Just a small and old snippet that might be helpful or an example: Some years ago I’s in need of getting to know early about new released Linux kernel versions. Therefore I wrote a (not sophisticated but working) crontabbed script checking the kernel page for a new stable Linux kernel and alerting me via mail if a new version is found with link to the changelog:

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#!/bin/bash
CURRENTVERSION=`w3m -dump \
 http://www.kernel.org/kdist/finger_banner \
 | head -n 1 | awk '{print $10}'`
SAVEDVERSION=`cat ~/bin/kernelversion.log \
 | tail -n 1 | awk '{print $2}'`
SAVEDDATE=`cat ~/bin/kernelversion.log \
 | tail -n 1 | awk '{print $1}'`
MAILADDRESS=mail@address.tld
 
if [[ "$CURRENTVERSION" != "$SAVEDVERSION" ]]
  then
  CURRENTDATE=`date +'%Y-%m-%d'`
  echo "$CURRENTDATE $CURRENTVERSION" \
  >> ~/bin/kernelversion.log
  echo -e "Detected new kernel version \
   ${CURRENTVERSION} on ${CURRENTDATE} \
   (replacing version ${SAVEDVERSION} from\
   ${SAVEDDATE}). Please check \
   http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-\
   ${CURRENTVERSION} forr details." \
 | mail -s "new kernel ${CURRENTVERSION}" \
 ${MAILADDRESS}
fi

The only real bug in this script is that it does not detect network issues and therefore alerts you when it is not able to get a http response. But this could be fixed with one or two lines of code. And yes most lines could be more elegant Probably today there are better channels like rss or even an old mailing list with announcements that I never looked for, but this snippet does it’s job very well.

update:

Fixed the broken wrapping of the script. Sorry about this. (Thank you Jeremy.)

Jonne stated that of course using a feed like http://kernel.org/kdist/rss.xml is the better choice today. He is surely right about this  though sometimes receiving a mail is a need.