安装vue脚手架成功的标志是什么

安装 Vue 脚手架成功的标志是在命令行工具中输入 `vue` 命令后，能够正确输出 Vue 脚手架的帮助信息。如果安装成功，你应该能够看到类似下面这样的输出：

Usage: vue <command> [options]

Options:
  -V, --version               output the version number
  -h, --help                  output usage information

Commands:
  create [options] <app-name> create a new project powered by vue-cli-service
  add [options] <plugin>      install a plugin and invoke its generator in an already created project
  invoke <plugin>             invoke the generator of a plugin in an already created project
  inspect [options] [paths...] inspect the webpack config in a project with vue-cli-service
  serve [options] [entry]     serve a .js or .vue file in development mode with zero config
  build [options] [entry]     build a .js or .vue file in production mode with zero config
  ui [options]                start and open the vue-cli ui
  init <template> <app-name>  generate a project from a remote template (legacy API, requires @vue/cli-init)
  config [value]              inspect and modify the config
  outdated [options]          (experimental) check for outdated vue-cli plugins and upgrade prompts

如果你看到了类似的输出，那么就说明 Vue 脚手架已经成功安装了。