since I switch between linux and macos a lot I wrote a dotfile function called "clip" that will work the same on both. nice thing is it will automatically paste if nothing is piped to it to copy so there's no need to use separate commands... although I just realized it might be nice to have a "passthrough" mode that both copies and pastes if you add this to a pipeline in order to capture some intermediate part to the clipboard

    if [[ "$(uname)" == "Darwin" ]]; then
      clip() {
        [ -t 0 ] && pbpaste || pbcopy
      }
    else # assume linux if not macos
      clip() {
        [ -t 0 ] && xclip -o -selection clipboard || xclip -selection clipboard
      }
    fi