Linux inode, Symbolic link, physical link

1. The inode is the structure of the saved file attribute in Linux and the actual contents of the file are stored in the block. The address information for the block of the file is stored in the inode.

2. You can use the command Ll-di file_path to view the inode of a file/directory. (When the operating system looks for files, it is also based on the file's directory-level lookup of the inode.) The block information for the current directory's subdirectory information is also in the inode of the current directory)

3. The block information that holds the file in the inode of the file, whether the block information is the actual block address of the file or the block information of the other inode determines whether the file is a physical link to the file or a symbolic link. 1 is a good illustration:

4. In real programming, opening a file in a process returns an integer file descriptor that is not an inode, but rather a subscript for a file table in the system that stores the inode location of the file. When you fork a sub-process, you simply copy the index to the child process, and the inode and the System File table are the same. This means that the child process is shared with the parent process on the file.

   fd_father-> File Table->inode->block

   ^

   Fd_son--------

5. Hard Links: Multiple filenames can point to the same inode.
   

6. Figure 1:

   Physical links

   Symbolic Links

   
   

Linux inode, Symbolic link, physical link