cssgrep prints the part of HTML files, that match a given CSS selector. Solution based on this answer on StackOverflow: http://stackoverflow.com/a/14187086/113195

cssgrep.sh

#!/bin/bash

function _usage() {
    cat <<USAGE
usage: $(basename $0) PATTERN [FILES]

Print the HTML that matches the CSS selector PATTERN.
USAGE
}

PATTERN=$1
shift
FILES="$@"

if [[ $PATTERN == "-h" || $PATTERN == "--help" ]]; then
    _usage
    exit
fi

if [[ $# == 0 ]]; then
    FILES=.
fi

for file in $(find $FILES -type f -name \*.html -or -name \*.htm)
do
    # Ignore errors, write the results to standard output.
    CONTENT=$(hxnormalize -l 240 -x "$file" 2>/dev/null | hxselect "$PATTERN")
    if [[ $CONTENT != "" ]]; then
      echo -e "\e[32m$file: \e[0m$CONTENT"
    fi
done