Using CRON jobs to visit url?

Question

I have a web application that has to perform a repeated tasks, Sending messages and alerts, I, already, use a script page do those tasks when it loaded in the browser i.e http://example.com/tasks.php and I included it by the mean of iframe in every page of my web application.

Now I want to change this to use CRON jobs because the first approach may leads to jam performance, So How could I make a CRON job that visits http://example.com/tasks.php. However, I don't want this CRON job creating output files such as day.*!

I host the application on shared hosting service that permits CRON jobs via cPanel.

score 245 · Accepted Answer · answered Nov 06 '12 at 21:18

245

* * * * * wget -O - http://yoursite.com/tasks.php >/dev/null 2>&1

That should work for you. Just have a wget script that loads the page.

Using -O - means that the output of the web request will be sent to STDOUT (standard output)

by adding >/dev/null we instruct standard output to be redirect to a black hole. by adding 2>&1 we instruct STDERR (errors) to also be sent to STDOUT, and thus all output will be sent to a blackhole. (so it will load the website, but never write a file anywhere)

answered Nov 06 '12 at 21:18

Mitch Dempsey

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what are all these asterisks at the begining – Ashkan Mobayen Khiabani Nov 04 '16 at 11:46
@AshkanMobayenKhiabani They are part of the cron syntax: http://www.nncron.ru/help/EN/working/cron-format.htm – Mitch Dempsey Nov 04 '16 at 18:49
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The only solution that worked for me under Raspbian Stretch Lite. Perfect! :D – that-ben Dec 12 '17 at 17:04
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One note: it's a good idea to quote the URL, if it contains a query it may not work without everything being quoted. – jackJoe Mar 30 '19 at 11:17

score 28 · Answer 2 · edited May 23 '17 at 12:02

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You can use curl as is in this thread

For the lazy:

*/5 * * * * curl --request GET 'http://exemple.com/path/check.php?param1=1'

This will be executed every 5 minutes.

edited May 23 '17 at 12:02

Community

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answered Jul 16 '15 at 05:45

Jerzy Drożdż

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score 25 · Answer 3 · answered Nov 06 '12 at 21:25

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You don't need the redirection, use only

* * * * * wget -qO /dev/null http://yoursite.com/tasks.php

answered Nov 06 '12 at 21:25

Diego Torres Milano

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Why is the redirection not needed? – Bradley Flood Jun 16 '14 at 02:48
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`-q|--quiet Turn off Wget's output.` – Diego Torres Milano Jun 16 '14 at 02:55
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your command also use redirection but in other form -qO /dev/null, isn't it? – Pavel Nazarov Sep 22 '16 at 10:44
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Strictly speaking, not a redirection as *I/O redirection* is a shell thing – Diego Torres Milano Sep 22 '16 at 14:37

score 10 · Answer 4 · answered Nov 06 '12 at 21:30

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You can also use the local commandline php-cli:

* * * * * php /local/root/path/to/tasks.php > /dev/null

It is faster and decrease load for your webserver.

answered Nov 06 '12 at 21:30

mrraka

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score 8 · Answer 5 · answered Apr 11 '14 at 06:29

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i use this commands

wget -q -O /dev/null "http://example.com/some/cron/job.php" > /dev/null 2>&1

Cron task:

* * * * * wget -q -O /dev/null "http://example.com/some/cron/job.php" > /dev/null 2>&1

answered Apr 11 '14 at 06:29

Abbas Arif

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This one need some explaining, but it works very well. Especially if, like me, you have an ampersand in your URL. Putting the url inside quotes is a solution. Why do you putt /dev/null before the url ? – Gfra54 Jul 01 '15 at 11:01
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This is probably late reply but its never too late. Reason is: **/dev/null** is a special filesystem object that throws away everything written into it. Redirecting a stream into it means hiding an output. The **2>&1** part means "redirect both the output and the error streams". – Abbas Arif Mar 29 '16 at 00:05
Ok so, it means that the content of wget is redirected to /dev/null (so it is basically deleted and ignored) ? Thanks – Gfra54 Apr 19 '16 at 14:24
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Yes output sent to **/dev/null** is ignored. – Abbas Arif Apr 20 '16 at 19:56

score 2 · Answer 6 · edited Jun 05 '16 at 12:37

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you can use this for url with parameters:

lynx -dump "http://vps-managed.com/tasks.php?code=23456"

lynx is available on all systems by default.

edited Jun 05 '16 at 12:37

Wicher Visser

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answered Jun 05 '16 at 11:36

VPS-Managed.com

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-dump dumps the content of the page to file. That is a possibly undesired side effect. – Wicher Visser Jun 05 '16 at 11:56

Abdul Alim · Answer 7 · 2018-04-19T07:08:02.910

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You can use this command:

links https://www.honeymovies.com

edited Apr 19 '18 at 07:08

answered Feb 09 '17 at 05:44

Abdul Alim

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score 2 · Answer 8 · answered Apr 05 '17 at 06:36

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U can try this :-


    wget -q -O - http://www.example.com/ >/dev/null 2>&1

answered Apr 05 '17 at 06:36

Walk

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Val Kornea · Answer 9 · 2017-11-05T00:52:04.437

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* * * * * wget --quiet https://example.com/file --output-document=/dev/null

I find --quiet clearer than -q, and --output-document=/dev/null clearer than -O - > /dev/null

edited Nov 05 '17 at 00:52

answered Nov 05 '17 at 00:20

Val Kornea

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score 1 · Answer 10 · answered Sep 29 '22 at 17:50

For Cron job to work you just need to hit the url, without any output and without downloading anything.

I am using only the wget with this two parameters:

*/2 * * * * wget -q --spider https://example.com/

*/2 : run every 2 minutes

‘-q’ :Turn off Wget’s output.

--spider : When invoked with this option, Wget will behave as a Web spider, which means that it will not download the pages, just check that they are there.

Documentation: https://www.gnu.org/software/wget/manual/wget.pdf

score 0 · Answer 11 · answered Feb 10 '21 at 12:51

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Here is simple example. you can use it like

wget -q -O - http://example.com/backup >/dev/null 2>&1

and in start you can add your option like (*****). Its up to your system requirements either you want to run it every minute or hours etc.

answered Feb 10 '21 at 12:51

Saeed Awan

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Using CRON jobs to visit url?

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