Watching a file on disk
Paul Reinheimer wrote an article on a bug he was trying to solve.
If you want to watch the last lines of a file to see when it changes, try this in linux:
watch tail /path/to/file
Every 2 seconds, it will run tail on your file and display you the last 10 lines.
If the last line changed, you will see it appear in the next 2 seconds.
If you want to watch only line 30:
watch 'head -30 myfile | tail -1'
The watch utility seem to be installed by default on distribution like ubuntu and Suse.
PS: I tried posting this as a comment on Paul's blog but it told me:
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