Problem

Using different shells in windows, making sure the same set of environment variables is shared between windows, powershell, git bash, commandshell and wsl, and thus stays consistent.

Possible Solutions

Sharing environment variables seamlessly across Windows (including CMD, PowerShell, GUI apps), Git Bash, and WSL is a common challenge due to the different ways these environments handle variables. Here’s a practical guide:

1. Set Environment Variables in Windows System

Best for: Sharing variables with Windows GUI apps, CMD, PowerShell, and (with some tweaks) Git Bash and WSL.

Steps:

Open Environment Variables Dialog:
- Press Win + S, type “environment variables”, and select Edit the system environment variables.
- Click Environment Variables….
Add/Edit Variables:
- Under “User variables” or “System variables”, click New… or select and Edit….
- Add your variable (e.g., MY_VAR=somevalue).
Apply and Restart:
- Click OK to save.
- You must restart any open terminals or apps for changes to take effect.

Effects:

Windows GUI apps: Yes
CMD: Yes
PowerShell: Yes
Git Bash: Yes (inherits from Windows)
WSL: Not automatic (see below)

2. Access Windows Environment Variables in WSL

By default, WSL does not import all Windows environment variables, but you can access them via /mnt/c/Windows/System32/cmd.exe or by configuring WSL.

Option A: Import Specific Variables

Add this to your ~/.bashrc or ~/.profile in WSL:

export MY_VAR=$(cmd.exe /C "echo %MY_VAR%" | tr -d '\r')

Repeat for each variable you want to import.

Option B: Import All User Variables Automatically

Add this snippet to your ~/.bashrc:

for var in VAR1 VAR2 VAR3; do  
  export $var=$(cmd.exe /C "echo %$var%" | tr -d '\r')  
done

Replace VAR1 VAR2 VAR3 with your variable names.

3. Make WSL Environment Variables Available to Windows

If you set variables in WSL and want them available to Windows apps, you need to export them using wslvar or set them in Windows as above.

4. Git Bash

Git Bash inherits environment variables from Windows at launch. If you set them via the Windows GUI, they’ll be available in Git Bash after a restart.

5. PowerShell & CMD

Both inherit from the Windows environment at launch. You can also set session-only variables:

$env:MY_VAR = "somevalue"

But for sharing across all environments, use the Windows GUI method.

Summary Table

Method	CMD	PowerShell	Git Bash	WSL	GUI Apps
Set via Windows GUI	✔️	✔️	✔️	➖*	✔️
Set in .bashrc (WSL)	➖	➖	➖	✔️	➖
Import from Windows in WSL				✔️

* Needs manual import as shown above.

Tips

Always restart terminals after changing environment variables.
For secrets, consider using a secrets manager instead of environment variables.
For project-specific variables, consider .env files with tools like direnv.

In summary:
Set your shared environment variables via the Windows Environment Variables dialog for maximum cross-environment compatibility. In WSL, import them explicitly in your shell profile if needed.

Automation script

I want a script to take environment variables out of my bashrc, have them in a text file, and use that as input for the windows gui setup

Great idea! Here’s a workflow and script to extract environment variables from your ~/.bashrc, save them to a text file, and prepare them for easy import into the Windows Environment Variables GUI.

1. Extract Environment Variables from `~/.bashrc`

Suppose your ~/.bashrc contains lines like:

export MY_VAR1="value1"  
export MY_VAR2='value2'  
export PATH="$PATH:/my/custom/path"

We want to extract all export VAR=VALUE lines (excluding PATH if you wish), and write them as VAR=VALUE pairs in a text file.

Bash Script:

#!/bin/bash  
  
# Path to your bashrc  
BASHRC=~/.bashrc  
  
# Output file  
OUTFILE=~/env_vars_for_windows.txt  
  
# Extract export lines, ignore PATH, remove 'export', handle quotes  
grep '^export ' "$BASHRC" | \  
  grep -v '^export PATH=' | \  
  sed -E 's/^export ([A-Za-z_][A-Za-z0-9_]*)=(.*)$/\1=\2/' | \  
  sed -E 's/^([A-Za-z_][A-Za-z0-9_]*)=["'\'']?(.*?)["'\'']?$/\1=\2/' \  
  > "$OUTFILE"  
  
echo "Extracted environment variables to $OUTFILE"

How it works:

Finds lines starting with export
Skips the PATH
Removes the export keyword
Strips surrounding quotes

2. Format for Windows GUI Import

The Windows GUI expects variables as name/value pairs.
Open the generated env_vars_for_windows.txt, and for each line:

MY_VAR1=value1  
MY_VAR2=value2

You can copy-paste each pair into the Windows Environment Variables dialog:

Variable name: MY_VAR1
Value: value1

3. (Optional) CSV Format for Bulk Import

If you want to prepare a CSV for PowerShell bulk import or documentation:

awk -F= '{print $1 "," $2}' "$OUTFILE" > ~/env_vars_for_windows.csv

4. Automate Windows Import (Advanced)

If you want to automate setting these in Windows (instead of manual GUI entry), you can use PowerShell:

PowerShell Script Example:

# Save as set_env_vars.ps1  
Get-Content env_vars_for_windows.txt | ForEach-Object {  
    $parts = $_ -split '=', 2  
    [Environment]::SetEnvironmentVariable($parts[0], $parts[1], "User")  
}

Run this in PowerShell after copying the txt file to Windows.

