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Often, crontab scripts are not executed on schedule or as expected. There are numerous reasons for that:

  1. wrong crontab notation
  2. permissions problem
  3. environment variables

This community wiki aims to aggregate the top reasons for crontab scripts not being executed as expected. Write each reason in a separate answer.

Please include one reason per answer - details about why it's not executed - and fix(es) for that one reason.

Please write only cron-specific issues, e.g. commands that execute as expected from the shell but execute erroneously by cron.

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closed as too broad by jokerdino Oct 22 '13 at 17:34

There are either too many possible answers, or good answers would be too long for this format. Please add details to narrow the answer set or to isolate an issue that can be answered in a few paragraphs.If this question can be reworded to fit the rules in the help center, please edit the question.

31 Answers 31

I once was working on a shared server with lots of restrictions.

All the answers here (PATH, SHELL, bash -c,...) could not get my script to work in the crontab.

It did work perfectly when I put the command in a little script file with the PATH, SHELL, and shebang rather than in the crontab itself. I did have to change the permissions to 700.

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