awk or a combination of commands to read and calculate nth lines from pattern

Shell Programming and Scripting
1

Two numerical lines, found by either header line, need to be added
and the total placed in a new-header section. Also the total should
should be rounded or cut to a two decimal anynumber.XX format
with the AB string added on the end.

For example: The numerical lines from headers 2 and 3 are to be added together
and placed in the 4th line of the new-header grouping.
The new line would show 13.24 AB

The data file:
Each grouping contains 4 lines.
The line numbers may change every time the data file is accessed.
The numerical lines may or may not have a type (AB in this example) listed after the number.
The third line in the group, the info line, may or may not be the same.

Data file:

header1
header1 - description
info-abc
1.23 AB
header2
header2 - description
info-def
10.678 AB
header3
header3 - description
info-abc
2.5678

A new section would then be added to the end of the data with no empty line above:

new-header
new-header - description
info-xyz
13.24 AB
2

Hello jessandr,

Not that much clear, please do mention why 1st value of header is NOT being picked up?

Thanks,
R. Singh

3

Welcome to the forum.

Please become accustomed to supplying sufficient info on and context of your problem. On top of what RavinderSingh13 already said:

  • Where (in a larger file) should the new record be placed?
  • How should the new info line ("info-xyz" in your sample record) be constructed?
  • What be the header name if more than one new headers result?
4

Start with:

awk '
1
! (NR % 4) {if (length($2)) type=$2;}
! (NR % 12) || ! ((NR + 4) % 12) {sum+=$1;}
! (NR % 12) {
   print "new-header";
   print "new-header - description";
   print "info-xyz";
   printf "%.2f %s\n", sum, type;
}
' data_file