Bash, Awk, Sed? Find string within file and append digits within string?

Question

I wish to search a large text file line by line, and find each entry containing "N:;;" and just simply change it to "N:07401000000;;" and then the next occurrence of "N:;;" would be changed to "N:07401000002;;" and so on throughout the complete file of entries. Here is an example below of before and after.

Before:

BEGIN:VCARD
VERSION:2.1
N:;;
TEL;TYPE=CELLVOICE:07401000000
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:;;
TEL;TYPE=CELLVOICE:07401000001
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:;;
TEL;TYPE=CELLVOICE:07401000002
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:;;
TEL;TYPE=CELLVOICE:07401000003
END:VCARD

After result would look like this:

BEGIN:VCARD
VERSION:2.1
N:07401000000;;
TEL;TYPE=CELLVOICE:07401000000
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:07401000001;;
TEL;TYPE=CELLVOICE:07401000001
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:07401000002;;
TEL;TYPE=CELLVOICE:07401000002
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:07401000003;;
TEL;TYPE=CELLVOICE:07401000003
END:VCARD

Any help or ideas would be awesome.

Do you want the N values to start at a hard-coded value and increment or just copy the value from the subsequent CELLVOICE?

Actually that is a good idea. How about the value mentioned within CELLVOICE.

Answer 1

Here's the most robust and easily extensible way to do what you want:

$ cat tst.awk
BEGIN { RS="END:VCARD\\s*"; FS="\n"; OFS=":" }
{
    $0 = $0 gensub(/\s+$/,"",1,RT)

    for (i=1; i<=NF; i++) {
        name = gensub(/:.*/,"",1,$i)
        value = gensub(/.*:/,"",1,$i)
        n2v[name] = value
        names[i] = name
    }

    n2v["N"] = n2v["TEL;TYPE=CELLVOICE"] n2v["N"]

    for (i=1; i<=NF; i++) {
        name  = names[i]
        value = n2v[name]
        print name, value
    }
}

.

$ awk -f tst.awk file
BEGIN:VCARD
VERSION:2.1
N:07401000000;;
TEL;TYPE=CELLVOICE:07401000000
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:07401000001;;
TEL;TYPE=CELLVOICE:07401000001
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:07401000002;;
TEL;TYPE=CELLVOICE:07401000002
END:VCARD
BEGIN:VCARD
VERSION:2.1
N:07401000003;;
TEL;TYPE=CELLVOICE:07401000003
END:VCARD

The above uses GNU awk for gensub(), multi-char RS, and RT and the basic (and idiomatic) idea is to split the input into records that end with END:VCARD and for each record first create an array (n2v[]) that maps field names (the part before the first : on each line) to their values (the part after the first :) and then you can just manipulate every field by it's name so you can trivially change values, rearrange the order, fill in defaults, etc. etc.