Below code triggers exception:
string[] filenames=Directory.GetFiles( "path from config",
"*MAIN.txt|*CONT.txt", SearchOption.TopDirectoryOnly).ToArray()
I want to pull all files into a array from a directory containing MAIN.txt or CONT.txt in the file name.
But when i run the code it is giving me System.ArgumentException, Illegal characters in path exception.
To elaborate further, the reason you are getting the ArgumentException is because the second parameter is not valid.
The overload of the Directory.GetFiles method that you are using is expecting a string path, string searchPattern, and a SearchOption searchOption.
The searchPattern is not a regular expression. You can only use a combination of * and ? characters.
From the documentation:
The search string to match against the names of files in path. This parameter can contain a combination of valid literal path and wildcard (* and ?) characters, but it doesn't support regular expressions.
Alternative implementation using the System.Linq Concat extension method:
string[] mainFileNames = Directory.GetFiles(@"/Some/Path", "*MAIN.txt", SearchOption.TopDirectoryOnly);
string[] contFileNames = Directory.GetFiles(@"/Some/Path", "*CONT.txt", SearchOption.TopDirectoryOnly);
string[] allFileNames = mainFileNames.Concat(contFileNames).ToArray();
Those aren't regular expressions. Anyway, Directory.GetFiles doesn't support filename expressions with the | character. You'll need to call that method twice, and then combine the arrays together.
string[] mainNames=Directory.GetFiles("path from config","*MAIN.txt",SearchOption.TopDirectoryOnly);
string[] contNames=Directory.GetFiles("path from config","*CONT.txt",SearchOption.TopDirectoryOnly);
string[] fileNames= new string[mainNames.Length + contNames.Length];
Array.Copy(mainNames, fileNames, mainNames.Length);
Array.Copy(contNames, 0, fileNames, mainNames.Length, contNames.Length);
