Stripping comments out of a configuration file can be useful when submitting it to a forum for others to study. This is how to do this. ubuntu /etc/ssh $ grep -vE ‘^#’ sshd_configubuntu /etc/ssh $ grep -vE ‘^#’ sshd_config This will print the file to the terminal, allowing the user to copy the text with … Read more
How to strip all numbers out of a text stream This is how to remove all text from the output of a file and only keep the other formatting. homer@deep-thought ~/Desktop/b $ fortune -l | sed s/[a-z]/\ /gi; : 3:15 . . – . , ! — ’84homer@deep-thought ~/Desktop/b $ fortune -l | sed … Read more
Find out useful system information with the command line Find out what day Easter is? Use this useful command. ubuntu ~ $ ncal -e March 27 2016ubuntu ~ $ ncal -e March 27 2016 Display the date of Easter for Greek and Russian Orthodox Churches. ubuntu ~ $ ncal -o May 1 2016ubuntu ~ $ … Read more
Complex .bashrc file for Linux or UNIX Very good and very complex .bashrc file for a Linux or UNIX system. I used this one ages ago and it is great to use. I have tried this on FreeBSD and Open Solaris and it works on either. #!/bin/bash # mode:shell-script # sh-shell:bash # Modified to work … Read more
The Linux command-line offers many useful methods of creating many folders on your computer at once. This command will create a few folders on your system named one,two,three,four and create the folders five,six,seven,eight within each folder created. ~$ mkdir -p {one,two,three,four}/five/six/seven/eight~$ mkdir -p {one,two,three,four}/five/six/seven/eight This command will create four folders named one,two,three,four and put the … Read more
The BASH shell has many useful features that allow you to perform your tasks very easily. If you are running a program in a terminal and you wish to run another command whilst the first command is running, then press CTRL-Z to move the running process to the background. Then once you have finished the … Read more
Get exif information from your photos easily on Linux. The exif command for Linux allows a user to get exif information from a camera image. This example below shows the sample output from this interesting utility. Very good to manage the exif data in your photos. ─[user@parrot]─[~/Desktop] └──╼ $exif waterfall.jpg EXIF tags in ‘waterfall.jpg’ (’Intel’ … Read more
To undo the cd command if you typed it by accident, enter this command. ~$ cd -~$ cd – This will take you back in the directory history. A very useful trick. Typing this is another good trick. ~$ cd –~$ cd — This seems to take the user back two steps. Another useful way … Read more
I have just installed the Windows 10 15025 build and the bash shell. I have to say that it works way better than earlier versions. The apt update and the apt upgrade commands worked straight away. And ping works now. The networking is greatly improved. This is a good asset to the Windows 10 desktop … Read more
I am using Debian 8.0 and the bash shellshock bug still works. That is why I should use zsh instead. My home Fedora 25 machine uses the zsh shell and I do not have that problem at all. It is only the bash shell that has this vulnerability. This is very concerning, but I guess … Read more
How to update the GRUB bootloader menu on Linux To update the grub bootloader on your Linux box, this is another way to do this. grub-mkconfig > /boot/grub/grub.cfggrub-mkconfig > /boot/grub/grub.cfg This will update the grub2 bootloader and add any new kernels in /boot. Creating a new swapfile for your Linux system. Firstly we create a … Read more
The iostatcommand is another good way to get information about the hardware in your computer. This command displays information about the average CPU usage as well as reads and writes to your hard disk partitions. To install this utility, run this command. ubuntu ~ $ sudo apt-get install sysstatubuntu ~ $ sudo apt-get install sysstat … Read more
To list all the files installed by a certain Debian package, use this command. dpkg -L [PACKAGENAME]. For example. ubuntu ~ $ dpkg -L vim /. /usr /usr/bin /usr/bin/vim.basic /usr/share /usr/share/lintian /usr/share/lintian/overrides /usr/share/lintian/overrides/vim /usr/share/bug /usr/share/bug/vim /usr/share/bug/vim/presubj /usr/share/bug/vim/script /usr/share/doc /usr/share/doc/vimubuntu ~ $ dpkg -L vim /. /usr /usr/bin /usr/bin/vim.basic /usr/share /usr/share/lintian /usr/share/lintian/overrides /usr/share/lintian/overrides/vim /usr/share/bug /usr/share/bug/vim /usr/share/bug/vim/presubj … Read more
The bash shell has some very useful features when using the command line. This can make using the command line much faster. For example, if you forget to type sudo before a command, this can be fixed this way. jason$ fdisk -l /dev/sda fdisk: cannot open /dev/sda: Permission deniedjason$ fdisk -l /dev/sda fdisk: cannot open … Read more
Installing Powershell for Linux in Ubuntu 16.04 is very easy. I had problems with the packages, but I sorted it out very quickly. Firstly, download the Powershell Debian package. https://github.com/PowerShell/PowerShell/releases/download/v6.0.0-alpha.9/powershell_6.0.0-alpha.9-1ubuntu1.14.04.1_amd64.deb. Then the required libicu package. http://security.ubuntu.com/ubuntu/pool/main/i/icu/libicu52_52.1-3ubuntu0.4_amd64.deb. Then install the libicu package. jason$ sudo dpkg -i libicu52_52.1-3ubuntu0.4_amd64.deb Selecting previously unselected package libicu52:amd64. (Reading database … 490392 … Read more
This is a nice script to build a custom PS1 that looks awesome and is simple too. export PROMPT_COMMAND=__prompt_command function __prompt_command() { local EXIT="$?" local DEFAULT=’\[\e[0m\]’ local RED=’\[\e[0;31m\]’ local GREEN=’\[\e[0;32m\]’ local DARK_GRAY=’\[\e[0;90m\]’ local PURPLE=’\[\e[0;35m\]’ local YELLOW=’\[\e[0;33m\]’ PS1="\n${GREEN}\t${DEFAULT} " if [ "$EXIT" != "0" ]; then PS1+="${RED}$EXIT${DEFAULT} " else PS1+="$EXIT${DEFAULT} " fi … Read more
Search and replace on the bash shell is very useful for various one-liner shell commands. The below example shows how to replace a # character with a * character. jason@DESKTOP-R72SPS3:/mnt/c/Users/johnc/Documents$ cat ip.c | sed ‘s/#/*/gi;’ *include <stdio.h> int main() { printf("."); return 0; }jason@DESKTOP-R72SPS3:/mnt/c/Users/johnc/Documents$ cat ip.c | sed ‘s/#/*/gi;’ *include <stdio.h> int main() … Read more
The grep command on Linux is very good for filtering text to find certain strings. This is mostly used for filtering the output of a command to narrow down what the user is looking for. Find all instances of a word in a text file. jason@DESKTOP-R72SPS3:/usr/share/X11$ grep "dark" rgb.txt 47 79 79 dark slate gray … Read more
How to convert numbers to binary and back to decimal easily with the Linux command line. This would be very useful to any networking technician.
To login as root on Ubuntu 16.04, open the terminal and type this command. jason@jason-desktop:~$ sudo su – [sudo] password for jason: root@jason-desktop:~#jason@jason-desktop:~$ sudo su – [sudo] password for jason: root@jason-desktop:~# This will give you a root prompt. Then enter this command to unlock the root account. root@jason-desktop:~# passwd root Enter new UNIX password: Retype … Read more