sum of three columns

Shell Programming and Scripting
1

Hi All,
I have like this

M17XX-050-01 0100000000 QQSSS
0.0000e+00	1.712E+06	1.255E+07	0.0000e+00
0.0000e+00	1.722E+06	1.263E+07	0.0000e+00
...
0.0000e+00	1.204E+06	8.829E+06	0.0000e+00
M17XX-050-01 0100000000 WWSSS
0.0000e+00	7.564E+03	1.165E+01	0.0000e+00
0.0000e+00	8.008E+03	1.233E+01	0.0000e+00
...
0.0000e+00	7.286E+03	1.122E+01	0.0000e+00
0.0000e+00	7.286E+03	1.122E+01	0.0000e+00
...

So a description line, N lines with 4 columns, description line, N lines with 4 columns and so on.
I would like to have a file where I have in the first column the sum of the other three columns.
Do you have an efficient solution to solve the problem?
Thank you in advance,
Sarah

2 

awk '{if (NF==4) print $2+$3+$4 ;else print }' filename
3 
gawk '!/^M/{ $0=$2+$3+$4 }{print} END{ print "show desired output next time" } ' file
4

The first one gives something like (the other gets stuck)

M17XX-050-01 0100000000 AAAAA
0.0000e+00 927158
0.0000e+00 846126
...
0.0000e+00 413359
M17XX-050-01 0100000000 BBBBB
0.0000e+00 14262000
0.0000e+00 14352000
...
0.0000e+00 10033000

This should be the output

M17XX-050-01 0100000000 AAAAA			
9.2716E+05	9.2680E+05	3.5750E+02	0.0000E+00
8.4613E+05	8.4580E+05	3.2620E+02	0.0000E+00
...
4.1336E+05	4.1320E+05	1.5940E+02	0.0000E+00
M17XX-050-01 0100000000 BBBBB			
1.4262E+07	1.7120E+06	1.2550E+07	0.0000E+00
1.4352E+07	1.7220E+06	1.2630E+07	0.0000E+00
...
1.0033E+07	1.2040E+06	8.8290E+06	0.0000E+00
5 
awk -F'\t' '
  (/^[0-9]/ && $1 = sprintf("%.4E", $2 + $3 + $4)) || -3
  ' OFS='\t' infile

Use gawk if available, otherwise use nawk or /usr/xpg4/bin/awk.
Do not use /usr/bin/awk on Solaris.

6

Thank you,
does it carry out the sum only when the first coulmn is 0 or in any case?
I would need to to the sum only if the first column is 0.

7

No,
try this for the new requirement:

awk -F'\t' '
  (/^[0-9]/ && $1 == 0 && $1 = sprintf("%.4E",$2 + $3 + $4)) || -3
  ' OFS='\t' infile