#!/bin/sh
# 
# Linux kernel info mailer
#
# (P) & (C) 1997-2002 by Peter Bieringer <pb@bieringer.de>
#
#
# Changes to
#  1.00: inital release
#  1.10: fix empty mail sending
#  1.11: avoid "alpha" messages
# 20000707/PB: adapt for titan
# 20011009/PB: enhance anti noise feature
# 20020221/PB: minor redesign, use diff now
# 20020525/PB: anonymizing

#set -x

INFOPATH=/home/kernelinfo/tmp
INFONEW=kernelinfo.new
INFOOLD=kernelinfo.old

# Host to query with finger
QUERYHOST="ftp.kernel.org"

# Mail receipient
MAIL_RCPT="kernelinfo@localhost"

# 'finger' binary (for getting info)
FINGERBIN=/usr/bin/finger

# 'mail' binary (for sending mails)
MAILBIN=/usr/bin/Mail

# Keyword for detecting the 'alpha' line
KEY_ALPHADETECT="alpha|-ac"

#set -x 

# Primary tests
if [ ! -d $INFOPATH ]; then
	echo -e "\a Info directory doesn't exit"
	exit 2
fi

if [ ! -x $FINGERBIN ]; then
	echo -e "\a Needed binary '$FINGERBIN' doesn't exit"
	exit 2
fi

if [ ! -x $MAILBIN ]; then
	echo -e "\a Needed binary '$MAILBIN' doesn't exit"
	exit 2
fi

# functions
help()
{
 echo " -nm     send no mail"
 echo " -lh     query 'localhost' instead of '$QUERYHOST'"
 echo " -nam    no updated 'alpha' version triggers a mail"
 echo
}

getoptions()
{
    while [ ! "$1" = "" ]; do
    	if [ "$1" = "-?" ]; then
        	return 1
     	elif [ "$1" = "-nm" ]; then
            echo " Option 'no mail' set"
	    FLAG_NOMAIL=1
	    shift
     	elif [ "$1" = "-lh" ]; then
            echo " Option 'localhost' set"
	    QUERYHOST="localhost"
	    shift
     	elif [ "$1" = "-nam" ]; then
            echo " Option 'no 'alpha' triggered mail' set"
	    FLAG_NOALPHATRIGGER=1
	    shift
    	else
           echo " Option '$1' isn't understood!"
	fi
    done
}


## start

getoptions $* || { help; exit 1; }

echo "Get new information"
if [ "$FLAG_NOALPHATRIGGER" != 1 ]; then
	# normal finger
	$FINGERBIN @$QUERYHOST 2>/dev/null >$INFOPATH/$INFONEW || exit 1
else
	# also normal finger, but filtering lines with $KEY...
	$FINGERBIN @$QUERYHOST 2>/dev/null | egrep -i -v "$KEY_ALPHADETECT" 2>/dev/null >$INFOPATH/$INFONEW || exit 1
fi

# Test if answer is valid
LINES=`cat $INFOPATH/$INFONEW | wc -l`
if [ $LINES -le 2 ]; then
    echo " Answer isn't valid"
    exit 1
fi

# Compare with last answers
if [ -f $INFOPATH/$INFOOLD ]; then
    echo "Compare with old information"
    if diff -u $INFOPATH/$INFOOLD $INFOPATH/$INFONEW >/dev/null; then
	echo "Equal - nothing to do!" 
	exit 0
    else
	echo "Not equal!" 
    fi
else
	true
fi

if [ "$FLAG_NOMAIL" = 1 ]; then
    echo "Send no mail"
	diff -u $INFOPATH/$INFOOLD $INFOPATH/$INFONEW | grep -v "^---" | grep -v "^+++" | grep -v "^@@"
else
	diff -u $INFOPATH/$INFOOLD $INFOPATH/$INFONEW | grep -v "^---" | grep -v "^+++" | grep -v "^@@" | $MAILBIN -s'New Linux kernel is out!' $MAIL_RCPT
	cp $INFOPATH/$INFONEW $INFOPATH/$INFOOLD
fi