cp, mv, rsync: Copying Files Right

You’ll move files around constantly. Three commands cover 99% of the need: cp (copy), mv (move/rename), and rsync (smart copy that handles networks, incremental updates, and resumes).

cp: copy files

cp source.txt destination.txt
cp source.txt /tmp/                    # copy into a directory
cp file1 file2 file3 /backup/          # multiple sources, one dest
cp -r project/ project-backup/         # recursive (for directories)
cp -p source dest                       # preserve timestamps + permissions
cp -a source dest                       # archive mode: preserve everything
cp -i source dest                       # interactive — ask before overwrite
cp -u source dest                       # only overwrite if source is newer
cp -v source dest                       # verbose

Useful combos

cp -av project/ /backup/                # backup with everything preserved
cp -ru new-config/ /etc/myapp/          # update only changed files

mv: move or rename

The same command renames AND moves. Linux makes no distinction.

mv old-name new-name                    # rename
mv file.txt /tmp/                       # move
mv file1 file2 /backup/                 # multiple files, one dest
mv -i file.txt /tmp/                    # ask before overwrite
mv -n file.txt /tmp/                    # NEVER overwrite (no clobber)
mv -v file.txt /tmp/                    # verbose

Rename with patterns

Bash brace expansion is great for renaming:

mv myfile.{txt,bak}        # mv myfile.txt myfile.bak

# Rename many files at once with rename or for-loop
for f in *.JPG; do mv "$f" "${f%.JPG}.jpg"; done

rsync: the right tool for serious copies

rsync is what you want for backups, syncing folders, copying over the network, or anything where you might want to resume / re-run.

Local rsync

# Copy directory contents (note trailing slashes — they matter!)
rsync -av source/ destination/

# Mirror — make destination identical to source (deletes extras)
rsync -av --delete source/ destination/

# Dry run — show what WOULD happen
rsync -avn --delete source/ destination/

Trailing slash gotcha

This is the #1 rsync mistake.

• rsync -av source/ dest/ — copies CONTENTS of source into dest
• rsync -av source dest/ — copies the source FOLDER ITSELF into dest (creates dest/source/…)

rsync over SSH

# Copy local to remote
rsync -avz ./project/ user@server:/opt/project/

# Copy remote to local
rsync -avz user@server:/var/log/ ./logs/

# Resume a partial transfer (huge files, flaky network)
rsync -avz --partial --progress big.iso user@server:/data/

Useful rsync flags

-a    archive mode (recursive + permissions + timestamps + symlinks)
-v    verbose
-z    compress during transfer (saves bandwidth)
-h    human-readable sizes
-P    progress + partial (resume support)
--delete           remove files in dest that aren't in source
--exclude='*.log'  skip files matching pattern
--dry-run / -n     show what would happen without doing it
--bwlimit=10000    limit to 10 MB/s

scp: simple SSH copy

Old, simple, less powerful than rsync. Still works.

scp file.txt user@server:/tmp/
scp -r project/ user@server:/opt/
scp user@server:/var/log/syslog ./

Use rsync instead if you have it. scp is being deprecated.

cp vs rsync vs scp

Use case	Tool
Local copy, small set of files	cp
Local copy, big tree	rsync (faster on re-runs)
Backup script (incremental)	rsync
Sync code to server	rsync over SSH
One file to remote	scp or rsync
Resume an interrupted huge copy	rsync –partial

Common mistakes

• cp file destination when destination doesn’t exist — creates a file with the dest name (might not be what you wanted).
• Forgetting -r on cp for directories — “cp: -r not specified; omitting directory”.
• rsync trailing slash confusion — read the section above twice.
• rsync --delete on the wrong direction — wipes files you wanted to keep. Always --dry-run first.

What to learn next

Symbolic and hard links are how Linux handles “this file should appear in two places” without actually copying the data. Coming up next.