How to distinguish creating a hard link to a file from its normal copying?

A hard link is an additional name for an existing file in the file system. When creating a hard link, a new link to the same inode (physical data location) is created, not a new file. Unlike copying, which creates a new file with a separate inode and content, a hard link points to the same data.

To distinguish a hard link from a copy, you can check the number of links to the file using the ls -l or stat command. A hard link will have an increased number of links, while a copy will be a separate file with a link count of 1.

Example of creating a hard link and copying a file:

# Creating a file
echo "Hello" > file.txt

# Creating a hard link
ln file.txt hardlink.txt

# Copying the file
cp file.txt copy.txt

# Checking the number of links
ls -li file.txt hardlink.txt copy.txt

In the output, file.txt and hardlink.txt will have the same inode and a link count greater than 1, while copy.txt will have a different inode and a link count of 1.