Manual Reference Pages - FLASHER (1)
flasher - flash keyboard LEDs to indicate file writes
-u seconds ]
-k /dev/ttyXX ]
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 dont yet exist.
To terminate the daemon, run:
# kill cat /var/run/flasher.pid
flasher was designed to use the console to indicate file activity. When running
flasher in an X11 environment, it may be helpful to use the
-k option to specify what virtual terminal X11 is running under. For example, use
# flasher -k /dev/ttyv3 ...
when running X11 on FreeBSD on virtual terminal 4.
Similarly, when using X11 on virtual terminal 8 on Linux, start the daemon
# flasher -k /dev/tty8 ...
Indicate writes to the specified file using the Caps Lock LED.
-k /dev/ttyXX |
Use the specified tty (/dev/ttyXX) instead of the console.
Indicate writes to the specified file using the Num Lock LED.
Indicate writes to the specified file using the Scroll Lock LED.
-u number |
Scans the specified files for changes every number seconds (default: 60).
The following example will flash the Scroll Lock LED to indicate
/var/log/messages writes, and the Num Lock LED for writes to
# flasher -s /var/log/messages -n /var/mail/root
The following example will flash the Caps Lock LED to indicate writes
to either /var/log/httpd-error.log or /var/mail/root, and flash the Num
Lock LED to indicate writes to /var/log/messages.
# flasher -n /var/log/messages -c /var/log/httpd-error.log:/var/mail/root
/var/run/flasher.pid - flasher lock file
flasher must be run as the super-user.
Relative pathnames will be converted to absolute pathnames.
After the program has daemonized, any messages will be sent to syslog.
Murray Nesbitt (email@example.com)
Visit the GSP FreeBSD Man Page Interface.
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