Linux cp -l
If you want to create a hard link of a file instead of copying that file, you can use option 'l'.
Note: In creating hard link of the file the inode number of the two files will remain same. While in case of copying, inode number changes.
Note here that we have created a hard link of the file 'file1.txt' in 'usr'. Inode number of both the files are same.