在多个分支中寻找第一次提交的shell函数:

# Get the first commit hash of a given branch.
# Uses `git branch --contains` to backward (starts from HEAD) check each commits
# and output that branch's name.
first_commit_of_branch() {
    if [ $# -ne 1 ] || [ -z "${1}" ] ; then
        (>&2 echo "Error: Missing or empty branch name.")
        (>&2 echo "Usage: $0 branch_to_test")
        return 2
    fi
    local branch_to_test="${1}"; shift
    local commit_index_to_test
    local maximum_number_of_commit_to_test
    local branch_count_having_tested_commit

    git rev-parse --verify --quiet "${branch_to_test}" 2>&1 > /dev/null || {
        (>&2 echo "Error: Branch \"${branch_to_test}\" does not exists.")
        return 2
    }

    commit_index_to_test=0
    maximum_number_of_commit_to_test=$(git rev-list --count "${branch_to_test}")

    while [ ${commit_index_to_test} -le ${maximum_number_of_commit_to_test} ] ; do
        # Testing commit $branch_to_test~$commit_index_to_test…

        # If it fails, it means we tested all commits from the most recent of
        # branch $branch_to_test to the very first of the git DAG. So it must be it.
        git rev-parse --verify --quiet ${branch_to_test}~${commit_index_to_test} 2>&1 > /dev/null || {
            git rev-list --max-parents=0 "${branch_to_test}"
            return 0
        }

        branch_count_having_tested_commit="$( \
            git --no-pager branch --no-abbrev --verbose \
                --contains ${branch_to_test}~${commit_index_to_test} \
            | cut -c 3- \
            | cut -d ' ' -f 2 \
            | wc -l \
        )"

        # Tested commit found in more than one branch
        if [ ${branch_count_having_tested_commit} -gt 1 ] ; then
            if [ ${commit_index_to_test} -eq 0 ]; then
                (>&2 echo "Error: The most recent commit of branch \"${branch_to_test}\" (${branch_to_test}~${commit_index_to_test}) is already in more than one branch. This is likely a new branch without any commit (yet). Cannot continue.")
                return 1
            else
                # Commit $branch_to_test~$commit_index_to_test is in more than
                # one branch, stopping there…
                git rev-parse ${branch_to_test}~$((commit_index_to_test-1))
                return 0
            fi
        fi
        # else: Commit $branch_to_test~$commit_index_to_test is still only in
        #       branch ${branch_to_test} continuing…"
        commit_index_to_test=$((commit_index_to_test+1))
    done
}

警告:当在一个有子分支的分支上执行并且没有新的提交时，它会失败。

A---B---C---D      <- "main" branch
 \   \
  \   E---F        <- "work1" branch
   \       \
    \       G---H  <- "work1-b" branch
     \
      I---J        <- "work2" branch

first_commit_of_branch main # C
first_commit_of_branch work1 # (Fails)
first_commit_of_branch work1-b # G
first_commit_of_branch work2 # I

对于您的整体问题，我有一个解决方案(确定feature是否源自develop的提示)，但使用您概述的方法它不起作用。

你可以使用git branch——contains列出所有来自develop提示的分支，然后使用grep确保feature在其中。

git branch --contains develop | grep "^ *feature$"

如果是其中之一，则将“feature”打印到标准输出，并返回代码为0。否则，它将不打印任何东西，并有一个返回代码1。

Mark Reed的解决方案基本上是正确的。但是，请注意，提交行不仅应该包含星号，而且应该以星号开头!否则，包含星号的提交消息也包含在匹配的行中。所以它应该是:

git show-branch——| awk - f '[]^~[]' '/^\*/ && !/'"$ current_branch”/{打印2美元;退出}'

或者是更长的版本:

git show-branch -a           |
  awk '^\*'                  | # we want only lines that contain an asterisk
  awk -v "$current_branch"   | # but also don't contain the current branch
  head -n1                   | # and only the first such line
  sed 's/.*\[\(.*\)\].*/\1/' | # really, just the part of the line between []
  sed 's/[\^~].*//'            # and with any relative refs (^, ~n) removed`

当我做了像develop→release-v1.0.0→feature-foo这样的事情时，这对我来说并不管用。它会一直往回发展。请注意，其中涉及到一个基数调整，我不确定这是否加剧了我的问题……

下面给出了正确的提交哈希值:

git log --decorate \
  | grep 'commit' \
  | grep 'origin/' \
  | head -n 2 \
  | tail -n 1 \
  | awk '{ print $2 }' \
  | tr -d "\n"

我不喜欢解析半结构化文本输出时涉及的不安全假设，所以我想要一个更健壮的解决方案，假设更少:

# Search backwards in history for the first commit that is in a branch other than $1
# and output that branch's name.
parent_branch() {
    local result rev child_branch=$1
    rev=$(git rev-parse --revs-only $child_branch)
    while [[ -n $rev ]]; do
        result=$(git branch --contains $rev | grep -v " $child_branch$")
        if [[ -n $result ]]; then
            echo $result
            return 0
        fi
        rev=$(git rev-parse --revs-only $rev^)
    done
    return 1
}

注意:由于这是在历史上进行迭代，查看每个提交以找到第一个在不同分支中而不是$1的提交，因此分支越长，它的开销就越高。但是，由于通常情况下分支应该是相对短暂的，所以这不应该是一个太大的问题。

还要注意，我使用的是git branch——contains，所以这也会找到共享公共基础但已经超越它的分支。要只找到确切指向公共基的分支，请使用git branch——points-at。

如果你使用Sourcetree，查看你的提交细节→Parents。然后您将看到带下划线的提交数字(链接)。