如果还没有本地，则可以使用克隆进行拉取的 Git 快捷方式？

Git shortcut to pull with clone if no local there yet?

提问by inger

Is there a one-command way to get an up-to-date mirror of a remote repo? That is

有没有一种单一命令的方式来获取远程仓库的最新镜像？那是

• if local repo not there yet: clone
• if it's there: pull

• 如果本地仓库还没有：克隆
• 如果它在那里：拉

I know I could script this around (e.g if [ -d repo ]; then (cd repo && git pull); else git clone $repourl;fi ) , but I need the simplest possible cross-platform way (actually used for Jenkins-CI, which I know does this by default, however I need 2 repos for which support is limited).

我知道我可以围绕（例如if [ -d repo ]; then (cd repo && git pull); else git clone $repourl;fi ）编写脚本，但我需要最简单的跨平台方式（实际上用于 Jenkins-CI，我知道默认情况下会这样做，但是我需要 2 个支持有限的存储库）。

Git has similar shortcuts for other things (eg. checkout -b, and pull itself), so I'm wondering if I missed something. Thanks!

Git 对其他事情也有类似的快捷方式（例如 checkout -b 和 pull 自身），所以我想知道我是否遗漏了什么。谢谢！

采纳答案by VonC

git pullknows from where to clone because the local repo has a remote registered in its local config. It operates from a working tree.

git pull知道从哪里克隆，因为本地存储库在其本地配置中注册了一个远程。它从一个工作树运行。

But git clonedoesn't, it must have an explicit remote url passed in parameter in order to clone. It operates outside the working tree.

但git clone不是，它必须有一个显式的远程 url 传入参数才能克隆。它在工作树之外运行。

The main reason for such a shortcut to notexist is that:

这种快捷方式不存在的主要原因是：

• you git initrarely for a given repo: it is a one-time command in the life of the repo.
  Plus it might need additionalcommand to be complete: if you havesubmodules, for instance, you would need to add a git submodule update --init.
• you git pulloften within a given repo. git pull is in itself a shortcut (for git fetch+ git merge). Even git pull --rebaseis another shortcut for git fetch+ git rebase.

• 你git init很少使用给定的 repo：它是 repo 生命周期中的一次性命令。
  此外，它可能需要额外的命令才能完成：例如，如果您有子模块，则需要添加一个git submodule update --init.
• 你git pull经常在给定的回购中。git pull 本身就是一个快捷方式（对于git fetch+ git merge）。Evengit pull --rebase是git fetch+ 的另一个快捷方式git rebase。

Considering the number of times you are to use git init, such a shortcut is not an high priority.

考虑到您要使用的次数git init，这种快捷方式的优先级并不高。

So a script remains the surest way to define what you need.

因此，脚本仍然是定义所需内容的最可靠方式。

回答by Amber

There is not, given that the commands which operate on existing repos all assume that they're being run inside a given repo.

没有，因为在现有存储库上运行的命令都假设它们是在给定存储库中运行的。

That said, if you're running in a shell, you could simply make use of the shell built-ins. For instance, here's bash:

也就是说，如果您在 shell 中运行，则可以简单地使用 shell 内置程序。例如，这里是 bash：

if cd repo; then git pull; else git clone https://server/repo repo; fi

This checks to see if repois a valid directory, and if so, does a pullwithin it; otherwise it does a cloneto create the directory.

这会检查是否repo是有效目录，如果是，则pull在其中执行 a ；否则它会clone创建目录。

回答by jhrmnn

The cleanest one-liner might be

最干净的单线可能是

git -C repo pull || git clone https://server/repo repo

回答by Noam Manos

git -C repo pullwill only work on git 1.8.5or above. To achieve this on earlier versions, try:

git -C repo pull仅适用于git 1.8.5或更高版本。要在早期版本上实现这一点，请尝试：

remote_repo=https://server/repo
local_repo=repo

if [ -d $local_repo/.git ]; then pushd $local_repo; git pull; popd; else git clone $remote_repo; fi

回答by andylukem

If upgrading git is not an option, and you don't want to pass an argument for a repo, a scripting approach could be:

如果升级 git 不是一种选择，并且您不想为 repo 传递参数，则脚本方法可能是：

#!/bin/bash

function clone_pull {
  DIRECTORY=$(basename "" .git)
  if [ -d "$DIRECTORY" ]; then
    cd "$DIRECTORY"
    git pull
    cd ../
  else
    git clone ""
  fi
}

clone_pull https://github.com/<namespace>/<repo>
# or
clone_pull [email protected]:<namespace>/<repo>.git

回答by yoyo

Since you mentioned Jenkins, it is possible to clone or pull using the Jenkins SCM API. The checkoutmethod does exactly what you want.

由于您提到了 Jenkins，因此可以使用Jenkins SCM API进行克隆或拉取。该checkout方法完全符合您的要求。

You can run it from a groovy script like so:

你可以像这样从一个 groovy 脚本运行它：

dir (targetFolder) {
  checkout(scm: [$class: 'GitSCM', branches: [[name: 'master']], ...])
}

Note that it does not check out the specified branch in the git sense, but rather leaves the workspace on a detached head at the corresponding commit.

请注意，它不会检出 git 意义上的指定分支，而是将工作区留在相应提交时的分离头上。