问题描述
我有两个.bat文件，都使用延迟扩展，因此我可以在for循环中设置变量。
下面的示例已大大简化，仅用于显示问题
脚本one.bat
@echo off
setlocal enableextensions
setlocal enabledelayedexpansion
set j=0
for /L %%i in (1,1,2) do (
set j=%%i
set /A j=!j! + 1
echo %%i !j!
two.bat
echo %%i !j!
)
脚本two.bat
@echo off
setlocal enableextensions
setlocal enabledelayedexpansion
echo Hello World
exit /B 0
从two.bat返回的变量!j!丢失，并且echo重新打开。
J:\>one
1 2
Hello World
1 !j!
J:\>(
set j=2
set /A j=!j! + 1
echo 2 !j!
two.bat
echo 2 !j!
)
Missing operator.
2 !j!
Hello World
2 !j!
是的，我可以在two.bat中使one.bat成为子例程，但是它有一百行，而且我不想维护两个相同逻辑的副本
我在这里想念什么？
解决方法
您的假设错误是执行从文件two.bat返回，因为只有在使用call command 1 的情况下。
批处理文件one.bat在括号内的代码块中运行two.bat，该代码块已在命令堆栈 2 中，因此该块（有点）已完成终止执行。
您的输出完美地说明了会发生什么（因此我在这里进行了评论）：
J:\>one
1 2 /* first loop iteration,the first `echo %%i !j!` in the block is
executed as expected; */
Hello World /* `two.bat` is run; execution does NOT return to `one.bat`,because there is NO `call`,which would put a return point onto
the stack! the only thing remembered and thus accomplished is
the current command line or parenthesised block; */
1 !j! /* the second `echo %%i !j!` in the block is executed as it is
still buffered,but `two.bat` is already quit,hence implicit
`endlocal` commands have been executed,so all the nested
`setlocal` commands in your scripts are cancelled and delayed
expansion is disabled (default state); moreover,variable `j` is
no longer defined here; */
/* at this point,the parenthesised block,which is the loop body,has been executed,hence batch file context is left and Command
Prompt context applies,so `@echo off` from `one.bat` does no
longer apply here; */
J:\>( // this block is nothing but the echo of the second loop iteration,set j=2 // which is still buffered;
set /A j=!j! + 1
echo 2 !j!
two.bat
echo 2 !j!
)
Missing operator. /* this error message is caused by the attempt to execute
`set /A j=!j! + 1` (remember that delayed expansion is no longer
enabled and `j` is undefined); */
2 !j! // first `echo %%i !j!` in the buffered second loop iteration;
Hello World /* `two.bat` is run again; afterwards,batch file context is left
again and Command Prompt context applies; */
2 !j! // second `echo %%i !j!` in the buffered second loop iteration;
要证明执行是在批处理文件还是在命令提示符上下文下发生，只需将set /A j放置在one.bat中的循环主体中作为最后一条命令，这样您将获得一个附加输出0在输出1 !j!和第二个2 !j!之后，因为set /A在批处理文件上下文中不返回任何内容，但是在Command中输出了（最后）结果（没有尾随换行符）及时的环境； 0的值表明不再设置j。
1）有一些例外：被调用的批处理文件包含在管道中，或者由for /F loop运行和解析，因为批处理文件在新的{{3}中运行}在这种情况下。
2）如果被调用的批处理文件包含在带有串联命令的行中，则同样如此，因此，two.bat & echo Fine之类的东西在执行Fine时会回显two.bat。 sub>