For example,
$ NIX_REMOTE=file:///my-cache nix ls-store -lR /nix/store/f4kbgl8shhyy76rkk3nbxr0lz8d2ip7q-binutils-2.23.1
dr-xr-xr-x 0 ./bin
-r-xr-xr-x 30748 ./bin/addr2line
-r-xr-xr-x 66973 ./bin/ar
...
Similarly, "nix ls-nar" lists the contents of a NAR file, "nix
cat-nar" extracts a file from a NAR file, and "nix cat-store" extract
a file from a Nix store.