Question: Are there any substitutes, alternatives or bash tricks for delaying commands without using `sleep`? For example, performing the below command without actually using sleep:

```
$ sleep 10 && echo "This is a test"

```

Answer: 
Using the bash built-in variable `$SECONDS` and a busy-loop:

```
for((target=$((SECONDS + 10)); SECONDS < target; true)); do :; done

```
There is no built-in, that does the same as `sleep` (unless `sleep` is built-in). However there are some other commands that will wait.

A few include.

* `at` and `cron`: used to schedule tasks at a specific time.
* `inotifywait`: used to wait for a file, or files to be modified/removed/added/etc