Diff between symlink and hard link

🔗 Symlinks vs Hard Links in Linux

Links are a powerful feature in Linux that allow you to create references to files. There are two types of links: symlinks (symbolic links) and hard links. Here’s a comparison of both.

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🧰 Key Differences

Feature	Symlink (Symbolic Link)	Hard Link
Definition	A pointer or reference to another file	Another reference to the same inode (file data)
File Type	Can link to files or directories	Links only to files (not directories)
Inode	Points to the file name and path	Points directly to the inode (file’s data block)
Cross Filesystems	Can link across different filesystems	Cannot link across different filesystems
Link Target	Can point to a file that does not exist (broken link)	Always points to an existing file
File Deletion	If the original file is deleted, the symlink becomes broken	If the original file is deleted, hard links remain valid
Permissions	Can have different permissions from the original file	Shares the same permissions as the original file
Identification	Identified with l in ls -l (e.g., lrwxrwxrwx)	Identified with - in ls -l (e.g., -rw-r--r--)
Use Case	Used for creating shortcuts, linking across filesystems, or redirecting file paths	Used for file redundancy and reliability

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📝 Examples

Create a Symlink

ln -s /path/to/original/file /path/to/symlink

Create a Hard Link

ln /path/to/original/file /path/to/hardlink

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⚡ When to Use Symlinks vs Hard Links

• Use Symlinks when:

  • You need to link across filesystems.

  • You want to create a shortcut to a file or directory.

  • You don’t mind if the link becomes broken if the target is deleted.

• Use Hard Links when:

  • You want to create an additional reference to a file within the same filesystem.

  • You want the file to persist even if the original file is deleted (as long as there’s another link).

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💡 Additional Notes

• Symlinks are more flexible but can become broken if the target file is moved or deleted.

• Hard Links are more robust for file consistency, but they can only be created within the same filesystem and are limited to files (not directories).

• Hard Link links only to files (not directories), because hard link points directly to an inode, when creating a hard link to a directory, it would mean both the directory and the hard link share the same inode, so if hard links to directories were allowed, it would create potential cyclic dependencies, e.g., a directory could link to itself through its subdirs, leading to an infinite loop, which would make it impossible to traverse the file system.

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