Overcoming the 1024 character limit with setx

Question

I am trying to set environment variables using the setx command, such as follows

setx PATH "f:\common tools\git\bin;f:\common tools\python\app;f:\common tools\python\app\scripts;f:\common tools\ruby\bin;f:\masm32\bin;F:\Borland\BCC55\Bin;%PATH%"

However, I get the following error if the value is more then 1024 characters long:

WARNING: The data being saved is truncated to 1024 characters.

SUCCESS: Specified value was saved.

But some of the paths in the end are not saved in variable, I guess due to character limit as the error suggests.

Solution 1

Your best bet is to edit the registry directly.

Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Environment and edit the Path value (then reboot to activate the new value).

Note however that while you can enter a very long path, (up to the maximum environment variable length; 2,048 or 32,768 bytes depending on the source), not all software will be able to read and handle it correctly if it is too long.

Solution 2

if you are using windows vista or higher, you can make a symbolic link to the folder. for example:

mklink /d C:\pf "C:\Program Files"
mklink /d C:\pf86 "C:\Program Files (x86)"

would make a link so c:\pf would be your program files folder. I shaved off 300 characters from my path by using this trick.

(I know it's not related to setx but it is useful for people which are searching overcomming on 1024 char limit)

Solution 3

You could use a PowerShell script similar to the following:

$newPath = 'F:\common tools\git\bin;F:\common tools\python\app;F:\common tools\python\app\scripts;F:\common tools\ruby\bin;F:\masm32\bin;F:\Borland\BCC55\Bin'
$oldPath = [Environment]::GetEnvironmentVariable('PATH', 'Machine');
[Environment]::SetEnvironmentVariable('PATH', "$newPath;$oldPath",'Machine');

The Environment.SetEnvironmentVariable() API call will broadcast WM_SETTINGCHANGE so you do not need to reboot.

Solution 4

This open-source SetEnv command-line tool is good to edit the PATH and other environment variables without limitations. It uses a dynamic buffer so no static limitations like 1024.

http://www.codeproject.com/Articles/12153/SetEnv

The choice of a % as a prefix to append to a variable could have been better though, as makes the syntax difficult sometimes if used with other batch local variables...

Solution 5

A far superior tool than setx for path manipulation is pathed.exe. Unfortunately, it's limited to editing the path.

In addition to a superior user experience than setx, you don't have a 1024 character limit. Unlike direct registry manipulation, this application uses the Environment.SetEnvironmentVariable() API call which will broadcast WM_SETTINGCHANGE.

View more solutions

Comments

[John Alexiou]

Look into Rapid Environment Editor which allows you to edit all envirnoment variables graphically (you can also save a backup also).

[Chad Schouggins]

Is anyone else bother by this claiming success when it clearly does not do what was requested? Is it not troubling that this doesn't fail while leaving the path exactly how it was?

[cowlinator]

Does this still truncate on windows 10?

[Ivan]

Yes, it does on Windows 10

[dkocich]

it still does on windows 1909

[Beliaev Maksim]

For windows I can recommend a module to set variables through registry in Python. Also has CLI app: github.com/beliaev-maksim/py_setenv this has good control on user/system level and does not have limit in length as setx

[domih]

setx is the worst as it destroys your applications which depend on path, so use the powershell one-liner described in a comment by @mark-c below like so: powershell.exe -NoProfile -ExecutionPolicy Bypass -Command "[Environment]::SetEnvironmentVariable('path',\"%newPath%;$(‌​[Environment]::GetEn‌​vironmentVariable('p‌​ath','Machine'))\",'‌​Machine');"

[Madhur Ahuja]

Is reboot really required here ? How does setx do it ? Setx does not require reboot.

[Synetech]

Yes, a reboot is required. setx edits the registry as I indicated, then broadcasts a WM_SETTINGCHANGE message. This tells all top-level windows that a system setting has changed (in this case an environment variable). Without that, Explorer and programs you opened with it will not know about the change. You could broadcast the message yourself manually (I wrote a program to do just that, and a batch file to replace SETX that makes a registry edit followed by the broadcast), but just like setx and the System Properties envvar dialog, it has side-effects that make rebooting preferable.

[Madhur Ahuja]

Can you share your program with me ? I will be very useful.

[Synetech]

I suppose, but like I said, it won’t help. It has the same effects that setx and the Env-Var dialog do. It notifies the system that the vars. have changed, but they don’t actually take effect until you restart them. In other words, you have to exit and re-run every program that you want to know about the change. Is there a reason you can’t reboot? Can the longer path wait until you can?

