May 26, 2018
Monitors log or mail files for writes, and flashes a keyboard LED
Flasher monitors changes to one or more files, and indicates the number of writes to these files by briefly flashing a console LED once for each write. The flashing sequence is repeated, after a brief pause, until the files have been read. As the files are subsequently read, the number of LED flashes is reduced. When all monitored files have been read, the console LED will be disabled.
The most obvious use is to monitor specific system log or mail files.
Multiple LEDs can be used. Each possible LED -c, -n or -s takes a list of colon-separated file arguments. For example, when invoked as
# ./flasher -s /var/log/messages/var/mail/root
the Scroll Lock LED will flash once for each write made to either of these files, until the files are read. When /var/log/messages has been read, the Scroll Lock LED will continue to flash once for each write that has been made to /var/mail/root, until it also has been read.
The list of files can include files that don’t yet exist.