-
-
LFCA 11 🐧 The Shell — What It Is and How It Works
The shell is the program you talk to when you type commands in a terminal. It reads what you type, interprets it, runs programs, and shows you the output. On Linux it’s the primary way to interact with the system — every command, every script, every automation goes through it. The LFCA exam expects you…
-
LFCE 11 🐧 IPv6 — Why It Exists
IPv6 is not an incremental upgrade to IPv4. It is a replacement for the network layer of the internet, designed because IPv4’s 32-bit address space could not support the number of devices that would eventually need to connect. The exhaustion was not speculative. On February 3, 2011, IANA allocated the final five /8 blocks from…
-
LFCS 11 🐧 Moving and Renaming — mv
The mv command moves a file or directory from one location to another. It is also the command for renaming. On a Unix system, moving and renaming are the same operation: the file’s name changes, or its directory entry changes, or both. The mv command is the tool, and it is one of the most…
-
Linux CLI 11🐧 Input/Output and redirection
Every command in Linux works with three standard streams — and you can redirect them to files, other commands, or the void. This is one of the most powerful concepts in the shell. The Three Standard Streams Every process on Linux has three standard I/O streams: Stream Name Default Source/Destination File Descriptor stdin Standard Input…
-
LFCA 12 🐧 Basic Shell Navigation — pwd, cd, ls
Three commands form the foundation of every Linux session: pwd tells you where you are, cd moves you somewhere else, and ls shows you what’s there. They’re the first commands anyone learns and the ones you’ll type most often. On their own they’re simple; with their options and combinations they cover the whole of interactive…
-
LFCE 12 🐧 IPv6 — Address Types and Structure
IPv6 addresses are 128-bit identifiers, four times the length of their IPv4 counterparts. That length is not merely a larger number; it is the space in which the protocol’s addressing architecture is carved. Every IPv6 address belongs to one of three types—unicast, anycast, or multicast—and within those types, specific prefixes define scope and purpose. Unlike…
-
LFCS 12 🐧 Deleting Files and Directories — rm, rmdir
The rm command deletes files and directories. It is the most dangerous command in the shell because there is no trash bin, no undo, and no confirmation by default. The rmdir command deletes empty directories. The LFCS exam expects both commands to be automatic, and the exam tasks often require the cleanup of the files…
-
Linux CLI 12 🐧 pipelines and cat, grep, wc commands
Pipelines let you chain commands together — the output of one becomes the input to the next. Combined with cat, grep, and wc, they form the backbone of text processing on the command line. What Are Pipelines? A pipeline uses the | (pipe) operator to send the output of one command to the input of…
-