在阅读了许多答案和多个帖子，并花了半天时间尝试各种排列之后，这就是我想出的。

如果你在Windows上，你可以使用Git for Windows提供的Git Bash在Windows中运行这个脚本(安装或移植)。

这个脚本需要参数

- local path e.g. /d/source/project1
- Git URL e.g. https://username@bitbucket.org/username/project1.git
- password

if a password should not be entered on the command line in plain text,
then modify the script to check if GITPASS is empty; do not
replace and let Git prompt for a password

脚本将会

- Find the current branch
- Get the SHA1 of the remote on that branch
- Get the SHA1 of the local on that branch
- Compare them.

如果脚本打印了更改，那么您可以继续获取或拉取。脚本可能效率不高，但它为我完成了工作。

更新- 2015-10-30:stderr to dev null，防止将URL和密码打印到控制台。

#!/bin/bash

# Shell script to check if a Git pull is required.

LOCALPATH=$1
GITURL=$2
GITPASS=$3

cd $LOCALPATH
BRANCH="$(git rev-parse --abbrev-ref HEAD)"

echo
echo git url = $GITURL
echo branch = $BRANCH

# Bash replace - replace @ with :password@ in the GIT URL
GITURL2="${GITURL/@/:$GITPASS@}"
FOO="$(git ls-remote $GITURL2 -h $BRANCH 2> /dev/null)"
if [ "$?" != "0" ]; then
  echo cannot get remote status
  exit 2
fi
FOO_ARRAY=($FOO)
BAR=${FOO_ARRAY[0]}
echo [$BAR]

LOCALBAR="$(git rev-parse HEAD)"
echo [$LOCALBAR]
echo

if [ "$BAR" == "$LOCALBAR" ]; then
  #read -t10 -n1 -r -p 'Press any key in the next ten seconds...' key
  echo No changes
  exit 0
else
  #read -t10 -n1 -r -p 'Press any key in the next ten seconds...' key
  #echo pressed $key
  echo There are changes between local and remote repositories.
  exit 1
fi

所有这些复杂的建议，而解决方案却如此简单:

#!/bin/bash

BRANCH="<your branch name>"
LAST_UPDATE=`git show --no-notes --format=format:"%H" $BRANCH | head -n 1`
LAST_COMMIT=`git show --no-notes --format=format:"%H" origin/$BRANCH | head -n 1`

git remote update
if [ $LAST_COMMIT != $LAST_UPDATE ]; then
        echo "Updating your branch $BRANCH"
        git pull --no-edit
else
        echo "No updates available"
fi

我只是想把这篇文章作为一个实际的帖子，因为它很容易在评论中错过。

这个问题的正确答案来自@Jake Berger，非常感谢你，每个人都需要这个，每个人都在评论中错过了这个。 因此，对于每个纠结于此的人来说，这里是正确的答案，只需使用该命令的输出来了解是否需要进行git拉取。如果输出为0，那么显然没有什么要更新的。

@stackoverflow，给这家伙一个铃铛。 谢谢@杰克·伯格

# will give you the total number of "different" commits between the two
# Jake Berger Feb 5 '13 at 19:23
git rev-list HEAD...origin/master --count

我使用了一个基于Stephen Haberman回答的脚本版本:

if [ -n "$1" ]; then
    gitbin="git -C $1"
else
    gitbin="git"
fi

# Fetches from all the remotes, although --all can be replaced with origin
$gitbin fetch --all
if [ $($gitbin rev-parse HEAD) != $($gitbin rev-parse @{u}) ]; then
    $gitbin rebase @{u} --preserve-merges
fi

假设此脚本名为Git -fetch-and-rebase，可以使用本地Git存储库的可选参数目录名来调用它，以执行操作。如果调用脚本时不带参数，则假定当前目录是Git存储库的一部分。

例子:

# Operates on /abc/def/my-git-repo-dir
git-fetch-and-rebase /abc/def/my-git-repo-dir

# Operates on the Git repository which the current working directory is part of
git-fetch-and-rebase

这里也有。

下面是一个Bash一行代码，比较了当前分支的HEAD提交哈希和它的远程上游分支，不需要大量的git获取或git拉取——需要干运行操作:

[ $(git rev-parse HEAD) = $(git ls-remote $(git rev-parse --abbrev-ref @{u} | \
sed 's/\// /g') | cut -f1) ] && echo up to date || echo not up to date

以下是这条有点密集的线是如何被分解的:

Commands are grouped and nested using $(x) Bash command-substitution syntax. git rev-parse --abbrev-ref @{u} returns an abbreviated upstream ref (e.g. origin/master), which is then converted into space-separated fields by the piped sed command, e.g. origin master. This string is fed into git ls-remote which returns the head commit of the remote branch. This command will communicate with the remote repository. The piped cut command extracts just the first field (the commit hash), removing the tab-separated reference string. git rev-parse HEAD returns the local commit hash. The Bash syntax [ a = b ] && x || y completes the one-liner: this is a Bash string-comparison = within a test construct [ test ], followed by and-list and or-list constructs && true || false.

自动化git拉取所需的分支: 例如:./pull.sh "origin/main"

pull.sh

#!/bin/bash

UPSTREAM=${1:-'@{u}'}
DIFFCOMM=$(git fetch origin --quiet; git rev-list HEAD..."$UPSTREAM" --count)
if [ "$DIFFCOMM" -gt 0 ]; then
  echo "Pulling $UPSTREAM";
  git pull;
else
  echo "Up-to-date";
fi