Force a shell script to fflush

Question

I was wondering if it was possible to tell bash that all calls to echo or printf should be followed up by a subsequent call to fflush()

Answer 1

If comands use stdio and are connected to a terminal they'll be flushed per line. Otherwise you'll need to use something like stdbuf on commands in a pipe line http://www.pixelbeat.org/programming/stdio_buffering/

tl;dr: instead of printf ... try to put to the script stdbuf -o0 printf .., or stdbuf -oL printf ...