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 <https://habilis.net/cronic/>.

COPYRIGHT

       Copyright © 2007-2016 Chuck Houpt. Debian packaging © 2016, 2018 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)