使用read命令带-n参数时出现^?的原因及正常退格解决方法

The Root Cause #

When you use read -n in bash, the command switches to raw input mode. In this mode, your terminal doesn’t automatically handle control characters like backspace—it just passes them directly to the script as raw characters (which shows up as ^? for backspace).

Compare that to using read without -n: by default, bash uses cooked mode here. The terminal takes care of processing backspace, delete, and other editing keys for you, so you never see those weird ^? symbols—your input just gets corrected as you type.

The Fix #

To get back normal backspace functionality while using -n, you just need to enable bash’s built-in line editing with the -e flag. It’s also a good idea to add -r to disable backslash escaping (avoids unexpected behavior if you input text with backslashes).

Here’s your updated script:

#!/bin/bash
echo "Tell me something"
read -e -r -n 1000 text

With these flags, read will behave just like your regular command line input—backspace will delete characters as expected, and you won’t see those ^? artifacts anymore.

For older bash versions where -e might not be available, you could temporarily adjust your terminal settings with stty erase ^? before the read command, but using -e is the cleaner, more portable solution for most modern systems.

内容的提问来源于stack exchange，提问作者Martin