[root@test]# cat input a,b,c,d [root@test]# cat input | sed 's/','/\n/g' a b c d [root@test]# cat input | awk '$1=$1' RS=, OFS="\n" a b c d [root@test]# cat input | tr -s ',' '\n' a b c d
Enjoy 🙂
Category Archives: Centos
Install Oracle JDK
Go to the link : http://www.oracle.com/technetwork/java/javase/downloads/
Accept the license agreement and Download the tar.gz file (eg: jdk -8u65-linux-i586.tar.gz)
Extract the file using the command tar -xzvf jdk-8u65-linux-i586.tar.gz
Copy the extracted directory (In my case jdk1.8.0_65) to the required location say /scratch
alternatives –install /usr/bin/java java /scratch/jdk1.8.0_65/bin/java 20000
alternatives –config java
You can see the list of available java versions and select our installed one by typing the number corresponding to that one.
Run a script at boot time in CentOS 7
By default /etc/rc.local and /etc/rc.d/rc.local are no longer executable in CentOS7 with the new systemd-changes. Follow the below steps to make the script /root/g.sh run at boot time:
1. chmod +x /etc/rc.d/rc.local 2. chmod +x /root/g.sh 2. Mention your script at the bottom of the file /etc/rc.local (/etc/rc.local is a symlink to /etc/rc.d/rc.local)as below : sh /root/g.sh
Restart and check 🙂
Reset the password from single user mode in CentOS7
While booting up your machine, select the existing kernel and press ‘e’
Replace the entry ‘ro‘ with ‘rw init=/sysroot/bin/sh’
changed to
Press ctrl+x to save and start single user mode using the bash shell we mentioned above.
Run the below command and change password after that:
chroot /sysroot
passwd
Update selinux parameters as below :
touch /.autorelabel
Now reboot your machine. It may take some time to apply the apply the changes while booting up.
Thanks 🙂
Check whether the server is virtual or physical
1. Install the package : facter
In centOS : yum install facter
In ubuntu : apt-get install facter
2. Run the command :
facter virtual
3. Check the output.
for example :
[root@test1 ~]# facter virtual vmware
root@test2:~# facter virtual physical
Thanks 🙂
Change the color of your terminal
To change the color of the terminal :
tput setaf number
Use the below numbers for the corresponding color.
Black : 0
Red : 1
Green : 2
Yellow : 3
blue : 4
Magenta : 5
Cyan : 6
White : 7
Eg : For Green(my fav :)),
tput setaf 2
Enjoy 🙂
Import certificate and key into jks
1. First create a p12 file and import both the certificate and key into it using openssl.
openssl pkcs12 -export -name theg -in /etc/ssl/certs/theg.crt -inkey /etc/ssl/private/theg.key -out theg.p12
2.Convert the p12 format into jks format using keytool :
keytool -importkeystore -destkeystore theg.jks -srckeystore theg.p12 -srcstoretype pkcs12 -alias theg
Note : Here I used the name theg for my certificates and alias, change it accordingly.
