Exam CAS-004 topic 1 question 148 discussion

Hard to tell with the characters, but ^4[0-9]{12}(?:[0-9]{3})?$ is regex to find visa cards, which aligns closely with B.

I'll help out future peeps: A: grep -v '^4[0-9] {12}(?:[0-9]{3})?$' file B grep '^4[0-9]{12}(?:[0-9]{3})?$' file C grep '^6(?:011|5[0-9]{2})[0-9]{12}?'file D grep -v '^6(?:011|5[0-9]{2})[0-9]{12}?' file If you are wondering how i found this, I put the question into google and looked on chegg. They grey out the answer but the photo of the lines are there. Also, if you do an f12 in chegg you can sometimes find the greyed/obscured section and see what's there.

ChatGPT states that could be B or C. Visa cards start with 4 and Discovery cards with 60 or 65.

After research, I am going to go with B because VISA is more common

After opening my wallet, pulling out my personal credit card, and noting that the card number starts with '4', I've decided to change my answer to B.

chatgpt

The correct answer is C. The command grep '^6(?:011|5[09"€ 2}[ג }) [ 0ג€" 9 ] {12} ?' file is used to find credit card data in a file. This command searches for the pattern of credit card numbers that start with either 011 or 5 and are followed by either 0, 9, or 2. The pattern is then followed by any 12 digits

(^4[0-9]{12}(?:[0-9]{3})?$)|(^(?:5[1-5][0-9]{2}|222[1-9]|22[3-9][0-9]|2[3-6][0-9]{2}|27[01][0-9]|2720)[0-9]{12}$)|(3[47][0-9]{13})|(^3(?:0[0-5]|[68][0-9])[0-9]{11}$)|(^6(?:011|5[0-9]{2})[0-9]{12}$)|(^(?:2131|1800|35\d{3})\d{11}$)