Suggestion: `env` command to use in scripts

[lebdron]

asdf shell command sets an environment variable so that the same prompt can be used to call the right toolchain, while asdf direnv shell spawns a new shell or executes a command. This behavior makes it less convenient to use asdf direnv in scripts. The following is a workaround I currently use:

. "$HOME/.asdf/asdf.sh"
. "$HOME/.asdf/lib/utils.bash"
. "$HOME/.asdf/plugins/direnv/lib/tools-environment-lib.bash"

run_with_plugins() {
  while [ $# -gt 0 ]; do
    if [ "--" = "$1" ]; then
      shift
      break
    fi

    local plugin version

    plugin="$1"
    shift

    if [ $# -eq 0 ]; then
      log_error "Please specify a version for $plugin."
      exit 1
    fi
    version="$1"
    shift

    # log call removed

    # Set the appropriate ASDF_*_VERSION environment variable. This isn't
    # strictly necessary because we're not using shims, but it's nice because
    # it'll get `asdf current` to print out useful information, and if folks
    # have a special prompt configured (such as powerlevel10k), it'll know
    # about the newly activated tools.
    #
    # (this logic was copied from lib/commands/command-export-shell-version.bash)
    local upcase_name
    upcase_name=$(tr '[:lower:]-' '[:upper:]_' <<<"$plugin")
    local version_env_var="ASDF_${upcase_name}_VERSION"
    export "$version_env_var"="$version"

    # note that there is no `eval`
    _plugin_env_bash "$plugin" "$version" "$plugin $version not installed. Run 'asdf install $plugin $version' and try again."
  done
}

# example usage
eval "$(run_with_plugins rust 1.69.0)"
# `cargo` now available in the script, with the `bin` directory in PATH

The suggestion is to separate the logic with _plugin_env_bash from the current asdf direnv shell command so that it can be used separately, and reuse it in the current asdf direnv shell command.

[jfly]

This sounds like a great idea! I'd accept a PR implementing this.