使用带-p参数的mkdir遇语法错误，求解析-p及SUID含义

Hey there! Let's break down your issues step by step:

If you're hitting a syntax error when using mkdir -p, here are the most common fixes to check:

• Double-check the command formatting: Make sure there's no extra space between - and p (it should be mkdir -p, not mkdir - p).
• Verify your target path: If the directory path includes spaces or special characters (like * or ?), wrap the path in quotes to avoid parsing issues. For example:

  mkdir -p "my projects/2024/personal app"
  

• Example of correct usage: To create a nested directory structure in one go, run this command—it will automatically create all missing parent directories:

  mkdir -p docs/tutorials/bash/basics
  

You thought -p stood for "privileged"—that's a totally understandable mix-up! Actually, -p is short for parents. Its core purposes are:

• Create all missing parent directories in the specified path (no need to create each level one by one).
• Silently ignore errors if the target directory already exists (without -p, mkdir would throw an error if the directory is already there).

You nailed the basic definition of SUID, but let's add some practical context to that warning:

• SUID (Set User Identification) is a file permission bit that forces a program or script to run with the permissions of its owner, not the user executing it. For example, if a script owned by root has the SUID bit set, any regular user running it will temporarily have root-level access.
• The warning is a critical security heads-up: SUID-enabled scripts are risky. If the script has bugs or insecure code, an attacker could exploit it to gain elevated permissions on your system.
• A quick note for shell scripts: Most modern systems ignore the SUID bit for shell scripts as a security measure. So even if your script has the SUID flag set, it might not actually run with the owner's permissions—but it's still smart to remove the SUID bit if you don't explicitly need it. Use this command to disable it:

  chmod u-s your-script.sh
  

内容的提问来源于stack exchange，提问作者nrvaller