[API Proposal]: System.IO.File.GetLength(string)

[TonyValenti]

Background and motivation

Currently getting the size of a file requires creating a new instance of the FileInfo class and calling the Length instance method. This is clunky. A GetLength static method will be easier to use and pair nicely with existing Get(...) methods on System.IO.File.

API Proposal

namespace System.IO;

public static class File
{
    public static long GetLength(string path);
    public static long GetLength(SafeFileHandle fileHandle);
}

API Usage

// Fancy the value

var FileSize = Syste.IO.File.GetLength($@"C:\Text.txt");

Alternative Designs

Continue using FileInfo

Risks

No response

[jkotas]

long GetLength(SafeFileHandle fileHandle);

This one is exposed as RandomAccess.GetLength.

[teo-tsirpanis]

Getting the length of a file at the given path is not very useful in practice. You want to get the length of an open file handle, to prevent TOCTOU bugs. And per the above comment, there is already an API for that.

[adamsitnik]

I would recommend opening the file with File.OpenHandle, using the RandomAccess.GetLength(handle) to get length and then keep using the handle for following file operations (FileStream can be opened using the file handle etc).