是否需检测.vim/autoload/plug.vim存在再运行？Vim配置相关疑问

Let's break down exactly what this setup does, step by step:

1. The Detection Code's Role #

This block exists to guarantee Vim has the vim-plug plugin manager ready before loading any plugins—since every Plug '...' line later in your config relies entirely on vim-plug to work. Here's the play-by-play:

• First, it checks if ~/.vim/autoload/plug.vim (vim-plug's core script) is readable. If the file exists, we're good to go—Vim skips the install logic and moves straight to processing your plugin declarations.
• If that file is missing, it next verifies if the curl command is available on your system (vim-plug uses curl to automatically download its own installation script).
  • If curl isn't found, it throws a warning telling you to either install curl or manually set up vim-plug, then exits Vim. This prevents messy errors later, because without vim-plug, Vim won't recognize the Plug command at all.
  • If curl is available, it runs the download command to fetch the vim-plug script and save it to the correct autoload directory. Then it sets the g:not_finish_vimplug variable (a flag to track that vim-plug was just installed) and adds the VimEnter autocmd we'll cover next.

2. What autocmd VimEnter * PlugInstall Does #

This automatic command finishes the setup after a fresh vim-plug installation:

• autocmd is Vim's system for running commands automatically when specific events occur.
• VimEnter is the event that triggers after Vim has fully started up—meaning all your config files are loaded, and you're at the main editing interface.
• The * is a wildcard that ensures this autocmd applies no matter which file (or no file) you opened when launching Vim.
• PlugInstall is a vim-plug command that scans all your Plug '...' declarations, downloads each plugin to the correct directory in ~/.vim/plugged/, and handles any initial setup (like compiling plugin binaries if needed).
• Tying this to VimEnter is critical: when we first install vim-plug during startup, Vim hasn't yet parsed all the Plug lines in your config. Waiting until Vim fully loads ensures all plugin declarations are recognized, so PlugInstall can install every plugin you've listed in one go.

内容的提问来源于stack exchange，提问作者user9861429