# Beginning learner **URL:** \ **Category:** Shell Programming and Scripting\ **Created:** [July 10, 2017, 1:48am UTC](https://community.unix.com/t/beginning-learner/367362 "2017-07-10T01:48:50Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![shiver](https://community.unix.com/letter_avatar/shiver/32/6_22734026db12803ebb3e059622ac3534.png) [@shiver](https://community.unix.com/u/shiver)\ **Post date:** [July 10, 2017, 1:48am UTC](https://community.unix.com/t/beginning-learner/367362/1 "2017-07-10T01:48:50Z")
Hi guys, New member here, also new student! I'm just starting the Shell Programming, currently in chapter four in the Book in Unix, Linux, and OS X by Stephen G. Kochan & Patrick Wood (4th edition). I'm needing a little help with other possible ways to shorten this shell command: ```nohighlight /[0-9][0-9][0-9][0-9][\][0-9][0-9][0-9][0-9][0-9][0-9][\][0-9][0-9][0-9][0-9][0-9]/ ``` It's purpose is to bed used in ed with a file open with possible matches. This question was presented as follows: Using the Regular Expression techniques that we have discussed in class develop, test, and submit a regular expression that will identify each of the following patterns. An American Express credit card number that fits the following format: 4 digits followed by a space followed by 6 digits followed by a space followed by 5 digits. Any input or help would be greatly appreciated! If not, I'm happy to be a member here! 😃 Thanks ---
**Author:** ![vbe](https://community.unix.com/user_avatar/community.unix.com/vbe/32/266_2.png) [@vbe](https://community.unix.com/u/vbe)\ **Post date:** [July 10, 2017, 2:22am UTC](https://community.unix.com/t/beginning-learner/367362/2 "2017-07-10T02:22:47Z")
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