3.1. File and Directory Management
File management is the first skill tested in production: creating directories, moving files safely, understanding the difference between a hard link and a symbolic link. These operations look simple but carry edge cases — especially around links and device files — that appear regularly on the exam.
💡 First Principle: In Linux, a file is an inode containing metadata plus data blocks. A filename is just a label (a directory entry) pointing to an inode. This means a single file (inode) can have multiple names, and deleting one name doesn't destroy the data until all names are gone. This is what hard links are.
⚠️ Common Misconception: Many candidates assume that copying a file always creates two independent files. Hard links create two names for the same inode — modifying one modifies both, and deleting one leaves the data accessible via the other. Symbolic links are different: they're a separate inode containing a path reference, like a shortcut.
