json - getent passwd 以正确格式输出为 json

Question

我正在使用 jq 来尝试将 bash 命令输出转换为 json。但是，转换失败了。

使用这一行:

hostname && getent passwd | egrep -v '/s?bin/(nologin|shutdown|sync|halt)' | cut -d: -f1 | sudo xargs -I % sh -c  'echo %; chage -l %; echo' | jq --raw-input . | jq --slurp .

• 主机名必须是 json 的根元素
• 用户名必须是第一个元素
• getent passwd输出必须是username的子元素

是这样的: JSON

不使用 jq 的上述命令的输出结果为: Command Output

有人试过将 bash 输出正确地转换为 json 吗？谢谢

Answer 1

I'm using jq...

我知道 jq 在这里很流行，但我要推荐 Xidel为了这个任务。
虽然主要是一个 HTML/XML/JSON 解析器(使用 CSS、XPath、XQuery、JSONiq 和模式模板)，但 Xidel 也可以处理基本文本。

你说你想要一个像这样的 json:

{
  "hostname": "example",
  "users": [
    {
      "username": "example1",
      "details": {
        "LastPasswordChange": "Nov 12, 2018",
        "PasswordExpires": "never",
        "PasswordInactive": "never",
        "AccountExpires": "never",
        "MinDaysBetweenPasswordChange": "0",
        "MaxDaysBetweenPasswordChange": "99999",
        "NumOfDaysOfWarningBeforePasswordExpires": "7"
      }
    },
    {
      "username": "example2",
      "details": {
        "LastPasswordChange": "Nov 13, 2018",
        "PasswordExpires": "never",
        "PasswordInactive": "never",
        "AccountExpires": "never",
        "MinDaysBetweenPasswordChange": "0",
        "MaxDaysBetweenPasswordChange": "99999",
        "NumOfDaysOfWarningBeforePasswordExpires": "7"
      }
    }
  ]
}

这意味着 users 数组需要为每个用户分别填充对象(根据此 chage 程序的输出创建)。这就是为什么我会选择另一种方法。

假设getent passwd | egrep -v '/s?bin/(nologin|shutdown|sync|halt)' | cut -d: -f1 返回:

root
user1
user2

我们将通过管道传输到 Xidel 以首先创建一个基本的 json:

getent passwd | egrep -v '/s?bin/(nologin|shutdown|sync|halt)' | cut -d: -f1 | xidel -s - --xquery '
  {
    "hostname":"'$(hostname)'",
    "users":x:lines($raw) ! {
      "username":.
    }
  }
'

• 不需要在原始命令前加上 hostname &&，因为您只需从 Xidel 中调用它(这也使查询更容易)。
• 使用 x:lines($raw)，您可以从 Xidel 的输入(在本例中为标准输入)创建一个包含每一行的序列。要使用的替代函数是 tokenize($raw,"\n")。

查询输出:

{
  "hostname": "user",
  "users": [
    {
      "username": "root"
    },
    {
      "username": "user1"
    },
    {
      "username": "user2"
    }
  ]
}

接下来我们将从 Xidel 中调用 chage 来创建 details 对象:

getent passwd | egrep -v '/s?bin/(nologin|shutdown|sync|halt)' | cut -d: -f1 | xidel -s - --xquery '
  {
    "hostname":"'$(hostname)'",
    "users":x:lines($raw) ! {
      "username":.,
      "details":{|
        for $x in x:lines(
          system(x"chage -l {.}")
        )
        let $a:=tokenize(
          $x,
          ":"
        )
        return {
          normalize-space($a[1]):normalize-space($a[2])
        }
      |}
    }
  }
'

• system(x"chage -l {.}") 返回 chage -l root、chage -l user1 和chage -l user2.
• 使用 x:lines() 围绕它，您再次创建了每个新行的序列。例如，user2 输出的第一行:

Last password change                                  : Oct 23, 2018

• 对于这个序列(或行)中的每个项目，变量 $a 被创建，它保存这个项目一分为二的序列，以 : 作为分隔符. $a 因此对于第一项:

Last password change                                  # white-space up untill this point! 
 Oct 23, 2018

• 最后，属性值对被创建，空白标准化:

{
  "Last password change": "Oct 23, 2018"
}

查询输出:

