Get the n-th range by pattern

My input is like this:

start
content A
end
garbage
start
content B
end

I want to extract the second (or first, or third ...) start .. end block. With

sed -ne '/start/,/end开发者_运维问答/p'

I can filter out the garbage, but how do I get just "start content B end"?

But anyway, if you want sed - you get sed:)

/^start$/{
  x
  s/^/a/
  /^aaa$/{
    x
    :loop
    p
    /^end$/q
    n
    bloop
  }
  x
}

The number of a's in the middle match equals to which segment you want to get. You could also have it in regexp repetion like Dennis noted. That approach allows for specifying direct number to the script.

Note: the script should be run with -n sed option.

Get all range

$ awk 'BEGIN{RS="end";FS="start"}{ print $NF}' file

content A


content B

Get 2nd range

$ awk 'BEGIN{RS="end";FS="start"}{c++; if (c==2) print $NF}' file

content B

Ruby(1.9+), get first range

$ ruby -0777 -ne 'puts $_.scan(/start(.*?)end/m)[0]' file

content A