Ubuntu下Node.js与npm安装：首条命令解析及终端输入疑问

Hey there! Let's break this down clearly for you so you can get Node.js and npm installed smoothly on Ubuntu.

First, let's unpack what that first command is supposed to do:
Its core purpose is adding the official Nodesource Node.js 6.x software repository to Ubuntu's APT package manager. Ubuntu's default software repo usually has older Node.js versions, so your course wants you to use this dedicated repo to grab the specific 6.x release.

Let's break down the command parts:

• sudo: Runs the following command with admin (root) privileges—required because modifying system-level APT sources needs elevated access.
• bash -c "...": Launches a new bash shell to run the command inside the quotes.
• cat >/etc/apt/sources.list.d/nodesource.list: The cat command here reads input and writes it to the file /etc/apt/sources.list.d/nodesource.list (the > means overwrite the file if it exists, or create it if it doesn't).
• The lines starting with deb and deb-src are the actual repository details: they tell APT where to find Node.js 6.x packages for Ubuntu 16.04 (code-named xenial), including both pre-built binary packages and source code packages.

The Right Way to Input This Command #

The command format you got is broken—if you tried to input it as-is, your terminal would hang because cat >file waits for you to manually enter content. Here are two reliable fixes:

Method 1: Use a Heredoc for One-Shot Input

Paste this full command into your terminal and hit enter:

sudo bash -c "cat >/etc/apt/sources.list.d/nodesource.list <<EOL
deb https://deb.nodesource.com/node_6.x xenial main
deb-src https://deb.nodesource.com/node_6.x xenial main
EOL"

The <<EOL and closing EOL act as markers—bash will send everything between them to cat, writing it directly to the source file without hanging.

Method 2: Create the File Step-by-Step (Newbie-Friendly)

If the long command feels overwhelming, split it into simple steps:

1. Open the source file with a beginner-friendly text editor:

   sudo nano /etc/apt/sources.list.d/nodesource.list
   

2. In the editor, type these two lines:

   deb https://deb.nodesource.com/node_6.x xenial main
   deb-src https://deb.nodesource.com/node_6.x xenial main
   

3. Press Ctrl+O to save, then Ctrl+X to exit the editor.

Finish the Installation with the Remaining Commands #

Once the source file is set up, run these commands to complete the installation:

1. Add Nodesource's GPG key to verify package authenticity:

   curl -s https://deb.nodesource.com/gpgkey/nodesource.gpg.key | sudo apt-key add -
   

2. Update APT's package cache to recognize the new repo:

   sudo apt update
   

3. Install Node.js (npm will be included automatically):

   sudo apt install nodejs
   

You can verify it worked by running node -v and npm -v—they should show version 6.x numbers.

内容的提问来源于stack exchange，提问作者Sam_2207