1. File and Directory Management

• mkdir
  mkdir project

  Creates a directory named "project".
• cd
  cd project

  Changes directory to "project".
• touch
  touch file.txt

  Creates an empty file named "file.txt".
• rm
  rm file.txt

  Deletes the file "file.txt".
• rmdir
  rmdir empty_dir

  Deletes an empty directory.
• ls
  ls -l

  Lists files/directories in long format.
• cp
  cp file.txt backup/

  Copies "file.txt" to the "backup" directory.
• mv
  mv old_name.txt new_name.txt

  Renames "old_name.txt" to "new_name.txt".
• tree
  tree -L 2

  Shows directory structure (up to 2 levels).
• find
  find ~ -name "file.txt"

  Searches for "file.txt" in the home directory.

2. File Viewing and Editing

• cat
  cat file.txt

  Displays the contents of "file.txt".
• vi
  vi file.txt

  Opens "file.txt" in the vi text editor.
• nano
  nano config.conf

  Edits "config.conf" in nano editor.
• less
  less log.txt

  Views "log.txt" with pagination.
• head
  head -5 file.txt

  Shows first 5 lines of "file.txt".
• tail
  tail -f log.txt

  Displays real-time updates of "log.txt".
• more
  more largefile.txt

  Shows "largefile.txt" one screen at a time.
• od
  od -c file.txt

  Displays "file.txt" in octal format.
• hexdump
  hexdump -C file.bin

  Shows hex dump of "file.bin".
• view
  view -R file.txt

  Read-only view of "file.txt" in Vim.

3. File Manipulation

• ln
  ln -s file.txt link.txt

  Creates a symbolic link "link.txt" to "file.txt".

4. Search and Text Processing

• grep
  grep "error" log.txt

  Searches for "error" in "log.txt".

5. Permissions and Ownership

• chmod
  chmod 755 script.sh

  Sets permissions to rwxr-xr-x for "script.sh".

13. Compression and Archiving

• tar
  tar -cvf archive.tar folder/

  Creates a .tar archive of "folder".
• gzip
  gzip file.txt

  Compresses "file.txt" to "file.txt.gz".
• bzip2
  bzip2 log.txt

  Compresses "log.txt" to "log.txt.bz2".
• xz
  xz data.bin

  Compresses "data.bin" to "data.bin.xz".
• zip
  zip -r backup.zip folder/

  Zips "folder" into "backup.zip".
• unzip
  unzip backup.zip -d /opt/

  Extracts "backup.zip" to "/opt/".
• 7z
  7z a archive.7z file.txt

  Creates a 7z archive of "file.txt".
• rar
  rar a -m5 backup.rar folder/

  Compresses "folder" with RAR format.
• unrar
  unrar x backup.rar

  Extracts a RAR archive.
• zstd
  zstd input.txt

  Compresses using Zstandard algorithm.