CODEWITHSUNDEEP
c#fileconsole
ESD
ESD

Reputation: 544

find a file name knowing only the extension name

I am trying to verify if a file exist in a c# console program. The only thing is that the file can have any name.

The only thing that I know is the file extension and there can only be one file of this extension. How can I verify if it exist and then use it whatever the name is?

Upvotes: 0

Views: 1485

Answers (4)

Nicholas Carey
Nicholas Carey

Reputation: 74355

The problem with using Directory.GetFiles() is that is walks the entire filesystem first, then returns all matches as an array. Even if the very first file examined is the one and only match, it still walks the entire filesystem from the specified root before returning the one match.

Instead, use EnumerateFiles() to do a lazy walk, stopping when the first match is encountered, thus:

DirectoryInfo root        = new DirectoryInfo( @"C:\" ) ;
string        pattern     = "*.DesiredFileExtension" ;
FileInfo      desiredFile = root.EnumerateFiles( pattern , SearchOption.AllDirectories )
                                .First()
                                ;

It will throw an exception if the file's not found. Use FirstOrDefault() to get a null value instead.

Upvotes: 4

sa_ddam213
sa_ddam213

Reputation: 43636

Something like this may work

if (Directory.GetFiles(path, "*.ext").Any())
{
   var file = Directory.GetFiles(path, ".ext").First();
}

Upvotes: 1

wdavo
wdavo

Reputation: 5110

  string extension = "txt";
  string dir = @"C:\";

  var file = Directory.GetFiles(dir, "*." + extension).FirstOrDefault();

  if (file != null)
  {
    Console.WriteLine(file);
  }

If the file does not exist directly under 'dir', you will need to use SearchOption.AllDirectories for Directory.GetFiles

Upvotes: 1

slugster
slugster

Reputation: 49985

Try the Directory.GetFiles static method:

var fileMatches = Directory.GetFiles("folder to start search in", "*.exe", SearchOption.AllDirectories);
if (fileMatches.Length == 1)
{
    //my file was found
    //fileMatches[0] contains the path to my file
}

Note that with the SearchOption enum you can specify just the current folder or to search recursively.

Upvotes: 3

Related Questions