File Operations: Create, Copy, Move, Delete

File operations are what you do constantly. Create files. Copy them. Move them. Delete them.

Master these, and you can work with files efficiently. These are the basics. But basics matter.

Creating Files

touch: Create Empty Files

touch file.txt                # Create empty file
touch file1.txt file2.txt     # Create multiple
touch existing.txt            # Update timestamp

What it does: Creates empty files. Or updates the timestamp if the file exists.

Real example:

$ touch test.txt
$ ls -la test.txt
-rw-r--r-- 1 ubuntu ubuntu 0 Dec 28 10:30 test.txt

Zero bytes. Empty file.

My take: Use touch for empty files. Use editors or redirection for files with content.

Creating Files with Content

# Method 1: echo
echo "Hello, World!" > file.txt        # Create/overwrite
echo "More text" >> file.txt          # Append

# Method 2: heredoc
cat > file.txt << EOF
Line 1
Line 2
Line 3
EOF

# Method 3: editors
vim file.txt
nano file.txt

The > and >>: > overwrites. >> appends.

My take: Use > for new files. Use >> for adding to existing files. Use heredoc for multi-line content.

Copying Files

cp: Copy

cp file.txt backup.txt                # Copy with new name
cp file.txt /destination/             # Copy to directory
cp file1.txt file2.txt /dest/         # Copy multiple
cp -r directory/ /dest/               # Copy directory (recursive)
cp -i file.txt dest/                  # Interactive (ask before overwrite)
cp -u file.txt dest/                  # Update (only if newer)
cp -p file.txt dest/                  # Preserve permissions/timestamps
cp -v file.txt dest/                  # Verbose (show what's copied)

The -r flag: Required for directories. Recursive copy.

Real examples:

cp config.txt config.txt.backup
cp -r /home/ubuntu/projects /backup/
cp -i *.txt /backup/                 # Ask before overwriting

My take: cp -r for directories. cp -i when you're not sure. cp -v to see what's happening.

Moving Files

mv: Move or Rename

mv file.txt newname.txt               # Rename
mv file.txt /destination/             # Move
mv file1.txt file2.txt /dest/         # Move multiple
mv -i file.txt dest/                 # Interactive
mv -v file.txt dest/                 # Verbose

What it does: Moves files. Or renames them. Same command.

Real examples:

mv oldname.txt newname.txt            # Rename
mv file.txt /tmp/                     # Move
mv *.txt /backup/                     # Move all .txt files

My take: mv is simple. It moves. It renames. That's it.

Deleting Files

rm: Delete

rm file.txt                          # Delete file
rm file1.txt file2.txt               # Delete multiple
rm -r directory/                     # Delete directory
rm -f file.txt                       # Force (no confirmation)
rm -rf directory/                    # Force recursive (dangerous!)
rm -i file.txt                       # Interactive (ask first)
rm -v file.txt                       # Verbose

Warning: rm -rf is dangerous. It deletes without asking. Be very careful.

Real examples:

rm old_file.txt
rm -r old_directory/
rm -i *.txt                          # Ask before deleting each

My take: Use rm -i when you're not sure. Use rm -rf only when you're absolutely sure. There's no undo.

Directories

mkdir: Create Directories

mkdir dirname
mkdir -p path/to/dir                 # Create parent directories too
mkdir dir1 dir2 dir3                  # Create multiple

The -p flag: Creates parent directories if they don't exist.

Real example:

mkdir -p projects/2024/january

My take: Use -p when creating nested directories. It's safer.

rmdir: Remove Empty Directories

rmdir dirname                        # Remove empty directory
rmdir dir1 dir2                      # Remove multiple

What it does: Removes empty directories only.

My take: Use rm -r for directories with files. Use rmdir only for empty directories.

Common Patterns

Backup Before Delete

cp file.txt file.txt.backup
rm file.txt

My take: Always backup before deleting important files. You'll thank yourself later.

Move and Rename

mv oldname.txt newname.txt            # Same command

My take: There's no separate rename command. mv does both.

Copy with Timestamp

cp -p file.txt backup/               # Preserves timestamp

My take: Use -p when timestamps matter. Usually they don't, but sometimes they do.

Common Mistakes (I've Made These)

1. Forgetting -r for directories: cp directory/ doesn't work. Use cp -r directory/.

2. Using rm on directories: rm directory/ doesn't work. Use rm -r directory/.

3. Accidental overwrite: cp file.txt existing.txt overwrites. Use cp -i to be safe.

4. Deleting wrong thing: Always double-check before rm. There's no undo.

5. Spaces in paths: mv my file.txt doesn't work. Use quotes: mv "my file.txt".

Real-World Examples

Backup Files

for file in *.txt; do
    cp "$file" "${file}.backup"
done

Clean Up Old Files

find /tmp -mtime +7 -type f -delete

Organize Files

mkdir -p documents images scripts
mv *.pdf documents/
mv *.jpg images/
mv *.sh scripts/

What's Next?

Now that you can manipulate files, let's talk about Text Processing. We'll cover viewing and processing file contents.

Or practice. Create files. Copy them. Move them. Delete them. Get comfortable.

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Personal note: When I started, I'd delete files accidentally. Then I learned rm -i. Now I use it when I'm not sure. It's saved me from deleting important files many times. Be careful with rm. There's no undo.