I found this script somewhere, it makes a nice HTML file showing a demo of all your fonts. I made some small tweaks to the script so it works better. Here is a screen shot and the code below. Save it as fonts.sh then chmod +x the file and run it. Will output fonts.html that looks like this
#!/usr/bin/env bash
cat > fonts.html << __HEADER
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Sample of local fonts matching '$1'</title>
</head>
<body>
__HEADER
fc-list --format='%{family}\n' $1 | cut -d ',' -f 1 | sort -u | while IFS='' read -r fontfamily
do
cat >> fonts.html << __BODY
<hr/>
<div style="font-family: '${fontfamily}', 'serif'">
<h1>${fontfamily}</h1>
<p>
1lLiI -0O- == {} [] The quick brown fox jumped over the lazy brown dog<br/>
0123456789,.:;?/<>'"[]{}|\-=\`~!@#$%^&*()-=\\
</p>
</div>
__BODY
done
cat >> fonts.html << __FOOTER
<hr/>
</body>
</html>
__FOOTER
echo "fonts.html created"
