# Cheatsheet & Examples: rsync

rsync is a powerful command-line utility for synchronizing files and directories between locations, efficiently copying only the changes and supporting compression, encryption, and more.

## Basic File Copy  
Example Usage:  
`rsync -av /source/directory/ /destination/directory/`  
What it does:  
Copies files from the source to the destination, preserving permissions, timestamps, and other attributes.  
Command-line Arguments Explained:  
- `-a`: Archive mode, which preserves permissions, ownership, timestamps, symbolic links, and other file attributes.  
- `-v`: Verbose mode, providing detailed output during the transfer.  

## Synchronize with a Remote Server  
Example Usage:  
`rsync -avz /local/path/ user@remote:/remote/path/`  
What it does:  
Transfers files to a remote server using SSH (via `-z` compression) and preserves attributes.  
Command-line Arguments Explained:  
- `-a`: Archive mode for preserving file properties.  
- `-v`: Verbose output for tracking progress.  
- `-z`: Compress file data during transfer to reduce bandwidth usage.  

## Mirror Source to Destination (Delete Extra Files)  
Example Usage:  
`rsync -av --delete /source/directory/ /destination/directory/`  
What it does:  
Mirrors the source directory to the destination, removing files in the destination that aren't in the source.  
Command-line Arguments Explained:  
- `-a`: Archive mode for preserving attributes.  
- `-v`: Verbose output.  
- `--delete`: Deletes files in the destination that don't exist in the source.  

## Recursive File Copy (Include Subdirectories)  
Example Usage:  
`rsync -r /source/directory/ /destination/directory/`  
What it does:  
Copies all files and subdirectories recursively from the source to the destination.  
Command-line Arguments Explained:  
- `-r`: Recursive mode to copy directories and their contents.  

## Exclude Specific Files or Directories  
Example Usage:  
`rsync -av --exclude='*.tmp' /source/ /destination/`  
What it does:  
Copies files from the source to the destination while excluding files matching the specified pattern (e.g., `.tmp` files).  
Command-line Arguments Explained:  
- `-a`: Archive mode.  
- `-v`: Verbose output.  
- `--exclude='pattern'`: Skips files/directories matching the pattern during transfer.  

## Show Progress During Transfer  
Example Usage:  
`rsync -av --progress /source/ /destination/`  
What it does:  
Displays real-time progress of the file transfer, including percentage, speed, and estimated time.  
Command-line Arguments Explained:  
- `-a`: Preserves file attributes.  
- `-v`: Verbose output.  
- `--progress`: Shows progress details for each file.  

## Dry Run (Test Without Actual Copy)  
Example Usage:  
`rsync -av --dry-run /source/ /destination/`  
What it does:  
Simulates the sync operation without copying any files, helping verify the command's behavior.  
Command-line Arguments Explained:  
- `-a`: Preserves attributes.  
- `-v`: Verbose output.  
- `--dry-run`: Performs a trial run without modifying the destination.  

## Use Checksum for Exact File Comparison  
Example Usage:  
`rsync -av --checksum /source/ /destination/`  
What it does:  
Ensures files are copied based on checksums (not just size or timestamp) for precise synchronization.  
Command-line Arguments Explained:  
- `-a`: Preserves attributes.  
- `-v`: Verbose output.  
- `--checksum`: Compares files using checksums instead of size/timestamp.  

## Backup Existing Files on Destination  
Example Usage:  
`rsync -av --backup /source/ /destination/`  
What it does:  
Copies files to the destination and backs up existing files with a suffix (e.g., `.orig`) if they are overwritten.  
Command-line Arguments Explained:  
- `-a`: Preserves attributes.  
- `-v`: Verbose output.  
- `--backup`: Creates backups of destination files before overwriting.  

## Compress Data During Transfer  
Example Usage:  
`rsync -avz /local/path/ user@remote:/remote/path/`  
What it does:  
Transfers files to a remote location while compressing data to save bandwidth.  
Command-line Arguments Explained:  
- `-a`: Archive mode.  
- `-v`: Verbose output.  
- `-z`: Compresses data during transfer.  

## Synchronize with a Remote Server via SSH  
Example Usage:  
`rsync -av -e 'ssh -p 2222' /local/path/ user@remote:/remote/path/`  
What it does:  
Uses SSH with a custom port (e.g., 2222) to securely synchronize files with a remote server.  
Command-line Arguments Explained:  
- `-a`: Preserves file attributes.  
- `-v`: Verbose output.  
- `-e 'ssh -p port'`: Specifies the remote shell (SSH) and port for the connection.  

## Transfer Files to a Remote Server with Compression  
Example Usage:  
`rsync -avz /local/path/ user@remote:/remote/path/`  
What it does:  
Copies files to a remote server with compression enabled, optimized for network transfers.  
Command-line Arguments Explained:  
- `-a`: Archive mode.  
- `-v`: Verbose output.  
- `-z`: Compresses data during transfer.  

## Synchronize with a Remote Server Using Rsync Protocol  
Example Usage:  
`rsync -av /local/path/ user@remote::module/`  
What it does:  
Transfers files to a remote server using the rsync protocol (not SSH), assuming the remote has a defined module.  
Command-line Arguments Explained:  
- `-a`: Preserves attributes.  
- `-v`: Verbose output.  
- `user@remote::module`: Specifies the remote host and rsync module to use.  

## Exclude Multiple Patterns  
Example Usage:  
`rsync -av --exclude='logs/' --exclude='*.tmp' /source/ /destination/`  
What it does:  
Copies files while excluding multiple specified directories and file types.  
Command-line Arguments Explained:  
- `-a`: Preserves attributes.  
- `-v`: Verbose output.  
- `--exclude='pattern'`: Excludes files/directories matching the pattern (can be used multiple times).  

## Use Checksum and Backup Together  
Example Usage:  
`rsync -av --checksum --backup /source/ /destination/`  
What it does:  
Copies files using checksum validation and backs up existing destination files.  
Command-line Arguments Explained:  
- `-a`: Preserves attributes.  
- `-v`: Verbose output.  
- `--checksum`: Compares files via checksum.  
- `--backup`: Creates backups of overwritten files.