以上答案都没有考虑存在多个工作树的可能性。使用git update-ref或git branch -f更新当前在其他工作树中签出的分支会产生意想不到的副作用。

考虑一下我处理工作树的解决方案:

#! /usr/bin/env bash
set -euo pipefail

# Read the default remote from config, defaulting to "origin".
DEFAULT_REMOTE=$(git config --default origin --get clone.defaultRemoteName)

# Use first argument as remote name, fallback to default.
REMOTE=${1:-$DEFAULT_REMOTE}

# Resolve the rev that HEAD points at, so that we can give it
# a special treatment.
HEAD_REV=$(git rev-parse HEAD)

# Format that allows us to easily grep for local branches that are behind,
# and have an upstream at $REMOTE.
FORMAT="%(upstream:trackshort)%(upstream:remotename)|%(refname:short)"

# Get a list of revs that are checked out. We don't want to
# update refs that are pointing at them.
set +e
WORKTREE_REVS=$(git worktree list --porcelain | grep -Po "HEAD \K(.+)" | grep -v "$HEAD_REV")
set -e

git fetch $REMOTE

for BRANCH in $(git for-each-ref refs/heads --format="$FORMAT" | grep -Po "<$REMOTE\|\K(.+)")
do
    BRANCH_REV=$(git rev-parse $BRANCH)
    if [ "$BRANCH_REV" = "$HEAD_REV" ]
    then
        # This branch is currently checked out "here". Forward it carefully.
        set +e
        git merge --no-autostash --ff-only $BRANCH@{u}
        set -e
    elif grep -q "$BRANCH_REV" <<< "$WORKTREE_REVS"
    then
        # This branch is currently checked out by another. Leave it alone.
        echo "$BRANCH skipped, because it is checked out in another worktree. Use 'git worktree list' to diagnose."
    else
        # This branch is not checked out. Just update it!
        git update-ref refs/heads/$BRANCH $BRANCH@{u}
        echo "$BRANCH forwarded"
        fi
done

这里有很多答案，但没有一个是使用git-fetch直接更新本地ref，这比检查分支简单得多，也比git-update-ref更安全。

这里我们使用git-fetch来更新非当前分支，而git pull——ff-only用于当前分支。它:

不需要检查分支机构 仅在可以快进的情况下更新分支 当它不能快进时会报告吗

就是这样:

#!/bin/bash
currentbranchref="$(git symbolic-ref HEAD 2>&-)"
git branch -r | grep -v ' -> ' | while read remotebranch
do
    # Split <remote>/<branch> into remote and branchref parts
    remote="${remotebranch%%/*}"
    branchref="refs/heads/${remotebranch#*/}"

    if [ "$branchref" == "$currentbranchref" ]
    then
        echo "Updating current branch $branchref from $remote..."
        git pull --ff-only
    else
        echo "Updating non-current ref $branchref from $remote..."
        git fetch "$remote" "$branchref:$branchref"
    fi
done

从git-fetch的manpage:

   <refspec>
       The format of a <refspec> parameter is an optional plus +, followed by the source ref <src>,
       followed by a colon :, followed by the destination ref <dst>.

       The remote ref that matches <src> is fetched, and if <dst> is not empty string, the local ref
       that matches it is fast-forwarded using <src>. If the optional plus + is used, the local ref is
       updated even if it does not result in a fast-forward update.

通过指定git fetch <remote> <ref>:<ref>(没有任何+)，我们得到一个只在本地ref可以快进时更新它的fetch。

注意，这假设本地分支和远程分支的名称相同(并且您希望跟踪所有分支)，它实际上应该使用关于您拥有哪些本地分支以及它们被设置为跟踪的内容的信息。

为了完成Matt Connolly的回答，这是一种更安全的更新本地分支引用的方法，可以快进，而不签出分支。它不会更新不能快进的分支(即已经分离的分支)，也不会更新当前签出的分支(因为这样工作副本也应该更新)。

git fetch

head="$(git symbolic-ref HEAD)"
git for-each-ref --format="%(refname) %(upstream)" refs/heads | while read ref up; do
    if [ -n "$up" -a "$ref" != "$head" ]; then
        mine="$(git rev-parse "$ref")"
        theirs="$(git rev-parse "$up")"
        base="$(git merge-base "$ref" "$up")"
        if [ "$mine" != "$theirs" -a "$mine" == "$base" ]; then
            git update-ref "$ref" "$theirs"
        fi
    fi
done

将此脚本添加到Mac OS X的.profile中:

# Usage:
#   `git-pull-all` to pull all your local branches from origin
#   `git-pull-all remote` to pull all your local branches from a named remote

function git-pull-all() {
    START=$(git symbolic-ref --short -q HEAD);
    for branch in $(git branch | sed 's/^.//'); do
        git checkout $branch;
        git pull ${1:-origin} $branch || break;
    done;
    git checkout $START;
};

function git-push-all() {
    git push --all ${1:-origin};
};

这个命令会有帮助。

for branch in `git branch | sed 's/\*//g'`; do git checkout $branch && git rebase origin/$branch; done

似乎很多人都提供了类似的解决方案，但我想分享一下我的想法，并邀请其他人来贡献。这个解决方案有一个漂亮的彩色输出，优雅地处理您当前的工作目录，并且速度很快，因为它不做任何检出，并巧妙地保留您的工作目录。此外，它只是一个shell脚本，除了git之外没有其他依赖项。(目前只在OSX上测试过)

#!/usr/bin/env bash

gitup(){    
RED='\033[33;31m'
YELLO='\033[33;33m'
GREEN='\033[33;32m'
NC='\033[0m' # No Color

HEAD=$(git rev-parse HEAD)
CHANGED=$(git status --porcelain | wc -l)

echo "Fetching..."
git fetch --all --prune &>/dev/null
for branch in `git for-each-ref --format='%(refname:short)' refs/heads`; do

    LOCAL=$(git rev-parse --quiet --verify $branch)
    if [ "$HEAD" = "$LOCAL" ] && [ $CHANGED -gt 0 ]; then
        echo -e "${YELLO}WORKING${NC}\t\t$branch"
    elif git rev-parse --verify --quiet $branch@{u}&>/dev/null; then
        REMOTE=$(git rev-parse --quiet --verify $branch@{u})
        BASE=$(git merge-base $branch $branch@{u})

        if [ "$LOCAL" = "$REMOTE" ]; then
           echo -e "${GREEN}OK${NC}\t\t$branch" 
        elif [ "$LOCAL" = "$BASE" ]; then
            if [ "$HEAD" = "$LOCAL" ]; then
                git merge $REMOTE&>/dev/null
            else
                git branch -f $branch $REMOTE
            fi
            echo -e "${GREEN}UPDATED${NC}\t\t$branch"
        elif [ "$REMOTE" = "$BASE" ]; then
            echo -e "${RED}AHEAD${NC}\t\t$branch"
        else
            echo -e "${RED}DIVERGED${NC}\t\t$branch"
        fi
    else
        echo -e "${RED}NO REMOTE${NC}\t$branch"
    fi
done
}

https://github.com/davestimpert/gitup

对不起，我似乎也想出了与上面其他工具相同的名字。