CODEWITHSUNDEEP
cronembedded-linuxopenwrt
PrimuS
PrimuS

Reputation: 2683

wget not executed through cronjob but directly in console

I have an TP Link Archer C7 with 15.05 Chaos Calmer at home.

I am trying to get the cronjob to work. It looks like this:

* * * * * /usr/bin/wget --spider \"https://subdomain.domain.net/update.php\" >/dev/null 2>&1

Unfortunately this does not get executed. I also tried to do* * * * wget -O - https://subdomain.domain.net/update.php same result. BOTH versions are executed correctly if entered through the console directly.

Last line of logread

Tue Sep 20 11:55:00 2016 cron.info crond[10317]: USER xxx pid 16697 cmd /usr/bin/wget --spider \"https://subdomain.domain.net/update.php\" >/dev/null 2>&1

Looks correct? Any idea why it is not executed through the cronjob?

Upvotes: 4

Views: 3423

Answers (2)

Danny
Danny

Reputation: 1703

Your cron job does run, but wget runs into an error.

Also to get a log, i.s.o. redirecting to /dev/null, you cannot use /out.txt, as cron will have no write access to /, /tmp/wget.txt will do fine.

Same goes for the wget command, where does the output get stored? you should use use -p <directory prefix> option.

Secondly you need to handle if data is already in that directory, which could be to use -N and only download newer files and override the old ones.

Thirdly use the -q option when all is working to quiet down wget output.

Fourthly you cannot run the script every minute * * * * *, as previous run might not have finished yet, see format:

 # ┌───────────── min (0 - 59)
 # │ ┌────────────── hour (0 - 23)
 # │ │ ┌─────────────── day of month (1 - 31)
 # │ │ │ ┌──────────────── month (1 - 12)
 # │ │ │ │ ┌───────────────── day of week (0 - 6) (0 to 6 are Sunday to
 # │ │ │ │ │                  Saturday, or use names; 7 is also Sunday)
 # │ │ │ │ │
 # │ │ │ │ │
 # * * * * *  command to execute

For the sake of test let's run it every night at 1 past midnight.

Remark: To really make it correct, you should use a script file to execute and put wget command in there, where as the script file could make a lock in case you want to execute this frequently, see here for advice as this is beyond the scope of this question/answer.

And Number 5: don't need to escape the " with \", even so the " is not needed, so remove it.

In conclusion, make first a directory where data can be stored e.g. /wget_data

mkdir /wget_data
chmod 777 /wget_data

then adjust your cron line, add the -p <directory prefix> and -N and adjust the execute format:

1 0 * * *  /usr/bin/wget -N -p /wget_data --spider https://subdomain.domain.net/update.php >/tmp/wget.txt 2>&1

and restart your cron, can't advice on that, don't known what is used yet.

also wise would be to to test your command from the command line first with:

/usr/bin/wget -N -p /wget_data --spider https://subdomain.domain.net/update.php >/tmp/wget.txt 2>&1

and then cat /tmp/wget.txt to see if the command worked, and ls /wget_data to see if wget did collect data.

Upvotes: 3

Serj.by
Serj.by

Reputation: 604

Main things you need to check:

  1. If crond is up and running ( top , ps -A )
  2. If crond has enough permissions to execute wget ( ls -l /usr/bin )
  3. If wget does not produce any errors (don't throw away output to /dev/null, store it in some file and then check firstly - if file created at all, if not - tripple check things 1 and 2, if file is created and there is some information - it could be helpful)
  4. Related to items 1 and 2. Check what user running crond and try to execute command using this user.
  5. Try execute not wget but some command that will write some string to some file and check if it will works.

Upvotes: 1

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