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如何将环境变量的值设置为 Windows 批处理文件中命令的输出？

tag-icon • tag-icon windows script batch-file
如何将环境变量的值设置为 Windows 批处理文件中命令的输出？

如何将环境变量设置为 Windows 批处理文件中命令的输出？该命令将返回一个约 32 个字符的单个值（例如，键入 myfile.txt）。

答案1

尝试运行以下命令：

for /f "delims=" %a in ('mybatchfile.bat') do @set myenvvar=%a
echo %myenvvar%

答案2

暂时地：

for /f "delims=" %a in ('command to run') do @set example_environment_variable=%a


永久性：

for /f "delims=" %a in ('command to run') do @setx example_environment_variable=%a

旁注，set仅为该命令进程/窗口设置它，但setx为整个用户/系统设置它。

答案3

或者：

for /f "usebackq delims==" %v in (`echo new_value`) do set new_var=%v

为什么有人想使用这个版本？

根据for /?帮助，人们可能需要在处理文件名中的双引号时使用它（事实上，这就是我最终在这里的结果）：


usebackq        - specifies that the new semantics are in force,
                  where a back quoted string is executed as a
                  command and a single quoted string is a
                  literal string command and allows the use of
                  double quotes to quote file names in
                  file-set.

[...]

Finally, you can use the FOR /F command to parse the output of a
command.  You do this by making the file-set between the
parenthesis a back quoted string.  It will be treated as a command
line, which is passed to a child CMD.EXE and the output is captured
into memory and parsed as if it was a file.  So the following
example:

  FOR /F "usebackq delims==" %i IN (`set`) DO @echo %i

would enumerate the environment variable names in the current
environment.

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