crononag is a super-simple wrapper for commands running from cron to limit nagging emails.

There are a couple of existing cron wrappers around, but I needed to be able to customize the suppressed exit codes, and optionally always suppress stdout. I also wanted a simple deploy story. Existing solutions didn't meet these criteria, so I wrote this.

Since its inception, it has grown some additional useful features, including:

• Suppressing output based on matching regexp, regardless of exit code
• Forcing output based on matching regexp, regardless of exit code
• Ability to sleep for a random duration (up to a specified maximum), e.g. to spread load over a time window for jobs that run on multiple hosts

crononag [global options] command [command options] [arguments...]

Simply download crononag and either install the package, or put it on your path, then add crononag in front of the executable in your cron definition and enjoy the silence. You can remove any output redirections, eg:

diff a/cronjob b/cronjob
--- a/cronjob
+++ b/cronjob
@@ -1,3 +1,3 @@
 PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

-*/10 * * * * root noisycronjob --with args > /dev/null
+*/10 * * * * root crononag noisycronjob --with args

Now, your job will only produce output in the event of a non-zero exit code. Suppressed exit codes may be set using the option below.

Currently, crononag supports only very simple options:

-E, --suppress-exit-code [-E option -E option]       suppress output for specified exit code(s), may specify multiple times, defaults to 0
-R, --suppress-regexp [-R option -R option]          suppress output on matching regexp, may specify multiple times
-O, --omit-stdout                                    omit stdout, even on error, defaults to false
-f, --force-regexp [-f option -f option]             force output on matching regexp, may specify multiple times, overrides suppression
-s, --splay "0"                                      sleep for a random duration, up to the specified maximum, format is <decimal><unit>, eg: "5s", "2h45m", "12h", defaults to 0

Here are some alternative implementations, in no particular order:

• shush
• cronic
• cronwrap

This project rocks and uses the MIT-LICENSE