Unix addition ( Row wise)

Shell Programming and Scripting
1

Hi

I have a file like

a,1
b,2
d,3
a,2
b,3
c,7

Result Desired:
a,3
b,5
d,3
c,7

i.e on the bases of 1st field the addition is done of the 2nd field and result printed out.

Thanks

2

If output order is not a problem this simple perl script will do:

while(<>)
{
  chomp;
  @a= split(/,/);
  $sum{$a[0]} += $a[1];
}

foreach $key (keys %sum)
{
  print "$key,$sum{$key}\n";
}
3 
awk 'BEGIN{FS=","}
{ array[$1]+=$2 }
END{
for (i in array) print i,array 
}' "file"
4

If order is an issue

while(<>)
{
  chomp;
  @a= split(/,/);
  push (@order,$a[0]) if (!$sum{$a[0]});
  $sum{$a[0]} += $a[1];
}

foreach $key (@order)
{
  print "$key,$sum{$key}\n";
}