Validate File Name (Not File Characters)

[sheeeng]

Hi all,

I know that we can check for invalid file name characters as shown at
http://www.codeproject.com/useritems/reallyusefulpath.asp.

But how can we check a string for invalid file name such as CLOCK$,
AUX, CON, NUL, PRN, COM1, COM2, COM3, COM4, COM5, COM6, COM7, COM8,
COM9, LPT1, LPT2, LPT3, LPT4, LPT5, LPT6, LPT7, LPT8, LPT9?

There is a C++ implementation of it at
http://www.codeproject.com/file/isvalidfilename.asp. But anyone knows
how to implement it in C#?

Thanks in advance.

 

[Oliver Sturm]

Hello sheeeng,

There is a C++ implementation of it at
http://www.codeproject.com/file/isvalidfilename.asp. But anyone knows
how to implement it in C#?

Not sure I understand your question - translating the C++ code to C# seems
like a logical idea. Otherwise, the rules listed in the article don't look
very difficult to implement, so you might do better just reimplementing
the whole thing following those rules.


Oliver Sturm

 

[Morten Wennevik [C# MVP]]

I don't know how you may retrieve reserved device names, but assuming the
list in the article is complete, simply create a list of all the device
names (for instance a List<string>) and check the filename against this
list

[Pseudocode]
if( ReservedList.Contains( FirstSectionOfFilename( filepath ) ) )
{
// Notify user about invalid filename
}

FirstSectionOfFilename retrieves the first part of the filename ending at
the first dot, using SubString and IndexOf(".")

 

[sheeeng]

Thanks! I will try implement your Pseudocode now.

I don't know how you may retrieve reserved device names, but assuming the
list in the article is complete, simply create a list of all the device
names (for instance a List<string>) and check the filename against this
list

[Pseudocode]
if( ReservedList.Contains( FirstSectionOfFilename( filepath ) ) )
{
// Notify user about invalid filename
}

FirstSectionOfFilename retrieves the first part of the filename ending at
the first dot, using SubString and IndexOf(".")

Hello sheeeng,


Not sure I understand your question - translating the C++ code to C#
seems like a logical idea. Otherwise, the rules listed in the article
don't look very difficult to implement, so you might do better just
reimplementing the whole thing following those rules.


Oliver Sturm