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.
Continue reading Sync time on Linux via GSMAll posts by Malte
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.
List number of requests from specific IPs from Nginx access-Logs
less access.log | awk '{print $1}' | sort | uniq -c | sort -n | tail
Deny in iptables based on AS-number
iptables -N AS_DENY; iptables -I INPUT -j AS_DENY; whois -T route -i origin AS57169 | grep '^route:' | awk '{print $2}' | aggregate -q | xargs -n1 -I% iptables -A AS_DENY -s % -j DROP
Search for entrys containing a specific string
SELECT * FROM `Liste` WHERE Webseite LIKE '%http:// http://%%'
//the string in this case is "http:// http://"
Compress every folder in the current directory with strongest compression possible
for D in *; do [ -d "${D}" ] && tar -cf - $D | xz -9 -c - > $D.tar.xz; done