I am going through a couple of BASH scripts. And I came across something like this

```
VAR_S=$(dd if=${MY_FILE} bs=16 count=1 skip=1024 iflag=skip_bytes 2>/dev/null | hexdump -e '16/1 "%02x"')

```

Apparently the Variable VAR\_S should not be empty and I am trying to wrap my head around this statement. What does `if=${MY_FILE}` mean here. I am trying to figure out why VAR\_S is returning empty when I echo it.It seems to me like `if` is a simple variable being assigned the value of `MY_FILE`. In that case I dont understand the significance of assignment and why not just use `dd ${MY_FILE}`