[Help-bash] How not to wait for the input finishes if a program does not need to see all the input?

[ehsan ramezani]

Hi,

If one runs the following examples, both head and awk will wait until `sleep` 
is finished.

(echo 1; sleep 10; seq 10) | head -n 1
(echo 1; sleep 10; seq 10) | awk -e 'NR==1{print $1;exit}'

However, they only need the output from the first echo command. It is 
unnecessary that they wait until `sleep` is finished. I am wondering if this 
problem is related with the shell or the programs head/awk.

How one might let head and awk finish as soon as they see the first line?

Thanks in advance.

Best regards,
Ehsan