This thread started as "I'm not sure if this is offtopic" and it ended as such a great and fun to read discussion. Thank you all for these great script examples. I really enjoyed reading it. On 2017-Oct-25 17:10, m.roth at 5-cent.us wrote: > Tony Mountifield wrote: > > In article > > <b5215baacd93a6e85efc59947f9b8ed9.squirrel at host290.hostmonster.com>, > > <m.roth at 5-cent.us> wrote: > >> Warren Young wrote: > >> > On Oct 25, 2017, at 10:02 AM, Mark Haney <mark.haney at neonova.net> > >> wrote: > >> >> > >> >> I have a file with two columns 'email' and 'total' like this: > >> >> > >> >> me at example.com 20 > >> >> me at example.com 40 > >> >> you at domain.com 100 > >> >> you at domain.com 30 > >> >> > >> >> I need to get the total number of messages for each email address. > >> > > >> > This screams out for associative arrays. (Also called hashes, > >> > dictionaries, maps, etc.) > >> > > >> > That does limit you to CentOS 7+, or maybe 6+, as I recall. CentOS 5 > >> is > >> > definitely out, as that ships Bash 3, which lacks this feature. > >> <snip> > >> Associative arrays? > >> > >> Awk! Awk! (No, I am not a seagull...) > >> > >> sort file | awk '{ array[$1] += $2;} END { for (i in array) { print i > >> "\t" > >> array[i];}' > > > > Why the sort? It doesn't matter in what order the lines are read. > > Wouldn't this give you the same? > > > > awk '{ array[$1] += $2;} END { for (i in array) { print i "\t" > > array[i];}}' <file > > > You're right, not really necessary in this case. I was working with a > couple of awk scripts here at work, and it was needed in the middle.... > > mark > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centos