#environment variable

Vault on Windows Gotcha

Problem You’re trying to use the vault cli on windows. Many examples show the following steps to login This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters. Learn more about bidirectional Unicode characters Show hidden…

Environment Variables store information about our login sessions stored for the system to use commands. Many variables are set by default, while many of them are installed. Environment Variables apply to all the updated systems, but here we shall talk specifically about Linux. Here is how you can set environment variables on Linux:

Working of Environment Variables

Certain Variables are referenced to ensure working when we launch a terminal window. Not just this, these variables also make sure that any information which is required by the terminal is available to refer. These variables define the environment to look upon inside the terminal window, which is why these are known as Environment Variables.

Certain Environmental Variables stick to the system or has a global reach. While others are private and could only be seen by you. The third set of variables are those which depend upon your time, locale, and certain other settings.

Below mentioned is the information about your already existing variables and how to create it your own as well.

Environment and Inheritance

The starting of a shell goes through an initial stage only when these variables define the environment of the shell.

When a program is launched, it inherits the variables from the parent environment. But, this is totally customizable as you can avoid adding the variable to the new program which you do not want to be added.

Global Environment Variables

By protocol, these environment variables give uppercase names. Below mentioned are some global environment variables and what they represent:

_:  It stands for the last command that was typed.

HOME: It stands for the home directory of the current user.

LANG: It stands for the character encoding settings.

SHELL: It stands for the name of the shell that will pop up when you open the terminal window.

TERM: These are the copies of the terminal window.

USER: It holds the name of the person who is using the system currently.

PWD: It is the path to the current working directory.

OLDPWD: It is the path between the old directory and the current working directory.

LS_COLORS: These are the list of colors to highlight different types of files.

MAIL: If there is any mail system set up on your system, this holds the path to the current user’s mailbox.

PATH: It is a list of directories that search through to find command executables.

What is Tab Completion?

Tab completion is a process to fill the variable name for you. Type whatever name you think is suitable and press ‘Tab’. The name of the variable will automatically be updated. If in any case, this doesn’t work, you’ll need to distinguish the environmental variable from other names that begin with the same letters.

To add to the environment variable, type a suitable name, and an ‘=’ sign without leaving any spaces before and after the sign. The name can contain numbers, letters, or an underscore (_) sign. Keep in mind that the first character of the name cannot be a number.  Avoid putting in spaces but if there are some, do not forget to close the quote with quotation marks (“).

Save the file and then you may log out whenever you want to.

Because of the variable is global, it is accessible to any whoever logs in next.

Shell Environment Variables

Some of the shell environmental variables used in bash record its behavior and functionality. Some values get updated while you use the system while others remain the same. For example, the COLUMNS the environment variable will be updated to reflect changes you might make to the width of the terminal window:

BASHOPTS: These are the command-line options that were used when bash was launched.

BASH_VERSION: It is a string of words and numbers.

BASH_VERSINFO: The bash version as a digit.

COLUMNS: It is the current width of the terminal window.

DIRSTACK: These are the directories that have been included in the directory stack by the push command.

HISTFILESIZE: These are the maximum number of lines added to the history file.

HISTSIZE: These are the number of lines of history allowed in memory.

HOSTNAME: It is the hostname of the system.

IFS: The stands for Internal Field Separator used to separate input on the command line. By default, this is a space.

PS1: The PS1 condition variable holds the definition for the essential, default, and order brief. A lot of tokens called to get away from successions can be remembered for the meaning of your order brief. They speak to such things as the host-and username, the present working index, and the time.

PS2: At the point when an order traverses more than one line and more information is normal, the auxiliary order brief has appeared. The PS2 condition variable holds the meaning of this auxiliary brief, which, naturally, is more prominent than sign (>).

SHELLOPTS: Shell options you can set using the settings option.

UID: It is the user identifier of the current user.

Creating Session Environment Variables

To create environment variables for your own use, you must add the extension ‘.bashrc’ when you save a file. In the event that you need to have the environment variables accessible to remote meetings, for example, SSH associations, you’ll have to add them to your .bash_profile document, also.

