tlp – optimize and maximize your battery power.

If you are concerned about the battery life on your Linux laptop, then you should consider using tlp. tlp customizes your Linux distribution for maximum battery life and thus helps improving battery longevity when on Linux.

TLP brings you the benefits of advanced power management for Linux
without the need to understand every technical detail. TLP comes
with a default configuration already optimized for battery life.
Also an optional install of the smartmontools package enables hard
disk SMART data in tlp-stat (smartctl).

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unrar or unar – go open source way

Recently there was a utility released called unar, a open source replacement for unar.

Description::

The command-line utilities lsar and unar are capable of listing and extracting
files respectively in several formats including RARv3. unar can serve as a free
and open source replacement of unrar.

To install on fedora:

yum install unar

The utility provides 2 commands called lsar and unar, which can be used to list and extract rar archives.

terminal in browser.

Quite a lot of time, we are spending most of the time on Browsers and during this time, leaving the browser just to do some ls or some command for quickly checking something does not look productive and here is where butterfly is useful.

Just install butterfly with:

pip install butterfly

and then head over to :

http://localhost:57575

and voila you have a terminal in your browser.

Some nice linux tutorials

Some very nice articles and tutorials on Linux, find here. Pretty nice collection.

Sandbox Firefox – First step to security

First we will setup cgroup to limit cpu and memory usage, so here we go:

Add the configuration in /etc/cgconfig.conf

#------start cgconfig----------------
#new group
group firefox {
    perm {
        task {
#user your login id and group here, so that you can control this group
        uid = amitag;
        gid = amitag;
        }
        admin {
# same as above, set to your login id and group.
           uid = amitag;
           gid = amitag;
        }
    }
# set the limits for cpu.. by default there are 1024 shares of cpu with no other groups,
# so share of 102 would be around 10% .
    cpu{
        cpu.shares="102";
    }
# limit the cpus to be used to only 0-1
    cpuset{
        cpuset.cpus=0-1;
        cpuset.mems=0;
    }
# limit the maximum memory to 700Mb.
    memory {
        memory.limit_in_bytes="700M";
        memory.max_usage_in_bytes="0";
    }
}
#------end cgconfig----------------

mpd – change the music directory context for selinux.

For running mpd with different use, you may find necessary to change the SELinux context of your music directory. For this, you would need to run the below command:

chcon -R  -t mpd_user_data_t Music/

Related articles

• ACL, SELinux Contexts and Systemd
• SELinux

cgroups – use to control your cpu and memory

cgroups is a kernel feature and with userspace utilities, we can use the feature to control the cpu and memory for per process. So, lets first install the required tools.

sudo yum install libcgroup-tools

Now, we need to enable the service.

sudo systemctl enable cgconfig.service
sudo systemctl enable cgred.service

cgconfig.service is to enable configuration for cgroups and
cgred.service is to enable configuration for cgroups for processes depending on the name.