Number of non repeating lines - unique count
Here's how I'd solve the problem:
... | awk '{n[$0]++} END {for (line in n) if (n[line]==1) num++; print num}'But that's pretty opaque. Here's a (slightly) more legible way to look at it (requires bash version 4)
... | { declare -A count # count is an associative array # iterate over each line of the input # accumulate the number of times we've seen this line # # the construct "IFS= read -r line" ensures we capture the line exactly while IFS= read -r line; do (( count["$line"]++ )) done # now add up the number of lines who's count is only 1 num=0 for c in "${count[@]}"; do if (( $c == 1 )); then (( num++ )) fi done echo $num}