Usage 1: 3drename old_prefix new_prefix
  Will rename all datasets using the old_prefix to use the new_prefix;
    3drename fred ethel
  will change fred+orig.HEAD    to ethel+orig.HEAD
              fred+orig.BRIK    to ethel+orig.BRIK
              fred+tlrc.HEAD    to ethel+tlrc.HEAD
              fred+tlrc.BRIK.gz to ethel+tlrc.BRIK.gz

Usage 2: 3drename old_prefix+view new_prefix
  Will rename only the dataset with the given view (orig, acpc, tlrc).

You cannot have paths in the old or the new prefix

++ Compile date = May  7 2021 {AFNI_21.1.06:linux_ubuntu_16_64}