鱼壳：如何解释 git 响应？

Question

对于我的工作区环境，我目前正在创建一个脚本，以便在我的开发和发布分支之间轻松切换。不幸的是，repo 并不总是具有相似的分支名称，因此我检查分支是否存在以及分支是否已合并到 master。如果分支还没有合并到master，我知道我有最新的release分支。

        set repo_has_changes (git status --porcelain --untracked-files=no)

        if test -n $repo_has_changes
            echo 'Repo has changes...'
        else
            git checkout master

            for b in $releaseVersions
                set branch_on_origin (git branch -r --list origin/$b)
                set branch_not_merged_to_master (git branch -r --list --no-merged master origin/$b)

                if test -n $branch_on_origin
                    if test -z $branch_not_merged_to_master
                        git checkout $b
                        git pull
                        break
                    end
                end
            end
        end

在我的无知中，我以为我存储了 git 命令的结果，并将其存储在一个变量中。我将其解释为字符串。根据fish文档，我可以测试一个字符串是否非零。

-n STRING 如果 STRING 的长度不为零，则返回 true。

此脚本将始终回显“Repo has changes...”，而我 100% 确定它没有更改。 如果我回显 $repo_has_changes 我会看到一个空行。此外，如果我检查字符串的长度（以防字符串返回空格？xD），它也会返回一个空行。所以我假设 $repo_has_changes 是一个字符串可能是错误的。另外我不确定我是否能够以这种方式存储 git 结果。不幸的是，我无法找到一个好的来源。

Answer 1

不幸的是，fish 的test 是遵循 POSIX 的少数几个部分之一，它指定带有任何一个参数的 test 必须返回 true，以便于使用 test "thestring"。不幸的是，这也意味着 test -n 必须返回 true。

这确实意味着您需要引用传递给 test 的任何变量：

test -n "$branch_on_origin"

和

test -z "$branch_not_merged_to_master"

Answer 2

之前的回答几乎回答了我假设的问题。但是，我最近开发了自己的自定义鱼类提示，其中包括右手提示。我把我的 git 信息放在右边。两个文件我都不会附上，但我会提供右侧提示功能文件的内容。它不会准确显示您所要求的内容，但在函数中有涵盖相同信息等信息的示例。如果不出意外，我希望这将是在鱼提示符中处理 git 信息的一个很好的例子。

我的右侧提示函数文件（~/.config/fish/functions/fish_right_prompt.fish）：

function fish_right_prompt -d "Write out the right prompt"
    set -l last_status $status # Special variable for storing last `$status` returned by terminal.
    set -l is_git_repository (git rev-parse --is-inside-work-tree ^/dev/null) # Special variable indicating git.
    # ==============
    # Status Segment
    # ==============
    # This segment is not visible in the prompt by default. It checks the `$last_status` variable to see if the
    # terminal's last executed command or function returned an error status. If it did then the status segment is
    # generated based on the returned status code, formatted and colored accordingly, and printed to prompt.
    # --------------
    if not test $last_status -eq 0 # Test if `$last_status` is not equal to `0`.
        set_color -o red # Color the prompt bold red.
        # Eventually it would be cool to include conditional programming here to generate unique output for any
        # error cases to print to the prompt. For now, I'm just going to have this segment print a generic
        # formatted string to the prompt in the event of any errors.
        printf "%b" "\U203C Error Code $last_status \U203C"
        set_color normal
    end
    # ===========
    # Git Segment
    # ===========
    # An optional segment that is generated and printed to the prompt if the PWD is a git repository. If the
    # segment is generated it displays a variety of indicators and information depending on the current state of
    # repo.
    # -----------
    if test -n "$is_git_repository" # Test if the PWD is an active git repository.
        set_color A3A3A3 # Color the prompt grey. (Uses a hex color.)
        echo -n "[git:" # Echo the git repo indicator.
        set -l branch (git symbolic-ref --short HEAD ^/dev/null; or git show-ref --head -s --abbrev | head -n1 ^/dev/null)
        git diff-files --quiet --ignore-submodules ^/dev/null; or set -l has_unstaged_files
        git diff-index --quiet --ignore-submodules --cached HEAD ^/dev/null; or set -l has_staged_files
        if set -q has_unstaged_files # Check if the repo is unstaged.
            set_color red # Color the prompt red.
        else if set -q has_staged_files # Check if the repo is staged.
            set_color yellow # Color the prompt yellow.
        else # If the repo is clean then proceed.
            set_color green # Color the prompt green.
        end
        echo -n "$branch]" # Echo the git branch into the prompt.
        git rev-parse --abbrev-ref '@{upstream}' >/dev/null ^&1; and set -l has_upstream # Set `$has_upstream`.
        if set -q has_upstream # Check if the repository has any upstream.
            set -l commit_counts (git rev-list --left-right --count 'HEAD...@{upstream}' ^/dev/null) # Commit counts.
            set -l commits_to_push (echo $commit_counts | cut -f 1 ^/dev/null) # Commits to push.
            set -l commits_to_pull (echo $commit_counts | cut -f 2 ^/dev/null) # Commits to pull.
            if test $commits_to_push != 0 # Check if there any commits to push.
                if test $commits_to_pull -ne 0 # Check if there are any commits to pull.
                    set_color red # Color the prompt red.
                else if test $commits_to_push -gt 3 # Check if there are more than 3 commits to push.
                    set_color yellow # Color the prompt yellow.
                else # If there are no commits to pull, and no more than 3 commits to push, then proceed.
                    set_color green # Color the prompt green.
                end
                echo -n " ⇡ " # Echo the upstream push symbol.
            end
            if test $commits_to_pull != 0 # Check if there are any commits to pull.
                if test $commits_to_push -ne 0 # Check if there are any commits to push
                    set_color red # Color the prompt red.
                else if test $commits_to_pull -gt 3 # Check if there are more than 3 commits to pull.
                    set_color yellow # Color the prompt yellow.
                else # If no commits to push, and no more than 3 commits to pull, then proceed. 
                    set_color green # Color the prompt green.
                end
                echo -n " ⇣ " # Echo the upstream pull symbol.
            end
            set_color normal # Reset color and text decoration.
        end
        if test (git stash list | wc -l) -gt 0 # Check if there are any stashed changes.
            set_color A3A3A3 # Color the prompt grey. (Uses a hex color.)
            echo -n " ☰ " # Echo the stacked changes symbol.
        end
        set_color normal # Reset color and text decoration.
    end
    # -------------------------------------------------------------------------------------------------------------
    # That's all there is to right side secondary prompt. All other prompt segments can be found in the fish
    # function file for the primary prompt: `fish_prompt.fish`.
    # -------------------------------------------------------------------------------------------------------------
end