Category Archives: Linux

Sync time on Linux via GSM

The RaspberryPi and many similar single-board computers do not have an RTC or “Real Time Clock” and without internet connectivity cannot retain their time setting. Therefore most RaspberryPi Linux-distributions employ NTP to sync the time right after boot. If you are not able to use an internet connection and therefore no NTP, but have a GSM modem or phone and a valid sim card at hand, this guide may be suitable for your needs.

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Securing the RabbitMQ Management Console with SSL before version 3.7.10

This article was previously posted on, a blog of Richard Clayton, who released it under Attribution 3.0 Unported (CC-BY 3.0). His old blog recently went offline, therefore I am reposting this useful how-to on setting up SSL for the RabbitMQ management console.

This is an article in the RabbitMQ Configuration and Management Series.  For more articles like this, please visit the series’ index.

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Change Plesk spam-settings in bulk

Since Plesk per default uses the static userdb-driver of Dovecot, it may seem difficult to easily iterate through all mailboxes on the server, for example in order to change the spam-settings of all mailboxes on the systems at once while keeping the “individual settings per-mailbox” functionality enabled.

The following one-liner may be helpful in such case:

while read domain; do (while read user; do plesk bin spamassassin --update $user@$domain -status true -personal-conf true -action move -hits 6; done < <(ls -1 /var/qmail/mailnames/$domain)); done < <(ls -1 /var/qmail/mailnames/)

In this case, the domains and mailboxes are placed in/var/qmail due to a previous upgrade from qmail to Dovecot. If the directory in your case differs, make sure to change it in the one-liner, too.