file exists by file name pattern

Question

I am using:

File.Exists(filepath)

What I would like to do is swop this out for a pattern, because the first part of the filename changes.

For example: the file could be

01_peach.xml
02_peach.xml
03_peach.xml

How can I check if the file exists based on some kind of search pattern?

Answer 1

You can do a directory list with a pattern to check for files

string[] files = System.IO.Directory.GetFiles(path, "*_peach.xml", System.IO.SearchOption.TopDirectoryOnly);
if (files.Length > 0)
{
    //file exist
}

Answer 2

If you're using .net framework 4 or above you could use Directory.EnumerateFiles

bool exist = Directory.EnumerateFiles(path, "*_peach.xml").Any();

This could be more efficient than using Directory.GetFiles since you avoid iterating trough the entire file list.

Answer 3

Get a list of all matching files using System.IO.DirectoryInfo.GetFiles()

Also see SO Questions:

Is there a wildcard expansion option for .net apps?

How do I check if a filename matches a wildcard pattern

and many others...

Answer 4

For more advanced searching against a specific pattern, it might be worth using File Globbing which allows you to use search patterns like you would in a .gitignore file.

See here: https://learn.microsoft.com/en-us/dotnet/core/extensions/file-globbing

This allows you to add both inclusions & exclusions to your search.

Please see below the example code snippet from the Microsoft Source above:

Matcher matcher = new Matcher();
matcher.AddIncludePatterns(new[] { "*_peach.xml" });

IEnumerable<string> matchingFiles = matcher.GetResultsInFullPath(filepath);