Question

给定存储在变量中的绝对路径：

SET absolute_file_path=C:\path\containing\some.json

使用命令提示符，如何从C:\path\containing\中提取绝对目录路径C:\path\containing或%absolute_file_path%？

Answer 1

for有一些修饰符可以获取路径\ filename的部分内容：

SET absolute_file_path=C:\path\containing\some.json
for %%A in (%absolute_file_path%) do (
  echo file name: %%~nA
  echo file extension: %%~xA
  echo full file name: %%~nxA
  echo drive: %%~dA
  echo path: %%~pA
  echo drive/path: %%~dpA
  echo full qualified filename: %%~fA
)

call ed子例程具有相同的修饰符。请参阅for /?和call /?

Answer 2

@echo off
SET absolute_file_path=C:\path\containing\some.json

setlocal enabledelayedexpansion

set I=0
set L=-1
:l
if "!absolute_file_path:~%I%,1!"=="" goto ld
if "!absolute_file_path:~%I%,1!"=="\" set L=%I%
set /a I+=1
goto l
:ld
echo %L%

CALL SET ab_path=%%absolute_file_path:~0,%L%%%

echo %ab_path%

Answer 3

这实际上回答了你的问题：

let messageDB = Database.database().reference().child("Message")
let messageQuery = messageDb.queryOrdered(byChild:"fromID").queryEqual(toValue: (Auth.auth().currentUser?.uid)!)
messageQuery.observe(.childAdded) { (snapshot) in

从CMD中的％absolute_file_path％获取绝对目录路径

3 个答案: