grep to ignore patterns

I am extracting URLs from a website using cURL as below.

curl www.somesite.com | grep "<a href=.*title=" > new.txt

My new.txt file is as below.

<a href="http://website1.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" title="something">
<a href="http://website1.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" information="something" title="something">
<a href="http://website2.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" title="some_other_thing">
<a href="http://website2.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" information="something" title="something">
<a href="http://websitenotneeded.com" rel="nofollow noreferrer noopener" title="something NOTNEEDED">

However, I need to extract only the below information.

<a href="http://website1.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" title="something">
<a href="http://website2.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" information="something" title="something">

I am trying to ignore the <a href which have information in them and whose title end with NOTNEEDED.

How can I modify my grep statement?

Answers:

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Method 1

I’m not fully following your example + the description but it sounds like what you want is this:

$ grep -v "<a href=.*title=.*NOTNEEDED" sample.txt 
<a href="http://website1.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" title="something">
<a href="http://website1.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" information="something" title="something">
<a href="http://website2.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" title="some_other_thing">
<a href="http://website2.com" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" rel="nofollow noreferrer noopener" information="something" title="something">

So for your example:

$ curl www.example.com | grep -v "<a href=.*title=" | grep -v NOTNEEDED > new.txt

Method 2

The grep man page says:

-v, --invert-match
    Invert the sense of matching, to select non-matching lines. (-v is specified by POSIX .)

You can use regular expressions for multiple inversions:

grep -v 'red|green|blue'

or

grep -v red | grep -v green | grep -v blue

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0