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 does the file descriptor $"3u"$ represent?

$($Hint: It's not a standard stream$)$

$($Difficultly: Basic to Intermediate$)$

The following output is intended to be an additional aid towards answering the above question: cooteworkbench:$/$home$/$userll netstat $-$auntp Active Internet connections $($servers and established$)$