How to print a greedy range of lines using awk - regex

Question

I've encountered the following problem and haven't found a solution nor why awk behaves in this strange way.
So let's say I have the following text in a file:
startcue
This shouldn't be found.
startcue
This is the text I want to find.
endcue
startcue
This shouldn't be found either.
And I want to find the lines "startcue", "This is the text I want to find.", and "endcue".
I naively assumed that a simple range search by awk '/startcue/,/endcue/' would do it, but this prints out the whole file. I guess awk somehow finds the first range, but as the third startcue triggers on the printing of lines, it prints all the lines until the end of the file (still, this all seems a bit strange to me).
Now to the question: How can I get awk to print out just the lines I wan't? And maybe as an extra question: Can anybody explain awk's behaviour?
Thanks

Answer 1

$ awk '/startcue/{f=1; buf=""} f{buf = buf $0 RS} /endcue/{printf "%s",buf; f=0}' file
startcue
This is the text I want to find.
endcue

Answer 2

Here is a simple way to do it.
Since data is separated by blank lines, I set RS to nothing.
This makes awk to work with data in blocks.
Then find all blocks starting with startcue and ending with endcue
awk -v RS="" '/^startcue/ && /endcue$/' file
startcue
This is the text I want to find.
endcue
If startcue and endcue are always start line and end line and does only appears once int the block, this should do: (PS testing does show that it does not matter if there are more or less hits in the block. This always prints the block if both startclue and endcue are found)
awk -v RS="" '/startcue/ && /endcue/' file
startcue
This is the text I want to find.
endcue
And this should work too:
awk -v RS="" '/startcue.*endcue/' file
startcue
This is the text I want to find.
endcue

Answer 3

To summarize the problem, you want print lines from startcue to endcue but not if the endcue is missing. Ed Morton's approach is good. Here is yet another approach:
$ tac file | awk '/endcue/,/startcue/' | tac
startcue
This is the text I want to find.
endcue
How it works
tac file
This prints the lines in reverse order. tac is just like cat except that the lines come out in reverse order.
awk '/endcue/,/startcue/'
This prints all lines starting from endcue and finishing with startcue. When done this way, passages with missing endcues are not printed.
tac
This reverses the lines once again so that are back in the correct order.
How awk ranges work
Consider:
awk '/startcue/,/endcue/' file
This tells awk to start printing when if finds startcue and continue printing until if finds endcue. This is exactly what it does on your file.
There is no implied rule that the range /startcue/,/endcue/ cannot itself contain multiple instances of startcue. awk simply starts printing when it sees the first occurrence of startcue and continues until if finds endcue.

Answer 4

no buffering needed :
{m,n,g}awk 'BEGIN { _ +=_ ^= ORS = FS = RS = "\nendcue\n"
sub("end", "?start", RS)
__= substr(RS, _+--_) } (NF=_<NF) && $!_=__$_'
startcue
This is the text I want to find.
endcue