#! /bin/sh

# grep a value of a CIF-like tag; take into account values that are on
# the next line an that may span several lines

PATTERN="$1"
shift

awk "/${PATTERN}/ {
        if( NF == 1 ) {
            getline
        }
        if( match( \$0, \"^;\" )) {
            getline
            while( !match( \$0, \"^;\" )) {
                getline
            }
        }
        next
    }
    !/${PATTERN}/ { print }
" ${1+"$@"}