This package defines functions that turns simple strings to ansi strings. Turning a string into an ansi string can be to add color to a text, add color in the background of a text or adding a style, such as bold, underscore or italic.
Add ansi
to your Cask file:
(depends-on "ansi")
All colors, background colors and styles can be accessed via a
function with the ansi-
prefix. For example:
;; Color text
(ansi-red "foo")
(ansi-blue "bar")
;; Color background
(ansi-on-red "foo")
(ansi-on-blue "bar")
;; Add style
(ansi-bold "foo")
(ansi-blink "bar")
It can become quite cumbersome to use those function names if the
coloring is a little bit more advanced. To simplify this, there's a
DSL, which makes this much more pleasant. If within a with-ansi
block, the ansi-
prefix is not necessary anymore. This is the same
as the above.
;; Color text
(with-ansi
(red "foo")
(blue "bar"))
;; Color background
(with-ansi
(on-red "foo")
(on-blue "bar"))
;; Add style
(with-ansi
(bold "foo")
(blink "bar"))
You can also use ansi-apply
if you only have the name of the color:
(ansi-apply 'red "foo %s" "bar")
Ansi supports CSI codes, for example moving the cursor:
(ansi-up)
(ansi-down 3)
(ansi-csi-apply 'forward)
(ansi-csi-apply "J" 10)
Lets say you want to make a text bold, red and blinking. You can do this with nesting.
;; Without DSL
(ansi-bold
(ansi-red (ansi-blink "foo bar")))
;; Using DSL
(with-ansi
(bold (red (blink "foo bar"))))
If you are on a dumb terminal, not running on tty or you just want to
disable colors, you can inhibit all special/control sequences by
setting ansi-inhibit-ansi
to t
. Text will still be formated and
output, but without the special/control sequences.
If you are running your Emacs code from shell, for example as a wrapper for a binary for your package, you can detect whether you are running in a tty with this code:
INHIBIT_ANSI="t"
if [ -t 1 ] ; then
INHIBIT_ANSI="nil"
fi
## here you run your script
exec emacs --batch --no-init-file --no-site-file --no-splash \
--eval "(ansi-inhibit-ansi $INHIBIT_ANSI)" \ ## << disable ansi if not tty
--load=elsa --funcall=elsa-run ## load your package and run your fn