Bash字符串拼接后通过curl发送JSON至GitHub API的问题排查

尝试通过curl调用GitHub API添加issue评论，执行的脚本如下：

body="\"\:warning\: \:exclamation\: Your pull request is not linked to any issue, please make the corresponding changes in the very first comments body by adding \'Fixes #issue-number\' or \'Resolves #issue-number\'. If your pull request isn\'t linked to any issue, ignore this comment\!\""
echo $body
json="'{\"body\": ${body} }'"
echo $json
statusCode=`curl -X POST -H 'Accept: application/vnd.github+json' -H 'Authorization: token ****' -H 'Content-Type: application/json' https://api.github.com/repos/Ismoh/NoitaMP/issues/79/comments -d $json`
echo "statusCode="$statusCode

执行echo $body输出：

"\"\:warning\: \:exclamation\: Your pull request is not linked to any issue, please make the corresponding changes in the very first comments body by adding \'Fixes #issue-number\' or \'Resolves #issue-number\'. If your pull request isn\'t linked to any issue, ignore this comment\!\""

执行echo $json输出：

'{"body": "\"\:warning\: \:exclamation\: Your pull request is not linked to any issue, please make the corresponding changes in the very first comments body by adding \'Fixes #issue-number\' or \'Resolves #issue-number\'. If your pull request isn\'t linked to any issue, ignore this comment\!\" }'

执行curl时出现错误，核心错误包括：

{
  "message": "Problems parsing JSON",
  "documentation_url": "https://docs.github.com/rest/reference/issues#create-an-issue-comment"
}
curl: (6) Could not resolve host: Your
...
curl: (3) unmatched close brace/bracket in URL position 1:
}'

GitHub API官方示例：

curl \
  -X POST \
  -H "Accept: application/vnd.github+json" \
  -H "Authorization: Bearer <YOUR-TOKEN>" \
  https://api.github.com/repos/OWNER/REPO/issues/ISSUE_NUMBER/comments \
  -d '{"body":"Me too"}'

疑问：操作哪里出错了？有没有更合适的JSON字符串转义方法？已尝试jq -Rsa .但无效。

1. 变量引用未加引号导致参数拆分：-d $json没有用双引号包裹，shell会将JSON中的空格作为参数分隔符，把文本内容拆分成多个curl参数，curl错误地将这些内容当作URL处理，从而出现"无法解析主机"的错误。
2. 手动JSON转义错误：手动拼接JSON时，对引号、特殊字符的转义处理混乱，生成的JSON格式不符合规范，导致GitHub API无法解析。
3. 错误的JSON拼接方式：用单引号包裹整个JSON字符串，同时内部又包含转义的双引号，这种写法容易出现格式冲突，进一步破坏JSON结构。

方法一：用jq自动生成JSON（推荐） #

jq可以自动处理JSON所需的转义逻辑，避免手动转义的错误，写法更简洁可靠：

# 定义原始文本，无需手动转义任何字符
body=":warning: :exclamation: Your pull request is not linked to any issue, please make the corresponding changes in the very first comments body by adding 'Fixes #issue-number' or 'Resolves #issue-number'. If your pull request isn't linked to any issue, ignore this comment!"

# 用jq生成符合规范的JSON，自动处理转义
json=$(jq -n --arg body "$body" '{"body": $body}')

# curl调用时，必须用双引号包裹$json，防止shell拆分参数
statusCode=$(curl -X POST \
  -H 'Accept: application/vnd.github+json' \
  -H 'Authorization: token ****' \
  -H 'Content-Type: application/json' \
  https://api.github.com/repos/Ismoh/NoitaMP/issues/79/comments \
  -d "$json")

echo "statusCode=$statusCode"

说明：jq -n --arg body "$body" '{"body": $body}'会将shell变量$body安全传入jq，自动生成正确转义的JSON字符串，完全符合GitHub API的格式要求。

方法二：手动修正转义和变量引用（不推荐） #

如果坚持手动拼接，需要严格处理引号和变量引用：

# 用单引号定义body，内部单引号通过'\''转义
body=':warning: :exclamation: Your pull request is not linked to any issue, please make the corresponding changes in the very first comments body by adding '\''Fixes #issue-number'\'' or '\''Resolves #issue-number'\''. If your pull request isn'\''t linked to any issue, ignore this comment!'

# 拼接JSON，确保双引号正确转义
json="{\"body\": \"$body\"}"

# curl调用时用双引号包裹$json
statusCode=$(curl -X POST \
  -H 'Accept: application/vnd.github+json' \
  -H 'Authorization: token ****' \
  -H 'Content-Type: application/json' \
  https://api.github.com/repos/Ismoh/NoitaMP/issues/79/comments \
  -d "$json")

echo "statusCode=$statusCode"

内容的提问来源于stack exchange，提问作者Ismoh