I have been using my MacBook a lot now that it is my main computer at work. So much so that I found it necessary to invert my scroll wheel on my mouse on my windows desktop to behave like my MacBook. I've also been using
While in the process of writing the scripts to configure my bash environment on my Windows machine, I found the need to be able to access environment variables that are set in Windows. With WSL, the only environment variables that really come over to bash is PATH.
I googled around for a bit, but didn't find any way to actually do this. Then I remembered that WSL has interop between Windows and WSL. This means that I can execute a Windows executable and redirect the output back to bash. Which means I should be able to execute powershell.exe to get the information I need.
I first started with a test of just doing:
$ echo $(powershell.exe -Command "gci ENV:")
And that gave me what I wanted back. Now there are some differences in the paths between WSL and Windows, so I knew I would also have to adjust for that.
What I did was put a file called ~/.env.ps1 in my home path.
#!~/bin/powershell
# Will return all the environment variables in KEY=VALUE format
function Get-EnvironmentVariables {
return (Get-ChildItem ENV: | foreach { "WIN_$(Get-LinuxSafeValue -Value ($_.Name -replace '\(|\)','').ToUpper())=$(Convert-ToWSLPath -Path $_.Value)" })
}
# converts the C:\foo\bar path to the WSL counter part of /mnt/c/foo/bar
function Convert-ToWSLPath {
param (
[Parameter(Mandatory=$true)]
$Path
)
(Get-LinuxSafeValue -Value (($Path -split ';' | foreach {
if ($_ -ne $null -and $_ -ne '' -and $_.Length -gt 0) {
(( (Fix-Path -Path $_) -replace '(^[A-Za-z])\:(.*)', '/mnt/$1$2') -replace '\\','/')
}
} ) -join ':'));
}
function Fix-Path {
param (
[Parameter(Mandatory=$true)]
$Path
)
if ( $Path -match '^[A-Z]\:' ) {
return $Path.Substring(0,1).ToLower()+$Path.Substring(1);
} else {
return $Path
}
}
# Ouputs a string of exports that can be evaluated
function Import-EnvironmentVariables {
return (Get-EnvironmentVariables | foreach { "export $_;" }) | Out-String
}
# Just escapes special characters
function Get-LinuxSafeValue {
param (
[Parameter(Mandatory=$true)]
$Value
)
process {
return $Value -replace "(\s|'|`"|\$|\#|&|!|~|``|\*|\?|\(|\)|\|)",'\$1';
}
}Now in my `.bashrc` I have the following:
#!/usr/bin/env bash source ~/.wsl_helper.bash eval $(winenv)
If I run env now, I get output like the following:
WIN_ONEDRIVE=/mnt/d/users/rconr/onedrive PATH=~/bin:/foo:/usr/bin WIN_PATH=/mnt/c/windows:/mnt/c/windows/system32
Notice the environment variables that are prefixed with WIN_? These are environment variables directly from Windows. I can now add additional steps to my .bashrc using these variables.
ln -s "$WIN_ONEDRIVE" ~/OneDrive
Additionally, I added a script to my
~/bin folder that is in my path called powershell. This will allow me to make "native" style calls to powershell from within bash scripts.
#!/usr/bin/env bash
# rename to `powershell`
# chmod +x powershell
. ~/.wsl_helper.bash
PS_WORKING_DIR=$(lxssdir)
if [ -f "$1" ] && "$1" ~= ".ps1$"; then
powershell.exe -NoLogo -ExecutionPolicy ByPass -Command "Set-Location '${PS_WORKING_DIR}'; Invoke-Command -ScriptBlock ([ScriptBlock]::Create((Get-Content $1))) ${*:2}"
elif [ -f "$1" ] && "$1" ~!= "\.ps1$"; then
powershell.exe -NoLogo -ExecutionPolicy ByPass -Command "Set-Location '${PS_WORKING_DIR}'; Invoke-Command -ScriptBlock ([ScriptBlock]::Create((Get-Content $1))) ${*:2}"
else
powershell.exe -NoLogo -ExecutionPolicy ByPass ${*:1}
fi
unset PS_WORKING_DIRIn the powershell file, you will see a call to source a file called .wsl_helper.bash. This script has some helper functions that will do things like transform a path from a Windows style path to a linux WSL path, and do the opposite as well.
#!/usr/bin/env bash
# This is the translated path to where the LXSS root directory is
export LXSS_ROOT=/mnt/c/Users/$USER/AppData/Local/lxss
# translate to linux path from windows path
function windir() {
echo "$1" | sed -e 's|^\([a-z]\):\(.*\)|/mnt/\L\1\E\2|' -e 's|\\|/|g'
}
# translate the path back to windows path
function wsldir() {
echo "$1" | sed -e 's|^/mnt/\([a-z]\)/\(.*\)|\U\1\:\\\E\2|' -e 's|/|\\|g'
}
# gets the lxss path from windows
function lxssdir() {
if [ $# -eq 0 ]; then
if echo "$PWD" | grep "^/mnt/[a-zA-Z]/" > /dev/null 2>&1; then
echo "$PWD";
else
echo "$LXSS_ROOT$PWD";
fi
else
echo "$LXSS_ROOT$1";
fi
}
function printwinenv() {
_winenv --get
}
# this will load the output exports of the windows envrionment variables
function winenv() {
_winenv --import
}
function _winenv() {
if [ $# -eq 0 ]; then
CMD_VERB="Get"
else
while test $# -gt 0; do
case "$1" in
-g|--get)
CMD_VERB="Get"
shift
;;
-i|--import)
CMD_VERB="Import"
shift
;;
*)
CMD_VERB="Get"
break
;;
esac
done
fi
CMD_DIR=$(wsldir "$LXSS_ROOT$HOME/\.env.ps1")
echo $(powershell.exe -Command "Import-Module -Name $CMD_DIR; $CMD_VERB-EnvironmentVariables") | sed -e 's|\r|\n|g' -e 's|^[\s\t]*||g';
}
