Shell Programming and Scripting

awk '
/\}/ {block=0; delete S}
(block==1) {
  if ($0 in S) {next} else {S[$0]}
}
{print}
/\{/ {block=1}
' input

awk '
/\}/ {block=0; found=0}
(block==1) {
  if (found==1 && $0==S) {next} else {S=$0; found=1}
}
{print}
/\{/ {block=1}
' input

{
   aaa
   bbb
   aaa
}

aaa
bbb
aaa

{
   aaa
   aaa
   ccc
}

 $ cat file
{
   aaa
   bbb
   aaa
   ccc
}
ads
dvsah
{
   aaa
   aaa
}


$  awk '/\{/ {f=NR} f && !A[f,$0]++ {print} !f{print} /\}/{f=0}' file
{
   aaa
   bbb
   ccc
}
ads
dvsah
{
   aaa
}