kdewall, simple workaround missing /utmp entry

[Achim Bohnet <ach@mpe.mpg.de>]

Hi,

Some may know konsole adds no /utmp entry (good) but also
currently kwrited only wastes memory (bad).  I've had to
write a little script to make use kwrited.  (If I shutdown
our server a second time without some users getting an info msg
.... oh oh).

I'm open for suggestions and better solutions ;)

Share and enjoy,
Achim

#!/bin/bash

## kdewall:	simple wall for Debian/KDE
##
##		KDE KDE users which use only konsole never see
##		wall messages (no utmp entry 'cause Debian
##		does not like libtempter and it has not HAVE_LIBUTIL)
##		(at least now kwrited does not only waste memory :)
		
prg="${0##*/}"

if [ $# -ne 1 ]; then
	echo "Usage:  $prg  msgfile" >&2
	exit 
fi

if [ -f "$1" -a -r "$1" ]; then
	msgfile="$1"
else
	echo "File not found or not readable: '$1'" >&2
	exit 
fi

msgheader="Message from '$USER@$HOSTNAME' (`date`):"

# selection of kwrited processes:
#	o find all /bin/cat processes
# 	o check if parent is kwrited
#	o write to all ptys of bin

echo "informing kwriteds ..."
ps ax -o pid,ppid,cmd | grep /bin/cat | grep -v grep |
	while read pid ppid foo; do
		#ps -o pid,ppid,cmd -p $ppid;
		#ps -o ppid,pid,tty,cmd -p $pid --no-header

	 	pty=/dev/"`ps -o tty -p $pid --no-header`"	
		if [ -w "$pty" ]; then
			case "$pty" in
			   /dev/pts/[0-9]*)
				printf "\n$msgheader\n"	> "$pty"
				cat "$msgfile"		> "$pty"
				printf "\n--\n" 		> "$pty"

				echo "$prg: msg send to '$pty'"
			   	;;
			   *)
				echo "$prg: Invalid pty name: '$pty'" >&2
			   	;;
			esac
		else
			echo "$prg: '$pty' not writeable" >&2
		fi
	done
echo "using wall ..."
wall "$msgfile"

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