CODEWITHSUNDEEP
bashgrep
A. Palmer
A. Palmer

Reputation: 149

Grep byte offset in consecutive lines of piped output

I am trying to export the byte offset of a specific character on every line of a piped input. For example, the output abc.txt:

....gugucaA....
.....guauAgggu..
.....ggguguAau..

should return:

11:A
10:A
12:A

I have tried using:

cat abc.txt | while read -r line; do grep -aob 'A'; done

As explained here https://unix.stackexchange.com/a/7561/327888.

However, this only offsets the output and retains the cumulative byte offsets of all 'A's.

ie.

11:A
21:A
33:A

Am I missing an option? Any help would be greatly appreciated!

Upvotes: 1

Views: 237

Answers (3)

Sundeep
Sundeep

Reputation: 23667

If you just need the offset:

$ awk '{print index($0, "A")-1}' ip.txt
10
9
11

$ perl -lne 'print index($_, "A")' ip.txt
10
9
11

Upvotes: 3

builder-7000
builder-7000

Reputation: 7627

No need for multiple grep invocations. If your version of grep supports the P option you could do:

grep -Po "[^A ]+(?=A)" inputfile | awk '{print length}'

output:

10
9
11

Upvotes: 1

Cyrus
Cyrus

Reputation: 88583

while read -r line; do grep -ob 'A' <<< "$line"; done < abc.txt

Output:

10:A
9:A
11:A

Upvotes: 3

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