[SOLVED] Sed command to change a specific cronjob

Issue

I want to modify my cronjob by using sed cmd

my cronjob is as below

* * * * * root /apps/filebeat-cybersoc-3/config_updater.sh

i used sed to modify my line so i tape the cmd below

sed -i 's|* * * * * root /apps/filebeat-cybersoc-3/config_updater.sh|* * * * * root /apps/filebeat-cybersoc-3/config_updater.sh > /apps/filebeat-cybersoc-3/logs/config_updater.log|' /etc/cron.d/filebeat-cybersoc-3

i dont get the result as expected i got this :

* * * * * * * * * root /apps/filebeat-cybersoc-3/config_updater.sh > /apps/filebeat-cybersoc-3/logs/config_updater.log

instead of :

* * * * * root /apps/filebeat-cybersoc-3/config_updater.sh > /apps/filebeat-cybersoc-3/logs/config_updater.log

Solution

You're overthinking the problem - all you need is (assuming that you only have that one line in the file)

 sed -i 's|$|> /apps/filebeat-cybersoc-3/logs/config_updater.log|' /etc/cron.d/filebeat-cybersoc-3

where s|$| searches for the end of line and then you just attach the redirect.

As Nahuel pointed out in the comment above: * is a quantifier in regex, so that won't work without escaping.

Otherwise:

sed -i 's|^\* \* \* \* \* root /apps/filebeat-cybersoc-3/config_updater.sh|* * * * * root /apps/filebeat-cybersoc-3/config_updater.sh > /apps/filebeat-cybersoc-3/logs/config_updater.log|' /etc/cron.d/filebeat-cybersoc-3

Answered By - tink

Answer Checked By - David Goodson (WPSolving Volunteer)