This command shows the File Descriptor $($FD$)$ in this output.

The character after the number i$.$e $\text{'}1u\text{'},$ represents the mode in which the file is opened:

$"$r$"$ for read,

$"$w$"$ for write,

$"$u$"$ for read and write.

What streams do the file descriptors $"$Or$,""1$u$,"$ and $"2$u$"$ represent?

$($Difficultly: Basic to Intermediate$)$

The following output is intended to be an additional aid towards answering the above question: