Linux - Newbie This 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.
Are you new to LinuxQuestions.org? Visit the following links:
Site Howto |
Site FAQ |
Sitemap |
Register Now
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.
|
|
01-07-2008, 05:01 PM
|
#1
|
LQ Newbie
Registered: Oct 2007
Posts: 26
Rep:
|
how to use grep to print just the matching expression and nothing else
hi,
i'm trying to do a simple thing where, lets say i have:
Code:
$ echo "Hello World" | grep "Hello"
>> Hello World
This works as expected, but is there a way I can print just the matching regular expression?
So in the above example, only "Hello" would print.
|
|
|
01-07-2008, 05:08 PM
|
#2
|
Senior Member
Registered: Nov 2006
Location: California
Distribution: Fedora , CentOS , RHEL
Posts: 1,979
|
I would do it with sed...
Code:
echo "Hello World" | sed -e 's/World//g'
|
|
|
01-07-2008, 05:13 PM
|
#3
|
LQ Newbie
Registered: Oct 2007
Posts: 26
Original Poster
Rep:
|
this works in this example.
but it will not work as soon as the string changes to something else, for example "Hello World Once Again".
what i'm trying to do is that i have a line of HTML data, and i want to print just the selective HTML tags (and the text between them). i do not want to print the entire line.
any ideas on how i may do this will be much appreciated!
|
|
|
01-07-2008, 05:24 PM
|
#4
|
Senior Member
Registered: Oct 2003
Location: UK
Distribution: Kubuntu 12.10 (using awesome wm though)
Posts: 3,530
Rep:
|
Do you mean like the -o option ( only matching)?
Code:
$ echo "hello world" |grep -o hello
hello
|
|
|
01-07-2008, 05:28 PM
|
#5
|
LQ Veteran
Registered: Nov 2005
Location: Annapolis, MD
Distribution: Mint
Posts: 17,809
|
sed -n 's/.*\(from\).*/\1/p' filename
Finds from anywhere in a line and prints it. Only works for one instance
Edit: Matthew's grep -o method looks to be better.
Last edited by pixellany; 01-07-2008 at 05:31 PM.
|
|
|
01-07-2008, 06:02 PM
|
#6
|
Senior Member
Registered: Nov 2006
Location: California
Distribution: Fedora , CentOS , RHEL
Posts: 1,979
|
Quote:
Originally Posted by new_2_unix
this works in this example.
but it will not work as soon as the string changes to something else, for example "Hello World Once Again".
what i'm trying to do is that i have a line of HTML data, and i want to print just the selective HTML tags (and the text between them). i do not want to print the entire line.
any ideas on how i may do this will be much appreciated!
|
Now that I know this... I agree with pixellany grep -o would work better.
-C
|
|
|
All times are GMT -5. The time now is 08:33 PM.
|
LinuxQuestions.org is looking for people interested in writing
Editorials, Articles, Reviews, and more. If you'd like to contribute
content, let us know.
|
Latest Threads
LQ News
|
|