Question

Will using “yes” command waste lot of cpu cycles ?

I have a long running script (script code not in my control) which accepts something as input just once. Then the script runs for long time .
To automate I use “yes” command to feed the input

yes hello | myscript

Will yes command steal/waste lot of cpu cycles ?. As per the docs i read it keeps printing the string argument to piped program

I gave top command , i didnt see “yes” there in top

Answer 1

yes will print the string “hello” when it has the chance – this means that the receiving end (your script) must be waiting for I/O (i.e., expecting input). So: no, yes does not take any CPU when the receiving end does not wait for input, the process is blocked.

See the run state of the process yes in a ps auxf for confirmation.