The following is working as expected. (do not want to use nmap) I need to use nc (or any other built-in centOS) command in shell script to check the port 6379 of a remote server. I want the script to exit quickly if no response received in less than 1 second. But it seems that nc will wait for too long before quitting with exit code of 1
How do I "quickly" check if the port is listening?
# time nc -z 18.104.22.168 1234 real 0m21.001s user 0m0.000s sys 0m0.000s # echo $? 1 # time nc -z 22.214.171.124 6379 Connection to 126.96.36.199 6379 port [tcp/*] succeeded! real 0m0.272s user 0m0.000s sys 0m0.008s # echo $? 0