Zig 0.17.0-dev (Split by item)

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fileSetLength

Dispatch.fileSetLength

fn fileSetLength(userdata: ?*anyopaque, file: File, length: u64) File.SetLengthError!void

File

lib/std/Io/Dispatch.zig:3615

Code

fn fileSetLength(userdata: ?*anyopaque, file: File, length: u64) File.SetLengthError!void {
    const ev: *Evented = @ptrCast(@alignCast(userdata));
    _ = ev;

    const signed_len: i64 = @bitCast(length);
    if (signed_len < 0) return error.FileTooBig; // Avoid ambiguous EINVAL errors.

    while (true) switch (c.errno(c.ftruncate(file.handle, signed_len))) {
        .SUCCESS => return,
        .INTR => {},
        .FBIG => return error.FileTooBig,
        .IO => return error.InputOutput,
        .PERM => return error.PermissionDenied,
        .TXTBSY => return error.FileBusy,
        .BADF => |err| return errnoBug(err), // Handle not open for writing.
        .INVAL => return error.NonResizable, // This is returned for /dev/null for example.
        else => |err| return unexpectedErrno(err),
    };
}