批處理文件，讀取JSON文件轉換成字符串

Question

我需要讀取一個JSON文件：

{ 
    "key": { 
     "subkey": "value" 
    } 
} 

這樣我就可以把它作爲一個參數的命令：

program -e SETTINGS=<JSON FILE AS STRING> 

Answer 1

合併的答案，這些問題...

• How to read entire content of a text file in batch
• Escape 「double quotes」 inside batch's input parameters

...我們可以寫出下面的批處理文件：

:: Make it possible to read immediate value of variable using !variable! syntax. 
setlocal enabledelayedexpansion 

:: Read file "test.json" into variable data, removing line breaks. 
set data= 
for /f "delims=" %%x in (test.json) do set "data=!data!%%x" 

:: Escape double quotes in data 
set data=%data:"=\"% 

:: Finally call program with the entire content of the JSON file as parameter 
program -e "SETTINGS=%data%" 

注意使用cmd.exe命令的處理器，maximum length for a commandline and also for environment variables is 8191 characters的時候，所以這顯然限制了JSON文件的最大尺寸可以通過。