With this script you select your texture and then material (no matter whether it is already connected or not) and then execure the script to add a gamma correct node added between your texture and materia. No matter how expensive is your shader, so safe is the material that it would add a gamma node without any damage to your existing connections.
Risk at your own use :D
no Use at your own risk.

It is very useful for the project that you have many built networks, and you find the need of Gamma Node to go through all the existing connection, so it would be too hard to add a connection between many already made connections.
Look! first select the texture and then the material, ignore if there is any connection made to color/diffuse channel. all Maya materials as well as mia_material are supported.

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