Stream Buffer

• libc Stdout Buffering
  • Why Buffering Exists
  • Buffering Anti-Patterns
  • When Programs Buffer, And When They Don’t
  • More Grep Examples
    • Examples
  • Setbuf
  • Stdbuf
  • C++ IOStreams
• stdio_buffering
  • buffering in standard streams
  • stdio output buffering problems
  • stdio input buffering problems
  • stdio buffer control
  • possible stdio buffer control enhancements

tools

unbuffer

https://expect.sourceforge.net/example/unbuffer.man.html

unbuffer disables the output buffering that occurs when program output is redirected. For example, suppose you are watching the output from a fifo by running it through od and then more.

    od -c /tmp/fifo | more

You will not see anything until a full page of output has been produced.

You can disable this automatic buffering as follows:

    unbuffer od -c /tmp/fifo | more

When you have a pipeline, unbuffer must be applied to each element except the last (since that doesn’t have its output redirected). Example:

        unbuffer p1 | unbuffer p2 | unbuffer p3 | p4