如何在嵌套循环批处理脚本中中断内循环 [英] How to break inner loop in nested loop batch script

问题描述

我的目标是逐行比较两个文件并捕获更改.为此，我使用了两个嵌套循环.在某些情况下，我坚持制动内循环.

MY goal is to compare two files line by line and capture the changes. For that i am using two nested loops. I am stuck with braking the inner loop on some condition.

我在内循环外使用标签来打破它，但不起作用.它也去标记和终止外循环.

I am using label outside the inner loop for break it, but not working. It goes to label and terminate outer loop also.

@ echo off
SETLOCAL EnableDelayedExpansion
for /F "skip=8 tokens=* delims=." %%a in (sample.txt) do (for /F "skip=8 tokens=* delims=." %%b in (test.txt) do (if %%a==%%b (goto :next) else ( echo %%a) 
)
: Next
echo out of inner loop
)

任何人都可以帮忙......?

Anyone can help....?

推荐答案

转到 :label 总是会中断所有循环.

A goto :label always breaks all loops.

但是你可以把你的内部循环放在一个单独的函数中，然后它就可以工作了.

But you can put your inner loop in a separated function, then it could work.

@echo off
SETLOCAL EnableDelayedExpansion
for /F "skip=8 tokens=* delims=." %%a in (sample.txt) do (
    call :myInnerLoop "%%a"
)

echo out of inner loop
)
goto :eof


:myInnerLoop
for /F "skip=8 tokens=* delims=." %%b in (test.txt) do (
    if "%~1"=="%%b" (
        goto :next
    ) else ( 
        echo %%a
    )
:next
goto :eof

请注意，中断 FOR/L 循环并没有按预期工作，for 循环总是计数到最后，但是如果中断它，内部代码的执行就会停止，但它可能真的很慢.

One remark, breaking of FOR /L loops does not work as expected, the for-loop always count to the end, but if you break it, the execution of the inner code is stopped, but it could be really slow.

@echo ON
FOR /L %%n IN (1,1,1000000) DO (
  echo %%n - count
  goto :break
)
:break

概念证明

@echo off
SETLOCAL EnableDelayedExpansion
for %%a in (a b c) DO (
   echo Outer loop %%a
   call :inner %%a
)
goto :eof
:inner
for %%b in (U V W X Y Z) DO (
  if %%b==X (
    echo    break
    goto :break
  )
  echo    Inner loop    Outer=%1 Inner=%%b
)
:break
goto :eof

输出

Outer loop a
   Inner loop    Outer=a Inner=U
   Inner loop    Outer=a Inner=V
   Inner loop    Outer=a Inner=W
   break
Outer loop b
   Inner loop    Outer=b Inner=U
   Inner loop    Outer=b Inner=V
   Inner loop    Outer=b Inner=W
   break
Outer loop c
   Inner loop    Outer=c Inner=U
   Inner loop    Outer=c Inner=V
   Inner loop    Outer=c Inner=W
   break

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