Category: Linux

Link: A Primer for Scheduling Cron Jobs in Linux

Cron jobs in Linux are simple scheduled tasks that can be set to run commands at specific times. Unfortunately, the syntax isn’t the easiest to use or remember, but in this month’s column I’ll share some examples and tips to help you better understand and utilize cron jobs.

Full article here:
A Primer for Scheduling Cron Jobs in Linux (ServerWatch)

Note that if you have Webmin installed on a system, it may be easier to use that to schedule cron jobs.

Is elitism the reason many open source projects self destruct?

The author of this article seems to think so. He appears to be primarily talking about Ubuntu here, but we strongly suspect that the same thing has happened with several other open source projects:

The Achilles Heel of Open Source: Elitism (Linux Advocates)

Related:

Mark Shuttleworth: Canonical leads Ubuntu, not ‘your whims’ (The Register)

Link: How to protect Apache with Fail2ban

Around 2 years ago I wrote an article about fail2ban.

Fail2ban is an intrusion prevention framework written in the Python programming language. It is able to run on POSIX systems that have an interface to a packet-control system or firewall installed locally (such as, iptables or TCP Wrapper).

Fail2ban’s main function is to block selected IP addresses that may belong to hosts that are trying to breach the system’s security. It determines the hosts to be blocked by monitoring log files (e.g. /var/log/pwdfail, /var/log/auth.log, etc.) and bans any host IP that makes too many login attempts or performs any other unwanted action within a time frame defined by the administrator.

Today I want to show you some configurations that you can use to improve the security of your Apache.

Read the rest here:
How to protect Apache with Fail2ban (Linuxaria)

If you ever play video using VLC and it is jerky or drops frames, try this

In VLC’s preferences, note the setting for “Use GPU accelerated decoding” — on most systems with modern graphics hardware this should be checked, but is not by default. So, check the box and then click Save. You can always change it back if it makes things worse, or causes videos to not play at all.

VLC Preferences — Input and Codecs settings — use GPU accelerated decoding
VLC Preferences — Input and Codecs settings — use GPU accelerated decoding

This setting does not seem to be available in OS X versions of VLC.

Linux: Bash scripts to switch displays using xrandr (via Reddit)

We love simple solutions to problems, and this falls into that category.

A Reddit user has posted a pair of scripts to switch between two displays (a monitor and a TV) in Ubuntu 12.04, but these should be usable in many other versions of Linux as well. He writes:

I currently have a 40″ TV on HDMI (we’ll call this HDMI) and a 22″ monitor (DVI). I don’t want to dual screen these, I simply want one on at a time.

After a bit of difficulty at the start, this is what he came up with.

To switch the monitor off and the TV on:

#!/bin/bash
xrandr --output DVI --off
xrandr --output HDMI --auto
exit

To switch the TV off and the monitor on:

#!/bin/bash
xrandr --output HDMI --off
xrandr --output DVI --auto
exit

Be sure to make the scripts executable before running them.