[Synetech]

Oh and editing an env.var. actually causes problems if you don’t reboot because any environment variables that contain other variables will stop being expanded. For example, I just broadcast it and now this is my path and I get an error because the path is now “broken”/empty. None of the vars will expand properly again until I reboot. Unfortunately this is “normal”. :-|

[Justin Dearing]

I found a small PowerShell script that will broadcast the WM_SETTINGCHANGE message.

[Synetech]

> SetEnv tool is good to edit the PATH and other environment variables without limitations Indeed. In fact, I had personally worked with Darka on that page to help make SetEnv even better so that it can fully support expanding/sub-variables (the Dynamic Variable Expansion section), which actually helps to reduce the length of the raw path.

[Art]

You can use the above registry method via the REG add command and then use SETX to set some other variable to itself (ie: SETX /M USERNAME %USERNAME%). This will cause the WM_SETTINGCHANGE message to be set and give your the ability to set the path from a batch file.

[Fedor Alexander Steeman]

Don't you also need the following line: [Environment]::SetEnvironmentVariable('path', "$newPath",'Machine');

[Ehtesh Choudhury]

There's a list of other tools (including pathed.exe) at superuser.com/questions/297947/is-there-a-convenient-way-to-‌​edit-path-in-windows‌​-7

[G-Man Says 'Reinstate Monica']

Can you explain a bit more about what you are suggesting here?

[Fantastory]

It is just a ready to use command to workaround setx 1024 character limit. Example is shown directly on PATH variable. Although the previous answers are helpful they lack a final solution.

[twasbrillig]

In the 3rd line, I'm not sure what benefit the extra dollar signs and parentheses bring. Couldn't you just say [Environment]::SetEnvironmentVariable('path', "$newPath;$oldPath",'Machine') ?

[Justin Dearing]

@twasbrillig I'm just careful when I'm including a variable in a string. in this case its unecessary.

[Andrew Morton]

Be careful if you have used fsutil.exe behavior set disable8dot3 1.

[Andrew Steitz]

@AndrewMorton good point but wouldn't that be "handled" by the fact that the script doesn't "generate" the 8.3 name, it just reports the 8.3 name that the file system assigned? So if a folder did not have an 8.3 name, the script would not propose a substitute. However, using fsutil 8dot3name strip AFTER using the script would definitely cause problems for affected folders.

[Andrew Morton]

Unfortunately I don't have a spare drive or system to check it on. However, having used some fsutil 8dot3name strip earlier today and considering that (a) it checks the registry first and (b) the path is stored in the registry, my earlier concern may be unwarranted, as long as the user does not use the /f (force) option.

[Braden Best]

What about the dialog box that allows you to set %PATH%? Editing the registry seems a bit extreme.

[Shital Shah]

For current user, use HKEY_CURRENT_USER\Environment

[Mark C]

You can call this from an Administrator Command Prompt: @"%SystemRoot%\System32\WindowsPowerShell\v1.0\powershell.ex‌​e" -NoProfile -ExecutionPolicy Bypass -Command "[Environment]::SetEnvironmentVariable('path',\"C:\Program Files (x86)\GNU\GnuPG;$([Environment]::GetEnvironmentVariable('pat‌​h','Machine'))\",'Ma‌​chine');"

[Ivan]

Link is now broken

[Eugene Petrov]

WARNING! This possibly will break things, it will write %path%;c:\...[snip]...\7z to the user path variable, dropping anything else you had there.

[AnnanFay]

The PATH environment variable used by programs is a combination of the machine and local PATH variables. In addition to destroying the current data in the local path I don't think this does anything. Having %path% in the local path environment variable should have no effect.

[Smart Manoj]

superuser.com/questions/297947/…

[Ekrem Dinçel]

@JustinDearing the link is broken, may you update it?

[Synetech]

@EkremDİNÇEL, it's archived in the Wayback Machine.

[Admin]

No reboot required. I did this and restarting the command prompt window, all variables are initialized. No reboot.

[Synetech]

@BosnianCoder, it depends on how you start the command-prompt. If you start it from Explorer, then it will/*should* have the new data. But if you run it from another program like if you have Task Manager running in the tray, or in my case, I use AutoHotkey to open a command prompt using a hotkey, then it won't work until you re-run that program (for some reason, either broadcasting WM_SETTINGCHANGE isn't working, or setx just doesn't do it right 🤷). Either way, saying to reboot is a blanket step to cover all scenarios.

[Amit Naidu]

Useful when you are an administrator. For the rest of us: You do not have sufficient privilege to perform this operation. In a pinch,subst can do something similar.

[Amit Naidu]

System path and user path are separate for a reason. This combines them and puts everything in the system path. That is a major change to the environment behavior and is not expected by a user who is just looking to add something to their user path variable.