_conda_pack_activate() {
    local _CONDA_SHELL_FLAVOR
    if [ -n "${BASH_VERSION:+x}" ]; then
        _CONDA_SHELL_FLAVOR=bash
    elif [ -n "${ZSH_VERSION:+x}" ]; then
        _CONDA_SHELL_FLAVOR=zsh
    elif [ -n "${KSH_VERSION:+x}" ]; then
        _CONDA_SHELL_FLAVOR=ksh
    elif [ -n "${POSH_VERSION:+x}" ]; then
        _CONDA_SHELL_FLAVOR=posh
    else
        # https://unix.stackexchange.com/a/120138/92065
        local _q="$(ps -p$$ -o cmd="",comm="",fname="" 2>/dev/null | sed 's/^-//' | grep -oE '\w+' | head -n1)"
        if [ "$_q" = dash ]; then
            _CONDA_SHELL_FLAVOR=dash
        else
            (>&2 echo "Unrecognized shell.")
            return 1
        fi
    fi

    # https://unix.stackexchange.com/questions/4650/determining-path-to-sourced-shell-script/
    local script_dir
    case "$_CONDA_SHELL_FLAVOR" in
        bash) script_dir="$(dirname "${BASH_SOURCE[0]}")";;
        zsh) script_dir="$(dirname "${(%):-%x}")";;  # http://stackoverflow.com/a/28336473/2127762
        dash) x=$(lsof -p $$ -Fn0 | tail -1); script_dir="$(dirname "${x#*n}")";;
        *) script_dir="$(cd "$(dirname "$_")" && echo "$PWD")";;
    esac

    local full_path_script_dir="$(cd "${script_dir}" > /dev/null && pwd)"
    local full_path_env="$(dirname "$full_path_script_dir")"
    local env_name="$(basename "$full_path_env")"

    # If there's already a source env
    if [ -n "$CONDA_PREFIX" ]; then
        # If the source env differs from this env
        if [ "$CONDA_PREFIX" != "$full_path_env" ]; then
            # Check whether deactivate is a function or executable
            type deactivate >/dev/null 2>/dev/null
            if [ $? -eq 0 ]; then
                . deactivate >/dev/null 2>/dev/null
            fi
        else
            return 0  # nothing to do
        fi
    fi
    export CONDA_PREFIX="$full_path_env"
    export _CONDA_PACK_OLD_PS1="$PS1"
    PATH="$full_path_env/bin:$PATH"
    PS1="($env_name) $PS1"

    case "$_CONDA_SHELL_FLAVOR" in
        zsh) rehash;;
        posh) ;;
        *) hash -r;;
    esac

    # Run the activate scripts
    local _script_dir="${full_path_env}/etc/conda/activate.d"
    if [ -d "$_script_dir" ] && [ -n "$(ls -A "$_script_dir")" ]; then
        local _path
        for _path in "$_script_dir"/*.sh; do
            . "$_path"
        done
    fi
}

_conda_pack_activate