Linux Fundamentals for Hackers

Linux is the operating system of choice for security professionals and hackers alike. Understanding the filesystem hierarchy, process management, and shell fundamentals is mandatory for anyone serious about offensive security.

Linux filesystem: / (root), /etc (configuration files), /home (user home directories), /var (variable data, logs), /tmp (temporary files — often world-writable), /usr (user programs), /bin and /sbin (binaries and system binaries), /proc (virtual filesystem for process info).

Essential commands: ls -la (list with hidden files), find / -name "*.conf" (find files), grep -r "password" /etc (recursive search), chmod/chown (permissions), ps aux (process list), netstat -tulpn (network connections), cat /etc/passwd (user list).