regex - Extracting portion of a file within braces using regular expression -

i have file of following form :

some text more text . . . . . . data { 1 2 3 5 yes 10 2 3 4 5 no  11 } text text 

i want extract data portion of file using regular expression using following procedure:

proc extractdata {filename} {     set sgd [open $filename r]     set sgdcontents [read $sgd]     regexp "data \\{(?.*)\\}" $sgdcontents -> data     puts $data } 

but giving following error:

couldn't compile regular expression pattern: quantifier operand invalid 

i not able figure out wrong regular expression. highly appreciated.

use regular expression

regexp {data \{(.*)\}} $sgdcontents wholematch submatch puts $submatch 

wholematch matches entire pattern. in case is

data { 1 2 3 5 yes 10 2 3 4 5 no  11 } 

and submatch matches content inside braces below:

1 2 3 5 yes 10 2 3 4 5 no  11