The dig command is apart of the bind-utils package. You can install it with.
sudo yum install bind-utils -y
Now run dig
dig localhost
Install dig on CentOS
Reply
Category Archives: Linux
Install Microsoft Teams Preview on Linux
Download the correct package for your distribution of Linux from
https://teams.microsoft.com/downloads
You should be able to open the installer and it should install, if not you can run the following commands from a terminal
The install instructions are for Debian/Ubuntu/Linux Mint.
Install using dpkg
sudo dpkg -i Downloads/teams_1.2.00.32451_amd64.deb
Launch Teams by typing
teams
Or you can launch it from your Applications Menu
After Teams is installed and launched, sign in to your Microsoft account.
DD show show status of progress
You can have dd show the progress of a write by specifying “status=progress” in the command line arguments.
sudo dd if=Downloads/CentOS-8-x86_64-1905-boot.iso of=/dev/sdb status=progress
Example:
bob@localhost:~$ sudo dd if=Downloads/CentOS-8-x86_64-1905-boot.iso of=/dev/sdb status=progress 559690240 bytes (560 MB, 534 MiB) copied, 96 s, 5.8 MB/s <-- This is shown while writing. 1093632+0 records in 1093632+0 records out 559939584 bytes (560 MB, 534 MiB) copied, 96.0339 s, 5.8 MB/s
no matching key exchange method found. Their offer: diffie-hellman-group1-sha1
Work around is to use the -o option and specify KexAlgorithms with the correct option.
ssh -o KexAlgorithms=+diffie-hellman-group1-sha1 admin@192.168.11.1
List of errors from devices
The following are errors that are returned when trying to ssh to a device.
Cambium 450i PMP Equipment
Unable to negotiate with 192.168.0.1 port 22: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1,diffie-hellman-group14-sha1
Find system uptime in Linux
There are a few different ways to find out the system up time in Linux.
cat /proc/uptime
admin@localhost [~]# cat /proc/uptime 306350.37 2218975.63 admin@localhost [~]#
Taking the above command one step further, we can run it in the date command to see the system start up date.
date --date="cat /proc/uptime | awk '{print $1}'seconds ago"
uptime command
[admin@localhost ~]$ uptime 6:25AM up 2 days, 6:24, 3 users, load averages: 0.00, 0.00, 0.00 [admin@localhost ~]$
w command
[admin@localhost ~]$ w 6:27AM up 2 days, 6:25, 2 users, load averages: 0.00, 0.00, 0.00 USER TTY FROM LOGIN@ IDLE WHAT admin p1 localhost. 6:09AM 13 su (bash) admin p2 localhost. 6:25AM - w [admin@localhost ~]$
Reference links
https://sharadchhetri.com/2013/03/18/4-different-commands-to-find-system-uptime-in-linux/
How To Fix “no matching host key type found. Their offer: ssh-rsa,ssh-dss”
2023 Update: Recent versions of REHL have completely disabled DES which can cause issues even when using the +ssh-rsa or +ssh-rsa. You can use the following command to enable SHA1, however, upgrading the server would be recommended.
update-crypto-policies --set DEFAULT:SHA1
Reason for it not working is some of the older weaker SSH encryption algorithms have been disabled. You can allow ssh to use it by specifying the following option.
-oHostKeyAlgorithms=+ssh-dss
The whole command would look like
ssh -o HostKeyAlgorithms=+ssh-dss root@192.168.111.4
Set screen brightness with xrandr
Find active screens with
xrandr | grep " connected"Example output
HDMI-0 connected 1920x1080+0+0 (normal left inverted right x axis y axis) 527mm x 296mm
eDP-1-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 294mm x 165mmSet desired screen brightness. Range is from 0-1
xrandr --output eDP-1-1 --brightness .5Create LUKS Encrypted Thumb Drive
Find the thumb drive with lsblk, dmesg, or sudo fdisk -l. In the following examples we are using /dev/sdc1, replace as needed.
sudo cryptsetup --verbose --verify-passphrase luksFormat /dev/sdc1 sudo cryptsetup luksOpen /dev/sdc1 encrypted_usb sudo mkfs.ext4 /dev/mapper/encrypted_usb
Now we can mount the drive. We are mounting it to /mnt change if needed.
sudo mount /dev/mapper/encrypted_usb /mnt
Or go ahead and close the channel and remove the drive
sudo cryptsetup luksClose /dev/mapper/encrypted_usb
Command Explanation
sudo cryptsetup --verbose --verify-passphrase luksFormat /dev/sdc1
Wipe /dev/sdc1 and set the password when prompted for it.
sudo cryptsetup luksOpen /dev/sdc1 encrypted_usb
Open up a secure channel to the drive, and decrypt it so we can access it
sudo mkfs.ext4 /dev/mapper/encrypted_usb
Using the channel we created in the previous command, we can now format the drive.
sudo cryptsetup luksClose /dev/mapper/encrypted_usb
We can now close the channel for the drive and remove it.
Show human readable time in dmesg
The -T option lets dmesg show user readable time.
Example:
$ dmesg -t ... [Sat Nov 15 12:15:12 2019] CPU1: Package temperature/speed normal [Sat Nov 15 12:14:12 2019] CPU3: Package temperature/speed normal [Sat Nov 15 12:14:12 2019] CPU0: Package temperature/speed normal [Sat Nov 15 12:14:12 2019] CPU4: Package temperature/speed normal $
dmesg time options
$ dmesg -h | grep time
-d, --show-delta show time delta between printed messages
-e, --reltime show local time and time delta in readable format
-T, --ctime show human-readable timestamp (may be inaccurate!)
-t, --notime don't show any timestamp with messages
--time-format show timestamp using the given format:
[delta|reltime|ctime|notime|iso]
Suspending/resume will make ctime and iso timestamps inaccurate.
Install Go and dep on Ubuntu
Should be able to install with apt.
apt install -y golang go-dep
Print versions
$ dep version
dep:
version : devel
build date :
git hash :
go version : go1.8.3
go compiler : gc
platform : linux/amd64
$ go version go version go1.10.4 linux/amd64