Summary

Run the bash script above in WSL or Git Bash.
Open the resulting text file.
Copy each variable into the Windows Environment Variables dialog, or use PowerShell for automation.

Let me know if you want a ready-to-use script for any step, or further automation!

I want a fully integrated script E2E to keep them in sync, for the powershell, what happens if it already exists ?

Absolutely! Here’s a fully integrated, end-to-end solution to keep your environment variables in sync between your ~/.bashrc (Linux/WSL/Git Bash) and Windows (PowerShell, CMD, GUI apps). This solution:

Extracts variables from ~/.bashrc
Exports them to a text file
Transfers the file to Windows (if running from WSL)
Runs a PowerShell script to set/update Windows user environment variables
Handles existing variables (updates them)
Can be run repeatedly to keep things in sync

🟢 E2E Sync Script: Bash + PowerShell

1. Bash Script (`sync_env_to_windows.sh`)

This script:

Extracts all export VAR=VALUE lines from your ~/.bashrc (excluding PATH)
Writes them as VAR=VALUE pairs to a file
Copies the file to your Windows home directory (if running in WSL)
Optionally invokes the PowerShell script automatically

#!/bin/bash  
  
set -e  
  
# 1. Extract environment variables from ~/.bashrc  
BASHRC="$HOME/.bashrc"  
OUTFILE="$HOME/env_vars_for_windows.txt"  
  
grep '^export ' "$BASHRC" | \  
  grep -v '^export PATH=' | \  
  sed -E 's/^export ([A-Za-z_][A-Za-z0-9_]*)=(.*)$/\1=\2/' | \  
  sed -E 's/^([A-Za-z_][A-Za-z0-9_]*)=["'\'']?(.*?)["'\'']?$/\1=\2/' \  
  > "$OUTFILE"  
  
echo "Extracted environment variables to $OUTFILE"  
  
# 2. Copy file to Windows home if running in WSL  
if grep -qi microsoft /proc/version; then  
    WIN_HOME=$(wslpath "$(cmd.exe /c "<nul set /p=%UserProfile%" 2>/dev/null | tr -d '\r')")  
    cp "$OUTFILE" "$WIN_HOME\\env_vars_for_windows.txt"  
    echo "Copied env_vars_for_windows.txt to $WIN_HOME"  
    POWERSHELL_PATH="powershell.exe"  
else  
    echo "Not running in WSL, skipping copy."  
    POWERSHELL_PATH="powershell"  
fi  
  
# 3. Optionally invoke PowerShell script automatically  
echo "To update Windows environment variables, run:"  
echo "    $POWERSHELL_PATH -ExecutionPolicy Bypass -File set_env_vars.ps1"

2. PowerShell Script (`set_env_vars.ps1`)

This script:

Reads the env_vars_for_windows.txt
Sets/updates each variable as a User environment variable
If the variable already exists, it is updated (overwritten)
Notifies you of each change

# set_env_vars.ps1  
$envFile = "$HOME\env_vars_for_windows.txt"  
if (!(Test-Path $envFile)) {  
    Write-Error "File not found: $envFile"  
    exit 1  
}  
  
Get-Content $envFile | ForEach-Object {  
    if ($_ -match '^([A-Za-z_][A-Za-z0-9_]*)=(.*)$') {  
        $name = $matches[1]  
        $value = $matches[2]  
        # Set or update user environment variable  
        [Environment]::SetEnvironmentVariable($name, $value, "User")  
        Write-Host "Set $name=$value"  
    }  
}  
Write-Host "`nDone. You may need to restart your terminal or log out/in for changes to take effect."

What happens if the variable already exists?

The value is updated (overwritten) with the new value from your bashrc.

3. How To Use

A. Place both scripts in your home directory.

B. Run the Bash script from WSL or Git Bash:

bash sync_env_to_windows.sh

C. Run the PowerShell script from Windows:

powershell -ExecutionPolicy Bypass -File set_env_vars.ps1

Or, if you’re in WSL:

powershell.exe -ExecutionPolicy Bypass -File set_env_vars.ps1

4. Notes & Tips

Restart required: After updating env vars, restart terminals/apps for changes to take effect.
Sync direction: This syncs from bashrc → Windows. For two-way sync, more scripting is needed.
Secrets: Don’t store secrets in plain text files or bashrc.
Project-specific: For project-specific vars, consider .env files and tools like direnv.

5. Advanced: Make It Automatic

You can add the Bash script as a function or alias in your shell profile and run it whenever you update your bashrc.

6. Troubleshooting

If you get permission errors on PowerShell, use Run as Administrator or adjust Execution Policy.

🚀 Summary Table

Step	Tool	Effect on Existing Vars
Extract from bashrc	Bash/WSL	N/A
Set in Windows	PowerShell	Overwrites/updates

Let me know if you want a two-way sync or further automation!

ThirdBrAIn.tech

Explorer

How to share environment variables across environments in windows