (which most XEmacs versions has), or that you have `compface' installed on your system. If either is true, Gnus will default to displaying X-Face headers.

The variable that controls this is the gnus-article-x-face-command variable. If this variable is a string, this string will be executed in a sub-shell. If it is a function, this function will be called with the face as the argument. If the gnus-article-x-face-too-ugly (which is a regexp) matches the From header, the face will not be shown.

The default action under Emacs 20 is to fork off the display program(3) to view the face.

Under XEmacs or Emacs 21+ with suitable image support, the default action is to display the face before the From header. (It's nicer if XEmacs has been compiled with X-Face support--that will make display somewhat faster. If there's no native X-Face support, Gnus will try to convert the X-Face header using external programs from the pbmplus package and friends.(4))

(Note: x-face is used in the variable/function names, not xface).

Gnus provides a few convenience functions and variables to allow easier insertion of X-Face headers in outgoing messages.

gnus-random-x-face goes through all the `pbm' files in gnus-x-face-directory and picks one at random, and then converts it to the X-Face format by using the gnus-convert-pbm-to-x-face-command shell command. The `pbm' files should be 48x48 pixels big. It returns the X-Face header data as a string.

gnus-insert-random-x-face-header calls gnus-random-x-face and inserts a `X-Face' header with the randomly generated data.

gnus-x-face-from-file takes a GIF file as the parameter, and then converts the file to X-Face format by using the gnus-convert-image-to-x-face-command shell command.

Here's how you would typically use the first function. Put something like the following in your `~/.gnus.el' file:

(setq message-required-news-headers (nconc message-required-news-headers (list '(X-Face . gnus-random-x-face))))

Using the last function would be something like this:

(setq message-required-news-headers (nconc message-required-news-headers (list '(X-Face . (lambda () (gnus-x-face-from-file "~/My-face.gif"))))))