Comprehensive List of Common Linux Commands and Their Functions

Linux commands are divided into two main types: built‑in shell commands and external Linux utilities. The following table lists common commands, grouped by their functional categories, and provides a brief English description of each command’s purpose.

Command

Function Description man View the manual page for a command, similar to a dictionary of command options. help Show help for built‑in shell commands such as cd. ls List directory contents and file attributes. cd Change the current working directory. cp Copy files or directories. mv Move or rename files. rm Remove one or more files or directories. mkdir Create a new directory. pwd Print the absolute path of the current directory. cat Concatenate and display file contents. tac Display file contents in reverse order. more Paginate file output. less Paginate file output with backward navigation. head Show the beginning of a file. tail Show the end of a file. grep / egrep Search for patterns in text. find Search for files and directories. chmod Change file or directory permissions. chown Change file owner and group. ps Display a snapshot of current processes. top Real‑time display of system resource usage. df Report file system disk space usage. du Estimate file and directory space usage. ssh Secure remote login using the SSH protocol. scp Securely copy files between hosts. wget Download files from the command line. ping Test network connectivity between hosts. netstat / ss Display network connection status. crontab Schedule recurring tasks. kill / killall / pkill Terminate processes by PID or name. tar Create or extract archive files. gzip / zip / unzip Compress and decompress files. chmod / chown / chgrp Manage file permissions and ownership. useradd / usermod / userdel Add, modify, or delete system users. groupadd Create a new user group. passwd Change a user’s password. who / w / last Show logged‑in users and login history. history Display the command execution history. alias / unalias Define or remove command aliases. shutdown / reboot / poweroff Control system power state.

The list covers essential commands for file manipulation, text processing, system monitoring, user and group management, networking, compression, permission handling, and process control, serving as a quick reference for Linux system administrators and developers.