Basic Linux Commands for Day-to-Day Usage.

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Introduction to Linux Commands

• What are Linux Commands?
  • Instructions that users can give to the Linux operating system through the command line interface (CLI).
  • Essential for navigating, managing files, and interacting with the system.

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Navigating Directories

• pwd (Print Working Directory)
  Displays the current directory you're in.

  $ pwd

  Example output: /home/user

• ls (List)
  Lists files and directories in the current directory.

  $ ls

  Example output: Documents/ Downloads/ Pictures/

• cd (Change Directory)
  Changes the current directory.

  $ cd /home/user/Documents

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Managing Files

• touch
  Creates an empty file or updates a file's timestamp.

  $ touch newfile.txt

• cp (Copy)
  Copies files or directories.

  $ cp file1.txt /home/user/Backup/
  $ cp -r /home/user/Documents/project /home/user/Backup/

• mv (Move/Rename)
  Moves or renames files or directories.

  $ mv oldname.txt newname.txt

• rm (Remove)
  Deletes files and folders.

  $ rm file1.txt
  $ rm -rf folder/

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Viewing File Content

• cat
  Displays the contents of a file.

  $ cat file.txt

• less
  View file content one screen at a time.

  $ less largefile.txt

• head / tail
  Shows the first/last 10 lines of a file.

  $ head file.txt
  $ tail file.txt

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System Monitoring Commands

• top
  Displays a real-time view of running processes.

  $ top

• df (Disk Free)
  Shows available disk space on file systems.

  $ df -h

• free
  Displays available and used memory.

  $ free -h

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Searching & Finding Files

• find
  Search for files in a directory hierarchy.

  $ find /home/user -name "file.txt"

• grep
  Searches for a pattern within files.

  $ grep "error" logfile.txt

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Basic Networking Commands

• ping
  Checks the connectivity to another machine.

  $ ping google.com

• ifconfig / ip
  Displays or configures network interfaces.

  $ ifconfig
  $ ip addr show

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File Permissions

• chmod
  Changes file or directory permissions.

  $ chmod 755 script.sh

• chown
  Changes file ownership.

  $ chown user:user file.txt

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Package Management (Ubuntu Example)

• apt-get update
  Updates the package lists.

  $ sudo apt-get update

• apt-get install
  Installs a package.

  $ sudo apt-get install vim

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Explore further

1. More on ls and cp
2. File Permissions