Example file containing a list of IPs: $ nl list_of_IPs 1 1.2.3.4 2 5.6.7.8 3 9.10.11.12 4 13.14.15.16 5 17.18.19.20 6 21.22.23.24 7 25.26.27.28 8 some junk which should not be here 9 29.30.31.32 10 9.10.11.12 11 9.10.11.12 12 9.10.11.12 13 1001.4.5.6 Having defined functions summaryIP and verifyIP (from previous commandlinefu.com posting): $ summaryIP list_of_IPs 4 9.10.11.12 1 5.6.7.8 1 29.30.31.32 1 25.26.27.28 1 21.22.23.24 1 17.18.19.20 1 13.14.15.16 1 1.2.3.4
Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?
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... | while read ip X; do
ip contains the first field as delimited by $IFS and X contains the rest of the line. That means we don't need the first awk any more. . We can drop the braces around ${ip} (I think you've spent too long in some other scripting language) However, it's best to quote the filename "$1". As for the second awk, I'd go "old-school" and replace it with sort, uniq, sort. . That leaves:function summaryIP() { while read ip x; do verifyIP $ip && echo $ip; done < "$1" | sort | uniq -c | sort -rn; }
111 characters, down from 206 :-) . For extra points, replace "$1" with "${1:-/dev/stdin}" to allow both:summaryIP FILENAME
cat FILENAME | summaryIP
.function summaryIP() { while read ip x; do verifyIP $ip && echo $ip; done < "${1:-/dev/stdin}" | sort | uniq -c | sort -rn; }