VI delete everything except a pattern

Question

I have a huge JSON output and I just need to delete everything except a small string in each line.

The string has the format

"title": "someServerName"

the "someServerName" (the section within quotes) can vary wildly.

The closest I've come is this:

:%s/\("title":\s"*"\)

But this just manages to delete

"title": "

The only thing I want left in each line is

"title": "someServerName"

EDIT to answer the posted question:

The Text I'm going to be working with will have a format similar to

{"_links": {"self": {"href": "/api/v2/servers/32", "title": "someServerName"},tons_of_other_json_crap_goes_here

All I want left at the end is:

"title": "someServerName"

Answer 1

It should be .* rather than * to match a group of any characters. This does the job:

%s/^.*\("title":\s".*"\).*$/\1/

Explanation of each part:

• %s/ Substitute on each matching line.
• ^.* Ignore any characters starting from beginning of line.
• \("title":\s".*"\) Capture the title and server name. ".*" will match any characters between quotes.
• .*$ Ignore the rest of the line.
• /\1/ The result of the substitution will be the first captured group. The group was captured by parentheses \(...\).

Answer 2

This sounds like a job for grep.

:%!grep -o '"title":\s*"[^"]*"'

For more help with Vim's filtering see :h :range!.

See man grep for more information on the -o/--only-matching flag.