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CMD 脚本比 BAT 脚本运行速度更快吗？

tag-icon • tag-icon scripting batch-file
CMD 脚本比 BAT 脚本运行速度更快吗？

我最近听别人说，Windows 管理员应该使用 CMD 登录脚本而不是 BAT 登录脚本，因为 CMD 登录脚本运行或执行速度更快。显然，BAT 脚本的速度非常慢。

我搜索了一下，但找不到任何证据来支持这一说法。我只是想知道这是不是谣言，或者是否有人对此有更多了解？

答案1

尽管脚本的运行方式存在一些BAT差异CMD，这里讨论（凭借功绩Hammer 的评论）命令被解析并执行相继在此记住下一个命令偏移量（0在起点）并从磁盘再次打开脚本文件以执行下一个命令。

1000脚本中的命令将暗示1000对同一文件的磁盘操作（打开-读取-关闭）。为了准确起见，我不会讲述线但关于命令。
那是BAT导致脚本CMD运行缓慢的真正原因。

为了证明：运行一个简单的示例脚本忽略提示删除该文件；脚本type本身会：

==> 725431.cmd
725431.cmd script. Please follow instructions.
Press any key to continue . . .
Please erase d:\bat\725431.cmd file prior to continuing.
Press any key to continue . . .
you didn't erase d:\bat\725431.cmd file prior to continuing?
---
@echo off
echo %~nx0 script. Please follow instructions.
pause
echo Please erase %~f0 file prior to continuing.
pause
echo you didn't erase %~f0 file prior to continuing?
echo ---
type "%~f0"

运行上述脚本观察提示删除文件；The batch file cannot be found错误显示批处理解析器无法获取下一个echo命令：

==> 725431.cmd
725431.cmd script. Please follow instructions.
Press any key to continue . . .
Please erase d:\bat\725431.cmd file prior to continuing.
Press any key to continue . . .
The batch file cannot be found.

为了完整起见，这里有一个标准的文件系统错误消息：

==> type 725431.cmd
The system cannot find the file specified.

相反，类似（例如）PowerShell脚本被缓存在内存中。再次运行示例脚本忽略提示先删除文件；脚本type本身会：

PS D:\PShell> D:\PShell\SF\725431.ps1
D:\PShell\SF\725431.ps1 script. Please follow instructions.
Press Enter to continue...: 
Please erase D:\PShell\SF\725431.ps1 file prior to continuing.
Press Enter to continue...: 
you didn't erase D:\PShell\SF\725431.ps1 file prior to continuing?
---
echo "$PSCommandPath script. Please follow instructions."
pause
echo "Please erase $PSCommandPath file prior to continuing."
pause
echo "you didn't erase $PSCommandPath file prior to continuing?"
echo "---"
Get-Content $PSCommandPath

运行脚本观察提示删除该文件。这样做会显示后者echo和Get-Content被缓存在内存中：

PS D:\PShell> D:\PShell\SF\725431.ps1
D:\PShell\SF\725431.ps1 script. Please follow instructions.
Press Enter to continue...: 
Please erase D:\PShell\SF\725431.ps1 file prior to continuing.
Press Enter to continue...: 
you didn't erase D:\PShell\SF\725431.ps1 file prior to continuing?
---
Get-Content : Cannot find path 'D:\PShell\SF\725431.ps1' because it does not ex
ist.
At D:\PShell\SF\725431.ps1:8 char:1
+ Get-Content $PSCommandPath
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (D:\PShell\SF\725431.ps1:String) 
    [Get-Content], ItemNotFoundException
    + FullyQualifiedErrorId : PathNotFound,Microsoft.PowerShell.Commands.GetCo 
   ntentCommand

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