Published 2025-01-15.
Last modified 2025-01-17.
Time to read: 3 minutes.
git collection.
Git URLs that rely upon SSH can be specified in various ways. The following three examples accomplish exactly the same thing.
You can use the scp-like SSH syntax.
The scp-like syntax assumes that relative paths are based from the user home directory.
My home directory on server gojira is /home/mslinn.
$ git clone gojira:bare_repo1
$ git clone gojira:/home/mslinn/bare_repo1
You can also use the standard SSH URI syntax for Git URLs. The SSH Git syntax requires an absolute path.
$ ssh://gojira/home/mslinn/bare_repo1
Do Not Mention Port 22
SSH runs on port 22 by default, so there is no need to specify port 22 in a URL or URI. Doing so only makes the URL more complicated.
ssh://git@git.my_domain.com:22/path/to/my/repo
Avoid This Common Problem
If you use the URL syntax, the port separator is a slash, not a colon.
This example, which does not work, has two colons in it.
As well, this example specifies the default port for ssh (22), which unnecessarily complicates the URL.
ssh://git@git.myurl.de:22/mnt/raid/git-repos/reponame/info/lfs
ssh://git@git.myurl.de/22/mnt/raid/git-repos/reponame/info/lfs
Historical Background
The explanation of these two formats is historical:
All three of the remote operation programs in OpenSSH (ssh, scp, sftp),
accept arguments that comply to the SSH URI scheme, described in its own
IETF specification.
Broadly speaking, any URI is composed of five components: scheme, authority, path, query, and fragment. Furthermore, the authority can be composed of user info, host, and port. In the case of the SSH URI scheme, only scheme, authority, and path are allowed.
scheme authority path
| | |
/‾‾\/‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾\/‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾‾\
ssh://git@github.com:22/myuser/myrepo.git
\_/\_________/\_/
| | |
user host port
However, there's an alternative syntax that's quite similar to the standard SSH URI scheme, but not exactly compliant with it.
This syntax is a heritage from the old rcp (remote copy) program created in 1981,
almost a decade and a half before the creation of the URI protocol.
When the Berkeley r-commands were released,
to specify the destination of an operation in rsh (remote shell) or rlogin (remote login)
it was only required to specify the remote machine in which the operation was going to be performed,
and probably the user in that machine as well.
At that time, the consensus was the syntax username@hostname.
The rcp program, however, had an additional condition: to copy files from, or to, one remote location,
the developer was required to specify the path of the file in that remote machine, in addition to the user and host,
just as the cp program does.
The syntax they devised was to append the path to the end of the user/host declaration,
separated by a colon: username@hostname:path/to/file
(as described in its own man page).
git@github.com:myuser/myrepo.git \_/ \________/ \_______________/ | | | user host path
When the OpenSSH team implemented the scp program,
they wanted to provide a familiar API to the developers already using rcp,
so they decided to keep support for this old, custom syntax, in addition to the new standardized SSH URI scheme.
Then, in 2005, Git entered the scene with native support for SSH, probably using OpenSSH under the hood,
and the rcp-like syntax ended up being used when SSH is used for remote operations like
clone, fetch, push, and pull.
The Git documentation calls this syntax scp-like syntax, and it is briefly described in the scp man page, the git-clone docs, and the Git protocols docs. In the end, despite its lack of standardization, it seems to be the syntax used by all cloud Git services like GitHub or Bitbucket, when offering a URL for cloning repos.
