在批处理文件中循环通过ASCII代码 [英] Loop through ASCII codes in batch file

问题描述

我想回声A到Z，而不输入 for %% J in（A B C D E F G H I J K L M N O P Q R S T U V W X Y Z）do echo %% J 这么长的和不完整的命令。所以我想知道我是否可以循环通过ASCII代码。像对于%% J在（ASCII的A ie.65到Z）中做的事情做回声%% J

I want to echo A to Z without typing for %%J in (A B C D E F G H I J K L M N O P Q R S T U V W X Y Z) do echo %%J such long and unfruitful commands out. So I was wondering if i can cycle through ASCII codes. Something like for %%J in (ASCII of A ie.65 to Z) do echo %%J

任何帮助将不胜感激。

推荐答案

令人惊讶的是，有一个解决方案使用未记录的内置环境变量，名为 = ExitCodeAscii ，其中包含ASCII当前退出代码 ^1的字符（ ErrorLevel ）：

Surprisingly, there is a solution that makes use of an undocumented built-in environment variable named =ExitCodeAscii, which holds the ASCII character of the current exit code¹ (ErrorLevel):

@echo off
for /L %%A in (65,1,90) do (
    cmd /C exit %%A
    call echo %%^=ExitCodeAscii%%
)

代表/ L 循环遍历 A 到 Z 的（十进制）字符代码。 cmd / C exit %% A 设置当前迭代代码的返回代码（ ErrorLevel ）， c $ c> echo 作为一个字符。 call 与double - ％一起引入命令行的第二个解析阶段，以获取当前值 = ExitCodeAscii ，而不是在执行整个循环之前出现的值一个简单的命令行如 echo％= ExitCodeAscii％）。或者，也可以使用延迟展开。

The for /L loop walks through the (decimal) character codes of A to Z. cmd /C exit %%A sets the return code (ErrorLevel) to the currently iterated code, which is echo-ed as a character afterwards. call, together with the double-%-signs introduce a second parsing phase for the command line in order to get the current value of =ExitCodeAscii rather than the one present before the entire for /L loop is executed (this would happen with a simple command line like echo %=ExitCodeAscii%). Alternatively, delayed expansion could be used also.

基本思路归功于 rojo ，并在此帖子中应用：如何在批处理中获得随机字母输出。

The basic idea is credited to rojo and applied in this post: How do i get a random letter output in batch.

_{1）退出代码）不一定与 ErrorLevel 值相同。但是，命令行 cmd / C exit 1 将这两个值设置为 1 。要确保退出代码等于 ErrorLevel ，请使用 cmd / C exit％ErrorLevel％。}

_{1) The exit code (or return code) is not necessarily the same thing as the ErrorLevel value. However, the command line cmd /C exit 1 sets both values to 1. To ensure that the exit code equals ErrorLevel, use something like cmd /C exit %ErrorLevel%.}

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