start up and shut down script

I am using PostgreSQL 8.0.0.

i have noted the following lines in the script to start or shut down postmaster.
Can you please let me know why they are needed

if [ "`uname`" = "Linux" ]; then
INITD=/etc/rc.d/init.d
. $INITD/functions
# Get config.
. /etc/sysconfig/network
fi

and

if [ "`uname`" = "Linux" ]; then
[ "${NETWORKING}" = "no" ] && exit 0
fi

who will define $NETWORKING ?

are these calls OS specific , for instance they are for red hat

for a diffrent OS like Enterprise Suse Linux 10 the above script will not work,
because the file $INITD/functions is not there in case of Suse Linux installation

Similarly . /etc/sysconfig/network
is not a file but a directory in Suse Linux 10.


thanks
surabhi