I’m pleased to announce Federated Media Publishing’s first open-source contribution.

cronviz: Visualize your cron jobs.

It’s 3 AM. Do you know where your cron jobs are?

Use case

You have a problem: something’s causing performance issues on the application server between 1 and 4 AM, and the cron jobs seem a likely culprit.

Naturally, you eyeball your crontab to find out what’s running during those hours.

Now you have two problems.

Over time, cron jobs accrete into an impenetrable, opaque mass of text. Trying to get a comprehensive sense of all the various run times, and finding patterns therein, can be exceedingly difficult. Crontabs are written for computers to interpret — not humans.

Cronviz can help, by turning this…

* * * * * /usr/bin/foo
*/10 * * * * /usr/bin/bar
*/15 * * * * /usr/bin/baz
*/30 * * * * /usr/bin/qux
8 */8 * * * /usr/bin/quux
* * * * * /usr/bin/corge
*/30 23,0,1 * * * /usr/bin/grault
*/5 * * * * /usr/bin/garply
0 * * * * /usr/bin/waldo
0 0 4,22 * * /usr/bin/fred
0 1 * * * /usr/bin/plugh
0 13 * * * /usr/bin/xyzzy
0 2 * * * /usr/bin/thud
30 6 * * 1,2,3,4,5 /usr/bin/wibble
30 7 * * * /usr/bin/wobble
30 8 * * * /usr/bin/wubble
33 */2 * * * /usr/bin/flob
35 1 * * * /usr/bin/whatever
45 * * * * /usr/bin/whoever
45 1 * * * /usr/bin/whomever
* * * * * /usr/bin/whenever

into…

A screenshot of cronviz fed some sample input, featuring more metasyntactic variable names than you ever knew existed

cronviz is hosted at Github — check it out!