We usually have to transfer files between two computers, such as config, log, image. There are a lot of tools that could do it, but if we only know one approach, we would have trouble quickly, so I’m going to show you five tools relate to the topic.
scp is a command line utility that allows you to copy files and directories between two locations securely. It put at first order is because it’s the best choice if we could. With
scp, we could:
- copy from your local to a remote
- copy from a remote to your local system
- copy between two remotes from your local
When scp transferring data, both password and files are encrypted so anyone could see the packet can’t get any sensitive.
The format of the command is:
scp [OPTION] [user@]SRC_HOST:]file1 [user@]DEST_HOST:]file2
$ scp log.txt email@example.com:~/
Means copy the
./log.txt to the home directory of
188.8.131.52 this computer.
scp just like
cp, as you thought, copy remote to local was:
$ scp firstname.lastname@example.org:~/log.txt ./
If you want to copy between two remote:
$ scp email@example.com:~/log.txt firstname.lastname@example.org:~/
Usually, you need a key to use
scp, to add it into command, use the option
-i to do that:
$ scp -i /path/to/key $src $dst
There are a lot of useful options, just quickly pick some at here:
-r: recursively copy the directories
-P: specific port
-C: force compress data
To get more information, take a look at scp man page
scp is powerful, sometimes the environment couldn’t use it.
nc is a network testing tool actually, but if you use:
$ nc -l 8888 | tar zvf -
Nice, you listen on port
8888 now, next thing is transfer data to it.
$ tar cvf - ./file | nc localhost 8888
For a lazy guy:
# listen $ nc -l 8888 > file $ nc localhost 8888 < file
nc would close after receiving some data, so if we don’t want that, try:
$ while true; do nc -l 8888 | tar zvf -; done
If you have no choice or want to provide a long time server, and no like to remember a lot of pipeline command, try
$ python3 -m http.server
It would start a file server at your command location.
nc section, could see we already use this tool,
tar is helpful while the file is quite big, reduce the size to improve our life.
# compress $ tar cvf file # extract $ tar zvf file
To get more information: tar man page
At the previous section, we are assuming the target have public ip could reach easily. But life is hard. Sometimes we didn’t have public ip; for this situation,
ngrok could help.
This tool has to download by yourself.
Let’s show how to use it:
# expose localhost:8080 by HTTP $ ngrok http 8080 # expose localhost:8080 by TCP $ ngrok tcp 8080
The TCP is beneficial for
nc command. And HTTP is useful while you create a file server.
In this tutorial, you learn how to transfer files by different tools and solve the limited networking environment issue to transfer data between different computers. Thanks for reading.