Fhyujk

What is the difference between rolling more dice versus fewer dice?

Is this ordinary workplace experiences for a job in Software Engineering?

Should I reinstall Linux when changing the laptop's CPU?

Constexpr if with a non-bool condition

Why did Luke use his left hand to shoot?

How can a large fleets maintain formation in interstellar space?

Why do cars have plastic shrouds over the engine?

Avoid page break between paragraphs

A starship is travelling at 0.9c and collides with a small rock. Will it leave a clean hole through, or will more happen?

What to look for when criticizing poetry?

A curious equality of integrals involving the prime counting function?

Is there any risk in sharing info about technologies and products we use with a supplier?

Why publish a research paper when a blog post or a lecture slide can have more citation count than a journal paper?

"on its way" vs. "in its way"

In Linux what happens if 1000 files in a directory are moved to another location while another 300 files were added to the source directory?

Salsa20 Implementation: Sum of 2 Words with Carries Suppressed

Citing paywalled articles accessed via illegal web sharing

Play Zip, Zap, Zop

Do "fields" always combine by addition?

Identify KNO3 and KH2PO4 at home

Move fast ...... Or you will lose

Am I a Rude Number?

Is using an 'empty' metaphor considered bad style?

How do you voice extended chords?

Crontab: Ubuntu running script (noob)

Where is the user crontab stored?How do I create a script file for terminal commands?What is the correct way to edit a crontab file?Cannot run bash script from crontab when it works from command line bashBash script not working properly from crontabHelp, ubuntu server 14.04 crontab cannot run my database backup script, but other simple script is okCrontab says command not foundCrontab working but root crontab doesn'tDifficulties running script at startuproot's crontab job not workingRunning pgrep in a crontabPATH issue with Cron - Not running bash/python scriptScript works manually, but not when called by Cron

4

I'm new to crontab and would like to run the following script from /etc/crontab:

0 15    * * *   root    bash-c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

I have tried with and without bash-c option, yet the script doesn't run.

My objective is:

1. Get this script running from Crontab


2. Get this script running on startup

Help is appreciated.

bash scripts cron

share|improve this question

edited 7 hours ago

dessert

24.1k670104

asked 7 hours ago

orrporrp

212

New contributor

orrp is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Consider putting this in your user crontab (i.e. crontab -e as user dell) instead of in the system crontab as root.
  
  – marcelm
  47 mins ago
  

  
  
  
  

add a comment | 

4

I'm new to crontab and would like to run the following script from /etc/crontab:

0 15    * * *   root    bash-c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

I have tried with and without bash-c option, yet the script doesn't run.

My objective is:

1. Get this script running from Crontab


2. Get this script running on startup

Help is appreciated.

bash scripts cron

share|improve this question

edited 7 hours ago

dessert

24.1k670104

asked 7 hours ago

orrporrp

212

New contributor

orrp is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  Consider putting this in your user crontab (i.e. crontab -e as user dell) instead of in the system crontab as root.
  
  – marcelm
  47 mins ago
  

  
  
  
  

add a comment | 

I'm new to crontab and would like to run the following script from /etc/crontab:

0 15    * * *   root    bash-c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

I have tried with and without bash-c option, yet the script doesn't run.

My objective is:

1. Get this script running from Crontab


2. Get this script running on startup

Help is appreciated.

bash scripts cron

share|improve this question

edited 7 hours ago

dessert

24.1k670104

asked 7 hours ago

orrporrp

212

New contributor

orrp is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

0 15    * * *   root    bash-c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

share|improve this question

edited 7 hours ago

dessert

24.1k670104

asked 7 hours ago

orrporrp

212

New contributor

orrp is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

share|improve this question

edited 7 hours ago

dessert

24.1k670104

asked 7 hours ago

orrporrp

212

New contributor

orrp is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

edited 7 hours ago

dessert

24.1k670104

edited 7 hours ago

dessert

24.1k670104

asked 7 hours ago

orrporrp

212

New contributor

orrp is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.

asked 7 hours ago

orrporrp

212

1 Answer
1

active

oldest

votes

10

You're missing a space after the command bash and the argument -c.

This should work:

0 15    * * *  root bash -c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

---

Some additional hints:

• Don't run a crontab as user root if you don't need to.


• You wrote that you put it in /etc/crontab file. Don't edit crontab files directly, rather use crontab -e command or sudo crontab -e for commands which need root rights. Note, that you don't put the user field in the "other" crontab files.



• If you have more than one command you can use bash -c as you do, but I'd rather put the commands in a script and execute this from crontab.




• To run a script on startup, you can use @reboot instead of 0 15 * * *.

share|improve this answer

edited 6 hours ago

answered 6 hours ago

RoVoRoVo

7,6541843

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  
  “I'm not sure what the word root is about here.” See the header of /etc/crontab: Unlike any other crontab you don't have to run the crontab command to install the new version when you edit this file and files in /etc/cron.d. These files also have username fields, that none of the other crontabs do. However, in this case, only the user’s home folder is involved, so root should be not used in this case.
  
  – Melebius
  6 hours ago
  
  
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  thanks, as I never edited /etc/crontab directly I didn't even know this... :-D
  
  – RoVo
  6 hours ago
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  See also Two Other Types of Crontab
  
  – steeldriver
  6 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  I suspect there may be a more fundamental issue with running a bash -c command from cron, since IIRC each command is implicitly executed by /bin/sh -c (or, more exactly, $SHELL -c). It may be necessary to set SHELL=/bin/bash (to suport brace expansion etc.) and then run the command without the bash -c wrapper. But really the best approach (as you note) is to put the bash code in an external script file.
  
