diff --git a/lib/std/fs/file.zig b/lib/std/fs/file.zig index 7acbc9e2f6..45cb5e3218 100644 --- a/lib/std/fs/file.zig +++ b/lib/std/fs/file.zig @@ -724,14 +724,12 @@ pub const File = struct { try in_file.reader().skipBytes(args.in_offset, .{ .buf_size = 4096 }); - var buffer: [4096]u8 = undefined; - const in_len = args.in_len orelse math.maxInt(u64); - var index: usize = 0; - while (index < in_len) { - const ask = math.min(buffer.len, in_len - index); - const amt = try in_file.read(buffer[0..ask]); - if (amt == 0) break; - index += try self.write(buffer[0..amt]); + var fifo = std.fifo.LinearFifo(u8, .{ .Static = 4096 }).init(); + if (args.in_len) |len| { + var stream = std.io.earlyEOFReader(in_file.reader(), len); + try fifo.pump(stream.reader(), self.writer()); + } else { + try fifo.pump(in_file.reader(), self.writer()); } try self.writevAll(trailers);