Crontab not working

[rdh61]

Hi,

I cannot get crontab to run my script. Cognisant of the possibility that my script might be wrongly constructed, as a test I added this dummy job to crontab:

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* * * * * env > /home/[myusername]/env.output

as suggested here: https://askubuntu.com/questions/23009/w ... ot-working.

No output is produced.

I checked that crontab is running (pgrep cron) and that timezone is updated (sudo service cron restart).

Help greatly appreciated.

Many thanks.

[SimonPeter]

...

Try /usr/bin/env instead (this one can be run without a shell):

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* * * * * /usr/bin/env > /home/[myusername]/env.output

To run the shell when the command is not run in the shell, use /bin/sh -c '<your_command>' (for POSIX sh scripts) or /bin/bash -c '<your_command>' (for BASH scripts).

[rdh61]

Try /usr/bin/env instead (this one can be run without a shell):

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* * * * * /usr/bin/env > /home/[myusername]/env.output

To run the shell when the command is not run in the shell, use /bin/sh -c '<your_command>' (for POSIX sh scripts) or /bin/bash -c '<your_command>' (for BASH scripts).

Thank you, that worked, but I am afraid I have no idea what it means to run a command "in the shell" or to "run the shell when the command is not run in the shell".

Please could you tell me then what is wrong with the real script I want to run? It is this:

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0 8 * * * /opt/FreeFileSync/FreeFileSync '/home/robert/BatchRun.ffs_batch'

Many thanks.

[SimonPeter]

...

Thank you, that worked, but I am afraid I have no idea what it means to run a command "in the shell" or to "run the shell when the command is not run in the shell".

Please could you tell me then what is wrong with the real script I want to run? It is this:

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0 8 * * * /opt/FreeFileSync/FreeFileSync '/home/robert/BatchRun.ffs_batch'

Many thanks.

I think the line should be amended to

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0 8 * * * /bin/sh -c 'echo "FreeFileSync started on $(date)" > /home/robert/FreeFileSync_last_started_on.txt ; /opt/FreeFileSync/FreeFileSync "/home/robert/BatchRun.ffs_batch"'

This also creates a text file named FreeFileSync_last_started_on.txt in your home directory.
Before adding to crontab, please verify this works by running it in a Terminal.

"Without a shell" means that the program is run using its executable (binary / script) + arguments only (not using a shell).
eg. system calls from the exec() family in C/C++, QProcess::start() etc.,

"With a shell" means to run a command in the shell ( /bin/sh for most POSIX systems).
eg. system() call in C/C++, the Terminal app (ie. x-terminal-emulator), the TTY shell etc.,

[RIH]

The format to get FreeFileSync work in cron is...


env DISPLAY=:0.0 Full path to FreeFileSync program FreeFileSync Full path to the FreeFileSync batch job backup.ffs_batch
Where the pieces in red are user submitted.

I just cracked it...
The secret is the Display bit..

[AndyMH]

You might have a look at unison instead of freefilesync. unison is native linux whereas freefilesync is ported from win. I run it in a script at startup to sync important files to my NAS, I also use notify-send so the script sends me a notification telling me what it has done.

[rdh61]

You might have a look at unison instead of freefilesync. unison is native linux whereas freefilesync is ported from win. I run it in a script at startup to sync important files to my NAS, I also use notify-send so the script sends me a notification telling me what it has done.

Would you be so kind as to post the script here?

[rdh61]

I think the line should be amended to

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0 8 * * * /bin/sh -c 'echo "FreeFileSync started on $(date)" > /home/robert/FreeFileSync_last_started_on.txt ; /opt/FreeFileSync/FreeFileSync "/home/robert/BatchRun.ffs_batch"'

This also creates a text file named FreeFileSync_last_started_on.txt in your home directory.
Before adding to crontab, please verify this works by running it in a Terminal.

This works. Thank you very much. I also changed the script to * * * * * to facilitate testing.

UPDATE: No, it doesn't work, it sends the last_started file, but it is not actually syncing my files.

[AndyMH]

Would you be so kind as to post the script here?

Have PMed you.

[rdh61]

Would you be so kind as to post the script here?

Have PMed you.

Thank you!

[rdh61]

The format to get FreeFileSync work in cron is...


env DISPLAY=:0.0 Full path to FreeFileSync program FreeFileSync Full path to the FreeFileSync batch job backup.ffs_batch
Where the pieces in red are user submitted.

I just cracked it...
The secret is the Display bit..

Thanks for your response.

As is, this does not work for me. When I run this command in the terminal I am told that there is no file FreeFileSync. If I delete that part of the command, I am told there is no file backup.ffs_batch. If I then delete that part of the command it works, that is:

env DISPLAY=:0.0 Full-path-to-FreeFileSync-program Full-path-to-the-FreeFileSync-batch-job

So that's good. I would also like it to log when it has run in a file in my home folder. Do you know how that can be achieved?

Thanks again.

[AndyMH]

https://www.cyberciti.biz/faq/unix-linu ... ll-script/

[RIH]

As is, this does not work for me.

Then I don't believe that you have entered your paths correctly.

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env DISPLAY=:0.0 /home/bob/Programs/FreeFileSync/FreeFileSync /home/bob/Programs/FreeFileSync/backup.ffs_batch

Works fine for me both in Terminal & as a cron job..

[rdh61]

https://www.cyberciti.biz/faq/unix-linu ... ll-script/

Thank you!

[rdh61]

As is, this does not work for me.

Then I don't believe that you have entered your paths correctly.

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env DISPLAY=:0.0 /home/bob/Programs/FreeFileSync/FreeFileSync /home/bob/Programs/FreeFileSync/backup.ffs_batch

Works fine for me both in Terminal & as a cron job..

Yes, thank you. I figured that was it. I had misinterpreted your original message.