File & Directory Management – Linux Teaching Plan

1. pwd – Print Working Directory

Shows the absolute path of the current directory.

pwd
/Users/student/Documents/Labs/Linux

• After navigating to a nested directory, run pwd and verify the full path.
• Combine pwd with echo to show the current path in a script.

2. ls – List Directory Contents

Displays files and directories in the current location.

ls
README.md   scripts   logs

Common options

• ls -l – long format (permissions, owner, size)
• ls -a – include hidden files (those starting with .)
• ls -lh – human‑readable sizes

ls -l
drwxr-xr-x  3 student staff  96 Aug 12 09:30 scripts
-rw-r--r--  1 student staff  45 Aug 11 12:00 README.md

• List all files in the home directory, including hidden ones.
• Show a long format listing of the logs directory.

3. cd – Change Directory

Moves between directories.

cd /var/log
cd ../home
cd ~
cd -

• Navigate to /tmp, then back to the previous directory.
• Use cd ~ to return to the home directory from anywhere.

4. mkdir – Make Directory

Creates new directories.

mkdir newdir
mkdir -p parent/child/grandchild
mkdir -m 755 secure

• Create a directory structure project/src/docs in one command.
• Set the permissions of a new directory to 750.

5. rmdir – Remove Empty Directory

Deletes an empty directory.

rmdir emptydir
rmdir -p nested/empty/dir

• Create and then delete an empty directory.
• Try to delete a non‑empty directory and observe the error.

6. rm – Remove Files & Directories

Deletes files or recursively removes directories.

rm file.txt
rm -i file.txt
rm -r dir
rm -f /tmp/unwanted.log

• Delete a file after confirming with -i.
• Use -r to delete a directory that contains files.
• Attempt to remove a file with -f that you do not own (observe the result).

7. touch – Create or Update File Timestamps

Creates an empty file or updates its last-modified time.

touch newfile.txt
touch -a oldfile.txt
touch -m -t 202309301200 newfile.txt

• Create an empty file named todo.txt.
• Update only the access time of an existing file.
• Set a custom modification time using the -t option.

8. cp – Copy Files & Directories

Copies files or directories, optionally preserving attributes.

cp source.txt dest.txt
cp -r src_dir/ dest_dir/
cp -p file1 file2

• Copy a single file to a new name.
• Recursively copy a directory to another location.
• Copy a file preserving permissions and timestamps.

9. mv – Move or Rename

Moves files or directories, or renames them.

mv oldname.txt newname.txt
mv file.txt /tmp/
mv -i existing.txt newfile.txt

• Rename a file from old.txt to new.txt.
• Move a file into a different directory.
• Try to overwrite an existing file with -i to confirm behavior.

10. chmod – Change File Permissions

Alters read/write/execute permissions using numeric or symbolic modes.

chmod 644 file.txt
chmod u=rwx,g=rx,o=r file.txt
chmod -R 755 /var/www/html

• Set a file to read-only for the owner.
• Grant execute permission to everyone for a script.
• Recursively set 755 permissions on a directory tree.

11. chown – Change File Owner & Group

Assigns a new owner or group to files or directories.

chown alice file.txt
chown alice:staff file.txt
chown -R bob:developers /home/bob/projects

• Change the owner of a file you own to another user (use sudo if needed).
• Change the group of a directory to staff.
• Recursively change ownership of a directory tree.

12. find – Search for Files & Directories

Searches based on name, type, size, modification time, etc.

find . -name "*.log"
find /var -type d -name "conf.d"
find /tmp -size +1M -exec rm {} \;
find . -mtime -7 -print

• Locate all .sh files in the current directory tree.
• Delete all files larger than 10 MB in /var/tmp.
• Print the paths of files modified in the last 24 hours.