You can learn a file’s inode number and the number of links to it by running ‘ ls -li ‘, ‘ stat ‘ or ‘ find -ls ‘. You can search for hard links to inode number NUM by using ‘ -inum NUM ‘.
Find if the file has hard links
It can still be identified using the same ls command but you will need to use the long listing format by using the -l command line option. In the long listing format, the second column denotes the number of hard links to the file.
Use the ls -l command to check whether a given file is a symbolic link, and to find the file or directory that symbolic link point to. The first character “l”, indicates that the file is a symlink. The “->” symbol shows the file the symlink points to.
A hard link is a file all its own, and the file references or points to the exact spot on a hard drive where the Inode stores the data. A soft link isn’t a separate file, it points to the name of the original file, rather than to a spot on the hard drive.
A hard link is a file that points to the same underlying inode, as another file. In case you delete one file, it removes one link to the underlying inode. Whereas a symbolic link (also known as soft link) is a link to another filename in the filesystem.
In some file systems, the number of hard links is limited more strictly by their on-disk format. For example, as of Linux 3.11, the ext4 file system limits the number of hard links on a file to 65,000. Windows limits enforces a limit of 1024 hard links to a file on NTFS volumes.
If you want to remove only the link and thus keep the original file, you have to use unlink. Have you read what unlink(1) does? It’s a shallow wrapper around the unlink(2) system call, the same system call that rm(1) uses for all files that aren’t directories.
What is inode Linux?
By definition, an inode is an index node. It serves as a unique identifier for a specific piece of metadata on a given filesystem. Each piece of metadata describes what we think of as a file. That’s right, inodes operate on each filesystem, independent of the others.
The real test is to use the ls -li command. This command will show the inode for each of the two files. If the inodes match, then the files really are hard links, sharing disk space and the inode structure which houses their metadata (owner, permissions, etc.).
You can check if a file is a symlink with [ -L file ] . Similarly, you can test if a file is a regular file with [ -f file ] , but in that case, the check is done after resolving symlinks. hardlinks are not a type of file, they are just different names for a file (of any type).
find follows symbolic links to directories when searching directory trees. ‘ -lname ‘ and ‘ -ilname ‘ always return false (unless they happen to match broken symbolic links).
Replace source_file with the name of the existing file for which you want to create the symbolic link (this file can be any existing file or directory across the file systems). Replace myfile with the name of the symbolic link. The ln command then creates the symbolic link.
How to create a hard links in Linux or Unix
- Create hard link between sfile1file and link1file, run: ln sfile1file link1file.
- To make symbolic links instead of hard links, use: ln -s source link.
- To verify soft or hard links on Linux, run: ls -l source link.
If you find two files with identical properties but are unsure if they are hard-linked, use the ls -i command to view the inode number. Files that are hard-linked together share the same inode number. The shared inode number is 2730074, meaning these files are identical data.
To view the symbolic links in a directory:
- Open a terminal and move to that directory.
- Type the command: ls -la. This shall long list all the files in the directory even if they are hidden.
- The files that start with l are your symbolic link files.