swatch

Swatch is designed to monitor system activity. It reads a configuration file which contains pattern(s) to look for and action(s) to perform when each pattern is found. A typical action is echoing the matched line in a variety of colours and formats including reverse video, bold, underline, and normal, which swatch knows how to do internally. Other actions include sending mail or executing an arbitrary program on the line. Swatch is written in Perl and uses Perl regular expressions for line matching.