bash Shell脚本检查指定的Git分支是否存在？
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Shell script to check if specified Git branch exists?
提问by hzxu
I need to create a Git branch using shell script, but since the branch may exist, I need to be aware of that. Currently I'm using:
我需要使用 shell 脚本创建一个 Git 分支，但由于分支可能存在，我需要注意这一点。目前我正在使用：
if [ `git branch | grep $branch_name` ]
then
echo "Branch named $branch_name already exists"
else
echo "Branch named $branch_name does not exist"
fi
But the problem is the grepcommand finds branch name without matching the exact name, that is, if I grep namethen branch with a name branch-namewould be matched.
但问题是该grep命令会在不匹配确切名称的情况下查找分支名称，也就是说，如果我grep name再branch-name匹配具有名称的分支。
So is there a better way to do this?
那么有没有更好的方法来做到这一点？
Thanks!
谢谢！
回答by Heath
NOTE: This always returns true. This is not the right answer to the question, even though it has been accepted....
注意：这总是返回 true。这不是问题的正确答案，即使它已被接受......
You could always use word boundaries around the name like \<and \>, but instead let Git do the work for you:
您总是可以在名称周围使用单词边界，例如\<and \>，而是让 Git 为您完成工作：
if [ `git branch --list $branch_name` ]
then
echo "Branch name $branch_name already exists."
fi
回答by David
I like Heath's solution, but if you still want to pipe to grep, you can use regex anchors, similar to the following, to preclude matching a substring:
我喜欢 Heath 的解决方案，但如果您仍想通过管道传递给 grep，则可以使用类似于以下内容的正则表达式锚点来排除匹配子字符串：
if [ `git branch | egrep "^[[:space:]]+${branchname}$"` ]
then
echo "Branch exists"
fi
Note that you need to use the spacecharacter class because the output of the command is indented.
请注意，您需要使用space字符类，因为命令的输出是缩进的。
