NAME

       cronic - a shell script to help control the most annoying feature of cron: unwanted emailed output

SYNOPSIS

       cronic [COMMAND]

DESCRIPTION

       Cronic  is  a  small shim shell script for wrapping cron jobs so that cron only sends email when an error
       has occurred.

       Cronic defines an error as any non-trace error output or a non-zero result code.

       Cronic filters Bash execution traces (or anything matching PS4) from the error output, so jobs can be run
       with execution tracing to aid forensic debugging.

       Cronic has no options, it simply executes its arguments.

       0 1 * * * cronic backup

       With cronic, you can turn on Bash's strict error  handling  and  debug  options  (exit  on  error,  unset
       variable detection and execution tracing) to make sure problems are caught early.

EXAMPLES

       Example cron job:

              #!/bin/bash
              set -o errexit -o nounset -o xtrace
              cp -rp data1 /backup
              cp -rp data2 /backup
              cp -rp data3 /backup

       When  an  error  is detected, Cronic outputs a report listing the result code, error output, and combined
       trace and error output. The combined output can help put error messages in context.

       Example email from cron with cronic info:

              From: user@example.net (Cron Daemon)
              To: user@example.net
              Subject: Cron <user@server> cronic backup

              Cronic detected failure or error output for the command:
              backup

              RESULT CODE: 1

              ERROR OUTPUT:
              cp: data2: Permission denied

              STANDARD OUTPUT:

              TRACE-ERROR OUTPUT:
              + cp -rp data1 /backup
              + cp -rp data2 /backup
              cp: data2: Permission denied

VERSION HISTORY

       v3 - Use mktemp -d to avoid race-conditions and security problems.

       v2 - Corrected command  evaluation,  so  shell  meta-chars  are  preserved  correctly  (Thanks  to  Frank
       Wallingford for the fix).

       v1 - Initial release.

OTHER TOOLS

       Joey Hess has written a simpler perl version of cronic, named chronic.  It is available in Debian as part
       of moreutils.

AUTHOR

       Cronic was written by Chuck Houpt.
       This man page was formatted from the cronic home page by Daniel Lange.

REPORTING BUGS

       Please  report bugs upstream to Chuck Houpt <chuck@habilis.net> and use the Debian bugtracker for Debian-
       specific issues.
       The cronic home page is <http://habilis.net/cronic/>.

COPYRIGHT

       Copyright © 2007 Chuck Houpt. Debian packaging © 2016 Daniel Lange.
       License CCO: Public Domain dedication v1.0 <https://creativecommons.org/publicdomain/zero/1.0/>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to  the  extent
       permitted by law.

SEE ALSO

       crontab(5), bash(1)

admin                                            April 2016 - v3                                       cronic(1)