Can Legendary be used to install and update Unreal Engine on Windows?

[LRSFC-DanJ]

Epic's idea of academic deployment of Unreal Engine on multiple classroom machines is "use the Launcher to install it on one machine, then mirror that machine to the rest of your machines. Or, you can signup for our GitHub and compile it yourself". This doesn't work well for us as we haven't used mirroring/imaging as a process for deployment for many years now, and we don't have the resources or time to compile the software ourselves every time there is an update.

As far as I can tell Epic's Launcher doesn't provide any way to automate or script installations, but it looks like Legendary does.

So my question is, can Legendary be used to install/update Unreal Engine? On Windows specifically would be our interest.

[derrod]

Yes, by default UE is not included in the list, but the --inckude-ue flag will show you available versions that you can install. Be aware though that legendary does not currently support selective downloads for UE, so it would download everything which is larger than what you'd get with the epic launcher.

This can be worked around via the config and checking the install tags for the parts you need after doing an install via the Epic Launcher first. I believe updating should work fine with that as well (within one release, e.g. 4.26).

However since different engine releases (e.g. 4.25 and 4.26) are different products on the platform, updating from one to another is not possible and you would have to re-download the new release from scratch.

Better UE and also UE Marketplace support is on my todo list for the future, if you have any specific things that you're missing please leave some feedback.

[derrod]

Items without an install tags should work by also specifying the empty install tag via --install-tag ""

[LRSFC-DanJ]

Excellent. It looks like the following set of --install-tags produces a set of files and folders that seems identical to the one produced by the Epic Games Launcher:

starter_content
templates
engine_source
platform_Android
platform_IOS
platform_Linux
""

I can then store this somewhere central and just use a script to robocopy it out to my target classroom machines.

[codecat]

They released Unreal Engine 5 Early Access. Is this installable via Legendary? I don't see it in the list when doing list-games --include-ue. The install URL on their site points to com.epicgames.launcher://ue/ue5ea.

[derrod]

You first have to add it to your account, which I'm not sure is currently possible via the website. So unfortunately you'll have to run the official launcher at least once to get it on your account.

[codecat]

Unfortunate, but that worked! It now shows up as:

UE5 Early Access (App name: UE_5.0EA | Version: 5.0.0-16433597+++UE5+Release-5.0-EarlyAccess-Windows)

[danj2k]

On a slight tangent, I've just noticed that it's possible to use the Windows version of Legendary to download stuff that's intended for the Mac platform by specifying --platform Mac, but how do you deal with the permissions issue? I can see the manifest contains flags like bIsUnixExecutable, are there any options for list-files that also output what permissions are required for each file? As this would also solve my problems in finding a way to deploy it to our Macs as well.

Also an update on the Windows situation, I was able to successfully deploy the Windows version of Unreal Engine 4.26.1 to a classroom of 24 machines using the set of files and folders Legendary downloaded.

[derrod]

The json output to list-files contains the flags property, if a file is supposed to be an executable the flag will be >= 4 (or is_executable = flag & 0x4). That is because the newer manifest format uses a combined flags field.

[LRSFC-DanJ]

Is there an explanation anywhere of what the various flags are? I can also see entries with flags values of 1, 2, 3, and 5 when I do legendary.exe list-files UE_4.26 --platform Mac --json --install-tag "starter_content" --install-tag "templates" --install-tag "engine_source" --install-tag "platform_Android" --install-tag "platform_IOS" --install-tag "platform_Linux" --install-tag "" > UE_4_26-Mac.json.

EDIT: nevermind, I found it:

    @property
    def read_only(self):
        return self.flags & 0x1

    @property
    def compressed(self):
        return self.flags & 0x2

    @property
    def executable(self):
        return self.flags & 0x4

I guess I don't need to care about things being compressed? So read-only is probably the only other one I need to worry about. And I assume by extension that means that anything that's not specifically read-only should be read-write?

So to check I've got this right, here's what I'm thinking:

flags == 0 means chmod 666
flags == 1 means chmod 644
flags == 2 means chmod 666
flags == 3 means chmod 644
flags == 4 means chmod 777
flags == 5 means chmod 755

Does that seem correct?

[derrod]

Seems correct, I don't know how the Mac version of the EGS handles file permissions since I never looked into it.