What Are Some Of The Basic Unix Commands?

Some basic Unix commands commonly used for file and directory management, system information, and other tasks are:

1. File and Directory Operations

• ls: List the contents of a directory.

  ls        # List files in the current directory
  ls -l     # List files with detailed information (permissions, owner, etc.)
  ls -a     # List all files, including hidden files (those starting with a dot)
  

• cd: Change the current directory.

  cd /path/to/directory  # Change to a specific directory
  cd ..                  # Move up one level (to the parent directory)
  cd ~                   # Change to the home directory
  

• pwd: Print the current working directory.

  pwd
  

• mkdir: Create a new directory.

  mkdir new_directory
  

• rmdir: Remove an empty directory.

  rmdir directory_name
  

• rm: Remove files or directories.

  rm file_name           # Remove a file
  rm -r directory_name   # Remove a directory and its contents
  rm -f file_name        # Force remove a file (without confirmation)
  

• cp: Copy files or directories.

  cp source_file destination_file        # Copy a file
  cp -r source_directory destination_directory # Copy a directory and its contents
  

• mv: Move or rename files or directories.

  mv source_file destination_file      # Rename or move a file
  mv source_directory destination_directory # Move a directory
  

2. Viewing and Editing Files

• cat: Display the contents of a file.

  cat file_name
  

• less: View the contents of a file one page at a time.

  less file_name
  

• more: Similar to less, but with fewer navigation options.

  more file_name
  

• head: Display the first few lines of a file.

  head file_name       # By default, shows the first 10 lines
  head -n 20 file_name # Display the first 20 lines
  

• tail: Display the last few lines of a file.

  tail file_name       # By default, shows the last 10 lines
  tail -n 20 file_name # Display the last 20 lines
  

• nano or vim: Text editors for editing files.

  nano file_name   # Open file in nano editor
  vim file_name    # Open file in vim editor
  

3. File Permissions

• chmod: Change file permissions.

  chmod 755 file_name  # Give read, write, and execute permissions to the owner, and read/execute to others
  chmod +x file_name   # Add execute permission to a file
  

• chown: Change the owner and group of a file or directory.

  chown user:group file_name  # Change owner and group of a file
  

• chgrp: Change the group ownership of a file or directory.

  chgrp group file_name  # Change group of a file
  

4. Process Management

• ps: Display information about running processes.

  ps               # Show processes running in the current terminal
  ps aux           # Show all running processes
  

• top: Display real-time system resource usage and processes.

  top
  

• kill: Terminate a running process by its PID (Process ID).

  kill PID         # Terminate the process with the given PID
  kill -9 PID      # Forcefully terminate the process
  

• bg: Resume a job in the background.

  bg job_number
  

• fg: Bring a background job to the foreground.

  fg job_number
  

5. System Information

• uname: Display system information.

  uname -a         # Display all information about the system (kernel version, etc.)
  uname -r         # Display the kernel version
  

• df: Display disk space usage.

  df               # Display the space available on all mounted filesystems
  df -h            # Display human-readable output (in MB, GB, etc.)
  

• du: Estimate file and directory space usage.

  du file_name     # Display the size of a file
  du -sh directory_name  # Display the size of a directory (human-readable format)
  

• free: Display memory usage.

  free             # Show free and used memory
  free -h          # Show memory in a human-readable format
  

• uptime: Display how long the system has been running.

  uptime
  

• whoami: Display the current logged-in user.

  whoami
  

6. Searching and Finding Files

• find: Search for files in a directory hierarchy.

  find /path/to/search -name "filename"   # Search for a file by name
  find /path/to/search -type f           # Search for regular files
  find /path/to/search -type d           # Search for directories
  

• grep: Search for a pattern in a file.

  grep "pattern" file_name     # Search for a pattern in a file
  grep -r "pattern" directory  # Search recursively in a directory
  

• locate: Find the location of a file by name (faster than find).

  locate filename
  

7. Networking

• ping: Send ICMP packets to test network connectivity.

  ping www.example.com     # Ping a website
  

• ifconfig or ip a: Display network interface configurations.

  ifconfig      # Show network interfaces (older command)
  ip a          # Show network interfaces (recommended in modern Linux)
  

• netstat: Display network connections, routing tables, and interface statistics.

  netstat        # Display active network connections
  netstat -tuln  # Display listening ports
  

8. File Compression

• tar: Create or extract compressed archive files.

  tar -cvf archive.tar directory_name  # Create a tar archive
  tar -xvf archive.tar                # Extract a tar archive
  tar -czvf archive.tar.gz directory_name  # Create a compressed tarball (.tar.gz)
  tar -xzvf archive.tar.gz                # Extract a compressed tarball
  

• gzip: Compress files using the gzip algorithm.

  gzip file_name       # Compress a file
  gunzip file_name.gz  # Decompress a file
  

These are just a few of the basic Unix commands to help you navigate and perform common tasks in a Unix-like environment.