Question

I have a CSV file which looks like:

  height,  comment, name
  152,  he was late, for example, on Tuesday, Fred
  162, , Sam

I cannot parse this file because it includes a variable number of unenclosed commas in the comment field (but no other fields). I would like to fix the file using awk (which is very new to me) so that the commas in the second field become semi-colons:

  height,  comment, name
  152,  he was late; for example; on Tuesday, Fred
  162, , Sam

(Enclosing the entire field in quotes will not solve my problem because my CSV parser does not understand quotes.)

So far I am looking at using NF to work out the number of unenclosed commas and then replacing them using gsub with an unpleasant regex, but I feel I should be able to leverage awk to write a more readable program and I am not sure NF behaves this way.

Answer 1

Essentially just a brute-force solution, but fairly easy to understand. Invoke with

$ awk -F "," -f test.awk test.dat

The awk file.

$ cat test.awk
{
    printf "%s, ", $1

    if (NF > 3) {
        for (i = 2; i < NF; i++) {
            printf "%s;", $i
        }
        printf ", "
    }
    else {
        printf "%s, ", $2
    }

    printf "%s\n", $NF
}