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Usually, I use the scp command to transfer files on *nixes.
What's the difference between SFTP and SCP? Don't they both work on SSH?
nos
Posted 2010-04-26T17:36:01.417
Reputation: 3 699
What's the difference between SCP and SFTP?
Answers
100
In a nutshell, SCP can only be used for transferring files, and it is non-interactive (i.e., everything has to be specified on the command line). SFTP is more elaborate, and allows interactive commands to do things like creating directories, deleting directories and files (all subject to system permissions, of course), etc.
Alex
Posted 2010-04-26T17:36:01.417
Reputation: 1 848
105
From Wikipedia:
Compared to the earlier SCP protocol, which allows only file transfers, the SFTP protocol allows for a range of operations on remote files – it is more like a remote file system protocol. An SFTP client's extra capabilities compared to an SCP client include resuming interrupted transfers, directory listings, and remote file removal. [1] For these reasons it is relatively simple to implement a GUI SFTP client compared with a GUI SCP client.
and
Although both SCP and SFTP utilize the same SSH encryption during file transfer with the same general level of overhead, SCP is usually much faster than SFTP at transferring files, especially on high latency networks. This happens because SCP implements a more efficient transfer algorithm, one which does not require waiting for packet confirmations. This leads to faster speed but comes at the expense of not being able to interrupt a transfer, so unlike SFTP, SCP transfer cannot be canceled without terminating the session.
Jarvin
Posted 2010-04-26T17:36:01.417
Reputation: 6 712
4"But comes at the expense of not being able to interrupt a transfer". That's a pretty important trade-off. – aaaaaa – 2016-06-25T01:42:28.507
aaaaaa, "without terminating the session" which is not a big deal if all the session is for is copying the file. If you are copying a lot of files, the client can also wait for an individual file copy to complete. – Victor Sergienko – 2019-09-18T18:56:12.627
18"SCP is usually much faster than SFTP at transferring files." – Micah Bolen – 2013-10-04T10:35:10.507
9
From a purely command line perspective :
- scp doesn't have an interactive mode nor can it read command scripts, that means everything must be written on the command line.
- sftp has an interactive mode and can read commands from a file.
Other important difference between the 2 commands is that sftp cannot put a local file to a remote location using a single command line, although it can get remote file, while scp can do both.
sftp get remote file
sftp user@host:/path/to/remote.file [/path/to/local.file]
scp get remote file
scp user@host:/path/to/remote.file [/path/to/local.file]
scp put remote file
scp /path/to/local.file user@host:[/path/to/remote.file]
Stéphane Ch.
Posted 2010-04-26T17:36:01.417
Reputation: 101
2Putting a file: sftp {user}@{host}:{remote_dir} <<< $'put {local_file_path}' – gdw2 – 2019-04-18T17:16:35.270
3
SSH (Secure SHell) is a cryptographic network protocol to allow remote login and other network services to operate securely over an unsecured network.
Differences: SFTP is works on interactive mode (session) and SCP works on non-interactive. Using SFTP we can access remote file system i.e. creating, deleting, and listing files.
Similarities: Both SCP(Secure Copy Protocol) and SFTP (SSH File Transfer Protocol) are network protocols, which supports file management between hosts on a network. Both uses SSH.
Premraj
Posted 2010-04-26T17:36:01.417
Reputation: 1 228
2
Most differences of the two protocols have already been said in other answers, and more verbosely in https://unix.stackexchange.com/q/8707/19088
Another difference, according to the documentation of curl, is that the SCP protocol is not very portable and usually only works between Unix systems.
By the way, curl implements both protocols and unlike the default OpenSSH SFTP client implementation, it is non-interactive for both SFTP and SCP.
And note that there is also the FISH protocol, which allows you to transfer files via SSH without the need of SCP or SFTP. As far as I know FISH is not very popular, currently implemented in just a few file managers (Midnight Commander and some that are KDE-based) and Lftp.
Pere
Posted 2010-04-26T17:36:01.417
Reputation: 749
2"Another difference, according to the documentation of curl, is that the SCP protocol is not very portable and usually only works between Unix systems." The irony of this part of your answer is that the most popular SCP GUI is called WinSCP, and - you've guessed it - it is a Windows Program. – brett – 2018-02-26T18:11:06.943
1@brett the most popular client is probably OpenSSH's scp, I would say it is highly deployed. WinSCP is an SCP/SFTP/etc client but is nowadays mostly used as an (S)FTP client: "In June 2003 version 3.0 was released, introducing support for the alternative to SCP, the SFTP protocol. Over time it evolved from the alternative to the primary protocol. Despite this, the well-established name “WinSCP” was preserved." (from History of WinSCP: winscp.net/eng/docs/project_history) – Pere – 2018-02-26T21:39:21.217
34Regarding interactivity: The difference you describe is about specific SFTP/SCP clients as implemented in OpenSSH. It's nothing about the protocols themselves. It's perfectly possible to implement interactive SCP client or non-interactive SFTP client. – Martin Prikryl – 2014-10-08T06:06:39.857
4One more thing: scp does not work if the server only permits SFTP access via the line
ForceCommand internal-sftp. I thinkPermitTTY noalso prevents scp access but allows sftp access, though I could have just mistyped my password every single time I tried. But those two things should not prevent sftp. Source: personal experience. – ecube – 2016-10-10T07:27:42.647Can I assume that any SFTP server is also capable of accepting SCP transfers? – gus – 2017-04-25T08:00:22.847
@gus no, see ecube's comment – Pere – 2017-08-13T18:30:59.920