| Description | Command | Example |
|---|---|---|
How to get date in YYYYMMDDhhmmss format
|
date +%Y%m%d%H%M%S | date +%Y%m%d%H%M%S 20150701164849 |
| How to get hostname | uname -n | |
| How to unzip and untar a file | gunzip -c filename | tar -xvf - | |
| How to check if a file is non zero size | if [ -s file ] | |
| How to check if a variable is empty | if [ -z file] | |
| How to check if a directory is present | if [ -d file] | |
| How to check if a file is present | if [ -f file] | |
| How to extract file name from path | echo filename | sed -e's/.*\///' | # echo "/opt/app/tmp/pom.xml" | sed -e's/.*\///' pom.xml |
| How to zip a file | cat $file | gzip -c > $FILENAME | |
| How to retrieve return status from a shell | $CTI/common/shells/SendToETL.sh TOPO $FILENAME RC=$? echo "Return status = $RC" |
|
| How to run a command on a remote server | ssh -l user hostname '. ./.profile;echo $JAVA_HOME' | ssh -l jm416b abc.com '. ./.profile;echo $JAVA_HOME' |
| How to view contents of a zip file | zcat file.gz | |
| How to retrieve result to an integer variable | integer RESULT=$(wc -l $DIFFFILE | cut -d' ' -f1) | |
| Numeric comparison | if [ $RESULT -gt 0 ] | you can also use -gt,-ge,-le,-lt,-eq,-ne |
| String comparison | if [ "$HLCS" != "" ] | use = = for equality |
| Convert uppercase to lowercase | DNS=$(echo "$DNS" | tr '[A-Z]' '[a-z]' | |
| Convert lowercase to uppercase | DNS=$(echo "$DNS" | tr '[a-z]' '[A-Z]' | |
| A file is newer than another | if [[ FILE1 -nt FILE2 ]]; then
echo FILE1 is newer than FILE2 fi |
|
| A file is older than another | if [[ FILE1 -nt FILE2 ]]; then echo FILE1 is newer than FILE2 fi |
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In this post I will explain how to setup a minikube single node kubernetes cluster using AWS EC2 instance which would help anyone who is trying to learn kubernetes and also help them to gain practical knowledge in kubernetes by running kubernetes commands, creating kubernetes objects etc. Minikube is a single node kubernetes cluster which means a kubernetes cluster with only one node that is a single VM. Minikube is only used for learning purposes and it is not an alternative for a real kubernetes cluster and should not be used for development and production usage. In this example I have launched an AWS EC2 instance with below configuration where I will install minikube and related tools. AWS EC2 Instance Configuration AMI: Ubuntu Free tier eligible 64 bit Instance type : t2-large ( For me t2-small or t2-micro is giving performance issues due to less memory) Once the EC2 instance is up and running, login to the instance using below command on terminal. If you are using wi...
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