Linux commands, from your first prompt onward.

Pattern-scanning and text-processing language for field-based data

Legacy C/C++ source code beautifier (mostly superseded)

Resume a stopped job and run it in the background

Display a text calendar in the terminal

Concatenate and print file contents

Change the shell's current working directory

Change the group ownership of a file or directory

Change file and directory permissions

Compare two files byte by byte

Copy files and directories

Historical C program execution tracer (obsolete, superseded by gdb/strace/ltrace)

Transfer data to/from a URL over many protocols

Extract columns or fields from each line of input

Generate a cross-reference listing of a C program (legacy tool)

Display or set the system date and time

Report free and used disk space on mounted filesystems

Compare files line by line and show differences

Query DNS servers and display detailed DNS records

Read hardware info from DMI/SMBIOS tables

Show disk usage of files and directories

Query and change network interface driver and hardware settings

Convert tabs in input to spaces

View or modify a disk's partition table

Bring a background or stopped job to the foreground

Determine a file's type by inspecting its contents

Search a directory tree for files matching criteria

Display system memory usage: RAM and swap

Interactive File Transfer Protocol client

GNU C++ compiler front end

GNU C compiler front end

GNOME's simple graphical text editor

Search text using patterns

Create a new group

Decompress .gz files

Compress files using the DEFLATE algorithm

Get/set SATA and IDE disk drive parameters

Print the first lines of a file

Simple DNS lookup utility

Show or set the system's hostname and IP addresses

Interactive, colorized process viewer with tree view and mouse support

Show user and group IDs for the current or named user

Display and configure network interfaces

Reformat C source code according to configurable style rules

Report CPU and device/partition I/O statistics

Join lines of two sorted files on a common field

Send a signal to a process by PID

Send a signal to all processes matching a name

Show login history and system reboot records

Page through text interactively, one screen at a time

Create hard or symbolic links between files

Find files by name using a prebuilt index, fast but can be stale

Display lines in a sorted file starting with a given string

Submit a file to the print queue

List directory contents

Show Linux Standard Base and distribution information

List open files and the processes holding them open

List PCI devices and hardware attached to the system

List USB devices and controllers attached to the system

Build automation tool that runs rules from a Makefile

Create new directories

Page through text one screen at a time, forward only

Report per-processor CPU usage statistics

Move or rename files and directories

Display network connections, routing tables, and listening ports

List symbols from object files and executables

Merge corresponding lines of files side by side into columns

General-purpose scripting language, historically a sysadmin staple for text processing

Test host reachability and measure latency with ICMP echo

Show a snapshot of currently running processes

Print the full path of the current working directory

Legacy remote file copy (unencrypted, obsolete)

Legacy remote login protocol (unencrypted, obsolete)

Remove files and directories

Remove empty directories

Low-level tool to install, query, and verify RPM packages

Legacy remote shell/command execution (unencrypted, obsolete)

Efficiently synchronize files and directories

Securely copy files to/from a remote host over SSH

Stream editor for filtering and transforming text

Secure interactive file transfer over SSH

Print the size of code, data, and BSS sections in an object file

Sort lines of text files

Split a file into smaller pieces

Secure encrypted remote login and command execution

Remove symbol table and debugging information from a binary

Print the last lines of a file, and follow it as it grows

Archive files into a single .tar file, optionally compressed

Capture and display network packets on an interface

Connect to a remote host/port over unencrypted Telnet

Trivial File Transfer Protocol client for minimal, unauthenticated transfers

Interactive live view of top resource-consuming processes

Create empty files or update file timestamps

Translate, squeeze, or delete characters from input

Display Linux kernel and system information

Restore files compressed with the legacy .Z format

Convert runs of spaces back into tabs

Report or filter out repeated adjacent lines

Show how long the system has been running and load averages

Create a new user account

Delete a user account

Modify an existing user account

Modal terminal text editor

Report virtual memory, process, CPU, and IO statistics

Show who is logged in and what they are running

Repeatedly run a command and show periodic full-screen updates

Count lines, words, and bytes or characters

Non-interactive command-line downloader

List users currently logged into the system

Print the current effective username

Look up domain registration information

RPM-based package manager for RHEL/CentOS and older Fedora

Print gzip-compressed file contents to stdout

Compare compressed files without decompressing to disk

Show line-level differences between compressed files

Page through a compressed file without decompressing it to disk