Reading data from file/stdin in chunks

Help
,
4

I ended up using both advices, works just as I have imagined. Thanks everybody!

    var in = std.io.getStdIn();
    if (fileNamePointer.len != 0) {
        const cwd = std.fs.cwd();
        in = try cwd.openFile(fileNamePointer, .{});
    }
    defer in.close();

    var bufRead = std.io.bufferedReader(in.reader());

    const buffer = try allocator.alloc(u8, lineStop);

    printHeader(lineStop, wordLength);

    var offset: i64 = 0;

    while (true) {
        const len = try bufRead.reader().readAll(buffer);

        if (len == 0) break;