2.7. Miscellaneous ClientsSeveral other clients are included in addition to ssh and scp :
2.7.1. sftpThe scp command is convenient and useful, but many users are already familiar with FTP (File Transfer Protocol), a more widely used technique for transferring files on the Internet. sftp is a separate file-transfer tool layered on top of SSH. It was developed by SSH Communications Security and was originally available only in SSH2, but other implementations have since appeared (e.g., client support in SecureFX and server support in OpenSSH). sftp is available only in SSH2: it is implemented as an SSH2 subsystem [Section 5.7, "Subsystems"] and thus not readily adaptable to use with SSH1.
Due to the nature of the FTP protocol, FTP clients are difficult to secure using TCP port forwarding, unlike most other TCP-based clients. [Section 11.2, "FTP Forwarding"]sftp is advantageous for several reasons:
2.7.2. sloginslogin is an alternative name for ssh, just as rlogin is a synonym for rsh. On Unix systems, slogin is simply a symbolic link to ssh. Note that the slogin link is found in SSH1 and OpenSSH but not SSH2. We recommend using just ssh for consistency: it's found in all these implementations and is shorter to type.
2.7.3. Hostname Linksssh for SSH1 and OpenSSH also mimics rlogin in another respect: support for hostname links. If you make a link to the ssh executable, and the link name isn't in the set of standard names ssh recognizes, ssh has special behavior. It treats the link name as a hostname and attempts to connect to that remote host. For example, if you create a link called terpsichore.muses.org and then run it:
These are rsh, ssh, rlogin, slogin, ssh1, slogin1, ssh.old, slogin.old, ssh1.old, slogin1.old, and remsh.
It's equivalent to running:$ ln -s /usr/local/bin/ssh terpsichore.muses.org $ terpsichore.muses.org Welcome to Terpsichore! Last login January 21st, 201 B.C. terpsichore>
You can create a collection of these links for all commonly used remote hosts. Note that support for hostname links has been removed in SSH2. (We have never found them to be very useful, ourselves, but the capability does exist in SSH1 and OpenSSH.)$ ssh terpsichore.muses.org Welcome to Terpsichore! Last login January 21st, 201 B.C. terpsichore>
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