xtail

"xtail" watches the growth of files. 

It's like running a "tail -f"on a bunch of files at once. 

You can specify both filenames and directories on the command line.

If you specify a directory, it watches all the files in that directory.  It will notice when new files are created (and start watching them) or when old files are deleted (and stop watching them).

•  Original software: http://www.unicom.com/sw/xtail/
• spectacularly useful git repo: http://gitlab.com/nephros/openrepos-xtail