Monitoring websites for changes from the CLI

The watch command allows us to poll text-based resources, the content is rendered to the CLI and any changes between the polls detected are highlighted.

Check a remote resource for changes

This applies simple text-based to feeds

watch -n 10 -d -b curl -s https://[feed-provider]/feed

Check a website for changes

Using curl on Websites will typically return strings that are too long to show properly in the terminal. Instead we can use the text-based Lynx browser that manages to render quite a few websites sufficiently well.

To install on MacOS do

brew install lynx

We may need to add a line to the “character set” section of the Lynx config:

/usr/local/Cellar/lynx/[version]/etc/lynx.cfg

CHARACTER_SET:utf-8

then we watch:

watch -n 10 -d "lynx -dump -nolist https://[some-host]/incidents/01d59b"

Notifications

If the “live” highlighting is not enough we could use the --chgexit option which will exit the watch command when a change is detected. With this we can run it in a loop with another command that could send a notification, make a sound or trigger some kind of other automation.