Category: ubuntu

Locale Umloud Problems Cron

If you run scripts to handle text output by cronjobs your perhaps get problems with umlouds “ÖÄÜ” cause they are displayed by “**”. This is a problem cause cron uses “C” setting as locale, you can test it by setting it into root crontab: open crontab from root with: $su – root $crontab – insert * * * * * locale This will mail cron’s locale echo to the mailbox of root! Read root’s mail! After tests remove the locale entry at crontab! Howto fix for Scripts: open crontab from root with: $su – root $crontab -e insert (for German): […]

Postfix: Automatic UFW Firewall Updates

If you use a Mail Server with Postfix you got daily Spam Attacks by Scripts: How to fix? Install ufw Firewall Run a Scanner Script as  cronjob On Debian/Ubuntu: Install ufw: sudo apt-get update && sudo apt-get install ufw && sudo ufw enable && sudo  ufw logging off Scan Script: sudo nano /home/user/firewall-update.sh: #!/bin/bash # scan rejected cat /var/log/mail.log | grep rejected | cut -d"[" -f3 | cut -d"]" -f1|grep -v '^$' > /tmp/firewall.txt # insert to Firewall while read line; do sudo ufw insert 1 deny from $line to any; done < /tmp/firewall.txt # scan "denied" cat /var/log/mail.log | […]

Linux: Systemd ignore console-setup settings

If you work on older Laptops and you use a Console only System Setup like on Debian there is a Bug on systemd and the console-setup package since years. After reboot all Font Settings seems gone. But the Settings are not real gone, cause systemd does not pull the settings on boot! How to fix? edit the crontab of root by sudo su – crontab -e insert the /bin/setupcon command on “@reboot” means on every boot! @reboot     /bin/setupcon > /dev/null 2>&1 save and exit, reboot now now the PC should echo big Fonts for old eyes “Terminus 20×12 Frambuffermode”  

Nvidia: Legacy Driver Debian 9.0 Stretch Kernel 4.9 Bug Interface

Current is a UNFIXED Bug on Debian 9.0 Stretch which makes impossible to easy install DKMS Nvidia-Legacy Drivers 304/340 for older Geforce Cards https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=852152 To run nouveau on upgrade 8.0 to 9.0 go to /etc/modprobe.d and remove MANUAL all blacklist configs (*.conf) of nvidia cause some glued on upgrade and are not purged automatic by the upgrade. Cause they will block nouveau load at boot (xserver-xorg-video-nouveau) Then run on Terminal: $sudo update-initramfs -u -k all $sudo update-grub $sudo reboot Remarks: Older Hardware isn’t supported by Legacy Drivers after Nvidia-375!! If you not forced to upgrade to 9.0, then WAIT! up […]

Security: Disable USB Drive mount for Users

If you share your Systems and you want to disable USB Drive connects there is a small solution. By default the gvfs Service handle all automounts and drive scans. On old Linux Systems you could purge the complete gvfsd “Backend” but Ubuntu-Desktop forces some pakets to the default Desktop Package! If you purge it the working Desktop can be destroyed! It’s easier to disable the “USB Drivers” called Modules from load on Start! Cause Rules are “Software” and can FAIL unknown!! Howto? Edit the /etc/modprobe.d/blacklist.conf and add: blacklist usb_storage blacklist uas Update initramfs (Kernel Image) update-initramfs -u -k all reboot […]

Security: Isolated Browser eMail Programs

If you want to be more secure, on Linux you can isolate used programs on different Users! All you need is installed by default! Howto: Add a new User for eMail and Browser to the System with: $sudo adduser mailuser $sudo adduser webuser now install if not installed by default “gksu” User Switch $sudo apt-get install gksu copy now the default App Links to webuser’s Home Desktop, for mailuser enter mailuser’s name $cp /usr/share/applications/firefox-esr.desktop /home/webuser/Desktop/firefox-esr.desktop edit the firefox-esr.desktop by right click on nautilus or a editor and change command line: old: /usr/lib/firefox-esr/firefox-esr %u to: gksu -u webuser -w "/usr/lib/firefox-esr/firefox-esr %u" […]

Chrome Browser: Disable Password Passphrase Autologin Seahorse

Today i got a call and was asked how to STOP Seahorse from asking with a Passphrase Popup after opening Chrome or Chromium Browser: Seems that google implementated a new Tool for Security to Prevent Access to STORED Browser Passwords, BUT this won’t work on Desktops with USER AUTOLOGIN like Lightdm! Howto: open a Terminal an enter ln -s /usr/share/applications/google-chrome.desktop /home/username/Desktop/google-chrome.desktop Now open the new Icon on the desktop with the mouse right click Change Command Line for Chrome : google-chrome-stable –password-store=basic %U or for (chromium): Now open the Browser with the new Icon Link On Ubuntu you can hold the Icon […]

PDF/A: Setup Linux CUPS to Print Archive PDF/A

If you have a Office and you have to archive Documents and Prints over Years you should have heard that there is a special PDF Type called PDF/A which is set as default Archiving PDF File Type for decades. To use it you can use the Linux Print Server called CUPS to translate all digital Prints to PDF/A. This free Software Printer is known on all Linux Releases, and he can listen on USB and Network Interfaces on Documents. Also you can use Network Printers/Scanners like the Brother MFC-Series to Scan Documents and later to print them virtual as PDF/A […]

Linux: Bash Script Time Saver Session Timer

If you use daily the Internet you know how fast the Time passes. The Internet Research can grab a lot of time without that you feel it. Thats wasted time! For saving Time on Linux you display a Timer Message on the User Screen after some Time, which let you remark that XX Minutes are gone. The Linux Tool who can offer this is called “gxmessage” Howto: Install gxmessage if not installed with $sudo apt-get install gxmessage open the root Crontab with $crontab -e Enter this code (Username = User!): */10 * * * *    sudo -u username DISPLAY=:0.0 […]

Ubuntu: Release Change

If you use Ubuntu on your Systems, you perhaps read last weeks about a new Release Version. I am often asked, must i upgrade now? My answere at first is not really, cause the new Versions are not cleaned up by all bugs and the User or Admin must recheck against the new advantages of the new Releases for production usage. I prefer to wait 3 Month after a Release by Ubuntu is published. But if you setup a very new Hardware your are often forced to take the LAST Release Version, cause it supports newest Hardware Chips by the […]