Search for a specific word in each line and print rest of the line

Question

I have text file with server URL lines like:

request get https://abc.net/search?q=hello/world/hello/word/search=5&size=10
request get https://abc.net/search?q=hello/world/hello/world/hello/word=5

In this text file, I want the text after the word "search?q=" string and store in another file output file:

hello/world/hello/word/search=5&size=10
hello/world/hello/word/hello/world=5
hello1world1/hello/world/hello/word

Solution

sed -n '/search?q=/{s/.*search?q=//;p;}' infile > outfile

Explanation:

/search?q=/ makes the following command set (in curly braces) apply only to lines containing this regex.

s/.*search?q=// substitutes the second part (empty) for the first part.

Then p prints the line.

The -n flag suppresses the default printing of the line.

Actually, you can simplify this like so:

sed -n '/.*search?q=/{s///;p;}' infile > outfile

Because when the pattern fed to the s/ command is left blank, the last used pattern is used again.

---

EDIT: Thanks to RobertL for pointing out a simplification in the comments:

sed -n 's/.*search?q=//p' infile > outfile

This uses the p flag to the s command, which only prints out the line if a substitution was made.

Comments

[mikeserv]

cut -d= -f2- <in >out

[RobertL]

How about sed -n 's/.*search?q=//p' ?

[Wildcard]

Yes, that works too. I usually forget about the flags for the s command. Thanks.