Linux Filesystem Hierarchy

In this video I cover Linux file system hierarchy.  The somewhat loosely followed systems give some standardization to Linux distributions.

Lets look at $ man hier.

You will notice / root which is a must,  proc which is a pseudo file systems and some things missing like /dev/shm or shared memory system which is a tmpfs


Strip metadata from images command line

In this video I use Linux and ImageMagic to strip the location, camera information and other metadata from a jpg image file.

First we look at the image exif and other metadata with strings and identify

Next we strip the date with mogrify strip and diff the identify -verbose between the new and a backup.

Finally I go over mogrify -strip -auto-orient which will keep the proper photo geometry and orientation and we diff the strip difference.


Fedora 29 Mate spin post install

In this video I cover some of the things I do post install on a Fedora system.

OS update
$ dnf update

#install chrome

Set sudo wheel no password

$ sudo visudo

Block root on ssh
Disable dns lookups in sshd
Start and enable sshd
$ sudo systemctl start sshd
$ sudo systemctl enable sshd

Fix my bashrc
bind ‘”\e[A”: history-search-backward’
bind ‘”\e[B”: history-search-forward’

export HISTCONTROL=ignoreboth
export HISTSIZE=100000

Set up

Disable ipv6

Disable screen saver password and power magnet for virtual guest

Tuned set virtual guest

Everything is a file in Linux

In UNIX and Linux everything is a File. Well almost.

The correct statement would be everything is a file descriptor or a process. The point to everything is a file is that common tools can be used. I/O access can be done using the same set of operations. In windows you have different reads for sockets, files and pipes with different.  With Unix/Linux treating everything as a simple file descriptor you have one read system call.  This removes the need for having multiple operations with specific uses doing the same thing.

As example of everything is a file we will take a look at a directory file.

I hope the high level overview in this video explained why to go deeper into this would get into kernel development and beyond what I do.

Linux rev command

In this video I cover the rev or revers command in Linux. The rev command reverse lines characters. It comes with the util-linux package and can take input from a file or stranded out.

I think this command is little know because it doesn’t have many uses and there are other ways of doing it.