Can the glTF format be used for 3D printing? Can the glTF format be used for 3D printing?

If not, is there any tool can convert it to another format such as STL, OBJ, STEP, and IGES?
No, gltf is not a format that slicers accept commonly, and indeed, it is not even intended to be reverseable in the 1.0 format version. This has changed a little for the 2.0 standard. Some programs that allow exporting into the sliceable stl and  obj formats can also import gltf:


blender has an importer plugin - more  info here
SketchUpp has an importer plugin


You have to be careful though: formats like dae or stl are meant to transfer 3d objects usually without the loss of information or with just a minimal loss (stl, for example, does technically not contain a scale natively), while gltf is end users and does not contain all the information. This can lead to models getting distorted and destroyed on importing them into a rendering or modeling software.