  – steeldriver
  5 hours ago
  

  
  
  
  

add a comment | 

Your Answer

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "89"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});


}
});

orrp is a new contributor. Be nice, and check out our Code of Conduct.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2faskubuntu.com%2fquestions%2f1121615%2fcrontab-ubuntu-running-script-noob%23new-answer', 'question_page');
}
);

Post as a guest

Name

Email

Required, but never shown

10

You're missing a space after the command bash and the argument -c.

This should work:

0 15    * * *  root bash -c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

---

Some additional hints:

• Don't run a crontab as user root if you don't need to.


• You wrote that you put it in /etc/crontab file. Don't edit crontab files directly, rather use crontab -e command or sudo crontab -e for commands which need root rights. Note, that you don't put the user field in the "other" crontab files.



• If you have more than one command you can use bash -c as you do, but I'd rather put the commands in a script and execute this from crontab.




• To run a script on startup, you can use @reboot instead of 0 15 * * *.

share|improve this answer

edited 6 hours ago

answered 6 hours ago

RoVoRoVo

7,6541843

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  
  “I'm not sure what the word root is about here.” See the header of /etc/crontab: Unlike any other crontab you don't have to run the crontab command to install the new version when you edit this file and files in /etc/cron.d. These files also have username fields, that none of the other crontabs do. However, in this case, only the user’s home folder is involved, so root should be not used in this case.
  
  – Melebius
  6 hours ago
  
  
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  thanks, as I never edited /etc/crontab directly I didn't even know this... :-D
  
  – RoVo
  6 hours ago
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  See also Two Other Types of Crontab
  
  – steeldriver
  6 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  I suspect there may be a more fundamental issue with running a bash -c command from cron, since IIRC each command is implicitly executed by /bin/sh -c (or, more exactly, $SHELL -c). It may be necessary to set SHELL=/bin/bash (to suport brace expansion etc.) and then run the command without the bash -c wrapper. But really the best approach (as you note) is to put the bash code in an external script file.
  
  – steeldriver
  5 hours ago
  

  
  
  
  

add a comment | 

10

You're missing a space after the command bash and the argument -c.

This should work:

0 15    * * *  root bash -c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

---

Some additional hints:

• Don't run a crontab as user root if you don't need to.


• You wrote that you put it in /etc/crontab file. Don't edit crontab files directly, rather use crontab -e command or sudo crontab -e for commands which need root rights. Note, that you don't put the user field in the "other" crontab files.



• If you have more than one command you can use bash -c as you do, but I'd rather put the commands in a script and execute this from crontab.




• To run a script on startup, you can use @reboot instead of 0 15 * * *.

share|improve this answer

edited 6 hours ago

answered 6 hours ago

RoVoRoVo

7,6541843

• 
  
  
  

  
  5
  

  
  
  
  
  
  

  
  
  “I'm not sure what the word root is about here.” See the header of /etc/crontab: Unlike any other crontab you don't have to run the crontab command to install the new version when you edit this file and files in /etc/cron.d. These files also have username fields, that none of the other crontabs do. However, in this case, only the user’s home folder is involved, so root should be not used in this case.
  
  – Melebius
  6 hours ago
  
  
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  thanks, as I never edited /etc/crontab directly I didn't even know this... :-D
  
  – RoVo
  6 hours ago
  

  
  
  
  


• 
  
  
  

  
  2
  

  
  
  
  
  
  

  
  
  See also Two Other Types of Crontab
  
  – steeldriver
  6 hours ago
  

  
  
  
  


• 
  
  
  

  
  1
  

  
  
  
  
  
  

  
  
  I suspect there may be a more fundamental issue with running a bash -c command from cron, since IIRC each command is implicitly executed by /bin/sh -c (or, more exactly, $SHELL -c). It may be necessary to set SHELL=/bin/bash (to suport brace expansion etc.) and then run the command without the bash -c wrapper. But really the best approach (as you note) is to put the bash code in an external script file.
  
  – steeldriver
  5 hours ago
  

  
  
  
  

add a comment | 

You're missing a space after the command bash and the argument -c.

This should work:

0 15    * * *  root bash -c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

---

Some additional hints:

• Don't run a crontab as user root if you don't need to.


• You wrote that you put it in /etc/crontab file. Don't edit crontab files directly, rather use crontab -e command or sudo crontab -e for commands which need root rights. Note, that you don't put the user field in the "other" crontab files.



• If you have more than one command you can use bash -c as you do, but I'd rather put the commands in a script and execute this from crontab.




• To run a script on startup, you can use @reboot instead of 0 15 * * *.

share|improve this answer

edited 6 hours ago

answered 6 hours ago

RoVoRoVo

7,6541843

0 15    * * *  root bash -c 'for i in /home/dell/Downloads/*.{pdf,docx,png,jpg,PDF,DOCX}; do shred -zvu "$i" -n20; done'

share|improve this answer

edited 6 hours ago

answered 6 hours ago

RoVoRoVo

7,6541843

answered 6 hours ago

RoVoRoVo

7,6541843

answered 6 hours ago

RoVoRoVo

7,6541843