Excellent, that does it short and sweet. I don't think case matters but it doesn't hurt to make it lower.
I'm trying to get use to the shorter awk statements, mine are always so lengthy.
I'm trying to understand how the 'prev' is working or which portion of the statement actually is pointing to the previous line. Is that something built into awk?
The script has two parts to it...one part saves every line in the variable "prev"
1 {prev=$0}
The other part prints the previous "prev" and current "$0" lines if the logical AND of two conditions listed below is true.
Check whether the current line aka "$0" contains the keywords "DISK" and "External" AND (&&) if the previous line aka "prev" contains the keyword "USB"