Code:
$ cat update_apache
#!/bin/sh
FILE=httpd.conf
HOSTNAME=$1
YOU=$2
DOMAIN=$3
IP=$4
cat <<EOF >>${FILE}
<VirtualHost ${HOSTNAME}:80>
ServerAdmin ${YOU}@${DOMAIN}
ServerName ${IP}
DocumentRoot /www
ErrorLog logs/error_log
CustomLog logs/access_log combined
</VirtualHost>
EOF
$ sh update_apache hercules.utp.xnet j65nko pietje_puk.nl 81.00.00.01
$ cat httpd.conf
<VirtualHost hercules.utp.xnet:80>
ServerAdmin j65nko@pietje_puk.nl
ServerName 81.00.00.01
DocumentRoot /www
ErrorLog logs/error_log
CustomLog logs/access_log combined
</VirtualHost>