Linux Commands

List directory contents with various formatting options. The most frequently used command for viewing files and directories.

Copy files and directories from one location to another. Supports recursive copying and preserving file attributes.

Move or rename files and directories. Unlike cp, this command relocates the original file rather than creating a copy.

Remove files and directories permanently. Use with caution as deleted files cannot be easily recovered.

Create new directories in the file system. Supports creating multiple nested directories with a single command.

Create empty files or update the access and modification timestamps of existing files.

Search for files and directories in a directory hierarchy based on various criteria like name, size, or modification time.

Change the current working directory. Essential for navigating the Linux file system from the command line.

Print the current working directory path. Useful for confirming your location in the file system.

Display disk usage statistics for files and directories. Helps identify which files are consuming the most space.

Display the first lines of a file. By default shows the first 10 lines, useful for previewing file contents.

Display the last lines of a file. Commonly used with -f option to monitor log files in real-time.

Count lines, words, and characters in files. Essential for analyzing text file statistics and content length.

Number lines in files. Provides more control over line numbering than cat -n with various formatting options.

Search for patterns in files using regular expressions. One of the most powerful text processing tools in Linux.

Stream editor for filtering and transforming text. Powerful tool for text substitution, deletion, and manipulation.

Pattern scanning and processing language. Excellent for text processing, data extraction, and report generation.

Extract sections from lines of files. Useful for parsing delimited text and extracting specific columns.

Wrap text lines to a specified width. Useful for formatting text to fit within terminal or display constraints.

Join lines of two files based on a common field. Similar to database join operations for text files.

Filter out repeated lines in a file. Works with sorted input to remove or report duplicate lines.

Split a file into sections based on context patterns. Useful for dividing large files into manageable pieces.

Display file contents in octal and other formats. Useful for examining binary files or non-printable characters.

Read from standard input and write to standard output and files simultaneously. Useful for logging command output.

Change file permissions and access modes. Controls read, write, and execute permissions for owner, group, and others.

Change the group ownership of files and directories. Essential for managing shared file access between users.

Create new user accounts on the system. Allows specification of home directory, shell, and group membership.

Modify existing user account settings including username, home directory, shell, and group memberships.

Display the current username. Simple command to verify which user account you’re currently logged in as.

Change user passwords from the command line. Essential for maintaining account security and password management.

Display real-time system resource usage and running processes. Essential for monitoring CPU, memory, and process activity.

Display system information including kernel name, version, and architecture. Essential for system identification.

Display or set the system date and time. Supports various formatting options for different display needs.

Display a calendar for the current month or specified date. Useful for quick date reference from the terminal.

Execute a command repeatedly and display results. Perfect for monitoring changes in command output over time.

Measure the execution time of commands. Reports real, user, and system time for performance analysis.

Adjust process scheduling priority. Control CPU resource allocation for running and new processes.

Safely shut down or restart the system. Allows scheduling shutdowns and sending warning messages to logged-in users.

Securely connect to remote systems over an encrypted connection. The standard for secure remote system administration.

Securely copy files between hosts over SSH. Maintains the security of SSH while transferring files.

Display network connections, routing tables, and interface statistics. Essential for network troubleshooting and monitoring.

Create and extract archive files. Supports compression and is the standard for packaging multiple files together.

Convert and copy files at the block level. Used for creating disk images, backups, and low-level data operations.

Attach file systems to the directory tree. Essential for accessing storage devices and network shares.

Manage log file rotation, compression, and removal. Prevents log files from consuming excessive disk space.

Calculate and verify file checksums. Useful for verifying file integrity and detecting data corruption.

Query and display mounted filesystems. Provides detailed information about mount points, device names, and filesystem types.

Set environment variables that are inherited by child processes. Essential for configuring shell behavior and applications.

Create command shortcuts and abbreviations. Improves productivity by reducing typing for frequently used commands.

Arbitrary precision calculator for command line. Supports complex mathematical operations and scripting.

Schedule commands to run at a specific time. Useful for one-time task scheduling without cron complexity.

Output a string repeatedly until killed. Often used to automatically answer prompts in scripts.

Search manual page names and descriptions. Helps discover commands related to a specific topic or keyword.

Display manual pages for commands. The primary documentation system for learning command usage and options.