Linux Desktop Hacks

Make Applications Trigger On-Screen Alerts #27

Chapter 4, Related to X

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89

HACK

KMail

If you use the KDE KMail email client, you can have KMail execute a pro-

gram when new mail arrives. Here’s how you can have KMail display the on-

screen new-mail notification “You’ve got mail!” with XOSD.

First, you need to create a script that displays the on-screen alert “You’ve

got mail!”. KMail doesn’t allow you to insert the entire

echo and osd_cat

command line, but it will execute a script that displays the message. Fire up

your favorite editor, and enter this script into a file called ~/youhavemail.

(This script executes from your home directory, so you don’t need any spe-

cial privileges for it to work.)

#!/bin/bash

# figure out which display we're currently using

# then export the DISPLAY environment variable

HOST="$(xrdb -symbols | grep SERVERHOST | cut -d= -f2)"

DISPLAYNUM="$(xrdb -symbols | grep DISPLAY_NUM | cut -d= -f2)"

THISDISPLAY=$HOST:$DISPLAYNUM.0

export DISPLAY=$THISDISPLAY

echo "You've got mail"'!' | osd_cat -s 2 -c yellow -p middle \

-f -adobe-helvetica-bold-r-normal-*-*-240-*-*-p-*-*-* -d 30

The placement of various quotes in the text for the echo

command looks a bit odd, doesn’t it? Here’s why. The bash

shell interpreter will allow you to embed only a single quote

in a string that is enclosed by double quotes. If the string

“You’ve” wasn’t isolated within double quotes, the

echo

command would report ...