rsync Command Builder

What this tool does

It assembles an rsync command from options: archive, compression, progress, exclusions, SSH details, dry run. The output is text you copy. It never runs rsync and never opens an SSH connection.

The trailing slash, explained properly

This is the single most misunderstood detail of rsync:

rsync -a src/  dest/    # copies the CONTENTS of src into dest
rsync -a src   dest/    # copies the DIRECTORY src inside dest

With the slash, dest ends up containing what was inside src. Without it, dest ends up containing a src directory. Both are correct commands; they produce different trees. When a synchronisation “duplicates the folder” unexpectedly, this is almost always why.

—delete removes files at the destination

rsync -av --delete src/ deploy@example.com:/srv/app/

--delete makes the destination match the source exactly: anything that exists only at the destination is deleted. That is what you want for a mirror and a catastrophe for a backup directory that also holds files you care about.

For that reason the builder enables --dry-run as soon as you tick the box. Run that first: it prints exactly what would be transferred and deleted without touching anything. Only when the list is what you expect should you uncheck dry run.

Exclusions

Each --exclude takes a pattern, not necessarily a name:

--exclude=node_modules     any file or directory called node_modules
--exclude='*.log'          every file ending in .log
--exclude=/cache           only at the root of the transfer
--exclude='**/tmp/**'      anything under a tmp directory

Patterns are matched against the path relative to the transfer root, which is why a leading slash anchors the match and a bare name matches at any depth.

SSH options

If the remote endpoint uses a non-standard port, rsync needs to be told how to start SSH:

rsync -avz -e 'ssh -p 2222' ./app/ deploy@example.com:/srv/app/

The remote side is written user@host:path. If you omit the user, rsync uses your local username, which is rarely what you want on a server — be explicit.

A sane first command

When in doubt, start with -avz --dry-run. It tells you what would happen, keeps permissions and timestamps, and compresses the transfer. Once the dry run looks right, remove -n and run it for real. To build the list of files you want to move in the first place, the find command builder is the natural companion.