條目列表中的子字符串

我有一個包含文件名列表並基於擴展名的變量，我需要執行不同的操作。我不能夠提取擴展循環條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 
     ) 
)

內如果條件總是失敗。如何正確提取擴展名。

來源

2013-08-24 user2103630

我不知道，如果你可以使用這個：%% G：〜-4％

而且，你必須使用的變量延遲擴展。關鍵是使用'！'而不是某些地方的'％'。檢查「set /？」，它給出了一個（令人困惑）的例子。

我不記得很多問題背後的原理，但是這個工作對我來說：

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 
     ) 
)

來源

2013-08-24 02:22:03 zentrunix

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

從CMD shell窗口幫助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

來源

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.

來源

2013-08-24 05:14:02 foxidrive

條目列表中的子字符串

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