Emacs自动缩进及括号匹配高亮功能失效问题求助

Hey there, sorry to hear your go-to Emacs setup went off the rails after your time away—let’s work through these glitches step by step.

Auto-Indentation Broken Across All Modes #

First, let’s tackle the auto-indent problem since it’s affecting every file type:

• Verify the correct major mode is active
  Open a Python file (or any file you’d expect indentation for) and check the bottom status bar—does it show Python (or the relevant mode like Org/Java), or is it stuck on Fundamental? If it’s the latter, manually activate the mode with M-x python-mode (swap for your target mode) and see if indentation kicks in. If yes, your auto-mode-alist (which maps file extensions to modes) might have been altered. Check its current state with C-h v auto-mode-alist to confirm entries like ("\\.py\\'" . python-mode) still exist.

• Check core indentation modes
  The electric-indent-mode handles automatic indentation when you start a new line. Toggle it on with M-x electric-indent-mode—if indentation starts working, add (electric-indent-mode 1) to your init file to keep it enabled by default. Also, double-check variables like indent-tabs-mode (use C-h v indent-tabs-mode)—for Python, this should be nil (using spaces instead of tabs), and tab-width should match your expected indent size (usually 4).

• Rule out configuration conflicts
  Launch Emacs without loading your custom config by running emacs --no-init-file from the terminal. If indentation works here, the issue is in your personal init file (.emacs, .emacs.d/init.el) or a global company config that changed while you were gone. Try commenting out sections of your init file one by one, restarting Emacs each time, to pinpoint the conflicting code.

Bracket Highlighting Not Functioning #

Now let’s fix the matching bracket highlight problem:

• Ensure show-paren-mode is enabled
  This built-in mode is responsible for highlighting matching parentheses, brackets, and braces. Activate it with M-x show-paren-mode—if the highlighting starts working, add (show-paren-mode 1) to your init file to keep it turned on permanently.

• Check highlight visibility
  If the mode is enabled but you can’t see the highlight, the face (color/style) might blend into your theme. Customize the face with M-x customize-face show-paren-face—adjust the background/foreground colors to a high-contrast combo, then save the changes to your init file.

• Test with a clean config
  Use emacs --no-init-file again to see if bracket highlighting works here. If yes, your config has code that’s overriding or disabling show-paren-mode—look for lines setting show-paren-mode to 0, or plugins that might interfere with bracket matching.

Bonus: Check for Emacs Version Updates #

If your company updated the Emacs version while you were away, some old config syntax might be deprecated. Check your current version with M-x emacs-version—if it’s a major jump (e.g., from 26 to 29), you may need to update outdated functions or settings in your init file.

内容的提问来源于stack exchange，提问作者Ness