条目列表中的子字符串

我有一个包含文件名列表并基于扩展名的变量，我需要执行不同的操作。我不能够提取扩展循环条目列表中的子字符串

set BINARIES=file1.dll fil2.dll fil3.sys 

:: for each file in list of binaries do 
FOR %%G IN (%BINARIES%) DO (
    :: if extension is dll 
    if /i [%%G:~-4%]==[.dll] (
     echo dll file 
     ) else (
      echo sys file 
     ) 
)

内如果条件总是失败。如何正确提取扩展名。

来源

2013-08-24 user2103630

我不知道，如果你可以使用这个：%% G：〜-4％

而且，你必须使用的变量延迟扩展。关键是使用'！'而不是某些地方的'％'。检查“set /？”，它给出了一个（令人困惑）的例子。

我不记得很多问题背后的原理，但是这个工作对我来说：

setlocal enabledelayedexpansion 

set BINARIES=file1.dll fil2.dll fil3.sys 

:: for each file in list of binaries do 
FOR %%G IN (%BINARIES%) DO (
    :: if extension is dll 
    set x=%%g 
    set y=!x:~-4! 
    if /i [%y%]==[.dll] (
     echo dll file 
     ) else (
      echo sys file 
     ) 
)

来源

2013-08-24 02:22:03 zentrunix

if /i "%%~xG"==".dll"

从CMD shell窗口帮助for /?：

 
In addition, substitution of FOR variable references has been enhanced. 
You can now use the following optional syntax: 

    %~I   - expands %I removing any surrounding quotes (") 
    %~fI  - expands %I to a fully qualified path name 
    %~dI  - expands %I to a drive letter only 
    %~pI  - expands %I to a path only 
    %~nI  - expands %I to a file name only 
    %~xI  - expands %I to a file extension only 
    %~sI  - expanded path contains short names only 
    %~aI  - expands %I to file attributes of file 
    %~tI  - expands %I to date/time of file 
    %~zI  - expands %I to size of file 
    %~$PATH:I - searches the directories listed in the PATH 
        environment variable and expands %I to the 
        fully qualified name of the first one found. 
        If the environment variable name is not 
        defined or the file is not found by the 
        search, then this modifier expands to the 
        empty string 

The modifiers can be combined to get compound results: 

    %~dpI  - expands %I to a drive letter and path only 
    %~nxI  - expands %I to a file name and extension only 
    %~fsI  - expands %I to a full path name with short names only 
    %~dp$PATH:I - searches the directories listed in the PATH 
        environment variable for %I and expands to the 
        drive letter and path of the first one found. 
    %~ftzaI  - expands %I to a DIR like output line

来源

2013-08-24 03:12:52 captcha

set BINARIES=file1.dll fil2.dll fil3.sys 

FOR %%G IN (%BINARIES%) DO echo %%G has a %%~xG extension.

来源

2013-08-24 05:14:02 foxidrive

条目列表中的子字符串

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