I need to put in concrete bases under my porch posts so the posts are above ground. Is there an adjustable metal foot for this purpose? I don't want to replace the posts, just cut them off and anchor to the conrete bases.
Thanks,

Do youn already have cement footings poured for the posts? If yes then proper cutting is all that's needed. There should not be a need for adjustment if footers were done correctly

No, the posts are currently in the ground. The neighborhood including my propery has termites, that's why I need to get the post above ground.

You will have difficulty digging afooting directly where the post currently sit. You could go off to the side and set up a single temporary support, remove/cut the post and then dig a footer to your frost line. This will only lessen your chance of termintes, they are quite mobile. You could also spray or bait for them.

Yes, I understand all of that, my original question was, is there some type of adjustable metal anchor I can place on top of the new concrete footing (above ground level) to fasten the cut off post to?
Thanks,

Yes there are a number of metal brackets available for anchoring the base of a post. Look in the metal ties and brackets section (usually next to lumber) in Home Depot or Lowe's. These are not likely to be adjustable. You just have to cut the post to the correct length.
However, if your current posts are in the ground they almost have to be made of pressure treated material. Termites will not attack treated material.

Best approach is probably to:

Temporarily support porch,
Cut of post about 2 to 3' above ground,
Pour concrete pads,
Cut new section of post to fit between pad and upper section of post,
Anchor to pad and using a lap joint bolt to upper post,
Wrap post with a decorative piece of material covering joint.

Thank you, that sounds like a good way to go.