awk group by

Shell Programming and Scripting
1

Hi
I have a file in this format:
...
04/May/2009 16
04/May/2009 1
05/May/2009 3
05/May/2009 5
06/May/2009 1
06/May/2009 3
...

I need to sum for every day, What is the best way?
Thanks all

2

Use gawk, nawk or /usr/xpg4/bin/awk on Solaris.

awk 'END{for(d in _)print d, _[d]}{_[$1]+=$2}' infile
3 
 awk '{a[$1]=a[$1]+$2}END{for(i in a)print i,a}' file

-Devaraj Takhellambam