Find blocks of text, separated by newline, with occurring regexp

grep-block.awk

#!/usr/bin/awk -E

BEGIN {
 if ( ARGV[1] == "" ) {
  print "Usage: grep-block <regexp> [file1 file2 ...]"
  exit
 }
 search = ARGV[1]
 print "-" search "-"
 ARGV[1]=""

 IGNORECASE = 1;
 found = 0;
}

$0 ~ search {
 found = 1
}

// { # always
 out = out $0 "\n"
}

/$^/ { # empty line (block end)
 if ( found == 1 ) {
  print out
 }
 out = ""
 found = 0
}