Unbuffered Bash Output

Question

I have a bash script that I'm trying to write unbuffered output with. I have something like this:

...
mkfifo $PIPE
for SERVER in ${SERVERS[@]}; do
    ssh $SERVER command >$PIPE &
done

while read LINE; do
    echo ${LINE}
done <$PIPE

The problem is that all of the output of the script is buffered.

I know I can use something like stdbuf or unbuffer to the whole script, but I don't want my users to have to run stdbuf -o0 -e0 my_command every time.

Is there a way to achieve that effect within my script?

Thanks, Marc

Well, you could of course always have your script execute itself in the appropriate environment, leaving this detail hidden from your users. There might be a better solution, though. — 5gon12eder, Dec 02 '14 at 20:00
a stupid question here: what does `unbuffered` mean here? like stderr flushed by char? — Jason Hu, Oct 31 '17 at 18:08
Does this answer your question? [How to make output of any shell command unbuffered?](https://stackoverflow.com/q/3465619/608639) — jww, Nov 10 '19 at 13:21

score 1 · Answer 1 · edited Oct 31 '17 at 18:05

Why not create an alias to run stdbuf, which will in turn unbuffer the script output?

I understand you don't want the user to manually input the command with stdbuf. Why not let the user create an alias which will execute stdbuf running the script?

alias my_script='stdbuf -o0 -e0 <path_to_script>'

Now users can run the script from the terminal (terminal can also help to fill out script name) as follows:

my_script

score 0 · Answer 2 · answered May 16 '17 at 11:18

0

Using stdbuf on the script won't help; it won't apply to all of the commands inside the script.

The right place for stdbuf is at the command generating the output, i. e.

    ssh $SERVER stdbuf -o0 -e0 command >$PIPE &

answered May 16 '17 at 11:18

Armali

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Unbuffered Bash Output

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