if [ -n "$HOME" ] && [ -n "$USER" ]; then

    # Set up the per-user profile.
    # This part should be kept in sync with nixpkgs:nixos/modules/programs/shell.nix

    NIX_LINK=$HOME/.nix-profile

    NIX_USER_PROFILE_DIR=@localstatedir@/nix/profiles/per-user/$USER

    # Append ~/.nix-defexpr/channels to $NIX_PATH so that <nixpkgs>
    # paths work when the user has fetched the Nixpkgs channel.
    export NIX_PATH=${NIX_PATH:+$NIX_PATH:}$HOME/.nix-defexpr/channels

    # Set up environment.
    # This part should be kept in sync with nixpkgs:nixos/modules/programs/environment.nix
    export NIX_PROFILES="@localstatedir@/nix/profiles/default $HOME/.nix-profile"

    # Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
    if [ -e /etc/ssl/certs/ca-certificates.crt ]; then # NixOS, Ubuntu, Debian, Gentoo, Arch
        export NIX_SSL_CERT_FILE=/etc/ssl/certs/ca-certificates.crt
    elif [ -e /etc/ssl/ca-bundle.pem ]; then # openSUSE Tumbleweed
        export NIX_SSL_CERT_FILE=/etc/ssl/ca-bundle.pem
    elif [ -e /etc/ssl/certs/ca-bundle.crt ]; then # Old NixOS
        export NIX_SSL_CERT_FILE=/etc/ssl/certs/ca-bundle.crt
    elif [ -e /etc/pki/tls/certs/ca-bundle.crt ]; then # Fedora, CentOS
        export NIX_SSL_CERT_FILE=/etc/pki/tls/certs/ca-bundle.crt
    elif [ -e "$NIX_LINK/etc/ssl/certs/ca-bundle.crt" ]; then # fall back to cacert in Nix profile
        export NIX_SSL_CERT_FILE="$NIX_LINK/etc/ssl/certs/ca-bundle.crt"
    elif [ -e "$NIX_LINK/etc/ca-bundle.crt" ]; then # old cacert in Nix profile
        export NIX_SSL_CERT_FILE="$NIX_LINK/etc/ca-bundle.crt"
    fi

    if [ -n "${MANPATH-}" ]; then
        export MANPATH="$NIX_LINK/share/man:$MANPATH"
    fi

    export PATH="$NIX_LINK/bin:$PATH"
    unset NIX_LINK NIX_USER_PROFILE_DIR
fi