title: How to make asynchronous function calls in shell scripts
body: <p>I have a collection of curl commands to be executed by a shell script. Now what i want is all these commands have to be executed at a regular interval of time ( which is different for every curl url ) so what i want to do is make asynchronous calls to</p>
  
  <p><code>wait [sec]</code> </p>
  
  <p>command and execute different functions for different wait periods like </p>
  
  <p>start 5 timers one for 120s, 2 for 30s, 3 for 3000s etc.
  and then as soon as they get completed i want to trigger the execution of the handler function attached to every timeout.
  I can do this in javascript and nodejs easily as they are event driven programming language. But i have little knowledge about shell scripting. So, how else can i implement this or hotto make such asynchronous calls in the shell script?
  I dont know if i am clear enough, what other details should i mention if i am not?</p>