Remote Connections

Worldwide condition factors are open to remote login meetings, however on the off chance that you need your privately characterized condition factors accessible to you remotely, you should add them to your .bash_profile record. You can set a similar domain variable in the .bashrc and .bash_profile documents, with various qualities. This could be gotten by a content, say, to adjust its conduct for individuals utilizing the framework locally or remotely.

Gedit will be used to edit .bash_profile

Unsetting an Environment Variable

Unset command is used for the unsetting of an environment variable. Unsetting the global environment variable will make the command line unavailable.

A piece of important information to be noted here is these changes could only be seen by you in the session you’ve logged in while other global users who are logged in have access to it.

Environmental Control

Condition factors can be utilized to tell contents and applications on how they ought to carry on. They can be utilized to store settings or modest quantities of information. For instance, content can populate a domain with a worth that can be referenced by different contents without thinking of them to a document.

Mulesoft AnyPoint Studio Setup Scripted

Problem

You’re all excited to get started using Anypoint Studio 7. Then this little monster rears it’s ugly head.

Solution

Save the below to a file named Mulesoft_Setup.ps1

You will need to modify $javaDir to be your java install directory

You will need to modify $anypointStudioDir to be your Anypoint Studio 7 install directory

Run it with powershell -ExecutionPolicy ByPass -File…

Problem

Jenkins and building software tends to generate a lot of files. If you used the default install directory for windows, those files went to C:\Program Files (x86)\Jenkins . This is all well and good until the C drive starts running out of space. We can move the Jenkins HOME directory.

Solution

Backup using ThinBackup

Stop Jenkins service

Create new directory (e.g. E:\Jenkins)

Copy…

Set the environment variable RABBITMQ_BASE= to the desired directory. By default it goes to C:\Users\{user}\AppData\Roaming\RabbitMQ for the user that installed it not the current user.

Log out and log back in.

This makes sure the environment variable above is set

Check it by running set | find "RABBITMQ_BASE" in the command prompt

Download the latest RabbitMQ binary. You can use any version…

I run into a problem with setting up the ChromeDriver for sitespeed.io, I did not fully understood theinstallation instructions that was outlined in the ChromeDriverGetting started guide, mainly because I was unfamiliar with including the ChromeDriver location in my PATH environment variable on the MacBook that I’m using.. Don’t get me wrong, I’ve updated PATH variables on Windows for years but…

you can view all the current environment variables with

$ env $ env | grep SOMETHING

you can add new environment variables like so

$ export NAME=value

and remove them like this

$ unset NAME

this will only last for your session. if you want it to be always available, you need to declare it on startup. to do this, add the line into you ~/.bash_profile

a good scenario for wanting to do this might be to add a HTTP_PROXY you could do something like

$ vim ~/.bash_profile export HTTP_PROXY=user:[email protected]:8080 export HTTPS_PROXY=user:[email protected]:8080

시스템을 새로 설치하거나 library를 설치하면 환경변수를 새로 설정해야할 경우가 있습니다. 이 때 유용한 명령어가 바로 setx1 입니다.

setx /m Library C:\Users\[Account]\Documents\Libraries\ setx /m Armadillo ^%Library^%Armadillo\ setx /m Boost ^%Library^%Boost\ setx /m gtest ^%Library^%gtest\ setx /m OpenCV ^%Library^%OpenCV\ setx /m Path %Path%;^%Armadillo^%bin;^%OpenCV^%x64\vc12\bin;

위의 script는 실제로 제가 사용하는 batch 파일의 일부입니다. (저는 library를 사용자 계정 홈 디렉토리 아래에 Documents\Libraries에 설치하고 관리하고 있습니다.) /m 옵션은 시스템 환경변수로 추가하겠다는 의미입니다.

위 script가 하는 일은 다음과 같습니다.

library가 설치되는 기본 경로를 Library라는 시스템 환경변수로 등록

각각의 library에 대한 환경변수를 등록

Path에 각 library의 binary 또는 executable 파일 경로 추가