CODEWITHSUNDEEP
shellpipeshblocking
ernix
ernix

Reputation: 3643

How to make shell script non blocking?

Just a simple question: Why following one-linear not working? How to make IO non blocking?

$ while true; do date; sleep 1; done | tail -f

Upvotes: 1

Views: 585

Answers (2)

Thayne
Thayne

Reputation: 6992

If what you want to do is continually replace the last line with the date you could do this:

while true; do echo -en "\r"`date`; sleep 1; done

Upvotes: 1

Paul Draper
Paul Draper

Reputation: 83235

The problem is not with non-blocking IO; it's with your choice of tail.

This prints out each line with a colon (all of them):

while true; do date; sleep 1; done | grep :

The problem with tail is that it goes to the last 10 ten lines and then starts following. But in your case, it never reaches the end, so it can't print the last ten.

Upvotes: 2

Related Questions