scp flags & options
-r
Copy directories recursively.
scp -r ./project user@host:/home/user/
-P
Connect to a specific port on the remote host. Note: uppercase P (unlike ssh's lowercase -p).
scp -P 2222 file.txt user@host:/tmp/
-i
Use a specific private key file for authentication.
scp -i ~/.ssh/mykey file.txt user@host:/tmp/
-C
Enable compression during transfer.
scp -C largefile.tar.gz user@host:/data/
-p
Preserve modification times, access times, and modes from the original file.
scp -p file.txt user@host:/tmp/
-q
Quiet mode. Suppresses the progress meter and warnings.
scp -q file.txt user@host:/tmp/
-l
Limit bandwidth in Kbit/s.
scp -l 1000 largefile.tar.gz user@host:/data/
-3
Copy between two remote hosts through the local machine.
scp -3 user@host1:/file user@host2:/file