Deleting Column Selection in AWK

Question

I\'d like to delete a selection of columns from a list of CSV files. The awk call is in-line as it is used in a shell script. I don\'t know beforehand how many columns the files

Answer 1

BEGIN {FS=",";
       split("1,2,3,4",dropers,",")
      }

{ split($0,row,FS);
  for(i in dropers) delete row[i]; 
  print NF "," length(row) "<<<";
  out=""; 
  print NF "," length(row) ">>>";
  for(i in row){print row[i] "lulu"; 
                out = out "," row[i]}; 
  out = substr(out,2)
  sub(/[ \t]*$/,"",out);
  print out
}

with input:

a,b,c,d,e,f,g

prints:

7,3<<<
7,3>>>
elulu
flulu
glulu
e,f,g