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 Cheers Tony -- Tony Mountifield Work: tony at softins.co.uk - http://www.softins.co.uk Play: tony at mountifield.org - http://tony.mountifield.org