Linux commands

1. cd (Change Directory)

• Usage: cd [directory_path]

• Function: Changes the current working directory.

• Examples:

  • cd /home/user → Moves to the /home/user directory.

  • cd .. → Moves up one directory level.

  • cd → Moves to the user's home directory.

  
  

2. mkdir (Make Directory)

• Usage: mkdir [directory_name]

• Function: Creates a new directory.

• Examples:

  • mkdir new_folder → Creates a directory named new_folder.

  • mkdir -p dir1/dir2 → Creates a nested directory structure.

    
    

3. rm (Remove Files/Directories)

• Usage: rm [file_or_directory_name]

• Function: Removes files or directories.

• Examples:

  • rm file.txt → Deletes the file file.txt.

  • rm -r folder → Deletes the directory folder and its contents.

  • rm -i file.txt → Prompts for confirmation before deletion.

    
    

4. mv (Move/Rename Files)

• Usage: mv [source] [destination]

• Function: Moves or renames files or directories.

• Examples:

  • mv file.txt /tmp/ → Moves file.txt to the /tmp/ directory.

  • mv old_name.txt new_name.txt → Renames the file.

    
    

5. cp (Copy Files)

• Usage: cp [source] [destination]

• Function: Copies files or directories.

• Examples:

  • cp file.txt /tmp/ → Copies file.txt to /tmp/.

  • cp -r dir1 dir2 → Copies the directory dir1 to dir2.

    
    

6. ls (List Files)

• Usage: ls [options] [directory]

• Function: Lists the contents of a directory.

• Examples:

  • ls → Lists files in the current directory.

  • ls -l → Lists files in a long format with details.

  • ls -a → Lists all files, including hidden ones.

    
    

7. cat (Concatenate and View Files)

• Usage: cat [file_name]

• Function: Displays the contents of a file, or concatenates files.

• Examples:

  • cat file.txt → Displays the contents of file.txt.

  • cat file1.txt file2.txt > combined.txt → Combines two files into combined.txt.

    
    

8. find (Search for Files/Directories)

• Usage: find [path] [options]

• Function: Searches for files and directories in a specified path.

• Examples:

  • find / -name "file.txt" → Searches for file.txt from the root directory.

  • find . -type d → Finds directories in the current location.

    
    

9. grep (Search Text in Files)

• Usage: grep [pattern] [file_name]

• Function: Searches for a specific pattern of text in files.

• Examples:

  • grep "hello" file.txt → Searches for the word hello in file.txt.

  • grep -r "function" /path/to/code → Searches recursively for function in a directory.

• Examples:

  • grep "error" logfile.txt: Searches for the word error in logfile.txt.

  • grep -i "warning" logfile.txt: Case-insensitive search for warning.

  • grep -r "TODO" /project/: Recursively searches for TODO in /project/.