Use environment variables with Azure AI services

This guide shows you how to set and retrieve environment variables to handle your Azure AI services subscription credentials in a more secure way when you test out applications.

Set an environment variable

To set environment variables, use one the following commands, where the ENVIRONMENT_VARIABLE_KEY is the named key and value is the value stored in the environment variable.

Command Line

Use the following command to create and assign a persisted environment variable, given the input value.

:: Assigns the env var to the value
setx ENVIRONMENT_VARIABLE_KEY "value"

In a new instance of the Command Prompt, use the following command to read the environment variable.

:: Prints the env var value
echo %ENVIRONMENT_VARIABLE_KEY%

PowerShell

Use the following command to create and assign a persisted environment variable, given the input value.

# Assigns the env var to the value
[System.Environment]::SetEnvironmentVariable('ENVIRONMENT_VARIABLE_KEY', 'value', 'User')

In a new instance of the Windows PowerShell, use the following command to read the environment variable.

# Prints the env var value
[System.Environment]::GetEnvironmentVariable('ENVIRONMENT_VARIABLE_KEY')

Bash

Use the following command to create and assign a persisted environment variable, given the input value.

# Assigns the env var to the value
echo export ENVIRONMENT_VARIABLE_KEY="value" >> /etc/environment && source /etc/environment

In a new instance of the Bash, use the following command to read the environment variable.

# Prints the env var value
echo "${ENVIRONMENT_VARIABLE_KEY}"

# Or use printenv:
# printenv ENVIRONMENT_VARIABLE_KEY

Tip

After you set an environment variable, restart your integrated development environment (IDE) to ensure that the newly added environment variables are available.

Retrieve an environment variable

To use an environment variable in your code, it must be read into memory. Use one of the following code snippets, depending on which language you're using. These code snippets demonstrate how to get an environment variable given the ENVIRONMENT_VARIABLE_KEY and assign the value to a program variable named value.

C#

For more information, see Environment.GetEnvironmentVariable .

using static System.Environment;

class Program
{
    static void Main()
    {
        // Get the named env var, and assign it to the value variable
        var value =
            GetEnvironmentVariable(
                "ENVIRONMENT_VARIABLE_KEY");
    }
}

C++

For more information, see getenv_s and getenv.

#include <iostream> 
#include <stdlib.h>

std::string GetEnvironmentVariable(const char* name);

int main()
{
    // Get the named env var, and assign it to the value variable
    auto value = GetEnvironmentVariable("ENVIRONMENT_VARIABLE_KEY");
}

std::string GetEnvironmentVariable(const char* name)
{
#if defined(_MSC_VER)
    size_t requiredSize = 0;
    (void)getenv_s(&requiredSize, nullptr, 0, name);
    if (requiredSize == 0)
    {
        return "";
    }
    auto buffer = std::make_unique<char[]>(requiredSize);
    (void)getenv_s(&requiredSize, buffer.get(), requiredSize, name);
    return buffer.get();
#else
    auto value = getenv(name);
    return value ? value : "";
#endif
}

Java

For more information, see System.getenv .

import java.lang.*;

public class Program {
   public static void main(String[] args) throws Exception {
    // Get the named env var, and assign it to the value variable
    String value =
        System.getenv(
            "ENVIRONMENT_VARIABLE_KEY")
   }
}

Node.js

For more information, see process.env .

// Get the named env var, and assign it to the value variable
const value =
    process.env.ENVIRONMENT_VARIABLE_KEY;

Python

For more information, see os.environ .

import os

# Get the named env var, and assign it to the value variable
value = os.environ['ENVIRONMENT_VARIABLE_KEY']

Objective-C

For more information, see environment .

// Get the named env var, and assign it to the value variable
NSString* value =
    [[[NSProcessInfo processInfo]environment]objectForKey:@"ENVIRONMENT_VARIABLE_KEY"];

Next steps

• Explore Azure AI services and choose a service to get started.