How do I create a file AND any folders, if the folders don't exist?

Question

Hi folks,

imagine i wish to create (or overwrite) the following file :- C:\Temp\Bar\Foo\Test.txt

Using the File.Create(..) method, this can do it.

BUT, if i don't have either one of the following folders (from that example path, above)

• Temp
• Bar
• Foo

then i get an DirectoryNotFoundException thrown.

So .. given a path, how can we recursively create all the folders necessary to create the file .. for that path? If Temp or Bar folders exists, but Foo doesn't... then that is created also.

For simplicity, lets assume there's no Security concerns -- all permissions are fine, etc.

Answer 1

You will need to check both parts of the path (directory and filename) and create each if it does not exist.

Use File.Exists and Directory.Exists to find out whether they exist. Directory.CreateDirectory will create the whole path for you, so you only ever need to call that once if the directory does not exist, then simply create the file.

Answer 2

Use Directory.CreateDirectory before you create the file. It creates the folder recursively for you.

Answer 3

You should use Directory.CreateDirectory.

http://msdn.microsoft.com/en-us/library/54a0at6s.aspx

Answer 4

. given a path, how can we recursively create all the folders necessary to create the file .. for that path

Creates all directories and subdirectories as specified by path.

Directory.CreateDirectory(path);

then you may create a file.

Answer 5

// Determine whether the directory exists.
if (Directory.Exists(path)) 
{
    Console.WriteLine("That path exists already.");
    return;
}

// Try to create the directory.
DirectoryInfo di = Directory.CreateDirectory(path);
Console.WriteLine("The directory was created successfully at {0}.",
    Directory.GetCreationTime(path));

See this MSDN page.

Hope that helps out!

Answer 6

You want Directory.CreateDirectory()

Here is a class I use (converted to C#) that if you pass it a source directory and a destination it will copy all of the files and sub-folders of that directory to your destination:

using System.IO;

public class copyTemplateFiles
{


public static bool Copy(string Source, string destination)
{

    try {

        string[] Files = null;

        if (destination[destination.Length - 1] != Path.DirectorySeparatorChar) {
            destination += Path.DirectorySeparatorChar;
        }

        if (!Directory.Exists(destination)) {
            Directory.CreateDirectory(destination);
        }

        Files = Directory.GetFileSystemEntries(Source);
        foreach (string Element in Files) {
            // Sub directories
            if (Directory.Exists(Element)) {
                copyDirectory(Element, destination + Path.GetFileName(Element));
            } else {
                // Files in directory
                File.Copy(Element, destination + Path.GetFileName(Element), true);
            }
        }

    } catch (Exception ex) {
        return false;
    }

    return true;

}



private static void copyDirectory(string Source, string destination)
{
    string[] Files = null;

    if (destination[destination.Length - 1] != Path.DirectorySeparatorChar) {
        destination += Path.DirectorySeparatorChar;
    }

    if (!Directory.Exists(destination)) {
        Directory.CreateDirectory(destination);
    }

    Files = Directory.GetFileSystemEntries(Source);
    foreach (string Element in Files) {
        // Sub directories
        if (Directory.Exists(Element)) {
            copyDirectory(Element, destination + Path.GetFileName(Element));
        } else {
            // Files in directory
            File.Copy(Element, destination + Path.GetFileName(Element), true);
        }
    }

}

}

Answer 7

Assuming that your assembly/exe has FileIO permission is itself, well is not right. Your application may not run with admin rights. Its important to consider Code Access Security and requesting permissions Sample code:

FileIOPermission f2 = new FileIOPermission(FileIOPermissionAccess.Read, "C:\\test_r");
f2.AddPathList(FileIOPermissionAccess.Write | FileIOPermissionAccess.Read, "C:\\example\\out.txt");
try
{
    f2.Demand();
}
catch (SecurityException s)
{
    Console.WriteLine(s.Message);
}

Understanding .NET Code Access Security

Is “Code Access Security” of any real world use?