Linux - NewbieThis Linux forum is for members that are new to Linux.
Just starting out and have a question?
If it is not in the man pages or the how-to's this is the place!
Notices
Welcome to LinuxQuestions.org, a friendly and active Linux Community.
You are currently viewing LQ as a guest. By joining our community you will have the ability to post topics, receive our newsletter, use the advanced search, subscribe to threads and access many other special features. Registration is quick, simple and absolutely free. Join our community today!
Note that registered members see fewer ads, and ContentLink is completely disabled once you log in.
If you have any problems with the registration process or your account login, please contact us. If you need to reset your password, click here.
Having a problem logging in? Please visit this page to clear all LQ-related cookies.
Get a virtual cloud desktop with the Linux distro that you want in less than five minutes with Shells! With over 10 pre-installed distros to choose from, the worry-free installation life is here! Whether you are a digital nomad or just looking for flexibility, Shells can put your Linux machine on the device that you want to use.
Exclusive for LQ members, get up to 45% off per month. Click here for more info.
I am just learning Linux, using Bash. I have a small program that uses a menu to add, delete, search, and find players on a team roster. The roster list of players (database) is made of 6 fields, separated by colons. For example:
Entry#:Last Name:First Name:Position:Year:Phone Number
My problem is when my script runs to search for a player, which searches by entry #, there are sometimes multiple players listed.
The search script uses a grep command, and finds numbers in the entry # column and the phone # column.
Can I limit a grep command to search just the first column?
Look into 'cut' - then pipe that to grep. Though I'm sure there's a million ways to do it and you'll get several suggestions and at least one person will tell you to write in perl.
Did you check the man page? It'd be something like 'cut -d: -f5 | grep thing-I-want-to-find'
Oh. Oops. Row? Or column? Cut will chop a column from a line and grep will 'cut' a line from a list, so to speak. Come to think of it, cut's no good if you're wanting to extract the whole line. I don't really know regular expressions but, if the problem is that you have numbers at the beginning (numbering entries) and numbers at the end (phone numbers) and 'grep 5' gives you row 5 *and* everybody whose phone number has a five in it, then 'grep ^5' will do it. That basically means 'lines beginning with 5'. That's only useful for that specific, and I don't know that that's your complete situation, but you can do far more complicated stuff with those principles, anyway.
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.