The “every” command is that I wrote, inspired by the unix “at” command.  It adds command to your crontab for you, using an easier to remember syntax.  You can find it on github, here: https://github.com/iarna/App-Every

I was reminded because of this article on cron for perl programmers who are unix novices:

http://perltricks.com/article/43/2013/10/11/How-to-schedule-Perl-scripts-using-cron

Here’s how you’d write their examples using “every”:

$ every minute perl /path/to/Beacon.pl
SHELL=/bin/bash
PATH=/home/rebecca/bin:/opt/perl5/bin:/opt/perl5/perls/perl-5.16.2/bin:/opt/node/bin:/usr/local/bin:/usr/bin:/bin
*/1 * * * * cd "/home/rebecca";  perl /path/to/Beacon.pl

$ every 5 minutes perl /path/to/Beacon.pl
SHELL=/bin/bash
PATH=/home/rebecca/bin:/opt/perl5/bin:/opt/perl5/perls/perl-5.16.2/bin:/opt/node/bin:/usr/local/bin:/usr/bin:/bin
*/5 * * * * cd "/home/rebecca";  perl /path/to/Beacon.pl

$ every hour perl /path/to/Beacon.pl
SHELL=/bin/bash
PATH=/home/rebecca/bin:/opt/perl5/bin:/opt/perl5/perls/perl-5.16.2/bin:/opt/node/bin:/usr/local/bin:/usr/bin:/bin
49 */1 * * * cd "/home/rebecca";  perl /path/to/Beacon.pl

$ every 12 hours perl /path/to/Beacon.pl
SHELL=/bin/bash
PATH=/home/rebecca/bin:/opt/perl5/bin:/opt/perl5/perls/perl-5.16.2/bin:/opt/node/bin:/usr/local/bin:/usr/bin:/bin
49 */12 * * * cd "/home/rebecca";  perl /path/to/Beacon.pl

What’s more, there’s no need to specify the path to Perl, because unlike using crontab straight up, it will maintain your path.  Even better, you can use relative paths to refer to your script, eg:

$ every monday perl Beacon.pl

This works because every ensures that it executes from the place you set it up.  Just like “at” it uses all of the same context as your normal shell.