In this Video we cover the du command. du estimate’s the file space usage
First we look at the du mange page and then we cover some real world examples
Use du to list files size
du [file]
Make du human readable
du -h
Use du to list directory size (summarize)
du -sh /home
Use du to summarize directory’s under a parent
du -h –max-depth=1 /etc
Du one file system
du -sxh /mnt
Exclude files from du
du –exclude=’*.gz’
In this video we cover the df command. DF reports file system disk space usage. DF differs from du because it looks at the file system and not files or directories.
We look at the man page for df and then we do some examples and what the output means
List disk usage on all file systems
df -a
Df human readable
df -h /
Use DF to check inodes
df -i
Show only local filesystems
df -hl
In this video I install Android X86_64 8.1-r1 as a virtual machine on a Linux workstation. I cover a couple of gotcha’s I found pre and post install.
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
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.
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 https://rpmfusion.org/
Disable ipv6
Disable screen saver password and power magnet for virtual guest
Tuned set virtual guest
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.
In this video I go over the most important command in Linux which is the ls command. Ls is how to list directory content.
First we look at the ls man page. then we go over some ls examples
Ls show hidden file (all)
ls -a
Ls long listing
ls -l
Ls recursive
ls -lR
Ls human readable file sizes
ls -hs
Sorting by size with ls
ls -AlhS
Shoring by size in reverse
ls -AlhSr
Sorting by modified time with ls
ls -Alt
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.