{
  "hostname": "user",
  "users": [
    {
      "username": "root",
      "details": {
        "Last password change": "never",
        "Password expires": "never",
        "Password inactive": "never",
        "Account expires": "never",
        "Minimum number of days between password change": "0",
        "Maximum number of days between password change": "99999",
        "Number of days of warning before password expires": "7"
      }
    },
    {
      "username": "user1",
      "details": {
        "Last password change": "never",
        "Password expires": "never",
        "Password inactive": "never",
        "Account expires": "never",
        "Minimum number of days between password change": "0",
        "Maximum number of days between password change": "99999",
        "Number of days of warning before password expires": "7"
      }
    },
    {
      "username": "user2",
      "details": {
        "Last password change": "Oct 23, 2018",
        "Password expires": "never",
        "Password inactive": "never",
        "Account expires": "never",
        "Minimum number of days between password change": "0",
        "Maximum number of days between password change": "99999",
        "Number of days of warning before password expires": "7"
      }
    }
  ]
}

您可以更进一步:

getent passwd | egrep -v '/s?bin/(nologin|shutdown|sync|halt)' | cut -d: -f1 | xidel -s - --xquery '
  {
    "hostname":"'$(hostname)'",
    "users":x:lines($raw) ! {
      "username":.,
      "details":{|
        for $x in x:lines(
          system(x"chage -l {.}")
        )
        let $a:=tokenize(
          $x,
          ":"
        )
        return {
          string-join(
            for $x in tokenize(
              normalize-space($a[1]),
              " "
            )
            return
            upper-case(
              substring(
                $x,
                1,
                1
              )
            )||substring(
              $x,
              2
            )
          ):normalize-space($a[2]) ! (
            if (. castable as decimal) then
              number(.)
            else
              .
          )
        }
      |}
    }
  }
'

• 代替Last password change，使用...

string-join(for $x in tokenize(normalize-space($a[1])," ") return upper-case(substring($x,1,1))||substring($x,2))

...它返回:LastPasswordChange。

• 代替 "99999"(一个字符串)，用...

normalize-space($a[2]) ! (if (. castable as decimal) then number(.) else .)

...它返回:99999 作为 xs:decimal 原子类型。

查询输出:

{
  "hostname": "user",
  "users": [
    {
      "username": "root",
      "details": {
        "LastPasswordChange": "never",
        "PasswordExpires": "never",
        "PasswordInactive": "never",
        "AccountExpires": "never",
        "MinimumNumberOfDaysBetweenPasswordChange": 0,
        "MaximumNumberOfDaysBetweenPasswordChange": 99999,
        "NumberOfDaysOfWarningBeforePasswordExpires": 7
      }
    },
    {
      "username": "user1",
      "details": {
        "LastPasswordChange": "never",
        "PasswordExpires": "never",
        "PasswordInactive": "never",
        "AccountExpires": "never",
        "MinimumNumberOfDaysBetweenPasswordChange": 0,
        "MaximumNumberOfDaysBetweenPasswordChange": 99999,
        "NumberOfDaysOfWarningBeforePasswordExpires": 7
      }
    },
    {
      "username": "user2",
      "details": {
        "LastPasswordChange": "Oct 23, 2018",
        "PasswordExpires": "never",
        "PasswordInactive": "never",
        "AccountExpires": "never",
        "MinimumNumberOfDaysBetweenPasswordChange": 0,
        "MaximumNumberOfDaysBetweenPasswordChange": 99999,
        "NumberOfDaysOfWarningBeforePasswordExpires": 7
      }
    }
  ]
}

“美化”查询更容易阅读，但如果您更喜欢“缩小”版本:

getent passwd | egrep -v '/s?bin/(nologin|shutdown|sync|halt)' | cut -d: -f1 | xidel -s - --xquery '{"hostname":"'$(hostname)'","users":x:lines($raw) ! {"username":.,"details":{|for $x in x:lines(system(x"chage -l {.}")) let $a:=tokenize($x,":") return {string-join(for $x in tokenize(normalize-space($a[1])," ") return upper-case(substring($x,1,1))||substring($x,2)):normalize-space($a[2]) ! (if (. castable as decimal) then number(.) else .)}|}}}'