How to get the exit status a loop in bash

Question

I know how to check the status of the previously executed command using $?, and we can make that status using exit command. But for the loops in bash are always returning a

Answer 1

I think what you should be asking is: How can I wait until a file or a directory (/test) gets created by another process?

What you are doing up to now is polling with full power. Your loop will allocate up to 100% of the processing power of one core. The keyword is "polling", which is ethically wrong by the standards of computer scientists.

There are two remedies:

1. insert a sleep statement in your loop; advantage: very simple; disadvantage: the delay will be an arbitrary trade-off between CPU load and responsiveness. ("Arbitrary" is ethically wrong, too).
2. use a notification mechanism like inotify (see: man inotify); advantage: no CPU load, great responsiveness, no delays, no arbitrary constants in your code; disadvantage: inotify is a kernel API – you need some code to access it: inotify-tools or some C/Perl/Python code. Have a look at inotify and bash!