Replace String In a File

Question

I have a file as following

ID,SEQ,PO_NUM,BATCH,CREATE_DT
99001100788259,127856626,111,20230801
99001100788270,223412976,111,20230801
99001100788281,112120972,222,20230801

I want to replace the first two columns last 4 digits by adding 1 digit to each number as following:

99001100789360,127857737,111,20230801
99001100789381,223413087,111,20230801
99001100789392,112121083,222,20230801

0 should become 1 1 should become 2 2 should become 3 3 should become 4 4 should become 5 5 should become 6 6 should become 7 7 should become 8 8 should become 9 9 should become 0

I tried sed but not able to figure out the last 4 digits logic.

Answer 1

Here is one potential solution:

awk 'BEGIN {
    FS = ","
}

NR == 1 {
    print
}

NR > 1 {
    a = split($1, b, "")
    c = split($2, d, "")
    e = split($0, f, "")
    for (i = 1; i <= e; i++) {
        if (i > a - 4 && i <= a) {
            printf "%s", (f[i] + 1 == 10 ? "0" : f[i] + 1)
        } else if (i > a + c - 3 && i <= a + c + 1) {
            printf "%s", (f[i] + 1 == 10 ? "0" : f[i] + 1)
        } else {
            printf "%s%s", f[i], (i == e ? "\n" : "")
        }
    }
}' file.txt
ID,SEQ,PO_NUM,BATCH,CREATE_DT
99001100789360,127857737,111,20230801
99001100789381,223413087,111,20230801
99001100789392,112121083,222,20230801