In Debian's manpage of cron,

The files in /etc/cron.d/ are independent of /etc/crontab: they do not, for example, inherit environment variable settings from it.

and from the LinuxQuestions.org Forum: /etc/crontab vs /etc/cron.d vs /var/spool/cron/crontabs/,

scripts that are in /etc/cron.d/ don't load environment variables.

I'm assuming you added your command as root in the /etc/crontab file. If that's the fact then executing the crontab line will load the user's environment variables which don't get loaded when you put the script in /etc/cron.d.

I was wondering what the sentences highlighted by me mean? What is the "inherit"ance from?

  1. For /etc/cron.d/*, cron reset the environment variables, so don't load environment variables of the given users in the job definition lines.

    After creating /etc/cron.d/myjob

    35 * * * * t   echo $PATH  > /tmp/cron.log 2>&1

    /tmp/cron.log shows the default value of PATH is:


    which isn't the root's PATH:

    $ sudo su
    # echo $PATH
  2. In /etc/crontab, I added

    * * * * * root   echo $PATH    > /tmp/cron.log 2>&1
    * * * * * t    echo $PATH  > /tmp/cron.log.1 2>&1

    Then The PATH value for a root's cron job isn't the root's

    $ cat /tmp/cron.log

    The PATH value of my cron job isn't mine (modified in~/.profile) either

    $ cat /tmp/cron.log.1
    $ echo $PATH
    $ less ~/.profile | grep PATH


  • You can find out easily enough. Create a job that does env >/tmp/env and compare the various results from starting it in different cron files. – roaima Nov 3 '18 at 9:35
  • Thanks for the suggestion. Please see my update. – Tim Nov 3 '18 at 15:14

From man 5 crontab:

An active line in a crontab will be either an environment setting or a cron command.

That is: a not commented line (#) could be:

PATH = /bin:/sbin

Which will set the value of PATH for the whole crontab file.

If that value is not set, the built-in value (in-code) as shown on this answer is used.

Example of a crontab file setting the PATH:


# Edit this file to introduce tasks to be run by cron.
#.---------------- minute (m) (0 - 59)
#|      .------------- hour (h) (0 - 23)
#|      |       .---------- day of month (dom) (1 - 31)
#|      |       |       .------- month (mon) (1 - 12) OR jan,feb,mar,apr ...
#|      |       |       |       .---- day of week (dow) (0 - 6) (Sunday=0 or 7)  OR sun,mon,tue,wed,thu,fri,sat
#                                       .---- user
#|      |       |       |       |       |
#*      *       *       *       *       root   echo "the command to be executed"
#m      h       dom     mon     dow     user   command
*       *       *       *       *       root   echo "A crontab file test"

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.